Gastrointestinal System


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7


GASTROINTESTINAL SYSTEM


Sarah A. Martin






DEVELOPMENTAL ANATOMY OF THE GASTROINTESTINAL SYSTEM



A.    Embryologic Development of the Digestive Tract (Figure 7.1)



1.    The digestive tract develops from the primitive gut, which differentiates into the foregut, midgut, and hindgut by the fourth week of gestation (Little, 2015).



a.    Foregut. The foregut consists of the pharynx, esophagus, stomach, proximal duodenum, liver, pancreas, gallbladder, and extrahepatic bile ducts.



b.    Midgut. The midgut consists of the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon, and proximal part of transverse colon.



c.    Hindgut. The hindgut consists of the remainder of the colon and rectum.



2.    The esophagus and trachea are a single tube until the fourth week of gestation, at which time the tracheoesophageal septum begins to separate the structures.








image


FIGURE 7.1    Primitive gut.


Source: From Kenner, C., & Lott, J. W. (Eds.). (2014). Comprehensive neonatal nursing (5th ed., p. 18). New York, NY: Springer Publishing.







3.    Development of the gut is nearly complete by week 20 of gestation.


DEVELOPMENTAL PHYSIOLOGY OF THE GASTROINTESTINAL SYSTEM



A.    Gastric Activity



1.    Gastric motility in infants is decreased and somewhat irregular compared with the adult due to delayed maturation of feedback control mechanisms, delayed gastric emptying, and immature coordination of contractions between the antrum of the stomach and the duodenum.



2.    Gastroesophageal reflux (GER) is common during the first year because of a complex set of factors, including pressure−volume changes and anatomic relationships causing inappropriate relaxation of the lower esophageal sphincter (LES).


B.    Immature Neonatal Liver


The liver matures in function during the first year of life. Toxic substances are inefficiently detoxified.


ANATOMY AND PHYSIOLOGY OF THE GASTROINTESTINAL SYSTEM



A.    Structure and Function (Figure 7.2)



1.    Oral Cavity. The oral cavity serves as a reservoir for chewing and mixing food with saliva. Salivary glands include the submandibular, sublingual, and parotid glands. Saliva is composed of water, small amounts of mucus, sodium bicarbonate, chloride, potassium, and amylase. Amylase begins carbohydrate digestion.



2.    The esophagus propels swallowed food to the stomach. The upper esophageal sphincter prevents air from entering the esophagus during respiration. The LES closes after swallowing to prevent reflux of gastric contents into the esophagus.








532image


FIGURE 7.2    Gastrointestinal structures.


Source: Reprinted with permission from Jacob, S. W., & Francone, C. A. (1989). Elements of anatomy and physiology (2nd ed.). Philadelphia, PA: W. B. Saunders.







3.    Stomach



a.    The stomach is a hollow, muscular organ that acts as a reservoir for ingested food. It secretes digestive juices that mix with digested food (chyme). Parietal cells secrete hydrochloric acid and intrinsic factor. Intrinsic factor is a glycoprotein that is required for vitamin B12absorption. The secretion is regulated by stimuli (i.e., H2-histamine receptors). Chief cells secrete pepsinogen, which combines with hydrochloric acid to break down protein.



b.    Gastric emptying is affected by the volume of food, osmotic pressure, and chemical composition of the contents. Emptying is controlled by the pyloric sphincter. Delayed emptying is caused by foods with high fat content, solid foods, sedatives, sleep, and specific hormones (i.e., secretin and cholecystokinin). Accelerated emptying is caused by foods with high carbohydrate content, liquids, increased volume, and medications (e.g., metoclopramide, erythromycin ethylsuccinate [EES], and azithromycin [zithromax]).



4.    The small intestine is the primary site for digestion and absorption of fats, amino acids, proteins, carbohydrates, and vitamins. The small intestine is anatomically adapted to increase surface digestion and absorption due to folds of mucosa lined with villi and the brush-border membrane. The brush border contains digestive enzymes and contributes to the transfer of nutrients and electrolytes. The epithelial absorptive cells are called enterocytes. Glutamine (amino acid) stimulates the proliferation of enterocytes. The gastrointestinal (GI) tract continuously renews the cells lining its surface.



a.    The duodenum is the primary site for the absorption of iron, trace metals, and water-soluble vitamins.



b.    The jejunum is the principal absorption site for proteins and sugar carbohydrates. Ninety percent of nutrients and 50% of water and electrolytes are absorbed here.



c.    The ileum is responsible for absorption of bile salts and vitamin B12. The ileocecal valve controls the entry of digested material from the ileum into the large intestine and prevents reflux into the small intestine. Digestion in the ileum continues by the action of pancreatic enzymes, intestinal enzymes, and bile salts. Carbohydrates are broken down into monosaccharides and disaccharides and are absorbed by villous capillaries. Proteins are degraded to peptides and amino acids and are absorbed by villous capillaries. Fats are emulsified and reduced to fatty acids and monoglycerides.



5.    Large Intestine. The anatomic segments of the colon or large intestine include the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. Water and electrolytes are reabsorbed in the descending colon. Feces are stored 533in the rectum. The greatest growth of anaerobic and gram-negative aerobic bacteria is in the ascending colon. Bacteroides fragilis (anaerobic) and Escherichia coli (aerobic) play a role in metabolizing bile salts and synthesizing vitamins.



6.    Pancreas. The pancreas’s exocrine function is to secrete bicarbonate and enzymes (e.g., amylase, lipase) for digestion and absorption of fats, carbohydrates, and proteins. The pancreas’s endocrine function involves islet cells, which function in glucose homeostasis by synthesizing and secreting insulin.



7.    Liver



a.    Liver functions include the following:



i.    Formation of clotting (coagulation) factors I, II, V, VII, IX, X, and XI



ii.    Synthesis of plasma proteins (albumin, fibrinogen, and 60%−80% of globulins)



iii.    Synthesis and transportation of bile (bile salts, pigment, and cholesterol)



iv.    Storage of glycogen, fat, and fat-soluble vitamins



v.    Metabolism of fats, carbohydrates, and proteins



vi.    Metabolism and deactivation of bilirubin, ammonia, and many toxins by oxidation or conjugation reactions



b.    Three fourths of the blood supply to the liver is supplied by the portal venous system (blood rich in nutrients) and one fourth by the hepatic artery (blood rich in oxygen).



c.    Nutrients are absorbed from the GI tract and transported by either the portal or lymphatic circulation. The lymphatic system plays a pivotal role in transporting lipid-soluble substances.



8.    Biliary Tree and Gallbladder. The biliary tree serves as the conduit for bile flow from the liver to the duodenum. The gallbladder provides a storage and concentration site for bile.



9.    Splanchnic Circulation. The splanchnic circulation supplies blood to the stomach, small intestine, and colon. It receives one fourth of the body’s cardiac output. The major arterial branches are the celiac, superior mesenteric, and inferior mesenteric. Venous drainage from the stomach, pancreas, small intestine, and colon flows to the portal vein to the liver and then to the heart through the hepatic vein and inferior vena cava.


B.    Regulation of Fluid and Electrolyte Movement



1.    Large volumes of water, electrolytes, proteins, and bile salts are secreted and reabsorbed throughout the GI tract, resulting in massive fluid and electrolyte shifts.



2.    Fluid and electrolyte movement occur concurrently with digestion and absorption of nutrients.


CLINICAL ASSESSMENT OF THE GI SYSTEM



A.    General Principles of Abdominal Assessment


Examination of the abdomen can be difficult in a child. A frightened child will not cooperate with the examination. A child suffering from multisystem trauma will be unable to localize pain. The preferred order of assessment is inspection, auscultation, palpation, and percussion.


B.    Abdominal Examination Assessment Techniques



1.    Inspection. Evaluate for size, contour, symmetry, integrity, visible peristalsis, umbilicus, masses, and wounds. Underdeveloped abdominal musculature in children allows easier visualization of masses and fluid waves. Abdominal distention (the abdomen is normally rounded in infants and toddlers) is the hallmark sign of obstruction.



2.    Auscultation



a.    Determine the absence, presence, and character of peristalsis or bowel sounds (borborygmi). Bowel sounds are absent in paralytic ileus and peritonitis. A venous hum heard over the upper area of the abdomen suggests portal obstruction. A bruit (caused by turbulent blood flow through a partially occluded artery) suggests abnormal blood flow caused by an arteriovenous malformation (AVM) or aneurysm. High-pitched or hyperactive bowel sounds suggest an obstruction.



b.    Bowel sounds should be heard every 5 to 30 seconds. Listen to all four quadrants for a few minutes to confirm the presence or absence of bowel sounds.



3.    Palpation. Begin with light palpation and assess for guarding and tenderness. Consider using the diaphragm of your stethoscope with a focus on the child’s face when palpating to asses for pain. With deep palpation, assess for abdominal tone, masses, 534pulsations, fluid, and organ enlargement. The liver is normally palpated at the right costal margin (RCM) or is nonpalpable. Palpation should be started by the iliac crest to ensure hepatomegaly is appreciated. The spleen is not normally palpable.



4.    Percussion. Percussion is used to estimate the size of organs and aids in the diagnosis of ascites, obstruction, and peritonitis. Assess for abdominal distention, fluid, masses, or organ enlargement. Percussion of solid organs (liver and spleen) and ascites elicits dullness. Absence of dullness over the liver may be found with free air in the abdomen secondary to perforation. The stomach is tympanic when empty. Depending on contents, the intestines’ tone is hyperresonant to tympanic.


C.    Developmental Considerations



1.    The abdominal wall is less muscular in the infant and toddler, making the abdominal organs easier to palpate. In the infant, the liver can be palpated 1 to 2 cm below the RCM at the midclavicular line.


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535image



2.    In younger children, the contour of the abdomen is protuberant because of immature abdominal musculature. After 4 years of age, the abdomen is no longer protuberant when the child is in a supine position; but, because of lumbar lordosis, the abdomen remains protuberant when the child stands.


INVASIVE AND NONINVASIVE DIAGNOSTIC STUDIES



There are numerous laboratory and radiologic diagnostic studies that are obtained for children with a GI disorder. Common laboratory abnormalities for liver disease are summarized in Table 7.1. Diagnostic studies commonly used to determine GI disease are summarized in Table 7.2.


536TABLE 7.2    Common Diagnostic Studies for GI Disorders








































































Procedure


Purpose


Disorder


Abdominal x-ray


Flat plate


Cross table lateral


Lateral decubitus


Evaluate organ size, position, gas patterns, air−fluid levels, presence of free air, position of NG or NJ tube


Bowel obstruction, perforation, ileus, NEC


Fluoroscopy


Barium swallow


Examine the integrity of the esophagus, diagnoses structural abnormalities


Esophageal or strictures, GE reflux


Upper GI series


Examine the esophagus, stomach, and duodenum; diagnose structural abnormalities; delayed gastric emptying

 

Upper GI with small bowel follow-through


Same as upper GI with follow-up films of esophagus to small intestine


Small bowel disorders, malrotation, small bowel structure


Endoscopy


Flexible upper endoscopy


Directly visualize upper GI mucosa, diagnose lesions, determine source of bleeding


Esophageal varices, severe gastritis


Endoscopic retrograde cholangiopancreatography


Directly visualize the biliary and pancreatic ducts


Pseudocyst, gallstones, pancreatitis


Flexible colonoscopy


Directly visualize mucosa of large intestine, diagnose mucosal injury, bleeding source


Polyp, inflammatory bowel disease


Biopsy


Percutaneous liver biopsy


Obtain liver specimens


Biliary atresia, hepatitis


Nuclear scans


HIDA scan


Determine liver excretory function


Biliary atresia


Meckel scan


Evaluate location of bleeding (radioactive isotope is taken up by parietal cells)


Meckel’s diverticulum


Other scans


Abdominal ultrasound


Visualize organ structure, suspected appendicitis, intussusception, pyloric stenosis


Liver disease, trauma in unstable child (FAST scan), pancreatitis


Abdominal CT scan with contrast


Evaluate for vascular disorders; definitive imaging of solid organs; evaluate for infection, abscess, traumatic injury, appendicitis


Organ trauma, liver disease, pancreatitis, pseudocyst


MRI


Definitively image abdominal organs in stable child


Hepatic hemangioma, hepatic AVM, appendicitis


AVM, arteriovenous malformation; FAST, focused abdominal sonography for trauma; GE, gastroesophageal; GI, gastrointestinal; HIDA, hepatobilliary iminodiacetic acid; NEC, necrotizing enterocolitis; NG, nasogastric; NJ, nasojejunal.


Source: Modified from Simone, S. (2001). Gastrointestinal critical care problems. In M. A. Q. Curley & P. A. Moloney-Harmon (Eds.), Critical care nursing of infants and children (2nd ed., pp. 765–804). Philadelphia, PA: WB Saunders.


537PHARMACOLOGY



A.    Antibleeding Agents



1.    Vasopressin (Pitressin; Taketomo, Hodding, & Kraus, 2015)



a.    Action. Vasopressin is a nonselective, short-acting vasoconstrictor. It decreases splanchnic blood flow and portal hypertension.



b.    Uses. Used to treat acute massive GI hemorrhage.



c.    Dosage. Continuous intravenous (IV) infusion. Initial 0.002 to 0.005 units/kg/min; double as needed every 30 minutes to a maximum of 0.01 units/kg/min. If bleeding stops for 12 hours, taper the infusion off over 24 to 48 hours.



d.    Side effects include hypertension, bradycardia, arrhythmias, wheezing, bronchospasm, abdominal cramping, vomiting, water intoxication, decreased urine output, hyponatremia, decreased platelet count, and hemorrhage.



2.    Octreotide Acetate (Sandostatin; Taketomo et al., 2015)



a.    Action. Decreases splanchnic blood flow; inhibits gastrin synthesis and gastric acid output.



b.    Uses. Used to treat GI hemorrhage and intractable diarrhea. This agent has been used for the treatment of chylothorax. Sandostatin is used when conservative treatment fails.



c.    Dosage. Administer 1 to 2 mcg/kg IV bolus; infusion rate 1 to 2 mcg/kg/hr IV for GI hemorrhage, titrating the rate to response. Continuous IV infusion following a bolus dose of 1 mcg/kg followed by 1 mcg/kg/hr. Dosage of 1 to 10 mcg/kg every 12 hours (IV, subcutaneous [SC] administration) is used for intractable diarrhea. Dose reductions are recommended for patients with renal failure.



d.    Side effects include bradycardia, chest pain, hypertension, abdominal pain, nausea, diarrhea, headache, fat malabsorption, hypoglycemia or hyperglycemia, hypothyroidism, and possible anaphylactic shock. The incidence of gallstones and biliary sludge is approximately 33% in children receiving the medication for more than 12 months.



3.    Vitamin K1, Phytonadione (AquaMEPHYTON, mephyton; Taketomo et al., 2015)



a.    Action. Provides vitamin K activity and can be used as a cofactor in the liver synthesis of clotting factors II, VII, IX, and X; however, the mechanism of stimulation is unknown.



b.    Uses. Prevents and treats hypoprothrombinemia caused by malabsorption, drug- or anticoagulant-induced vitamin K deficiency.



c.    Dosage. Note: Dosing presented is for GI-specific diseases for which supplementation is needed and is based on international normalized ratio (INR).



i.    Biliary atresia. Infants 1 to 6 months old: INR more than 1.2 to 1.5: 2.5 mg PO QD (orally every day). INR more than 1.5 to 1.8 initial 2 to 5 mg intramuscular (IM) once followed by 2.5 mg PO once daily. INR more than 1.8 initial 2 to 5 mg IM followed by 5 mg PO once daily.



ii.    Cholestasis. Infants, child, and adolescents: administer 2.4 to 15 mg/d PO.



iii.    Liver disease. Infants, child and adolescents: administer 2.5 to 5 mg/d PO.



d.    Side effects include a transient flushing reaction, rare hypotension, hypertension, rare dizziness, rash, and urticaria. U.S. boxed warning: Severe reactions resembling anaphylaxis have occurred during and immediately after IV administration. IV administration should be used when other routes of administration are not feasible and the benefits outweigh the risks.


B.    Antiulcer/Gastroesophageal Reflux Disease Agents



1.    Cimetidine (Tagamet; Slaughter, Stenger, Reagan, & Jadcherla, 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. A histamine-2 receptor antagonist (H2 blocker) that decreases the secretion of acid.



b.    Uses. Used for short-term treatment of active duodenal ulcers and gastric ulcers, gastroesophageal reflux disease (GERD), or for long-term prophylaxis and prevention of upper GI tract bleeding.



c.    Dosage. Neonate: administer 5 to 10 mg/kg daily PO in divided doses every 6 to 12 hours. Infant: administer 10 to 20 mg/kg daily PO in divided doses every 6 to 12 hours. Child: administer 20 to 40 mg/kg daily PO in divided doses every 6 hours. Dose reductions are recommended for patients with renal impairment.



d.    Side effects include bradycardia, tachycardia, hypotension, diarrhea, nausea, vomiting, dizziness, headache, agitation, gynecomastia, 538elevated serum creatinine, elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT), neutropenia, pancytopenia, and thrombocytopenia.



e.    Additional warnings. The use of H2 blockers and proton-pump inhibitors (PPIs) has been associated with increased incidence of gastroenteritis and community-acquired 539pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and necrotizing enterocolitis (NEC; Slaughter et al., 2016).



2.    Ranitidine (Zantac; Slaughter et al., 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. A histamine-2 receptor antagonist that decreases the secretion of acid.



b.    Uses. Used for short-term treatment of active peptic ulcer disease, GERD, or long-term prophylaxis and prevention of hypersecretory states and bleeding.



c.    Dosage. GI bleed or stress ulcer prophylaxis. Infant: administer 2 to 6 mg/kg daily via IV divided every 8 hours. Child and adolescents: administer 3 to 6 mg/kg daily via IV, divided every 6 hours, for a maximum of 300 mg daily; 0.15 to 0.5 mg/kg/dose for one dose followed by 0.08 to 0.2 mg/kg/hr continuous IV infusion. GERD dosing is 5 to 10 mg kg/d divided twice daily; maximum daily dose is 300 mg daily. Dose reduction is recommended for patients with renal impairment.



d.    Side effects include bradycardia (rapid IV administration), tachycardia, agitation, headache, dizziness, nausea, vomiting, elevated serum creatinine, hepatitis, arthralgia, leukopenia, and thrombocytopenia.



e.    Additional warnings. The use of H2 blockers and PPIs has been associated with increased incidence of gastroenteritis and community-acquired pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and NEC (Slaughter et al., 2016).



3.    Famotidine (Pepcid; Slaughter et al., 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. A histamine-2 receptor antagonist that decreases the secretion of acid.



b.    Uses. Used in therapy and treatment of peptic ulcer disease, GERD, and hypersecretory states.



c.    Dosage. GERD: In infants, administer 0.5 to 1 mg/kg daily PO up to 8 weeks or 0.25 to 0.5 mg/kg daily via IV. In children and adolescent dosing is 0.25 to 0.5 mg/kg/dose every 12 hours up to 20 mg/dose. Stress ulcer prophylaxis: In infants, children, and adolescents, administer 0.5 to 1 mg/kg/dose every 12 hours, with a maximum dose of 20 mg/dose. Dose reductions are recommended for patients with renal impairment.



d.    Side effects include arrhythmias, tachycardia, headache, dizziness, constipation, diarrhea, thrombocytopenia, and pancytopenia.



e.    Additional warnings. The use of H2 blockers and PPIs has been associated with increased incidence of gastroenteritis and community-acquired pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and NEC (Slaughter et al., 2016).



4.    Omeprazole (Prilosec; Slaughter et al., 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. PPI; direct inhibitor of hydrochloric acid secretions at the cellular level. It demonstrates antimicrobial activity against Helicobacter pylori.



b.    Uses. Used for short-term treatment (4−8 weeks) of severe erosive esophagitis and severe GERD and duodenal ulcer disease associated with H. pylori.



c.    Dosage. GERD: In infants, administer 0.7 mg/kg/dose daily PO; for children greater than or equal to 1 year and adolescents 5 kg to less than 10 kg, administer 5 mg Q day PO; 10 kg to less than 20 kg, 10 mg Q day PO; greater than or equal to 20 kg, 20 mg Q day PO; Erosive esophagitis: 5 kg to less than 10 kg, administer 5 mg Q day PO; 10 kg to less than 20 kg, 10 mg Q day PO; greater than or equal to 20 kg, 20 mg Q day PO. H. pylori eradication: administer 1 to 2 mg/kg/d divided into two doses; maximum single dose of 20 mg. The capsule form of the medication is a sustained-release capsule. The capsule can be opened and the beads mixed with an acidic medium such as 1 tablespoon of applesauce. The tablets of medication should not be crushed. The manufacturer suggests using the suspension for administration in a nasogastric (NG) tube.



d.    Side effects include bradycardia, tachycardia, nausea, diarrhea, abdominal cramps, headache, dizziness, skin rash, elevated liver enzymes, hypomagnesemia, proteinuria, skin rash, and thrombocytopenia.



e.    Additional warnings. The use of H2 blockers and PPIs has been associated with increased incidence of gastroenteritis and community-acquired pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and NEC (Slaughter et al., 2016).



5.    Pantoprazole (Protonix; Slaughter et al., 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. In PPI, pantoprazole is a direct inhibitor of hydrochloric acid secretions at the cellular level. This PPI more directly inhibits acid secretion compared with other PPIs. It demonstrates antimicrobial activity against H. pylori.



b.    Uses. Used to treat GERD (Food and Drug Administration [FDA] approved in ages ≥5 years), pathological hypersecretory conditions, and as an adjunct to duodenal ulcer treatment associated with H. pylori.



c.    Dosage. GERD: Infants and children younger than 5 years, administer 1.2 mg/kg/d daily for 4 weeks; children 5 to 11 years, 20 or 40 mg PO daily; children and adolescents, 20 or 40 mg once daily. For gastric acid suppression when PO administration is not appropriate or tolerated, the dose is 0.8 or 1.6 mg IV once daily, maximum dose 80 mg.



d.    Side effects include hypotension, hypertension, headache, urticaria, pruritus, hyperglycemia, hypermagnesemia, nausea, vomiting, diarrhea, constipation, urinary frequency, elevated liver enzymes, elevated triglyceride levels, cough, and dyspnea. Anaphylaxis has been reported with IV administration.



e.    Additional warnings. The use of H2 blockers and PPIs has been associated with increased incidence of gastroenteritis and community-acquired pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and NEC (Slaughter et al., 2016).



6.    Lansoprazole (FIRST-Lansoprazole; Slaughter et al., 2016; Stark & Nylund, 2016; Taketomo et al., 2015)



a.    Action. PPI; acts as a direct inhibitor of hydrochloric acid secretion at the cellular level.



b.    Uses. For short-term treatment of symptomatic GERD (up to 8 weeks; FDA approved for ≥1 year); for duodenal ulcer treatment associated with H. pylori, erosive esophagitis, and hypersecretory conditions.



c.    Dosage. GERD: Infants 1 to 2 mg/kg/d for weight-based dosing; for fixed dosing in infants older than 3 months, administer 7.5 mg twice a day or 15 mg daily; children 1 to 11 years who weigh less than or equal to 30 kg, 15 mg daily for up to 12 weeks; children greater than 30 kg, 30 mg daily for up to 12 weeks; children 12 years or older, 15 mg once daily for up to 8 weeks.



d.    Side effects include hypertension, hypotension, nausea, dyspepsia, abdominal pain, diarrhea, constipation, elevated liver enzymes, dizziness, and headache.



e.    Additional warnings. The use of H2 blockers and PPIs has been associated with increased incidence of gastroenteritis and community-acquired pneumonia in children (Stark & Nylund, 2016). In neonates, there is an associated increased incidence of infectious complications and NEC (Slaughter et al., 2016).



7.    Sucralfate (Carafate; Taketomo et al., 2015)



a.    Action. Gastric protectant; paste formation and ulcer adhesion occur within 1 to 2 hours of administration and last up to 6 hours.



b.    Uses. Used for short-term management of duodenal ulcers and gastritis; typically may be used for esophageal, gastric, and rectal erosions.



c.    Dosage. Dose is not established; administer 40 to 80 mg/kg/d PO in divided doses every 6 hours. Administer 1 hour before meals or on an empty stomach.



d.    Side effects include constipation and rarely, anaphylaxis, bezoar formation, and hypersensitivity. Decreased absorption of concurrently administered drugs may occur. Safety and efficacy in children have not been established.



8.    Calcium Carbonate (Maalox; Taketomo et al., 2015)



a.    Action. Maalox is an antacid that neutralizes gastric acid.



b.    Uses. Provides symptomatic relief for peptic ulcer, gastritis, esophagitis, hiatal hernia, and treatment of hyperphosphatemia in end-stage renal failure.



c.    Dosage. In children 2 to 5 years, administer one tablet (400 mg calcium carbonate) as symptoms occur (not to exceed 3 tablets/d); children older than 5 years to 11 years, two tablets (800 mg) as symptoms occur (not to exceed 6 tablets/d); children older than 11 years, two to four tablets as symptoms occur (not to exceed 15 tablets/d).



d.    Side effects include headache, laxative effect, hypercalcemia, and hypophosphatemia.


540C.    Prokinetics



1.    Metoclopramide (Reglan; Taketomo et al., 2015)



a.    Action. A potent dopamine receptor antagonist that blocks dopamine receptors in the chemoreceptor trigger zone, preventing emesis; accelerates gastric emptying and intestinal transit time.



b.    Uses. For GERD, prevention of postoperative and chemotherapy-related nausea and vomiting, assist with postpyloric feeding tube placement, and diabetic gastroparesis.



c.    Dosage. Postpyloric feeding tube placement: In children younger than 6 years, administer 0.1 mg/kg once; 6 to 14 years, give 2.5 to 5 mg as a single dose; and older than 14 years, administer 10 mg as a single dose. GERD: In infants, children, and adolescents, administer 0.1 to 0.2 mg/kg/dose every 6 to 8 hours with a maximum dose of 10 mg.



d.    Side effects include extrapyramidal reactions, seizures, hypertension, hypotension, atrioventricular block, constipation, diarrhea, neutropenia, and leukopenia.



2.    Erythromycin (E.E.S.; Taketomo et al., 2015)



a.    Action. Works as a motilin receptor agonist and increases LES tone.



b.    Uses. A macrolide antibiotic that can be used as a prokinetic agent.



c.    Dosage. In children, an initial dose of 3 mg/kg QID (four times a day) PO.



d.    Side effects include QTc prolongation, ventricular arrhythmias, bradycardia, skin rash, abdominal pain, nausea, vomiting, diarrhea, eosinophilia, and cholestatic jaundice.


D.    Antidiarrheal Agents



1.    Imodium (Loperamide; Taketomo et al., 2015)



a.    Action. Acts directly on the intestinal muscles through the opioid receptor to inhibit peristalsis and transit time. The drug reduces stool volume, causes decreased fluid and electrolyte losses, and demonstrates antisecretory activity.



b.    Uses. Used for treatment of acute diarrhea (FDA approved in children ≥2 years) although manufacturer recommends avoiding use in children younger than 2 years as acute enteritis often necessitates treatment of fluid and electrolyte imbalances; for chronic diarrhea associated with inflammatory bowel disease and intestinal failure, and to decrease volume of ileostomy output.



c.    Dosage. Acute diarrhea: In children 2 to 5 years weighing 13 to less than 21 kg, a dose of 1 mg after each subsequent loose stool, with dose repeated for each subsequent stool for a maximum of 3 mg/d; children 6 to 8 years weighing 21 to 27 kg, administer 2 mg for first loose stool, with 1 mg/dose repeated for each subsequent stool for a maximum of 4 mg/d; children 9 to 11 years weighing 27.1 to 43 kg, administer 2 mg for first loose stool, with 1 mg/dose repeated for each subsequent stool for a maximum of 6 mg/d; children older than 12 years, 4 mg for first loose stool, with 2 mg/dose repeated for each subsequent stool for a maximum of 8 mg/d. For chronic diarrhea related to intestinal failure or other noninfectious causes, larger doses are generally needed. Dosing initial 1 to 1.5 mg/kg/d in four divided doses with final dose range up to 0.5 mg/kg BID (twice a day).



d.    Side effects include dizziness, abdominal cramping, and constipation.



2.    Clonidine (Catapres; Fragkos, Zárate-Lopez, & Frangos, 2016; Taketomo et al., 2015)



a.    Action. Stimulates α2-adrenoreceptors in the brainstem resulting in decreased sympathetic outflow.



b.    Uses. Use to decrease GI losses in children with stomas related to the constipating side effect of the medication. Other more established uses include treatment of hypertension and use for withdrawal prophylaxis.



c.    Dosage. For GI use, patches have been used in dosing of 0.1 to 0.3 mg/24 hr with patches changed weekly.



d.    Side effects include hypotension, cardiac arrhythmia, agitation, constipation, diarrhea, and abnormal hepatic function tests.


E.    Other Agents



1.    Lactulose (Cephulac; Taketomo et al., 2015)



a.    Action. Hyperosmotic laxative; ammonia detoxicant.



b.    Uses. Used to prevent and treat portal-systemic encephalopathy. This treatment is controversial because the benefit of this therapy can be diminished relative to potential fluid and electrolyte disturbances.



c.    Dosage. For infants, administer 2.5 to 10 mL/d PO divided three or four times per day. In children, 40 to 90 mL/d PO divided 541three to four times per day. Adjust dosage to produce two to three stools per day.



d.    Side effects include abdominal discomfort, diarrhea, nausea, and vomiting.



2.    Magnesium Hydroxide (Milk of Magnesia; Taketomo et al., 2015)



a.    Action. An antacid that can be used as a cathartic or laxative for constipation.



b.    Uses. Used for bowel evacuation and treatment of hyperacidity.



c.    Dosage. When used as a laxative in children ages 2 to 5 years, administer 5 to 15 mL/d PO or in divided doses. In children ages 6 to 12 years, administer 15 to 30 mL/d PO or in divided doses. As an antacid, administer 2.5 to 5 mL PO as needed.



d.    Side effects include hypotension, diarrhea, respiratory depression, and hypermagnesemia.



3.    Polyethylene Glycol-Electrolyte Solution (GoLYTELY; Taketomo et al., 2015)



a.    Action. Induces catharsis with strong electrolyte and osmotic effects.



b.    Uses. Used as a bowel preparation for procedures and for treatment of constipation.



c.    Dosage. For bowel preparation, 25 mL/kg/hr PO/NG until rectal effluent is clear.



d.    Side effects include metabolic acidosis, potential for electrolyte disturbances, nausea, cramps, and abdominal distension.



4.    Polyethylene Glycol 3350 (MiraLax)



a.    Action. An osmotic agent, causes water retention in the stool.



b.    Uses. Used to treat occasional constipation.



c.    Dosage. For infants, children, and adolescents, administer 0.2 to 0.8 mg/kg/d; maximum daily dose of 17 g/d.



d.    Side effects include metabolic acidosis, potential for electrolyte disturbances, nausea, cramps, and abdominal distension.


F.    Immunosuppressive Therapy



1.    Basic Principles. Combination therapy is used to maximize therapeutic benefit of agents while minimizing associated toxicities, including infection and malignancy. Institution of specific protocols and organ-specific therapies exist with goals of therapy to maintain sufficient drug levels to prevent rejection. Combination protocols are used to increase drug efficacy and minimize drug toxicity.



2.    Tacrolimus (Prograf; Taketomo et al., 2015)



a.    Action. A calcineurin inhibitor that suppresses the synthesis of interleukin-2, the cytokine needed for lymphocyte activation.



b.    Dosage. Administer 0.01 to 0.06 mg/kg daily via a continuous IV infusion or 0.10 to 0.3 mg/kg daily PO in divided doses twice a day. Dosing is variable depending on the organ transplanted and may be based on drug levels. Patients with renal or hepatic impairment should receive dosing from the lower end of the dosing ranges.



c.    Side effects. With IV use, greater toxicity is observed with a high anaphylaxis risk, including arrhythmias, hypertension, nephrotoxicity, central nervous system (CNS) effects (insomnia, headache, tremor, seizure, paresthesia), hyperkalemia, hypomagnesemia, hyperglycemia, GI tract symptoms, alopecia, and lymphoproliferative disease (LPD).



3.    Cyclosporine (Sandimmune; Taketomo et al., 2015)



a.    Action. A calcineurin inhibitor that binds to the intracellular protein cyclophilin that inhibits T-cell proliferation through inhibition of interleukin-2 synthesis.



b.    Dosage. Note that there are modified and nonmodified formulations of this medication. Nonmodified: administer 2 to 10 mg/kg daily via IV in divided doses every 8 to 24 hours for maintenance; postoperatively, administer 5 to 15 mg/kg daily PO divided every 12 to 24 hours; maintenance dosing is usually 3 to 10 mg/kg/d. Dosing is variable depending on the organ transplanted and may be based on drug levels. The PO dose is approximately three times the IV dose.



c.    Side effects include hypertension, nephrotoxicity, CNS toxicity (headache, tremor, seizure, paresthesia), hypomagnesemia, GI tract symptoms, gum hyperplasia, hirsutism, and LPD.



4.    Corticosteroids. Methylprednisolone (Solu-Medrol) and Prednisone (Taketomo et al., 2015)



a.    Action. An anti-inflammatory agent that depresses the immune system by decreasing T-lymphocytes and monocyte activation.



b.    Dosage



i.    Methylprednisolone. Administer 0.5 to 1.7 mg/kg daily via IV in divided doses every 6 to 12 hours.



542ii.    Prednisone. Administer 0.05 to 2 mg/kg daily PO in divided doses one to four times daily.



c.    Side effects include glucose intolerance, hyperglycemia, possible suppression of the hypothalamic−pituitary−axis, peptic ulcers, weight gain, hypertension, hyperlipidemia, sodium and water retention, osteoporosis, infection, abnormal hair growth and thinning, and increased risk of bruising and acne.



5.    Mycophenolate Mofetil (Cellcept; Taketomo et al., 2015)



a.    Action. An antimetabolite that inhibits T- and B-cell proliferation by inhibiting the inosine monophosphate dehydrogenase pathway, preventing lymphocyte proliferation.



b.    Dosage. Administer 600 mg/m2/dose twice daily PO; maximum daily dose of 2,000 mg/d.



c.    Side effects include hypertension, headache, rash, nausea, vomiting, dyspepsia, cough, leukopenia, neutropenia, thrombocytopenia, increased malignancy risk, and anemia. Females within child-bearing years must receive counseling on pregnancy risk and have a pregnancy test prior to starting therapy, 2 weeks after starting therapy, and at follow-up visits.



6.    Azathioprine (Imuran; Taketomo et al., 2015)



a.    Action. Azathioprine is an antimetabolite that inhibits DNA synthesis.



b.    Dosage. Initial dose is 3 to 5 mg/kg daily administered either PO or IV. Maintenance is 1 to 3 mg/kg per day taken once daily.



c.    Side effects include bone marrow suppression (anemia, leukopenia), hepatotoxicity, pancreatitis, nausea and vomiting, increased malignancy risk, and mucosal ulceration.


NUTRITIONAL CONCEPTS



A.    Nutrition Assessment



1.    Pediatric Critical Care Best Practices



a.    Thirty-one percent of pediatric intensive care unit (PICU) patients in an international point prevalence survey of 31 PICUs were determined to be malnourished (Mehta et al., 2012).



i.    Malnourished patients included both underweight and overweight children. There is greater morbidity and mortality in the underweight child as compared to the overweight child.



b.    Within 48 hours of admission, children in the PICU should undergo a detailed nutrition assessment, including a detailed dietary history, identification of changes in anthropometry, functional status, and nutrition-focused physical exam (Mehta et al., 2017).



2.    Anthropometrics



a.    An accurate weight (kg), length (cm), and body mass index should be documented at admission. Serial weight measurement is recommended as weight loss is the best single physical exam indicator of malnutrition risk.



b.    A head circumference should be obtained in children younger than 3 years old (Mehta et al., 2017).



c.    The z-scores for body mass index should be used to screen for extreme values (weight for length <2 years) or weight for age (if an accurate height is not available; Mehta et al., 2017).



3.    Assessment of Energy Needs (kcal/kg/d)



a.    Energy requirements are highly individual and vary widely (Verger, 2014).



i.    Energy needs are dynamic, changing from a hypermetabolic to hypometabolic state through the trajectory of the PICU stay, largely related to changes in energy consumption and limited energy reserves.



b.    The Society of Critical Care Medicine and A.S.P.E.N. recommend assessment of measured energy expenditure (MEE) by indirect calorimetry (IC; Mehta et al., 2017).



c.    If IC is not feasible, the Schofield or Food Agriculture Organization/World Health Organization (WHO)/United Nations University equations may be used without the addition of stress factors.



d.    Often, the requirement is determined by reference standards based on age for healthy children (Table 7.3), which should not be used for critically ill children.


B.    Macronutrient, Micronutrient, and Fluid Requirements



1.    Carbohydrate, protein, and fat are the macronutrients.



a.    Recommended caloric distribution varies and for carbohydrates is 40% to 70%, protein is 7% to 21%, and for fat is 30% to 55%.


543TABLE 7.3    Daily Estimated Energy Needs for Healthy Infants and Children

























Age


kcal/kg/d


Up to 6 months


90−110


6−12 months


80−100


12−36 months


75−90


4−6 years


65−75


7−10 years


55−75


11−18 years


40−55



i.    A minimum protein intake of 1.5 mg/kg/d is recommended (Mehta et al., 2017).



ii.    For obese patients, this guideline should be based on ideal body weight (Mehta et al., 2017).



b.    Diets high in carbohydrates can increase carbon dioxide product and hamper ventilator weaning.



2.    Micronutrients include vitamins, minerals, and electrolytes.



3.    Fluid requirements vary as a function of age, weight, and clinical condition.



a.    Calculation of maintenance fluids is used as a starting requirement for most children.



i.    First 10 kg (1−10 kg): 100 mL/kg



ii.    Next 10 kg (11−20 kg): 50 mL/kg



iii.    Over 20 kg (>20 kg): 20 to 25 mL/kg



iv.    For a 10-kg child, the fluid requirement is a 1,000 mL a day, or 40 mL/hr.


C.    Enteral Nutrition



1.    Enteral route is preferred and should be used if at all possible and determined within 24 to 48 hours of admission (Mehta et al., 2017).



a.    Promotes intestinal mucosal structure and gut absorptive and barrier functions (e.g., villi).



b.    Is associated with fewer infectious and metabolic complications.



2.    Estimated energy needs are greater for enteral feeds as all parenteral nutrition (PN) calories are directly absorbed. Most infants require 100 to 120 kcal/kg/d.



3.    Formula Selection



a.    Breast milk (BM) is the preferred source of nutrition for infants, nursing mothers should be provided with a breast pump if their infant is on NPO (nothing by mouth) status or cannot breastfeed. Selection of the appropriate formula is based on the patient’s age and disease process (e.g., less protein may be needed in children with liver or renal disease). Premature infants require specialty formulas that are higher in calories per ounce and have additional vitamins and minerals.



4.    Formulas have varying caloric density kcal/ounce.



a.    Infants require 19 to 20 kcal/ounce, may increase to 24 kcal/ounce, 27 kcal/ounce, or 30 kcal/ounce for fluid restriction or to promote weight gain.



b.    Children older than 12 months require 30 kcal/ounce formula.



c.    For children younger than 12 months with poor weight gain, consider 45 kcal/ounce.



5.    Enteral feeds can be administered orally, through an orogastric (OG)/NG tube, gastrostomy tube, or postpylorically through a gastrojejunostomy or jejunostomy tube.



6.    Enteral nutrition is needed if the child has delayed gastric motility, intestinal dysmotility, or inability to tolerate gastric feeds or is at high risk for aspiration.


D.    Parenteral Nutrition



1.    An IV mixture of macronutrients (carbohydrates [dextrose or glucose], protein, and fat), and micronutrients (electrolytes, minerals, vitamins, and trace elements) for children that are unable to absorb nutrients through the GI tract.



544a.    Dextrose provides 3.4 kcal/g and constitutes 60% to 70% of the total PN caloric composition.



b.    Protein can be administered as trophamine (recommended for infants younger than 1 year and for children with liver failure), or as clinisol or travasol (for children older than 1 year of age). Protein provides 4 kcal/g and should constitute up to 14% to 20% of the total PN caloric composition.



c.    Fat emulsions (intralipid) may be administered as a separate solution to provide a major source of calories (20% solution provides 2 kcal/mL) and should constitute 30% to 50% of the total PN caloric intake. Providing 0.5 g/kg/d prevents essential fatty acid deficiency states.



d.    Electrolytes, vitamins, minerals, and trace elements are added to these solutions to meet the child’s known nutritional requirements.



2.    PN can be administered through a peripheral or central line.



a.    Formulations with a dextrose concentration greater than 12.5% should be administered centrally.



3.    Common additives to the PN formulation include heparin, if central access is being used, and Ranitidine, if GI prophylaxis is indicated.



4.    PN formulations can be commercial standard solutions or compounded individualized admixtures.



5.    With PN, caloric needs are decreased by 10% to 15%, as compared to the enteral route.



6.    PN “goals” are generally not achieved for 5 days, as macronutrients should gradually be advanced.



a.    Possible alternatives to prescribing PN are to augment the child’s nutrition by using dextrose 10% in water (D10W) and intralipids.



7.    The Society of Critical Care Medicine and A.S.P.E.N. recommend not starting PN within the first 24 hours of PICU admission (Mehta et al., 2017). When PN should be initiated is not known and should be individualized and started within the first week of admission if unable to receive enteral nutrition (EN) or for severely malnourished patients or those at risk for nutritional deterioration (Mehta et al., 2017).



8.    Complications of PN administration include bacteremia if central line is present, catheter-associated central line infection (central line-associated bloodstream infection [CLABSI]), metabolic derangement, and cholestatic jaundice.


NURSING MANAGEMENT OF TUBES AND DRAINS



A.    NG Tube



1.    An NG tube can be used for gastric decompression, feeds, fluids administration, and medication administration or for lavage in case of poisonings or GI hemorrhage.



2.    The child’s size and indication for NG placement will determine the size and type of tube that should be inserted.



a.    Generally, smaller bore nonvented tubes are used for feeding.



b.    Tubes used for decompression should not be used for feeds or medication administration as the necessary decompression ports may be too distal in the esophagus to safety administer feeds or medication. Do not tie off or obstruct the vent to prevent the backflow of gastric contents as this will block the vent and negate the function of the sump port.



3.    See Table 7.4 for suggested steps for placing an NG tube.



4.    Abdominal radiography is the most reliable method of confirming placement of an enteral tube; however, its use to verify enteral tube placement is not widespread in clinical practice due to the necessary radiation exposure (Lyman et al., 2016; Taylor, 2013). Evidence suggests that pH testing of GI secretions is the most accurate nonradiographic means of determining placement of an NG tube, although results are not 100% reliable (Gilbertson, Rogers, & Ukoumunne, 2011). Gastric aspirate has a pH of 5 or less and is usually grassy green or clear and colorless, with off-white to tan shreds of mucus (Irving et al., 2014; Taylor, 2013).



5.    Nursing care involves adequately securing the tube to prevent inadvertent dislodgement, verifying position prior to use (if placement is in question radiologic verification is needed), flushing the tube after instilling medications or formula; if the tube is to be placed to suction, low intermittent suction should be used to minimize trauma to the gastric mucosa, recording input and output every 4 hours, and performing oral care every 4 hours.


545TABLE 7.4    Nasogastric Tube Placement






1.  Elevate the child’s head of bed as tolerated.


2.  To determine the length for nasal placement, measure from the child’s nare, to the tip of the earlobe to midway between the xiphoid process and the umbilicus. For oral placement, the measurement should be started at the mouth.


3.  Mark the correct length with an indelible marker or place a piece of tape around the tube.


4.  Lubricate the end of the tube with water-soluble lubricant.


5.  Insert the tube into the mouth or a patent nare and gently advance the tube. Encourage the child to swallow while inserting the tube.


6.  Verify the tube placement by checking gastric pH or obtaining radiologic confirmation if placement is in question.


7.  Secure the tube to the child’s face.


Sources: Ellett, M. L. C., Cohen, M. D., Perkins, S. M., Croffie, J. M. B., Lane, K. A., & Austin, J. K. (2012). Comparing methods of determining insertion length for placing gastric tubes in children 1 month to 17 years of age. Journal for Specialists in Pediatric Nursing, 17(1), 19−32. doi:10.1111/j.1744-6155.2011.00302.x; Ellett, M. L. C., Cohen, M. D., Perkins, S. M., Smith, C. E., Lane, K. A., & Austin, J. K. (2011). Predicting the insertion length for gastric tube placement in neonates. Journal of Obstetric, Gynecologic, and Neonatal Nursing, 40(4), 412−421. doi:10.1111/j.1552-6909.2011.01255.x


B.    Gastrostomy Tube



1.    A gastrostomy tube is used for fluid, feeds, and medication administration for children unable to tolerate oral intake. Only liquid medications should be administered through the gastrostomy tube. The tube may also be placed to gravity to allow for gastric decompression, although may not be as effective as decompression from an NG tube.



2.    Gastrostomy tubes can be inserted via endoscope or percutaneous endoscopic gastrostomy (PEG) technique or surgically using an open or laparoscopic technique.



3.    There are several types of tubes available, including low-profile skin-level devices (balloon and mushroom types) and balloon-ended tubes. The devices have a French size that indicates the diameter and a stem length, which is measured in centimeters.



4.    Nursing care includes preventing inadvertent dislodgement (e.g., cover the tube with clothing, flex-net, bandage wrap, and disconnect tube extension sets when not in use), rotating the tube on a daily basis, and flushing the tube after instilling formula or medications to maintain patency. The tube site should be cleaned with soap and water. Care considerations for a newly placed gastrostomy tube (GT) include placing the tube to gravity in the immediate postoperative periods, “racking” or venting the tube to ensure the child can tolerate his or her own gastric secretions, and finally initiating feeds. If there is inadvertent dislodgement of the tube, it should be replaced within 3 to 4 hours with a GT study after replacement to confirm the tube is intragastric. If the child has undergone a Nissen fundoplication at the same time as GT placement, tube feeds should be vented with a Farrell bag to allow the wrap to heal (the fundus of the stomach is wrapped and sutured around the distal esophagus and LES to prevent reflux) and allow for gastric decompression as needed.



5.    All devices with balloons will require periodic replacement as the balloons will break down. If the tube falls out and was in place for less than 4 months, notify a practitioner from the service that placed the tube as a GT study may be ordered to verify correct position.


C.    Nasojejunal Tube



1.    A nasojejunal (NJ) tube (also referred to as a postpyloric or postpyloric tube) can be used for continuous feed, fluids, or medication administration for children at risk for aspiration or who do not tolerate gastric feeds. Feeds should be administered at a continuous rate as a bolus feed into the intestine may result in dumping, causing increased stool output and feeding intolerance.



2.    The size of the tube is based on the size of the child. NJ tubes have either a guide wire or tungsten-weighted tip to facilitate placement.



3.    The approximate length of the tube to be inserted is determined by measuring from the exit port of the tube from the child’s nare to ear lobe, then from the ear lobe to the midway point between the xiphoid and umbilicus (Ellett et al., 2011, 2012).



4.    At some organizations, prokinetic agents are administered to aid in successful passage of the postpyloric tube. The child should be placed right side 546lying as tolerated so the pylorus is in the lowest position, which will aid in placement. If this is not tolerated, the child should be placed supine with the head of bed elevated. Once gastric placement is achieved, the tube should be passed through the pylorus, instilling air or water, and advance until resistance is met.



5.    Tube placement should be confirmed with an abdominal x-ray.



6.    Nursing care involves adequately securing the tube to prevent inadvertent dislodgement, and may be secured with a bridling device, flushing the tube after instilling medications or formula, and performing oral care every 4 hours.


D.    Surgical Drains



1.    Surgical drains may be placed in or near the surgical wound to prevent the buildup of fluid and maintained until the amounts taper. Drains may be maintained to allow for the evaluation of the type of drainage after resuming a regular diet (e.g., Jackson-Pratt® drain positioned by a biliary anastomosis for bile).



2.    There are two types of surgical drains, active drains (closed or closed suction drains) that use negative pressure to remove fluid, and passive drains (open) that depend on the high pressure in the wound and gravity to drain the surgical site (Durai & Ng, 2010). Active drains, such as a Jackson-Pratt or Hemovac drains, have an expandable chamber that creates suction to remove fluid from the wound. In order for the drain to work, the suction bulb must be depressed and emptied at a scheduled interval or when full in order for suction to be maintained. A passive drain, such as a Penrose drain, relies on gravity to remove fluid from the wound and is usually sutured in place.



3.    Document the intake and output every 4 hours. Notify the provider of a significant increase or decrease in the amount or character of the drainage. The drain should be secured to prevent inadvertent dislodgement. The surrounding skin should be assessed for irritation or breakdown.


NURSING MANAGEMENT OF WOUND AND STOMA CARE



A.    Wound Care



1.    Abdominal wound care is variable and can be as simple as assessment for a wound infection (e.g., redness, warmth, pain, edema, foul-smelling drainage, or wound separation) to complex dressing changes involving negative pressure therapy. For complex wound care, consultation with a wound ostomy continence (WOC) nurse is appropriate.



2.    Open-wound care should employ moist wound strategies. Wet to dry dressings will provide for gentle wound debridement and allow for wound granulation. Hydrocolloid and hydrofiber dressings (e.g., Aquacel) will allow for wicking of wound drainage, promoting an environment for wound healing.



3.    Wounds with excessive drainage should have frequent changes with absorptive dressings that will aid in wound healing (e.g., Mepilex, thick foam).


B.    Ostomy Care



1.    An ostomy is a stoma that is surgically created from either the small intestine (ileostomy) or large intestine (colostomy) with the purpose of diverting waste outside the body. An ostomy appliance is placed to allow for the collection of stool.



2.    Stoma Assessment. The bowel is highly vascularized and a stoma should be pink and moist. There are no nerves in a stoma. If a stoma becomes pale or dusky that should be reported to the provider as perfusion to that intestinal segment may be impaired. Stoma output varies related to what segment of the bowel is used for stoma creation; the more proximal the bowel the more acidic and liquid the output will appear. The more distal in the colon the stoma is placed, the thicker and more formed the stool, which will be thickest in the descending colon.



3.    The ostomy appliance should be changed every 3 days or sooner if it leaks. The wafer should not be in place for longer than 3 days unless the patient is in the immediate postop period and output is minimal. A warm wet washcloth can be used to remove the old pouch. The skin should be pushed down versus pulling off the wafer as this is generally less painful. Clean the skin with water and allow the skin to dry. The new wafer can be cut according to the pattern. If there is not a pattern, placing a paper towel on top of the stoma will give an approximate measure of the size (dark and wet area on the paper towel can be used as a pattern) and the size to cut on the wafer for the stoma opening. After removing the paper on the wafer, place the wafer on the skin surrounding the stoma. Hold the wafer in place for 5 minutes to allow the plastic to melt and best adhere to the skin. Apply the bag to the appliance if not a one piece or already attached.



5474.    Nursing care includes emptying the bag when it is one-third full to extend the wafer adhering for a longer time to the skin. Pouches that become filled with air should be relieved to prevent wafer dislodgement. Measure and document the stoma effluence every 4 hours. Placing two to three cotton balls in the bag if the output is liquid will help absorb the effluence and prolong adherence of the appliance. If available, a WOC nurse should be consulted to optimize stoma care and educate the child and parents.


GASTROESOPHAGEAL REFLUX DISEASE



A.    Definition and Etiology



1.    GER is the involuntary movement of gastric contents from the stomach to the esophagus with or without regurgitation or vomiting. In the majority of infants, GER resolves by 1 year of age. GERD occurs with persistent GER that results in complications and impacts the child’s quality of life.



2.    Etiology



a.    At-risk children include those with prematurity, congenital esophageal abnormalities, congenital diaphragmatic hernia, neurologic impairment, cystic fibrosis, history of lung transplant, respiratory disorders, obesity, and family history of GERD.


B.    Pathophysiology



1.    Normally, the LES rests when there is a peristaltic wave and this relaxation is transient.



2.    The LES rests (5−30 seconds) are of longer duration when the pressure in the esophagus is the same as the stomach (Barnhart, 2016) and is the physiological cause of GER.


C.    Clinical Presentation



1.    History



a.    Evaluate symptoms and what alleviates or aggravates them, dietary history, and comorbidities.



b.    GERD varies with age. Symptoms can range from persistent vomiting to intermittent spitting to apparent life-altering events with a significant decline at 1 year of age.



2.    Physical Examination



a.    No specific examination findings are diagnostic of GER/GERD



i.    Review anthropometric measurements and growth charts.



ii.    Spitting and nonbloody and nonbilious vomiting are the most common symptom in infants. Other symptoms include feeding refusal, poor weight gain, respiratory symptoms, arching, choking, and coughing (Papachrisanthou & Davis, 2015).



iii.    In children, the most common symptoms are vomiting, heartburn, abdominal pain, and anorexia (Papachrisanthou & Davis, 2016).



3.    Diagnostic Tests



a.    There is no single diagnostic test confirmatory of GER/GERD.



b.    According to the joint recommendations from the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (Vandenplas et al., 2009):



i.    Esophageal pH monitoring. This is a valid quantitative test of acid exposure; however, severity does not correlate with symptoms or complications.



ii.    Combined multiluminal impedance and pH monitoring. Detects acid and nonacid reflux episodes and is superior to pH monitoring for determining the relationship between the symptoms and disease.



iii.    Motility studies. Esophageal manometry studies may be abnormal but lack sensitivity and specificity for GERD diagnosis confirmation.



iv.    Endoscopy and biopsy. Endoscopically visible breaks in esophageal mucosa are the most reliable to diagnose reflux esophagitis and, although it is not diagnostic of GERD, it may be helpful for the diagnosis of other disorders.



v.    Upper GI. Not recommended for GERD diagnosis, may be helpful in determining alternate diagnoses.



vi.    Empiric trial of aid suppression. For the older child, a 4-week trial of a PPI is used for symptom improvement; however, this is not recommended in infants and younger children. Improvement in the child’s heartburn does not confirm the GERD diagnosis as clinical improvement may be related to spontaneous improvement or placebo effect.



5484.    Clinical Course



a.    Persistent GER symptoms that progress to GERD with complications, including esophagitis and respiratory complications are expected.


D.    Patient Care Management



1.    Preventive Care or “Lifestyle Changes”



a.    Infants



i.    Elevate head of bed to 30 degrees, minimize overfeeding, and consider a 1- to 2-week trial of hypoallergenic formula (Garth, 2016).



b.    Children



i.    Elevate head of bed, encourage left side-lying positioning, weight reduction if indicated; there is no evidence to support dietary modification (e.g., minimize caffeine, fatty or spicy foods, carbonation, eat small frequent meals; Garth 2016; Vandenplas et al., 2009).



2.    Direct Care



a.    Pharmacology



i.    Administer a PPI (up to 8 weeks)—not FDA approved in infants younger than 1 year.



ii.    Administer a histamine-2 receptor antagonist—generally first-line treatment.



iii.    Prokinetic agent—The adverse side effects outweigh potential benefit for GERD treatment and these agents are not recommended.



b.    Surgical intervention



i.    Indications for surgery include dependence on long-term medication therapy, nonadherence to medical therapy, repeated episodes of aspiration or related pneumonia episodes, and an apparent life-threatening event.



ii.    Nissen fundoplication may be performed open or laparoscopically and is a 360-degree circumferential wrap of the fundus of the stomach around the intra-abdominal esophagus.



3.    The child may be unable to “burp” or vomit, which can lead to gastric distension and, in rare cases, gastric rupture. The child may require placement of an NG tube or, if a gastrostomy tube is present, it is placed to gravity drainage. Feeds, if administered through an enteric tube, should be administered continuously and vented (with a Farrell bag or syringe) during the immediate postoperative period.


E.    Outcomes


Symptoms that begin after 3 years of age are less likely to resolve without intervention.


ACUTE ABDOMINAL TRAUMA



Acute abdominal trauma is more often blunt versus penetrating, which is considered blunt abdominal trauma. The organs most commonly injured are the spleen and liver.


A.    Definition and Etiology


Anatomic differences in children compared with adults include a body size that allows greater distribution of injury, a larger body surface area that allows for greater heat loss, abdominal organs that are more anterior with less SC fat protection, and a smaller blood volume resulting in hypovolemia with relatively smaller volume losses.


B.    Pathophysiology



1.    Blunt injuries are caused by compression of solid or hollow viscous organs against the spine; rapid acceleration and deceleration with subsequent tearing of structures; or increased abdominal pressure resulting in contusion, laceration, or rupture of organs with subsequent hemorrhage. Solid organs are injured more often than hollow organs, and the most commonly injured organ is the spleen. Blunt trauma can result in lethal injury without visible signs of trauma.



2.    Penetrating injuries are most often caused by gunshot or stab wounds. The most common injury is to the hollow viscera. The onset of peritonitis may be immediate. Wounds that penetrate the abdomen usually require surgical exploration.


C.    Clinical Presentation



1.    History. History is given by a parent or emergency responder report. If age appropriate, speak with the child and attempt to get a history. As with all trauma, if the history does not explain the injuries, providers should be suspicious of child maltreatment.



2.    Physical Examination



a.    Significant injuries to the head and extremities may overshadow abdominal injuries.



b.    Signs of injury are often subtle and include rebound tenderness, pain, rigidity, pallor, grunting 549respirations, hypotension, failure to respond to fluid resuscitation, and increasing abdominal girth. Acute abdominal distention occurs even with minor trauma, especially in infants and often in children as a result of crying and swallowing air. Distention may lead to vomiting and aspiration.



c.    Signs of retroperitoneal bleeding include Cullen’s sign (ecchymosis around the umbilicus) and Turner’s sign (ecchymosis over the flank).



3.    Diagnostic Tests



a.    Abdominal x-rays, supine and lateral, are useful for determining intraperitoneal free air, ground-glass appearance (suggests intraperitoneal blood or urine), associated lower rib fractures (indicates severe force), and signs of an ileus.



b.    Ultrasound (US), or FAST (focused abdominal sonography for trauma), is a rapid diagnostic tool used to identify intraperitoneal fluid in the hemodynamically unstable child with blunt trauma. However, FAST is poor at identifying organ-specific injury and therefore does not replace the abdominal CT as a tool for definitive diagnosis of abdominal injury. The sensitivity of the FAST exam is highly variable; however, use of FAST scans has reduced the number of CT scans in some institutions (Notrica, 2015).



c.    Abdominal CT scan is the standard of care for evaluation of the peritoneal cavity and retroperitoneum in the hemodynamically stable child. The use of IV contrast is recommended to evaluate organ perfusion, bowel integrity, and the presence of intraperitoneal fluid (Ellison et al., 2015).



d.    Diagnostic peritoneal lavage (DPL) is a technique that is rarely performed with the advent of newer imaging techniques (e.g., FAST exam) and involves the insertion of a catheter into the peritoneal cavity. Aspiration of blood is a positive tap. If no blood is obtained, then 10 mL/kg of normal saline (NS) or Ringer’s lactate solution (RL) is infused through the catheter and the effluent is drained by gravity. Cell count and chemistries are obtained. White cell counts greater than 500 cells/mL, red cells counts greater than 100,000 cells/mL, amylase greater than 175 mg/dL, and aspirating stool or blood is a positive tap. A tap positive for blood indicates hemoperitoneum but provides no information on the bleeding source.



e.    Complete blood count (CBC) and coagulation studies may help to evaluate bleeding.



f.    The utility of other laboratory tests in the diagnosis of intra-abdominal injury is controversial. Elevated AST and ALT suggest liver injury (see Table 7.1). Elevated amylase and lipase suggest pancreatic injury.



g.    Urinalysis should be obtained to evaluate for the presence of blood, which indicates kidney or bladder injury.


D.    Patient Care Management



1.    Preventive Care. Safety measures include appropriate child-restraint devices in automobiles and wearing appropriate protective gear when participating in contact sports.



2.    Direct Care



a.    Early management of airway, breathing, and circulation (ABC) has the most direct impact on survival. The critically ill child may require intubation and mechanical ventilation for stabilization of the airway and breathing. Circulatory stabilization requires the placement of large-bore IV lines and fluid resuscitation. Inadequate airway and fluid resuscitation are the leading causes of preventable death. Central venous pressure (CVP) and arterial blood pressure (BP) lines are placed to allow close monitoring of the child’s intravascular volume and BP.



b.    Current management of blunt abdominal trauma is based on the child’s hemodynamic status (e.g., hemoglobin [Hgb] >7 mg/dL) as compared to injury severity grading scales. The mainstay of treatment remains nonoperative management for blunt solid abdominal organ injury (McVay, Kokoska, Jackson, & Smith, 2008).



c.    Insertion of an NG or OG tube allows for gastric decompression, minimizes aspiration risk, and maximizes respiratory effort.



d.    Serial laboratory studies are necessary for evaluation of injury, especially following the hematocrit, which is imperative to assess for ongoing bleeding. For blunt injuries for which serial values are being monitored, phlebotomy may be discontinued after two to three stable values (McVay et al., 2008).



e.    Most solid-organ abdominal injuries are managed nonoperatively. The blood volume of a child is approximately 80 mL/kg. Fluid resuscitation guidelines include administering up to 40 mL/kg of saline or RL solution. If the child remains hemodynamically unstable, a blood transfusion should then be given. Indications for surgical exploration include massive fluid resuscitation 550(>40 mL/kg of blood transfusions or more than 50% of blood volume), penetrating trauma, signs of peritonitis, radiographic evidence of pneumoperitoneum, and certain blunt injuries (e.g., diaphragmatic injury or bladder rupture).



3.    Organ-Specific Care



a.    The spleen is the most commonly injured abdominal organ in blunt abdominal trauma.



i.    Signs and symptoms include left upper quadrant (LUQ) tenderness, bruising, or abrasion, positive Kehr’s sign (LUQ pain radiating to the left shoulder), signs of decreased perfusion (pallor, tachycardia, delayed capillary refill, and hypotension), and nausea and vomiting. Other signs may include Cullen’s or Turner’s sign.



ii.    Diagnostic studies. Abdominal x-ray examinations are rarely helpful but may demonstrate an elevated left hemidiaphragm or a medially displaced lateral stomach border suggesting splenic laceration. The hematocrit may be decreased related to bleeding, or leukocytosis may be noted. Definitive diagnosis is made by abdominal CT scan with contrast.


TABLE 7.5    Splenic Injury Scale















































Grade


Injury Description


I


Hematoma


Subcapsular, nonexpanding, <10% of surface area


Laceration


Capsular tear, nonbleeding, <1 cm of parenchymal depth


II


Hematoma


Subcapsular, nonexpanding, 10%−50% of surface area, intraparenchymal, nonexpanding, <5 cm in diameter


Laceration


Capsular tear, 1−3 cm of parenchymal depth that does not involve a trabecular vessel


III


Hematoma


Subcapsular, >50% of surface area or expanding, ruptured subcapsular or parenchymal hematoma, intraparenchymal hematoma, >5 cm or expanding


Laceration


>3 cm of parenchymal depth or involving trabecular vessels


IV


Hematoma


Ruptured intraparenchymal hematoma with active bleeding


Laceration


Laceration involving segmental or hilar vessel producing major devascularization (>25% of spleen)


V


Laceration


Completely shattered spleen


Vascular


Hilar vascular injury that devascularizes spleen


Source: Adapted from Lynch, J. M., Meza, M. P., Newman, B., Gardner, M. J., & Albanese, C. T. (1997). Computed tomography grade of splenic injury is predictive of the time required for radiographic healing. Journal of Pediatric Surgery, 32, 1093−1096. doi:10.1016/S0022-3468(97)90406-1



iii.    Classification is based on location and extent of injury (Table 7.5).



iv.    Management. The standard of care is nonoperative treatment in hemodynamically stable patients. See Table 7.6 for current activity restrictions, hospital length of stay, and imaging recommendations. Patients are NPO until stable. Surgery may include a splenectomy or splenorrhaphy. In most instances, suturing the injury or splenorrhaphy results in salvage of the spleen. The ultimate goal is preservation of the immune function of the spleen. Massive splenic injury requires a splenectomy. Postoperative care includes monitoring for potential complications such as atelectasis, bleeding, ileus, pain, and infection.


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v.    Complications include rebleeding or splenic laceration 3 to 5 days after the initial injury. Splenectomized children are at risk for overwhelming postsplenectomy infection (OSI). Streptococcus pneumoniae is the most common causative agent. Vaccination against encapsulated bacteria, including S. pneumoniae, Haemophilus influenzae type b, and Neisseria meningitides, is recommended after splenectomy. Daily penicillin prophylaxis is recommended in children younger than 5 years and for 2 years following splenectomy and longer if there are other immunosuppression factors or a history of OSI (Buzelé, Barbier, Sauvanet, & Fantin, 2016). Parents should be taught signs and symptoms of infection and when to seek medical attention. Children who sustain an isolated splenic injury are restricted from contact sports and strenuous physical activity for a period consisting of the grade of injury plus 2 weeks.



b.    The liver is second only to the spleen as a major source of hemorrhage and is the most common source of lethal hemorrhage. Bleeding stops spontaneously with most injuries.



i.    Signs and symptoms include right upper quadrant (RUQ) tenderness, ecchymosis, abrasion, enlarging abdominal girth, signs of shock, and associated injuries such as lower rib fractures, pelvic fracture, or head injury.



ii.    Diagnostic studies. Definitive diagnosis is made with abdominal CT scan with contrast. Elevated transaminases are highly suggestive of liver injury, especially AST greater than 200 IU/L and ALT greater than 100 IU/L (Puranik, Hayes, Long, & Mata, 2002). A rapidly falling hematocrit suggests severe liver injury. See Table 7.6 for suggested radiologic monitoring to assess healing or continued bleeding based on the grade of injury.



iii.    Classification. Injuries are graded according to increasing severity (Table 7.7).



iv.    Management is similar to the treatment of splenic injury and involves supportive care with a nonoperative approach (see Table 7.6). Nonoperative management requires close monitoring of vital signs and physical examinations. Fever, leukocytosis, and abdominal tenderness remote from the liver injury may indicate an occult injury. Serial hematocrits, coagulation studies, chemistries, and transaminase levels should be monitored for significant liver dysfunction and monitored until stable. Close monitoring for ongoing bleeding is necessary, and patients should remain on strict bed rest until they are stable. Surgery is indicated for the hemodynamically unstable child, signs of peritonitis, or transfusion requirements exceeding 50% of the estimated blood volume during the first 24 hours (Garcia & Brown, 2003). Children with isolated hepatic injury are restricted from contact sports and strenuous physical activity for a period consisting of the grade of injury plus 2 weeks.



v.    Complications of operative management include delayed bleeding, abscess formation, abdominal compartment syndrome, biliary obstruction, and biloma.



c.    The pancreas is located deep in the upper abdomen and is infrequently injured unless a significant sustained force compresses it against the spine. The classic injury is compression by bicycle handlebars in which the child flips over the bike and is impaled in the epigastrium by the handlebars. Other mechanisms include motor vehicle collisions and child maltreatment.



i.    Signs and symptoms include diffuse abdominal tenderness, deep epigastric pain radiating to the back, and bilious vomiting. Pain may diminish within the first 2 hours of injury and worsen with the release of enzymes over the next 6 to 8 hours (Intravia & DeBeradino, 2013).


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ii.    Diagnostic studies



1)  Amylase is elevated (reference range 0−88 IU/L). The extent of amylase increase alone does not correlate with the severity of injury and may be a nonspecific finding occurring with blunt injury in the absence of pancreatic injury.



2)  Lipase (reference range, 20−180 IU/L). Elevation of amylase to greater than 200 IU/L and lipase greater than 1,800 IU/L correlates with significant pancreatic injury (Nadler, Gardner, Schall, Lynch, & Ford, 1999).



3)  Diagnosis is usually made by abdominal CT scan with IV contrast.



4)  US is useful for diagnosis of pseudocyst.



5)  Magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP) may be necessary to visualize ductal disruption or posttraumatic stricture.



6)  Classification: Injury is graded based on the extent of parenchymal injury and the degree of disruption of the duct (Table 7.8).


553TABLE 7.8    Pancreatic Injury Severity Scale



















Class


Injury Description


I


Contusion or laceration without duct injury


II


Ductal transection or parenchymal injury with probable duct injury


III


Proximal transection or parenchymal injury with probable duct injury


IV


Combined pancreatic and duodenal injury


Source: Adapted from Jobst, M. A., Canty, T. G., & Lynch, F. P. (1999). Management of pancreatic injury in pediatric blunt abdominal trauma. Journal of Pediatric Surgery, 34(5), 818−823.



7)  Management is nonoperative if there is no ductal disruption; although operative intervention with ductal disruption is controversial (Englum, Gulack, Rice, Scarborough, & Adibe, 2016). Supportive care interventions include NPO, NG tube for gastric decompression, IV fluids, and pain management. Parenteral nutrition should be considered if NPO longer than 3 days. Children are monitored for signs of infection. If a pancreatic pseudocyst (a loculated collection of pancreatic juices) develops, patients require 6 to 8 weeks of bowel rest with PN. Surgery is usually indicated for the treatment of distal transection of the pancreas. Surgery involves drainage, partial resection, or repair of lacerated ducts.



8)  Complications include the development of pancreatic fistula or pseudocyst formation. Large cysts that have not resolved after 4 to 6 weeks require drainage. Surgical drainage, percutaneous by interventional radiology, and endoscopic drainage may be performed. Because the pancreas is stimulated with oral intake, feeding tolerance must be evaluated before pulling surgical drains.



d.    Stomach



i.    Signs and symptoms of injury include abrasion or contusion in the upper abdomen and bloody gastric drainage. A rigid abdomen with severe pain suggests perforation. Perforation leads to signs and symptoms of peritonitis within hours of injury.



ii.    Diagnostic studies. Abdominal x-ray detects free air or abnormal NG tube position.



iii.    Management includes surgical repair.



e.    Small and large intestine. Small bowel injuries are the third most common site of abdominal organ injury in blunt trauma (Wise, Mudd, & Wilson, 2002). Common mechanisms include the lap-belt syndrome and abuse. The colon and rectum are rarely injured in children, and injuries to these organs usually occur in the presence of maltreatment.



i.    Signs and symptoms include bloody gastric drainage, absent bowel sounds, tympanic sounds on percussion, midabdominal ecchymosis, seat-belt sign, and pain that increases as peritonitis develops. Signs and symptoms of peritonitis include severe abdominal pain, tenderness, guarding, distension or rigidity, redness, absent bowel sounds, fever, leukocytosis, and respiratory distress. Evaluation of a rectal injury requires rectal examination and is often done with the patient under anesthesia.



ii.    Diagnostic studies. Abdominal x-rays with supine and lateral decubitus views may reveal air−fluid levels, dilated loops of bowel, bowel-wall thickening, or a chance fracture (lumbar spine fracture). CT scan with IV contrast may have greater sensitivity and specificity.



iii.    Management requires surgical repair and generally involves segmental resection with primary anastomosis and possible ostomy placement. Supportive care includes frequent monitoring, NG decompression, replacement of excessive gastric output, stress ulcer prophylaxis, antibiotic therapy, fluid and electrolyte management, PN, and pain management.



iv.    Complications. Delayed perforation, stricture formation, adhesions, and short bowel syndrome may occur.


E.    Outcomes


See specific organ for complications.


ACUTE GI TRACT HEMORRHAGE



A.    Definition and Etiology



1.    Acute bleeding from the GI tract is usually classified as either upper or lower tract bleeding.



2.    Etiology is based on age. Tables 7.9 and 7.10 outline the causes of upper and lower GI bleeding.


B.    Pathophysiology


The child presenting with sudden massive blood loss is at risk for hemodynamic instability. The first priority is to determine the extent of the blood loss and establish whether perfusion is compromised. Greater than 15% circulating blood volume (CBV) loss results in stimulation of autonomic cardiovascular responses to maintain BP and perfusion. Greater than 20% CBV loss results in decreased systolic BP and metabolic acidosis. Rapid fluid resuscitation is required, or cardiovascular collapse and death may occur. Upper GI bleeding is defined as bleeding that originates proximal to the ligament of Treitz. Lower GI bleed occurs distally to ligament of Treitz.


554TABLE 7.9    Causes of Upper GI Bleeding in Infants and Children

























Neonates


Infants−Adolescents


Swallowed maternal blood, esophagitis


Esophagitis


Gastritis


Gastritis


Gastroduodenal ulcer


Gastroduodenal ulcer


Coagulopathy associated with infection, liver failure


Esophageal varices


Vascular anomaly


Gastrointestinal duplication


Hematologic (vitamin K deficiency)


Mallory−Weiss tear


Vascular anomaly


Coagulopathy


Caustic ingestion


GI, gastrointestinal.


TABLE 7.10    Causes of Lower GI Bleeding in Infants and Children



















Age


Causes


Neonates


Milk protein allergy


Necrotizing enterocolitis


Hirschsprung’s enterocolitis


Midgut volvulus


Hematologic (vitamin K deficiency)


Coagulopathy


Infant


Milk protein allergy


Anal fissure


Intussusception


Infectious enterocolitis


Meckel’s diverticulum


Vascular anomaly


Child


Anal fissure


Juvenile polyps


Infectious enterocolitis


Inflammatory bowel disease


Henoch−Schonlein purpura


Hemolytic-uremic syndrome


Vascular anomaly


Adolescent


Anal fissure


Infectious enterocolitis


Inflammatory bowel disease


Vasculitis


Hemorrhoids


NSAID enteropathy


GI, gastrointestinal; NSAID, nonsteroidal anti-inflammatory drug.


Sources: Adapted from Lirio, R. A. (2016). Management of upper gastrointestinal bleeding in children: Variceal and nonvariceal. Gastrointestinal Endoscopy Clinics of North America, 26(1), 63−73. doi:10.1016/j.giec.2015.09.003; Sahn, B., & Bitton, S. (2016). Lower gastrointestinal bleeding in children. Gastrointestinal Endoscopy Clinics of North America, 26(1), 75−98. doi:10.1016/j.giec.2015.08.007


C.    Clinical Presentation



1.    History



a.    Presentation of GI bleeding is shown in Table 7.11.



b.    Comorbidities (liver disease), medications (e.g., steroids, nonsteroidal anti-inflammatory drugs [NSAIDs]), and possible exposures should be assessed.



2.    Physical Examination



a.    The location of bleeding can be identified by the color and source of the bleeding. Hematemesis is the result of acute blood loss from the upper GI tract and presents as coffee grounds emesis or frank blood. Hematochezia is bright- or dark-red blood per rectum. Melena is caused by the digestion of blood in the GI tract and presents as black, tarry stools and indicates an upper GI source of bleeding. Occult bleeding is the result of chronic blood loss.



b.    Signs and symptoms of hypovolemic shock occur with acute bleeding and include tachycardia, weak peripheral pulses, pallor and mottled color, cool skin, and oliguria. BP may be normal despite significant blood loss; hypotension is a late sign of shock.



3.    Diagnostic Tests



a.    Laboratory studies. CBC needed to evaluate for anemia and thrombocytopenia; prothrombin time (PT) and partial thromboplastin time (PTT) to evaluate for coagulopathies; serum fibrinogen and fibrin split products to evaluate for disseminated intravascular coagulation (DIC); type and crossmatch for potential blood transfusion; guaiac test to evaluate for blood in stool or gastric fluid; chemistries, ammonia, and liver function tests (LFTs) to screen for liver dysfunction; and arterial blood gas (ABG) is measured to monitor for metabolic acidosis. If bloody diarrhea is present, send for stool culture and fecal leukocytes. A CBC, urinalysis, blood urea nitrogen (BUN), and creatinine should be obtained in patients with suspected hemolytic-uremic syndrome.


555TABLE 7.11    Presentation of GI Tract Bleeding























Presentation


Definitions


Acute bleeding


Hematemesis


Bloody vomitus; either fresh, bright-red blood or dark, digested blood with “coffee ground” appearance


Melena


Black, sticky, tarry, foul-smelling stools caused by digestion of blood in the GI tract (seen in both upper GI and lower GI tract bleeding)


Hematochezia


Fresh, bright-red blood passed from the rectum


Chronic bleeding


Occult


Trace amounts of blood in normal-appearing stools or gastric secretions; detectable only with a guaiac test


GI, gastrointestinal.


Source: Modified from Huether, S. E., McCance, K. L., & Tarmina, M. S. (1994). Alterations of digestive function. In K. L. McCance & S. E. Huether (Eds.), Pathophysiology: The biological basis for diseases in adults and children (2nd ed.). St Louis, MO: Mosby-Year Book.



b.    Abdominal x-ray examination involves a supine and lateral decubitus view to evaluate for bowel gas pattern suggesting bowel obstruction, air−fluid levels, or pneumoperitoneum. Bowel-wall thickening suggests colitis.



c.    Endoscopy provides direct visualization of the GI tract to determine injury, structural defects, or source of bleeding. An upper endoscopy is the preferred diagnostic procedure to evaluate bleeding of the upper GI tract and for therapeutic treatment (injection, cautery and mechanical therapy for nonvariceal bleeding, and variceal ligation or banding for variceal bleeding; Lirio, 2016). Colonoscopy is performed for lower GI bleeding.



d.    Radionuclide studies are indicated for midintestinal bleeding and are effective tests for locating subacute or intermittent bleeding. Two types are used: technetium-labeled sulfur colloid (more sensitive) and technetium-pertechnetate-labeled red blood cells (RBCs). Demonstration of IV Tc-99m pertechnetate uptake by ectopic gastric mucosa in a Meckel’s scan is helpful in diagnosing Meckel’s diverticulum.



4.    Clinical Course



a.    Course is variable depending on the source and etiology. Upper GI variceal bleeding can result in sudden, massive blood loss and hypovolemic shock.


D.    Patient Care Management



1.    Preventive Care



a.    Assess for signs of respiratory distress and hemodynamic instability.



2.    Direct Care



a.    Secure two large-bore IVs for fluid resuscitation as needed. Administer fluid (20 mL/kg of NS or RL) or blood transfusion (20 mL/kg or more as indicated) until peripheral circulation is adequate. After central line and arterial line placement, continuously monitor CVP and BP for response to fluid resuscitation and the need for continued therapy. The initial hematocrit may be misleading; if so, serial measurements are needed.



b.    Place an NG tube and administer room temperature saline lavage until bleeding stops.



c.    Administer H2-histamine receptor antagonists, PPIs, and sucralfate to minimize bleeding and prevent rebleeding.



d.    Endoscopic modalities, including injection, cautery, and mechanical therapy, may be used for nonvariceal and variceal ligation or banding for variceal bleeding (Lirio, 2016).



3.    Supportive Care



a.    Continuously monitor vital signs.



b.    Monitor PT, PTT, and fibrinogen for coagulopathies. Administer vitamin K (AquaMEPHYTON), platelets, or fresh frozen plasma (FFP) as necessary.



c.    Monitor electrolytes, BUN, and creatinine for potential renal dysfunction. Monitor urine output via a urinary catheter.



d.    Monitor serum ionized calcium following transfusion for potential hypocalcemia.



e.    Monitor for signs of further bleeding, including poor perfusion, abdominal pain, increased abdominal girth, decreased bowel sounds, hematemesis, and hematochezia.



556f.    Assess for signs and symptoms of abdominal perforation, including fever, severe or persistent abdominal pain, and abdominal rigidity.



4.    Esophageal Varices



a.    Acute treatment involves the administration of vasopressin (Pitressin), or octreotide (Sandostatin; see “Pharmacology” section earlier in this chapter). Insertion of a Sengstaken−Blakemore tube may be performed if endoscopy is not available. The tube has three separate lumens for gastric suction, inflation of gastric balloon, and inflation of esophageal balloon. Balloons must be deflated every 12 to 24 hours. Ensure patency of the gastric suction lumen by irrigating frequently. Frequent serious complications, including perforation or erosion of the esophagus or stomach (from hyperinflation or prolonged inflation of the balloons), limit its usefulness.



b.    Endoscopic variceal ligation or banding is the treatment of choice.



c.    Surgery is considered if other therapies are ineffective. Shunting procedures divert blood flow from the liver and allow decompression of the portal system with portal hypertension. Specific entities that may require surgery include Meckel’s diverticulum, duplication cyst, midgut volvulus, NEC, and intussusception (if radiologic enema reduction not effective), and a refractory bleeding ulcer.


E.    Outcomes


Complications include rebleeding, shock, sepsis, and DIC.


GI TRACT ABNORMALITIES



GI tract abnormalities are often detected in the prenatal period. Congenital anomalies are summarized in Table 7.12.


ACUTE SURGICAL ABDOMEN



A.    Definition and Etiology


Acute surgical abdomen refers to the sudden onset of abdominal pain and tenderness that warrants evaluation for surgical intervention that is usually caused by a bowel infarction, obstruction, or perforation. Causes in neonates include NEC, intussusception, and midgut volvulus. Causes in children and adolescents include appendicitis (a perforated appendix is a common cause of peritonitis), Meckel’s diverticulum, inflammatory bowel disease, omental torsion, ovarian torsion, intussusception (not reduced radiologically), incarcerated inguinal hernia, and trauma. Intraluminal bowel obstructions in children can be caused by foreign bodies, bezoars, with extramural causes from bowel adhesions, hernias, and internal volvulus.


B.    Pathophysiology



1.    Peritoneal inflammation (peritonitis) occurs as a result of injury or contamination. Primary peritonitis occurs with no obvious cause of contamination, but infection is indirectly introduced into the peritoneal cavity from the bloodstream or lymphatics. Secondary peritonitis occurs as a result of direct GI tract injury, such as with trauma. The inflammatory response causes exudation of fluid into the peritoneal cavity. Hypovolemia may occur as fluid shifts into the peritoneal cavity.



2.    Upper GI tract perforations result in leakage of hydrochloric acid, digestive enzymes, or bile causing chemical peritonitis.



3.    Lower GI tract perforation results in the leakage of fecal material, which releases aerobic and anaerobic bacteria into the peritoneum. Endotoxins may be released and cause bacterial peritonitis and sepsis.



4.    Injury to the peritoneum causes decreased bowel motility and usually results in an ileus.



5.    Obstruction can be complete, partial, or intermittent. Bowel proximal to the obstruction becomes distended due to a collection of air and GI tract contents. Distal bowel collapses from a lack of intraluminal content; therefore, proximal obstructions create more bowel collapse. With a distal obstruction, there is greater bowel distension and resultant abdominal distension.


C.    Clinical Presentation



1.    History. Variable depending on the location of the obstruction, the type of obstruction, and whether the obstruction is complete or partial. The onset, progression, location, and presence of other symptoms should be evaluated (e.g., stooling pattern, pain, NG output [bilious output indicative of an obstruction]). Presentation can be acute with signs of peritonitis (e.g., volvulus, traumatic visceral perforation, postsurgical bowel obstruction) or subtle and chronic with incomplete or recurring bouts of obstruction (e.g., intussusception).


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5622.    Physical Examination



a.    Obstruction results in abdominal distention, tenderness, bilious vomiting, possible fever, and absent or hyperactive bowel sounds. With a proximal obstruction, the abdomen may be scaphoid and with a distal obstruction, there is abdominal distension.



b.    Perforation causes fever, pain, and possibly signs of respiratory distress, including tachypnea, retractions, flaring, grunting, and acidosis.



c.    Signs of third spacing include increased abdominal girth and hypovolemia (tachycardia, decreased peripheral perfusion, decreased urine output, and hypotension [late sign]).



d.    Symptoms of peritonitis include fever, nausea, marked abdominal distention or rigidity, erythema over the abdomen, absent or hypoactive bowel sounds, diffuse abdominal pain, guarding of the abdomen, diarrhea, and rebound tenderness.



3.    Diagnostic Tests



a.    Abdominal x-ray examination may reveal a paucity of gas, dilated loops of bowel, or air−fluid levels with a bowel obstruction and is usually the first radiologic study done. A lateral view reveals the presence of free air with bowel perforation.



b.    Abdominal US or MRI are often done to evaluate for appendicitis as nonionizing radiation is employed. A recent systematic review reported MRI had comparable sensitivity (92%−100%) and specificity (89%−100%) for the diagnosis of appendicitis as compared to CT scan (Ogunmefun, Hardy, & Boynes, 2016).



c.    Abdominal CT scan with IV and PO contrast is used to evaluate suspected abscess or mass.



d.    Air enema is often done instead of a contrast enema and is a diagnostic and therapeutic treatment for intussusception. Typically, air enema results in successful reduction of the obstructed bowel with reported success rates of 50% to 80% (Makin & Davenport, 2016). Generally, water-soluble contrast is used if attempting reduction.



e.    Upper GI series is the gold standard for making the diagnosis of a midgut volvulus, although this abnormality is often appreciated from an abdominal CT scan.



4.    Clinical Course



a.    Varies depending on the surgical pathology. Generally, symptoms are progressive. A child with significant intra-abdominal pathology may eventually develop mental status changes and become somnolent.


D.    Patient Care Management



1.    Direct Care



a.    Provide frequent vital-sign monitoring with assessment for respiratory distress. Elevate the head of the bed 30 to 45 degrees to enhance respiratory effort.



b.    Place an NG tube for gastric decompression and drainage and maintain low intermittent suction if a complete or proximal obstruction is suspected.



c.    Monitor intake and output, as oliguria commonly requires fluid boluses. Placement of a urinary catheter may be indicated.



d.    Surgical intervention may be indicated for persistent abdominal pain, evidence of localized peritonitis (erythema over a portion of the abdomen), and the presence of free air on abdominal x-ray examination.



e.    Analgesia as needed for pain. Typically, an IV opioid is administered either as an intermittent bolus or a continuous infusion with or without a patient-controlled analgesia unit. Opioids will slow bowel motility and often the pain regimen includes IV Ofirmev (acetaminophen) or IV NSAIDs when the child is NPO.



f.    Administer broad-spectrum antibiotics with peritonitis.



2.    Supportive Care



a.    Perform pulmonary toilet to prevent atelectasis.



b.    Frequent ambulation should be encouraged.



c.    Deep vein thrombosis prophylaxis with use of sequential compression device and SC heparin or lovenox (enoxaparin) administration for at-risk children.


E.    Outcomes


Complications include sepsis, perforation, need for bowel resection, adhesions with resultant obstruction, and abscess formation.


NECROTIZING ENTEROCOLITIS



A.    Definition and Etiology



1.    NEC is a multifactorial disease of the bowel with the greatest incidence in the premature neonate.



5632.    NEC is usually a disease of the neonate and is characterized by widespread inflammation of the gut; however, older children can have presentations with classic findings, including pneumatosis intestinalis. NEC is seen primarily in premature infants (90%) and is related to dysbiosis or altered bacterial colonization of the intestinal flora (Gupta & Paria, 2016). In near-term and term infants, hypoxic or ischemic insults are dominant risk factors.



3.    Risk factors for the premature infant include receiving enteral feeds (greater incidence with commercial formulas as compared to BM) and presence of intrauterine growth retardation.


B.    Pathophysiology



Despite research efforts, the pathophysiology of NEC is yet to be determined. Current thought is the disease occurs because of the dysbiosis, which leads to an unbalanced proinflammatory response that leads to mucosal disruption and eventual bowel necrosis in infants being enterally fed. Although spontaneous intestinal perforation is often termed NEC; researchers postulate an alternate pathophysiology, as there is minimal gut inflammation (Gupta & Paria, 2016).


C.    Clinical Presentation



1.    History. Can have an abrupt onset with fulminant presentation rapidly progressing to death. In its milder forms, NEC has many of the same signs and symptoms of sepsis (e.g., feeding intolerance, increased gastric residual volumes, bloody stools).



2.    Physical Examination. See Table 7.13 for modified Bell’s criteria, which are routinely used to diagnosis and stage the disease.



3.    Diagnostic Tests



a.    Abdominal x-ray examination with supine and lateral views may reveal pneumatosis intestinalis, dilated loops of small bowel, and pneumoperitoneum if perforation has occurred.



b.    Abdominal US is becoming increasingly important in determining when surgical intervention may be indicated and is more sensitive in detecting portal venous gas and intra-abdominal free fluid (Gupta & Paria, 2016).



4.    Clinical Course



a.    Initially, symptoms of NEC are nonspecific and progress per Bell’s criteria as outlined in Table 7.13. The classic triad is abdominal distention, bilious vomiting, and blood in the stools.



b.    Signs of progressive NEC include discoloration of the abdominal wall, respiratory distress, hypotension, leukopenia, thrombocytopenia, and a WBC count reflecting a shift to the left.


D.    Patient Care Management



1.    Preventive Care. Preventive care focuses on preventing prematurity; there is and some evidence that there is a lower incidence in neonates who are prescribed probiotics and fed BM versus commercial formulas.



2.    Direct Care



a.    Infants are kept NPO with an NG tube to low intermittent suction for gastric decompression. Fluids and electrolytes are monitored, and PN is provided. When perforation has occurred, broad-spectrum antibiotic therapy is prescribed with a cephalosporin and aminoglycoside.



b.    Respiratory and cardiac status are closely monitored with frequent monitoring of vital signs and serial abdominal girth measurements.



c.    Guaiac stool testing is used to detect occult bleeding. Serial platelet counts and serial abdominal x-ray examinations are used to monitor progression.



d.    Surgery is indicated if signs of perforation, peritonitis, or clinical deterioration are evident despite medical management.



3.    Outcomes



a.    Complications include being rendered short-gut with intestinal failure.



b.    Mortality is 30% and for neonates requiring surgery, the mortality is as high as 45% (Hull et al., 2014).


HYPERBILIRUBINEMIA



A.    Definition and Etiology



1.    Hyperbilirubinemia is an elevation in the level of total serum bilirubin (TSB); it results from an imbalance between bilirubin production and excretion.



2.    Bilirubin is the byproduct of the heme portion of the breakdown of the hemoglobin molecule.



3.    Hyperbilirubinemia is an elevated level of serum bilirubin. Indirect prehepatic-unconjugated bilirubin elevations may be physiologic rather than pathologic. Direct posthepatic-conjugated bilirubin elevations are always pathologic. The terms direct and indirect are used interchangeably with conjugated and unconjugated hyperbilirubinemia. Direct hyperbilirubinemia includes conjugated and delta bilirubin measurements.


564TABLE 7.13    Staging Criteria for Necrotizing Enterocolitis
















Stage 1A (Suspect)


a.  Systemic manifestations: Temperature instability, lethargy, apnea, bradycardia


b.  GI tract manifestations: Poor feeding, increasing gastric residual volumes, emesis (may be bilious or have positive results for occult blood), mild abdominal distention, occult blood in stool


c.  Radiologic findings: Normal or intestinal dilation


Stage 1B (Suspect)


a.  Systemic manifestations: Temperature instability, lethargy, apnea, bradycardia


b.  GI tract manifestations: Poor feeding, increasing gastric residual volumes, emesis (may be bilious or have positive results for occult blood), mild abdominal distention, occult blood in stool, hematochezia


c.  Radiologic findings: Normal or intestinal dilation


Stage 2A (Definite—Mildly Ill)


a.  1B signs and symptoms


b.  Marked abdominal distention and decreased bowel sounds


c.  Abdominal radiographs show significant intestinal distention with ileus, pneumatosis intestinalis


Stage 2A (Definite—Moderately Ill)


a.  1B signs and symptoms plus thrombocytopenia and metabolic acidosis


b.  Marked abdominal distention and tenderness


c.  Abdominal radiographs with possible ascites and portal venous gas


Stage 3A (Advanced—Bowel Intact)


a.  Same signs and symptoms as in stage 2 plus deterioration in vital signs, increased apnea, shock, disseminated intravascular coagulation


b.  Same as 2A and evidence of peritonitis


Stage 3A (Advanced—Bowel Perforated)


a.  Same signs and symptoms as in stage 3A—bowel intact


b.  Same signs and symptoms as in stage 3A—bowel intact


c.  Abdominal radiographs show pneumoperitoneum


GI, gastrointestinal.


Sources: Modified from Bell, M. J., Ternberg, J. L., Feigin, R. D. Keating, J. P., Marshall, R., Barton, L., & Brotherton, T. (1978). Neonatal necrotizing enterocolitis: Therapeutic decisions based upon clinical staging. Annals of Surgery, 187(1), 1–7. Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC1396409; Gupta, A., & Paria, A. (2016). Etiology and medical management of NEC. Early Human Development, 97, 17−23. doi:10.1016/j.earlhumdev.2016.03.008



4.    Premature neonates; infants with traumatic births and increased hemolysis; breastfed infants; infants of East Asian, Native American, and Greek descent; ABO incompatibilities; Rh isoimmunization; glucose-6-phosphate dehydrogenase deficiency; pyruvate kinase deficiency; and infants of diabetic mothers are at higher risk for developing neonatal or physiologic jaundice or hyperbilirubinemia (Watson, 2009).


B.    Pathophysiology



1.    Fat-soluble bilirubin binds to albumin as indirect (prehepatic-unconjugated) bilirubin for transport to the liver. In the liver, fat-soluble bilirubin is detached from albumin and conjugated with glucuronic acid, rendering the bilirubin water soluble. Increases in indirect bilirubin result when the liver is not able to conjugate the bilirubin with impaired synthetic function.



2.    Direct (posthepatic-conjugated) bilirubin is excreted into the hepatic ducts and eventually into the intestine. Impaired excretion of direct bilirubin into the bile ducts leads to increased levels of conjugated bilirubin as increased amounts are reabsorbed into the blood.



3.    Impaired synthetic function and obstruction increase total bilirubin.



4.    Three types of jaundice (prehepatic, hepatocellular, cholestatic) can occur. Prehepatic jaundice is usually caused by hemolysis. The total bilirubin is increased with the majority of the bilirubin in the 565indirect form. Hepatocellular jaundice results from liver dysfunction characterized by hepatic inflammation (infection, hepatitis, drug induced). The total bilirubin is increased. Cholestatic jaundice results from failure of biliary excretion. An increase in direct bilirubin is present.



5.    Physiologic jaundice is a transient hyperbilirubinemia that is frequently observed in otherwise completely healthy newborns. Bilirubin values peak at day 3 of life and usually normalize by 2 weeks of age.


C.    Clinical Presentation



1.    History. Indirect hyperbilirubinemia is most common in premature infants in the neonatal period, with serum bilirubin levels peaking at 48 to 96 hours of life. If direct hyperbilirubinemia is present, the infant or child should be evaluated for other signs of liver disease.



2.    Physical Exam. Jaundice is an accumulation of yellow pigment in the skin and other tissues and is evident when total bilirubin is greater than 3 mg/dL. Kernicterus is the presence of yellow pigment in the basal ganglia of the brain and is a complication of severe unconjugated hyperbilirubinemia. Bilirubin can enter the brain if it is not bound to albumin (unconjugated) or if there has been damage to the blood−brain barrier. Signs of kernicterus include a sluggish Moro reflex, opisthotonus, hypotonia, vomiting, high-pitched cry, seizures, and paresis of gaze (sun-setting sign). Dark-colored urine and pale-colored stool may occur in conjugated hyperbilirubinemia.



3.    Diagnostic Tests. Indirect, direct, and total bilirubin levels are elevated. See Table 7.1 for reference ranges.


D.    Patient Care Management



1.    Management of indirect hyperbilirubinemia includes phototherapy by bilirubin lights or bilirubin blankets and is based on the infant’s age and TSB (American Academy of Pediatrics Subcommittee on Hyperbilirubinemia [AAP], 2004). As much skin surface as possible should be exposed. Cover eyes to protect from light and provide eye care every 4 hours. Fluid requirements are increased up to 20% because of increased insensible water losses. With excessive hyperbilirubinemia, exchange transfusion and pharmacologic interventions (i.e., phenobarbital administration) may be indicated.



2.    Management of direct hyperbilirubinemia depends on the etiology (see “Liver Failure” section)


E.    Outcomes


Indirect hyperbilirubinemia can result in kernicterus or brain damage.


PANCREATITIS



A.    Definition and Etiology



1.    Pancreatitis is a diagnosis that is increasingly occurring in children and is classified as acute, acute recurrent, and chronic, which is characterized by ongoing inflammation of the pancreas.



2.    Types of pancreatitis as defined by the International Study Group of Pediatric Pancreatitis (Morinville et al., 2012): acute, acute recurrent, and chronic.



a.    Acute pancreatitis (AP) requires two of the following:



i.    Abdominal pain compatible with AP



ii.    Serum amylase and/or lipase three or more times the upper limit of normal



iii.    Imaging with findings of AP



b.    Acute recurrent pancreatitis (ARP) is defined as two or more episodes of AP with interval return to baseline of at least a month with pain resolved and normalized amylase and lipase.



c.    Chronic pancreatitis (CP) requires



i.    Typical abdominal pain with imaging findings



ii.    Exocrine insufficiency with imaging findings



iii.    Endocrine insufficiency plus abdominal pain



3.    Causes are diverse and include biliary (e.g., gallstones or cholelithiasis associated with hemolytic disorders, including spherocytosis, beta-thalassemia, and sickle cell disease), anatomic (e.g., blunt abdominal trauma, such as bicycle handlebar injuries, motor vehicle crashes), medications (e.g., L-asparaginase, valproic acid, Prednisone), metabolic (e.g., diabetic ketoacidosis, hypertriglyceridemia, hypercalcemia), and genetic abnormalities (e.g., serine protease-inhibitor [SPINK1 N345], protease inhibitor [PRSS1 R122H], cystic fibrosis transmembrane conductance regulator 566[CFTR DeltaF508, 5T]; Kramer & Jeffery, 2014; Poddar, Yachha, Mathias, & Choudhuri, 2015).


B.    Pathophysiology



1.    Injury to the acinar cells leads to the release of proteases and other enzymes (e.g., elastase, lipase) with resultant autodigestion.



2.    The inflammatory cascade causes edema and local inflammation and triggers inflammatory mediators and trypsin to be released, causing abdominal pain.



3.    Release of inflammatory mediators leads to systemic inflammatory response syndrome (SIRS) with the potential for renal and pulmonary sequelae with resultant dehydration and the potential for thrombosis.



4.    AP involves a single episode; with recurrent episodes or CP, morphologic changes in the pancreas begin to interfere with exocrine and endocrine functions, resulting in CP.


C.    Clinical Presentation



1.    History. Classic symptoms of pancreatitis in children are abdominal pain that is typically most intense in the epigastrium, nausea, vomiting, and anorexia.



2.    Physical Examination. Symptom severity varies from mild abdominal pain to signs and symptoms of severe shock and end-organ failure. Although more common in adults, back and flank pain are also common as the organ is retroperitoneal. Moving and eating intensify the pain. A bluish discoloration around the umbilicus (Cullen’s sign) or in the flanks (Turner’s sign), signify hemorrhagic pancreatitis.



3.    Diagnostic Tests



a.    Laboratory tests



i.    Amylase and lipase are enzymes derived from pancreatic acinar cells and will be elevated; lipase has a longer half-life and may remain elevated, whereas amylase levels typically peak approximately 48 hours after the onset of pancreatitis and may normalize with delayed presentations (Abu-El-Haija, Lin, & Palermo, 2014).



ii.    Other labs that may be evaluated include calcium, triglyceride levels, CBC, liver transaminases, bilirubin level, and BUN.



b.    Radiologic findings (see Table 7.2)



i.    Abdominal US recommended as initial imaging as it can confirm the diagnosis and assist with identifying contributing abnormalities.



ii.    Abdominal CT scan is the second most common imaging method as it can diagnose and identify etiologies and visualize masses, necrosis, and hemorrhage (Abu-El-Haija et al., 2014).



iii.    Use of MRCP is controversial for an initial episode of AP. MRCP can detect intrahepatic and pancreatic duct abnormalities (Abu-El-Haija et al., 2014).



4.    Clinical Course. Varies based on the type of pancreatitis.


D.    Patient Care Management



1.    Preventive Care. Alleviate the cause of the pancreatitis.



2.    Direct Care for AP



a.    Hydration with aggressive IV fluid administration is indicated with the initiation of one and a half to two times maintenance dose with D5.9NS (Szabo, Fei, Cruz, & Abu-El-Haija, 2015).



b.    Nutrition management has changed from maintaining NPO status to early EN. Begin with a clear diet at admission and advance to a regular diet if tolerated within 6 hours (Szabo et al., 2015). The goal of early EN is to maintain the gut barrier and prevent bacterial translocation (Szabo et al., 2015). PN should be prescribed for children who do not tolerate EN.



c.    Pain management is usually accomplished with the use of opioids and nonsteroidal anti-inflammatory agents (e.g., Toradol [ketorolac], and IV Ofirmev [acetaminophen]). The use of morphine and other opiate derivatives is theoretically less desirable in patients with pancreatitis, because these medications increase spasm of the sphincter of Oddi and may cause additional pain, although there is no current evidence to support this.



d.    IV antibiotics should be administered when pancreatic necrosis is present.



e.    Surgical intervention is indicated with a cholecystectomy for gallstone pancreatitis; for CP, the modified Puestow procedure is most commonly performed.



5673.    Supportive Care. Prevent thrombotic events with deep vein thrombosis prophylaxis.


E.    Outcomes



1.    Complications include pseudocyst formation and endocrine dysfunction (e.g., hyperglycemia).



2.    Approximately 10% of children will develop CP after experiencing AP; the presence of a peripancreatic necrosis at initial presentation is an independent predictor of CP (Hao, Guo, Luo, & Guo, 2016).



3.    Median hospital stay is a week and most children have complete recovery.


GALLBLADDER DISEASE



A.    Definition and Etiology



1.    Gallbladder disease, or cholecystitis, is inflammation of the gallbladder, which is most commonly caused by gallstones.



2.    Gallbladder disease in children is increasing due to improved diagnostic modalities (US) and the obesity epidemic (Svensson & Makin, 2012).



3.    Cholecystitis is inflammation of the gallbladder, which most commonly caused by gallstones. There are two types of disease: acalculous or calculous, depending on the presence of cholelithiasis.



4.    There is a known spectrum of gallbladder disease, which ranges from biliary colic/dyskinesia, cholelithiasis, acute acalculous cholecystitis, choledocolithiasis to cholangitis.



5.    Etiologies for acalculous disease are most commonly associated with sepsis or a severe infection. Calculous from nonhemolytic cholelithiasis—formation of gallstones in the absence of a hemolytic disease, including obesity, PN administration, history of an ileal resection (e.g., NEC), volvulus, cystic fibrosis, medications (e.g., Ceftriaxone and Furosemide), and pregnancy. Calculous from hemolytic cholelithiasis—bile in these patients has an increased amount of unconjugated bilirubin, leading to the formation of gallbladder sludge and thus the increased risk for cholelithiasis, which can occur with sickle cell disease, thalassemia, spherocytosis, and Gilbert syndrome.


B.    Pathophysiology



1.    The gallbladder is stimulated to contract due to hormones (cholecystokinin and motilin) that are released when fats are present in the duodenum. Gallbladder contraction propels bile down the common bile duct, through the sphincter of Oddi, and into the duodenum (Mouat, 2012).



2.    Regardless of the etiology, there is stasis within the gallbladder.



3.    With gallstone presence there is sludge formation and inflammation, which may lead to obstruction and further inflammation (Mouat, 2012).



4.    Bile stasis and bacterial overgrowth lead to the release of lysolecithin (phospholipid) and other proinflammatory agents that exacerbate the inflammatory response (Mouat, 2012).



5.    The pain is attributed to the increased pressure within the gallbladder.


C.    Clinical Presentation



1.    History



a.    Acalculous. Episodic RUQ pain occurs.



b.    Calculous. With cholelithiasis—there can be “silent stones” that are recognized incidentally on imaging; these children can be asymptomatic.



2.    Physical Examination



a.    Acalculous. Fever, vomiting, and RUQ pain, and positive Murphy’s sign (pain on deep inspiration when the inflamed gallbladder is palpated).



b.    Calculous. Range of presentation from children having fever, RUQ/abdominal pain, positive Murphy’s sign, and vomiting.



3.    Diagnostic Tests



a.    Laboratory evaluation



i.    There may be elevated liver transaminases, bilirubin level, and white blood cell count.



b.    Radiologic evaluation



i.    US will reveal a thickened gallbladder that contains debris; gallstones may or may not be present.



ii.    ERCP can be done to evaluate the pancreas and common bile duct with possible stone removal if present.



iii.    MRCP can be done with no radiation exposure to define and evaluate the biliary 568structures; however, this is strictly diagnostic and there can be no intervention.



4.    Clinical Course. Variable depending on the etiology.


D.    Patient Care Management



1.    Acalculous



a.    Offer supportive care and administer antimicrobials for self-limiting cases.



b.    Cholecystectomy needed for progressive gallbladder distension or clinical deterioration.



2.    Calculous



a.    ERCP may be indicated if a stone is present with common bile duct dilation prior to a cholecystectomy. A surgeon may delay performing a cholecystectomy to allow for resolution of the inflammation, which will be evident with the resolution of fever, pain, and normalization of lab values.



b.    Cholecystectomy



i.    Gallbladder removal either by an open or laparoscopic technique.


E.    Outcomes


Complications include a bile leak and pancreatitis.


GI INFECTION



A.    Definition and Etiology



1.    GI infections include a multitude of acute diarrheal infections including viral, bacterial, and parasitic infection with organisms including Clostridium difficile and vancomycin-resistant enterococcus.



2.    Acute diarrhea is a sudden change in the frequency and consistency of stools.



3.    The most common etiology of diarrhea is viral. There has been a sustained decrease in the incidence of Rotavirus since the addition of Rotavirus vaccines to the recommended immunization schedule in 2006.



4.    C. difficile is an anaerobic, spore-forming, toxin-forming, gram-positive bacillus bacteria that is being diagnosed with increasing frequency and is associated with antibiotic usage. Vancomycin-resistant enterococcus is increasingly being diagnosed in children and is associated with C. difficile infection, the use of immunosuppressive therapies and significant antibiotic exposure.


B.    Pathophysiology



1.    Acute diarrhea alters the GI tract and can lead to dehydration. Dehydrated patients are deficient in both fluids and electrolytes and are at risk for acute kidney injury.



2.    C. difficile is a gram-positive organism and is part of the normal GI bacterial flora. When risk factors exist, C. difficile will replicate and lead to colonization. Once colonization of the colon occurs, the bacteria begin to release two distinct toxins. Toxin A is an enterotoxin that disrupts colonic mucosal adherence to the basement membrane and causes damage to the intestinal villi. Toxin B is a cytotoxin that induces apoptosis, which leads to neutrophilic infiltration and inflammation of the colon.


C.    Clinical Presentation



1.    History. Infection is often hospital acquired and is associated with antibiotic usage.



2.    Physical Examination. All children with diarrhea and dehydration will have a history of inadequate fluid intake and excessive fluid loss. The child may be febrile and usually is irritable, experiences abdominal pain and looks ill; there may or may not be associated vomiting. Signs of dehydration include sunken eyes, dry mucous membranes, and a sunken fontanelle in infants. The child will be tachycardic, and signs of compensated or hypovolemic shock may be present.



3.    Diagnostic Tests



a.    If there is blood or mucous in the stool, stool studies should be obtained. The stool should be sent to identify presence of white blood cells, bacterial culture, and C. difficile toxin (in children older than 1 year) and ova and parasites. Stool testing for children younger than 1 year is not recommended due to the high carriage rate (American Academy of Pediatrics Committee on Infectious Diseases, 2013).



b.    Initial blood work typically includes evaluation of a serum chemistry panel and a CBC. Once the serum sodium concentration is determined, the estimate of the severity of dehydration (based initially on clinical examination alone) is modified as needed. Often these children 569have a metabolic acidosis, which may be evident from the low carbon dioxide level and an elevated BUN from the dehydration on the chemistry panel.



4.    Clinical Course. Course is variable depending on the infecting organism and child’s comorbidities.


D.    Patient Care Management



1.    Preventive Care. Good handwashing with soap and water and donning appropriate personal protective equipment are the keys to preventing the transmission of these infectious diseases.



2.    Direct Care



a.    Children with diarrhea from a bacterial cause require contact isolation until associated symptoms resolve and antibiotic therapy is complete. Contact isolation must be enforced with meticulous attention to handwashing because most of these organisms are contagious and are a frequent cause of nosocomial infection.



b.    Obtain an accurate weight in kilograms as soon as possible after admission and on a daily basis during hospitalization. This weight measurement can be helpful in determining the severity of dehydration and evaluating the patient’s response to therapy. Weight measurements are most reliable if the child is weighed on the same scale at the same time every day.



c.    Take accurate intake and output measurements and notify the provider if the child’s urine output is less than 0.5 to 1 mL/kg/hr.



d.    Although the majority of acute diarrhea infections are caused by viral pathogens, antibiotics are administered for some bacteria or culture-proven parasitic infections.



i.    For positive C. difficile infection, the causative antibiotic is discontinued if possible, and a 7-day oral course of metronidazole (Flagyl) administered is provided. Oral vancomycin can also be administered to patients who cannot tolerate metronidazole or for any adolescent patients who are breastfeeding or pregnant.



3.    For the child who is experiencing concomitant vomiting and diarrhea, ondansetron (Zofran) can help with symptom control. For children with mild dehydration, the medication can be administered as an oral disintegrating tablet. IV administration is recommended for children with moderate or severe dehydration (see “Pharmacology” section).



4.    Supportive Care



a.    Treatment becomes supportive as diarrhea resolves. Initially, when stools are frequent and watery, the child is NPO and maintenance fluid requirements are provided intravenously.



b.    The irritated GI tract requires a period of rest, followed by the gradual resumption of oral feedings with oral electrolyte solutions. Once stool output has decreased and the child is no longer vomiting, clear liquids are offered and enteral feeding can be advanced slowly as tolerated to an age-appropriate diet. If diarrhea resumes during diet advancement, the child should be placed back on a clear diet or the last tolerated intake.


E.    Outcomes


Although these illnesses are self-limiting, they contribute to the morbidity of children cared for in the PICU.


HEPATIC FAILURE



Hepatic failure can occur as chronic, “decompensated” chronic, or acute-chronic liver failure and acute liver failure (ALF).


A.    Acute Liver Failure



1.    Definition of ALF



a.    The Pediatric Acute Liver Failure (PALF) study group has refined the definition of ALF as a syndrome, not a disease, with the following criteria:



i.    Hepatic-based coagulopathy defined as a PT ≥15 seconds or INR ≥1.5 not correctable with vitamin K in the presence of hepatic encephalopathy



ii.    PT ≥20 seconds or INR ≥2 regardless of hepatic encephalopathy



iii.    Biochemical evidence of acute liver injury



iv.    No known evidence of chronic liver disease (Sundaram, Alonso, Narkewicz, Zhang, & Squires, 2011)



b.    Other ALF definitions (Sundaram et al., 2011):



i.    Hyperacute liver failure is fulminant hepatic failure (FHF) with the time from jaundice to encephalopathy less than 7 days.



570ii.    ALF as FHF with the time from jaundice to encephalopathy between 7 and 28 days.



iii.    Subacute liver failure as FHF from the time from jaundice to encephalopathy more than 28 days.



2.    Liver disease is a significant problem, with 15,000 children hospitalized each year (American Liver Foundation, 2013), which is a statistic that has remained unchanged over the past 25 years.



3.    Etiology of ALF



a.    Hepatitis (inflammation of the liver) is the most frequently identified cause of hepatic failure. Hepatotropic viral infectious causes include the following:



i.    Hepatitis A virus (HAV)



1)  On average, the incubation period is 28 days.



2)  Serologic markers for HAV include hepatitis A antibodies of the immunoglobulin M (IgM) class (anti-HAV IgM), whose presence reflects active or recent HAV infection, and hepatitis A antibodies of the immunoglobulin G (IgG) class (anti-HAV IgG), whose presence reflects immunity.



3)  The Advisory Committee on Immunizations Practices recommend routine vaccination for children at age 2 years living in communities with high rates of hepatitis A (Alaska, Arizona, California, Idaho, Nevada, New Mexico, Oklahoma, Oregon, South Dakota, Utah, and Washington), for those who have planned travel to endemic areas, and day-care workers.



4)  Disease transmission is via the oral−fecal route. Food, water, and shellfish contaminated by the virus are the usual sources.



ii.    Hepatitis B virus (HBV)



1)  The incubation period is, on average, 80 days.



2)  Hepatitis B vaccine is part of the American Academy of Pediatrics recommended immunization schedule and has led to a decline in the incidence; need for booster unclear.



3)  Serologic markers of HBV include hepatitis B surface antigen (HbsAg), whose presence reflects acute or chronic infection; hepatitis B e antigen (HbeAg), whose presence reflects active HBV infection with active viral replication and high infectivity; antibody to hepatitis B surface antigen (anti-HBs), whose presence reflects clinical recovery and immunity; and HBV quantification with polymerase chain reaction (PCR), which reflects a specific quantity of active HBV.



4)  Disease transmission occurs through the exchange of blood or body fluids. Neonates can acquire the virus via maternal transmission.



5)  Disease presentation varies and may consist of a prodrome, followed by insidious onset, with symptoms usually resolving within 1 to 3 months. Unfortunately, there is a cadre of patients that develop chronic disease. A small percentage of infected individuals develop FHF.



iii.    Hepatitis C virus (HCV)



1)  Incubation time is 2 to 26 weeks.



2)  Serologic markers for HCV include anti-HCV antibody, indicating exposure to HCV and PCR, whose presence reflects HCV infection.



3)  Perinatal transmission is now the most common mode of acquiring HCV in children (Lee & Jonas, 2015).



4)  No vaccine available.



iv.    Clinical presentation of hepatitis involves three stages:



1)  Preicteric stage has a duration of approximately 1 week. Signs and symptoms include fever, chills, anorexia, malaise, abdominal pain, nausea, vomiting, joint pain, hepatomegaly, and lymphadenopathy. HAV is characterized by nonspecific features of viral illness, including fever, headache, anorexia, and nausea. HBV is characterized by arthralgia, arthritis, transient skin rash, and later malaise, nausea, vomiting, and low-grade fever. Jaundice usually occurs 10 to 12 days after the onset of symptoms.



2)  Icteric stage has a duration of 2 to 6 weeks. Signs and symptoms include weakness, fatigue, pallor, jaundice, dark urine, pale-colored stool, and pruritus.



5713)  During the posticteric stage, there is resolution of the jaundice, darkening of the stools, and normalization of LFT values. Complete recovery occurs in most cases.



v.    Other viral causes include herpes simplex virus, Epstein−Barr virus (EBV), adenovirus, parvovirus, varicella, and cytomegalovirus (which may be congenitally acquired). Infants are at risk if the mother is infected with a primary infection and active infection is present at birth.



b.    Neonatal “giant cell” hepatitis is a histologically descriptive term. The disease is characterized by large cells with many nuclei. The cause is most likely related to an autoimmune process.



c.    Drug-induced acute hepatic failure.



i.    The liver is the most common site for drug metabolism. Children receiving drugs known to be hepatotoxic should have serial LFT monitoring while receiving therapy. The risk of developing FHF increases with continued use of the drug in the presence of developing hepatitis.



ii.    The most common toxic drugs are acetaminophen (Tylenol), ecstasy (methyldioxymethamphetamine), anticonvulsants (phenytoin [Dilantin] and valproate [Depakene]), methotrexate, halothane, and isoniazid.



d.    Wilson disease is an autosomal-recessive disorder that results in excessive accumulation of copper in the organs. The biochemical disorder of copper metabolism is a defect in the copper adenosine triphosphatase transporter, with decreased copper excretion, defective incorporation of copper into ceruplasmin, and copper accumulation (Carlson, Al-Mateen, & Brewer, 2004). Liver dysfunction manifestations are variable and the child may present with FHF. Medical therapy includes administration of d-penicillamine and dietary restrictions of copper. Liver transplantation is indicated in the presence of FHF or cirrhosis with decompensation.



4.    Pathophysiology



a.    Pathophysiology of ALF is presumed to be multifactorial. Portal-systemic shunting (caused by progressive liver destruction) allows blood flow from the intestine to be shunted around the liver, bypassing any remaining viable hepatocytes. The liver is unable to remove toxic metabolites normally formed by intestinal bacterial degradation of proteins, amino acids, and blood (e.g., ammonia). Altered blood−brain permeability is hypothesized to be related to toxin(s) of intestinal origin bypassing the portal filtration, resulting in a disruption of the blood−brain barrier.



b.    Neurologic pathophysiology



i.    Multiple proposed etiologies



1)  Mechanism of the formation of cerebral edema is not known.



2)  High ammonia levels play a central role; although level does not correlate with exam and seems to be related to the accumulation of other neurotoxic substances.



c.    Renal pathophysiology



i.    More than one type of renal failure may be present. Careful differentiation of the type of renal failure must be made before appropriate therapy can be initiated.



ii.    Prerenal azotemia occurs when prerenal blood flow and renal perfusion are compromised. Treatment includes addressing the cause of decreased renal perfusion (i.e., fluid resuscitation).



iii.    Acute tubular necrosis is related to parenchymal damage to the kidney associated with a chronic prerenal or postrenal condition (e.g., toxic chemical exposure or glomerulonephritis). It may occur with concomitant sepsis, hemorrhage, and ischemia.



iv.    Hepatorenal syndrome (functional renal failure of liver disease) is likely to be related to an unidentified vasoconstrictive substance causing a decrease in renal perfusion resulting in oliguric renal failure in the presence of hepatic failure. Renal failure resolves with improvement of the hepatic dysfunction; however, the associated mortality is high.



d.    Hematologic pathophysiology



i.    Coagulopathy is related to an abnormal production of prothrombin and other clotting factors produced by the liver, signifying impaired hepatic synthetic function, and ineffective removal of activated clotting factors.



ii.    Hypersplenism results from increased portal venous pressures delaying the blood flow through the splanchnic bed with resultant congestion and enlargement of the spleen. Splenic overactivity increases destruction of RBCs, platelets, and WBCs. The sequelae of splenomegaly includes anemia, platelet dysfunction (quantitative and qualitative), leukopenia, and DIC.



5725.    Clinical Presentation



a.    History



b.    Physical examination



6.    Signs and Symptoms



a.    Staging of hepatic encephalopathy



i.    Stage I. Normal level of consciousness, periods of lethargy and euphoria



ii.    Stage II. Disorientation, increased drowsiness, and agitation with mood swings



iii.    Stage III. Marked confusion, sleeping most of the time



iv.    Stage IV. Coma



b.    Jaundice. Yellow discoloration of the skin, mucous membranes, and sclera is caused by excessive bilirubin levels.



c.    Renal-failure symptoms depend on the type of renal failure the child is experiencing. Azotemia should be evaluated carefully in the presence of hepatic failure, as nitrogenous wastes cannot be metabolized appropriately. Increased serum creatinine levels and oliguria are present.



d.    Coagulopathy is recognized by an elevated PT. A PT that is uncorrectable despite IV vitamin K (AquaMEPHYTON) administration reflects significant parenchymal disease. In addition, there will be platelet dysfunction. Other signs include bruising and bleeding from mucosal surfaces and the presence of petechiae.


B.    Chronic Liver Failure



1.    Definition



a.    The difference between acute and chronic disease presentation relates to the rate of parenchymal (organ-specific tissue) injury. Fibrosis leads to cirrhosis with development of portal hypertension evident by the presence of hepatosplenomegaly, varices, and ascites.



b.    Most children have a chronic presentation of hepatic failure versus an acute presentation.



2.    Etiology



a.    Nonalcoholic fatty liver disease



i.    Most common cause of chronic liver disease in children in Western countries.



ii.    Affects up to 10% of U.S. children (Corte et al., 2012).



iii.    Etiology



1)  Multifactorial



2)  Multihit



3)  Insulin resistance causes increased levels of fatty acids, which results in fatty infiltration or steatosis.



4)  Hit continues as the increased fatty acids cause apoptosis of the hepatocytes or a second hit from the gut and adipose tissue-derived endotoxin causes progression to nonalcoholic steatohepatitis (NASH).



3.    Diagnosis



a.    Liver biopsy for definitive diagnosis



b.    Elevated ALT



i.    Not excessive (1−4 × reference range)



ii.    Does not correlate with the degree of steatosis or fibrosis.



c.    Pediatric symptoms. Fatigue, hepatomegaly, obesity with central adiposity (waist circumference may correlate with disease severity), RUQ or epigastric pain, and acanthosis nigricans



d.    Treatment



i.    Gradual weight loss and physical activity



ii.    Pharmacologic agents:



  No evidence that any agents help



  Vitamin E and metformin are the most common agents that have been prescribed



4.    Pathophysiology



a.    Hepatosplenomegaly. The liver becomes firm and enlarged with regeneration, and the liver and spleen become enlarged due to vascular engorgement.



b.    Varices. With intrahepatic fibrosis, there is obstruction of blood flow with formation of collaterals in the esophagus and rectum. These veins are thin walled and prone to developing varicosities (i.e., rectal, esophageal) and GI tract bleeding.



c.    Ascites is related to the accumulation of fluid in the abdomen related to altered plasma oncotic pressure (decreased albumin production) and increased portal venous pressure. Increased abdominal girth, everted umbilicus, bulging flanks, positive fluid wave, and respiratory distress are noted.



d.    Malnutrition is evident because of inadequate bile salts and the child’s inability to absorb 573fat-soluble vitamins (A, D, E, and K). Poor weight gain and deficiencies of vitamin A (causing atrophy of the epithelial tissue and night blindness when severe), vitamin D (causing rickets), vitamin E (causing muscle degeneration, megaloblastic anemia, hemolytic anemia, creatinuria, target cell anemia, spur cell anemia, and peripheral neuropathy), and vitamin K (causing hypoprothrombinemia resulting in coagulopathy) are noted. Adequate glucose is necessary to maintain normal blood glucose levels.



e.    Pruritus is related to bile salt deposition on the epidermis related to defective biliary drainage causing an accumulation of pruritogens. Constant itching can be accompanied with skin breakdown and secondary infection.



f.    Asterixis. “Liver flap” is a flapping tremor of the hand noted when both arms are raised with forearms fixed and the hands dorsiflexed.



g.    Rickets are caused by an abnormal bone formation related to a deficiency of vitamin D, calcium, and phosphorus. Pathologic fractures and bone malformations result.



h.    Telangiectasis (vascular spiders, spider angiomas, spider nevi) are skin lesions consisting of a central arteriole from which smaller vessels radiate. Spontaneous bleeding from lesions can occur.



i.    Xanthomas are fatty nodules that develop in the SC skin layer due to disturbances in lipid metabolism.



5.    Signs and Symptoms of Chronic Liver Disease



a.    Jaundice



i.    Seen with both acute and chronic liver failure



ii.    Accumulation of yellow pigment in the tissues



iii.    Cephalocaudal distribution:



  Head and sclera = 5



  Trunk = 10



  Distal extremities = 15



6.    Diagnostic Tests



a.    Comprehensive blood chemistries, hematology and coagulation studies, US, CT scan, liver biopsy, endoscopy, and LFTs (see Table 7.2) may be useful in the determination of pathology as described previously.



7.    Patient Care Management



a.    Disease specific preventive care



b.    Direct care



i.    Management of encephalopathy



1)  Monitor for signs of increased ICP or neurologic dysfunction. Placement of an ICP monitoring device may be contraindicated in the presence of coagulopathy. Provide intubation when appropriate for airway control and hyperventilation.



2)  Intervene to decrease serum ammonia with administration of neomycin to decrease GI tract ammonia formation and lactulose (Cephulac) to acidify colonic flora and promote ammonia elimination. Restrict dietary protein.



ii.    To manage hepatorenal syndrome, monitor fluid and electrolyte status and correct electrolyte imbalances. Dialysis may be indicated (hemodialysis or continuous venovenous hemofiltration).



iii.    Manage coagulopathy by administering blood products (FFP by bolus or continuous infusion, platelets, packed RBCs, and factor VII); IV vitamin K (AquaMEPHYTON) therapy may be required.



iv.    Management of portal hypertension



1)  Variceal bleeding is treated with pharmacologic agents (i.e., vasopressin [Pitressin], octreotide [Sandostatin], and propranolol [Inderal]), endoscopic band ligation of varices, the Sengstaken−Blakemore tube (see “Acute Treatment of Esophageal Varices” in “Acute GI Tract Hemorrhage” section), or surgical intervention with a portosystemic shunt, or any combination of these. The use of propranolol (Inderal) is controversial as side effects, including heart block, exacerbation of asthma and altered physiologic response to hypoglycemia, may be detrimental. Currently, endoscopic banding or ligation is the most common initial treatment for children with hemorrhagic complications of variceal bleeding (Lirio, 2016). However, these procedures do not treat the cause of portal hypertension and for many children portosystemic shunting is appropriate.



2)  The goal of portosystemic shunts is to redirect portal blood flow into the systemic venous circulation, decreasing the 574portal venous pressure. Central shunts (portacaval shunt) are created by anastomosis of the portal vein to the inferior vena cava. Distal splenorenal shunts are created by anastomosis of the splenic vein to the left renal vein. Nonshunt surgical procedures, including the Sugiura procedure (devascularization of the upper and lower two thirds of greater and lesser curvature of the stomach and ligation of select gastric vessels), are not as successful as shunt procedures. Complications of shunting procedures include thrombosis of the anastomotic vessel, elevated ammonia levels, peptic ulcers, aggravated hepatic failure, and ascites.



3)  Management of splenomegaly. A spleen guard is a custom-fitted plastic device to cover and protect the spleen. Children with spleen guards must avoid contact sports.



4)  Management of ascites. Sodium restriction and diuretic therapy (IV furosemide [Lasix]), or hydrochlorothiazide and spironolactone (Aldactazide) can help to control fluids. Paracentesis may be used when respiratory compromise occurs. It may precipitate fluid shifts. Complications include infection and hemorrhage.



8.    Outcomes. Complications of acute hepatic failure include encephalopathy; cerebral edema, which is a major cause of mortality for children with FHF; hepatorenal syndrome; and coagulopathies resulting in GI tract, cerebral, and pulmonary hemorrhage. Associated mortality for children is as high as 70% to 90%.


LIVER TRANSPLANTATION



A.    Definition and Etiology



1.    Liver transplantation is replacement of the liver that has failed with a segment or whole-cadaver liver or a segment of the liver from a living related or nonrelated donor.



2.    Biliary atresia is the most common indication for pediatric liver transplantation. The incidence is one per 10,000 to 19,000 in Europe and North America (Verkade et al., 2016). Biliary atresia is a congenital defect of unknown cause that involves the absence or obstruction of the intrahepatic and extrahepatic bile ducts. With the development of fibrosis, bile flow is obstructed. Progressive disease with resultant fibrosis and eventual cirrhosis occurs.



3.    Metabolic Diseases



a.    Alpha-1 antitrypsin (α1AT) deficiency is transmitted via an autosomal-recessive trait. Only 5% to 20% of α1AT-deficient children develop liver disease. The disorder involves a deficiency of α1AT, which is a polymorphic glycoprotein synthesized by the liver. Liver dysfunction is usually evident as cholestasis during the neonatal period, and cirrhosis develops in later childhood. Children with α1AT deficiency are at increased risk for developing hepatocellular carcinoma.



b.    Tyrosinemia is an autosomal-recessive trait that results in deficiency of fumarylacetoacetate hydrolase (FAH) activity. Children with tyrosinemia have an increased risk for developing hepatocellular carcinoma.



c.    Urea cycle disorders are a group of diseases resulting from the lack of enzymes in the pathway that metabolizes proteins. They are associated with elevated levels of the metabolite byproduct, ammonia, for which liver transplantation is curative.



4.    Intrahepatic Cholestasis



a.    Progressive familial intrahepatic cholestasis (PFIC) is a group of autosomal-recessive inheritance disorders that constitute a group of three types of disorders (PFIC type 1, 2 [impaired bile salt secretion], and 3 [reduced biliary phospholipid secretion]) with varied clinical characteristics and familial patterns of occurrence (Srivastava, 2014). It is characterized by a paucity of bile duct development with the presence of cholestatic jaundice and pruritus. Children with PFIC type 2 have a high incidence of liver tumors and monitoring is recommended from infancy (Srivastava, 2014). Effective treatment includes nutritional support, surgical biliary diversion, and liver transplantation for many children (Srivastava, 2014).



b.    Alagille syndrome (arteriohepatic dysplasia) is an autosomal-dominant trait (Alagille et al., 1987). The syndrome’s characteristics include a broad forehead, indented chin, vertebral defects, pulmonary artery stenosis, and congenital heart disease. Cholestasis may resolve in infancy with recurrence later in childhood.



5.    Malignant Disease



a.    Hepatoblastoma usually occurs as a mass lesion composed of epithelial cells or a mixture 575of epithelial and mesenchymal components. Seventy-five percent of these cases occur before age 3 years. The abdomen may enlarge with the presence of an abdominal mass.



b.    Hepatocellular carcinoma is a highly malignant tumor characterized by anaplastic hepatocytes. It has a peak incidence in infancy, with another peak between the ages of 10 and 15 years. Signs and symptoms include abdominal swelling with associated pain and discomfort, fever, nausea, vomiting, weight loss, lethargy, and jaundice.


B.    Pathophysiology


Children with ALF and acute-on-chronic liver failure are often candidates for liver transplantation when end-stage liver disease occurs (see “Liver Failure” section).


C.    Clinical Presentation



1.    Contraindications to Transplantation. There are no absolute contraindications to liver transplantation. The presence of metastatic disease or sepsis is a relative contraindication.



2.    Pretransplant Considerations



a.    Pretransplant considerations involve a medical workup that includes a thorough history and examination, laboratory tests, assessment for evidence of portal hypertension, and assessment of portal vein patency. Family preparation and education are extensive and include education about the pretransplant process, the transplant operation, and care during the posttransplant period.



b.    The pediatric end-stage liver disease (PELD) model and model for end-stage liver disease (MELD) are used to generate a score for candidates to determine liver allocation. Scores for children 11 years and younger are determined by the PELD model and the scores for children 12 years and older are calculated based on the MELD model. The child’s PELD score is based on age, growth failure, bilirubin level, INR, albumin, and whether child is younger than 1 year old. The MELD score (which can range from 6 to 40) is based on bilirubin level, INR serum creatinine, and serum sodium (United Network for Organ Sharing [UNOS], 2017). Priority is given to patients who are status 1A (sudden and severe onset ALF and are expected to live hours to a few days) and 1B (very sick, chronically ill pediatric patients <18 years old), and children with certain diseases (e.g., certain metabolic diseases, hepatoblastoma; UNOS, 2017).


D.    Patient Care Management



1.    Liver transplantation orthotopic and living-related procedures



a.    Orthotopic liver transplant (OLTx) refers to the replacement of the diseased liver with the liver or liver segment from a cadaver. A living-related transplant is performed following the donation of part of the liver from a healthy donor. Increasingly, OLTx is being performed on children with shared donor grafts (e.g., split grafts).



b.    The transplant procedure is divided into three phases: preanhepatic (recipient’s hepatectomy), anhepatic (recipient liver has been excised and donor liver is implanted), and neohepatic (reperfusion of the new graft). There are vascular anastomoses (including the portal vein and hepatic artery) and a biliary reconstruction is done depending on the recipients’ disease process and size of the native bile duct. Children with biliary atresia or those with small bile ducts require biliary reconstruction to a piece of the intestine.



c.    This biliary anastomosis is generally performed via a roux limb and is created as either a hepaticojejunostomy or a choledochojejunostomy depending on which duct is attached to the jejunum. In children with a disease with a normal biliary system, biliary anastomosis can be completed as an anastomosis between the two bile ducts as a choledocholedocostomy.



2.    Postop Nursing Care



a.    Promote pulmonary toilet. After resolution of the existing coagulopathies, initiate chest physiotherapy. Evaluate diaphragm function with an US if the child fails extubation twice.



b.    Treat hypertension with antihypertensives. The first-line drug in the immediate postoperative period is institution specific; sodium nitroprusside, sublingual nifedipine (Procardia), or hydralazine are drugs that may be used when necessary.



c.    Monitor Jackson−Pratt drainage. Bloody drainage may indicate surgical bleeding. The presence of bile in a surgical drain could indicate a bile leak.



d.    Avoid rapid correction of coagulopathies. Hematocrit is maintained at approximately 30%. Subclinical anticoagulation is used for vessel thrombosis prophylaxis and is initiated 576when the PT is less than 17 seconds. Aspirin decreases platelet aggregation. Dipyridamole (Persantine) is a platelet adhesion inhibitor. Dextran decreases blood viscosity and platelet adhesiveness. Heparin may be used as a prophylactic anticoagulant.



e.    Other commonly used medications include immunosuppressive therapy (see “Pharmacology” section earlier in this chapter) and drugs for infection prophylaxis. Broad-spectrum IV antibiotics are given perioperatively. Co-trimoxazole (Bactrim) is prescribed indefinitely for Pneumocystis carinii, nocardia, and toxoplasmosis prophylaxis. Nystatin (Mycostatin) is an antifungal agent used for thrush prophylaxis.


E.    Complications and Outcomes



1.    Rejection



a.    Signs and symptoms may include fever, RUQ tenderness, light-colored stools, dark-colored urine; however, most rejection episodes are diagnosed with asymptomatic elevation of liver enzymes.



b.    Liver biopsy is used for definitive diagnosis. Before the biopsy, check platelet count and PT. If the child is being treated with anticoagulants, consideration should be given to holding anticoagulation prior to the biopsy. US marking is used when necessary (e.g., may be done in the presence of abnormal anatomic findings, as in the presence of a reduced-size graft following liver transplantation). Monitoring for complications of the biopsy includes frequent assessment of vital signs for the assessment of hemorrhage, chest x-ray examination to rule out pneumothorax, and serial hematocrit measurements.



c.    Treatment is augmentation of the child’s immunosuppression.



2.    Infection is the leading cause of morbidity and mortality following transplantation.



a.    Bacterial infections occur most often within the first 30 days. Common causes include preexisting disease conditions; central lines; surgical intervention; and posttransplantation factors, including transfusion requirements and dosing of immunosuppressive agents. Treatment is antibiotic therapy.



b.    Viral infections usually occur from 31 to 180 days following transplantation. Infections caused by opportunistic or immunomodulating viruses commonly occur in the first 6 months following transplantation. Common organisms include cytomegalovirus and EBV. After the 6-month posttransplant period, community-acquired infections are common as for any child. Primary infections occur when the patient becomes infected with a virus with no previous exposure. Secondary infection involves the reactivation of a latent virus. Recovery from a secondary infection is usually easier than recovery from a primary infection. Treatment is antiviral therapy. Acyclovir (Zovirax) inhibits viral DNA synthesis of the herpesviruses. Ganciclovir (Cytovene) inhibits the CMV DNA polymerase. Side effects include impaired renal function, neutropenia, thrombocytopenia, confusion, and nausea.



3.    LPD and EBV Infection. LPD is characterized by the development of continually proliferating B lymphocytes, presumably stimulated under the influence of EBV. LPD is diagnosed by tissue biopsy with histologic evidence and is necessary to guide treatment. Treatment involves reducing or discontinuing the child’s immunosuppression, initiating antiviral therapy, use of monoclonal antibody therapy (e.g., Rituximab), or chemotherapy.



4.    Survival is estimated to be at 80% at 1 year.


INTESTINAL FAILURE/SHORT GUT/INTESTINE TRANSPLANTATION



A.    Definition and Etiology



1.    Intestinal failure/short gut is the loss of the absorptive function of the intestine, with resulting malabsorption and malnutrition necessitating PN support. Although the terms intestinal failure and short gut syndrome (SGS) are sometimes used interchangeably, children can have intestinal failure when they have dysfunctional intestine with normal bowel length.



2.    Intestinal failure is inadequate GI function to maintain nutrition and hydration necessitating PN support because of malabsorption and malnutrition. SGS is the most common indication for intestine transplantation. Short gut can occur secondary to congenital and acquired disease processes.



a.    Congenital conditions include gastroschisis, malrotation with volvulus, intestinal atresias, and total colon Hirschsprung’s disease requiring surgical resection (see Table 7.12).



577b.    Acquired conditions include NEC (see “Necrotizing Enterocolitis” section) and traumatic injuries.



3.    Other indications include intestinal dysmotility (e.g., intestinal pseudoobstruction, aganglionosis) and enterocyte absorptive impairment (microvillus inclusion disease and tufting enteropathy), or disease-associated loss of absorption.


B.    Pathophysiology



1.    Each infant- or child-rendered short gut is unique as successful intestinal adaptation is dependent on the type and length of bowel segment present.



a.    At birth, the normal estimated bowel length is 250 ± 40 cm (Goulet, Ruemmele, Lacaille, & Colomb, 2004).



b.    Infants can experience acceptable intestinal adaptation with less than 15 cm of intestine if the ileocecal valve is intact, and with 30 to 45 cm of intestine if the ileocecal valve is absent or does not function (Fishbein & Matsumoto, 2006).



c.    Intestinal adaptation occurs by increasing existing bowel surface area and functional abilities over a period of weeks to many months and is dependent on the etiology of the SBS and the functional state of the remaining bowel.



d.    Intestinal adaptation is characterized by increasing intestinal mass, lengthening of villi, and improved absorption at the epithelial level.



e.    Successful adaptation is described as the ability to achieve normal growth, fluid balance, and electrolyte levels without PN.



2.    There are a multitude of mechanisms that contribute to malabsorption, including acid hypersecretion, rapid intestinal transit, and loss of surface area and impaired residual bowel with bacterial overgrowth and bile acid wasting.


C.    Clinical Presentation



1.    History. Most children younger than the age of 1 year are rendered short gut from a congenital anomaly or NEC. History is variable as there are both congenital and acquired etiologies with various disease trajectories.



2.    Physical Examination. Specific exam consideration includes careful monitoring of growth parameters, signs and symptoms of liver dysfunction (see “Liver Failure” section specifically findings with cholestasis), integrity of central venous access, and skin integrity of diapered patients as excess secretion of bile acids may result in a severe diaper rash.



3.    Diagnostic Tests



a.    An upper GI series with small bowel follow through may be done to determine bowel length and evaluate bowel caliber, if bowel lengthening procedure is being considered.



b.    A breath hydrogen test can be performed to evaluate for bacterial overgrowth.



c.    Although endoscopy is not indicated for this reason, if done, a culture of duodenal fluid can be obtained to evaluate for bacterial overgrowth.



4.    Clinical Course



a.    Trajectory is variable depending on etiology, remaining bowel, and retained function.


D.    Patient Care Management



1.    Preventive Care. Optimize the medical and surgical management of neonates with congenital disorders to promote intestinal adaptation and bowel salvage with the goal of optimizing the enteral diet, PN prescription, treatment of bacterial overgrowth, administration of antacids and antisecretory agents, and use of antidiarrheal (stool bulking) agents.



2.    Direct Care



a.    Monitor stool and urine output.



i.    Stool output should be replaced for output greater than 40 mL/kg/d. Most common replacement fluid is RL 0.5 mL:mL or mL:mL.



b.    Use enteral and PN nutrition.



i.    Fluid requirements are upwards of 100 to 200 mL/kg/d.



ii.    Caloric requirements are 100 to 150 kcal/kg/d.



iii.    EN promotes adaptation and BM is preferred with an associated shorter duration of PN dependence. If maternal or banked BM is not available, elemental hydrolyzed formulas are preferred. Duocal or microlipids may be used as caloric supplements.



iv.    PN prescriptions should minimize intralipids (0.5 gm/kg/d adequate to prevent 578essential fatty acid deficiency) levocarnitine should be added, trace elements manipulated (limit copper and selenium; remove manganese and chromium), glucose infusion rate should be optimized and wean or cycle PN as feasible. Alternative lipid formulations are being used that minimize the inflammatory effect on the liver, minimizing and reversing cholestatic changes. Unfortunately, available products are expensive and not FDA approved (Omegaven and Smoflipid 20% [soya oil, medium-chain triglyceride, olive oil, and fish oil]).



c.    Use oral and enteral rehydration solutions as needed and may augment IV fluids as stool replacement, which may be added to enteral feedings.



d.    Treat bacterial overgrowth with the cycling of antibiotics to prevent resistance. Metronidazole (Flagyl), sulfamethoxazole (Bactrim), and rifaximin (Xifaxin) are commonly used.



e.    Antacid therapy is prescribed to minimize acid hypersecretion.



f.    Administer antisecretory and antidiarrheal/bulking medications as prescribed (e.g., Imodium [loperamide] or Catapres [clonidine]; see “Pharmacology” section). Clonidine is most commonly used for children to slow ostomy effluence. Products to slow gastric motility (pectin and Benefiber) may be prescribed.



g.    Bowel-lengthening surgical procedures.



i.    Bowel-lengthening procedures are considered for dilated loops of bowel (>2 cm) or complications from the dilated bowel loops (e.g., bacteremia from bacterial intestinal translocation or intolerance of enteral feeding advances).



ii.    The Bianchi procedure is the oldest procedure and involves a longitudinal incision to create two tubes to lengthen the bowel that are reconnected to create a longer, narrower single-lumen intestinal segment. The Kimura procedure is an alternative procedure for children with SGS and inadequate mesentery who are not candidates for the Bianchi procedure. The serial transverse enteroplasty procedure augments bowel length and peristalsis by stapling dilated bowel in a zigzag fashion to achieve a greater mucosal absorptive surface area and decreased bowel diameter.



h.    Intestinal transplantation is considered for children experiencing complications of PN, including liver failure, loss of greater than two or more venous access devices, recurrent central-line catheter infections, and recurrent severe dehydration. The ideal intestine donor has the same blood type, weighs within 10% of the recipient’s body weight, and is of similar age as the recipient. All intestine recipients have a stoma to allow for bowel surveillance and access for endoscopy and biopsy. See Figure 7.3 for the common intestinal transplant procedures. Postop care for the intestine recipient is summarized in Table 7.14. Complications of intestine transplant procedures include rejection, infection, and posttransplant lymphoproliferative disease (PTLD). Signs and symptoms of intestinal graft rejection include a pale or dusky stoma, an increase or decrease in enteric output, abdominal pain, and guaiac-positive output. Postoperative endoscopic biopsies of the transplanted bowel are made through the child’s stoma on a routine and as-needed basis. Rejection is usually diagnosed with endoscopy and biopsy the gold standard.



3.    Supportive Care. Children with intestinal failure should be referred to an intestinal rehabilitation team, which is usually composed of a gastroenterologist with specific expertise, advanced practice nurse, nutritionist, surgeon, social worker, and speech therapist.


E.    Outcomes



1.    PN-induced cholestasis is a possible complication of intestinal failure in patients with resultant concomitant liver and intestinal failure. Cholestasis or a bilirubin level greater than 2 mg/dL occurs in 40% to 60% of children with intestinal failure (Sondheimer et al., 1998) and contributes to the greatest morbidity and mortality for these children.



a.    Measures to reduce the incidence of cholestasis



i.    PN manipulations with cycling, lipid minimization, and limiting and/or removing trace elements.



ii.    EN with the promotion of breastmilk as optimal.



iii.    Decrease central line infection rates with antibiotic and ethanol locks. Ethanol locks are incompatible with heparin and should be instilled for 2 to 4 hours.



iv.    Cycle enteral antibiotics to treat bowel bacterial overgrowth.


Feb 19, 2020 | Posted by in NURSING | Comments Off on Gastrointestinal System
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