Hematologic and Immunologic Dysfunction



Hematologic and Immunologic Dysfunction


Marilyn J. Hockenberry



Learning Objectives


On completion of this chapter, the reader will be able to:


• Distinguish among the various categories of anemia.


• Describe the prevention of iron deficiency anemia and the care of the child with iron deficiency anemia.


• Compare sickle cell anemia and β-thalassemia major in relation to pathophysiology and nursing care.


• Describe the mechanisms of inheritance and nursing care of the child with hemophilia.


• Relate the pathophysiology and clinical manifestations of leukemia.


• Demonstrate an understanding of the rationale of therapies for neoplastic disease.


• Outline a care plan for the child with neoplastic disease and the family.


• Contrast the pathophysiology and management of the immunodeficiency disorders.


• List nursing precautions and responsibilities during blood transfusion.


• Describe the types of hematopoietic stem cell transplants.



Hematologic Dysfunction


Several tests can be performed to assess hematologic function, including additional procedures to identify the cause of the dysfunction. The following discussion is limited to a description of the most common and one of the most valuable tests, the complete blood cell count (CBC). Other procedures, such as those related to iron, coagulation, and immune status, are discussed throughout the chapter as appropriate. The nurse should be familiar with the significance of the findings from the CBC (Table 43-1) and be aware of normal values for age, which are listed in Appendix B.



TABLE 43-1


TESTS PERFORMED AS PART OF A COMPLETE BLOOD COUNT



































































TEST (AVERAGE VALUE)* DESCRIPTION, COMMENTS
RBC count (4.5-5.5 million/mm3)
Hgb determination (11.5-15.5 g/dL)
Hct (35%-45%)
RBC Indices
MCV (77-95 fL)
MCH (25-33 pg/cell)
MCHC (31%-37% Hgb [g]/dL RBC)
RBC volume distribution width (13.4% ± 1.2%)
Reticulocyte count (0.5%-1.5% erythrocytes)
WBC count (4.5-13.5 × 103 cells/mm3)
Differential WBC count
Neutrophils (polys) (54%-62%) (3-5.8 × 103 cells/mm3)
Bands (3%-5%) (0.15-0.4 × 103 cells/mm3)
Eosinophils (1%-3%) (0.05-0.25 × 103 cells/mm3)
Basophils (0.075%) (0.015-0.030 × 103 cells/mm3)
Lymphocytes (25%-33%) (1.5-3.0 × 103 cells/mm3)
Monocytes (3%-7%)
ANC (>1000/mm3)
Platelet count (150-400 × 103/mm3)
Stained peripheral blood smear


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ANC, Absolute neutrophil count; Hct, hematocrit; Hgb, hemoglobin; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; MCV, mean corpuscular volume; RBC, red blood cell; WBC, white blood cell.


*See Appendix B for normal values according to age.


As with any disorder, the history and physical examination are essential to identify hematologic dysfunction, and the nurse is often the first person to suspect a problem based on information from these sources. Comments by the parent regarding the child’s lack of energy, food diary of poor sources of iron, frequent infections, and bleeding that is difficult to control offer clues to the more common disorders affecting the blood. A careful physical appraisal, especially of the skin, can reveal findings (e.g., pallor, petechiae, bruising) that may indicate minor or serious hematologic conditions. Nurses need to be aware of the clinical manifestations of blood diseases to assist in recognizing symptoms and establishing a diagnosis.



image Nursing Alert


A common term used in describing an abnormal CBC is shift to the left, which refers to the presence of immature neutrophils in the peripheral blood from hyperfunction of the bone marrow, as seen during a bacterial infection.



Red Blood Cell Disorders


Anemia


The term anemia describes a condition in which the number of red blood cells (RBCs) or the hemoglobin (Hgb or Hb) concentration is reduced below normal values for age. This diminishes the oxygen-carrying capacity of the blood, causing a reduction in the oxygen available to the tissues. Anemia is the most common hematologic disorder of infancy and childhood and is not a disease itself but an indication or manifestation of an underlying pathologic process.



Classification


Anemias are classified in relation to (1) etiology or physiology, manifested by erythrocyte or Hgb depletion, and (2) morphology, the characteristic changes in RBC size, shape, or color (Box 43-1). Although the morphologic classification is more useful in terms of laboratory evaluation of anemia, the etiologic approach provides direction for planning nursing care. For example, anemia with reduced Hgb concentration may be caused by a dietary depletion of iron and the principal intervention is replenishing iron stores. The classification of anemias is found in Fig. 43-1.



Box 43-1   Red Blood Cell Morphology





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FIG 43-1 Classifications of anemias. AIHA, Autoimmune hemolytic anemia; ALL, acute lymphoid leukemia; CMV, cytomegalovirus; DIC, disseminated intravascular coagulation; G6PD, glucose-6-phosphate dehydrogenase; ITP, idiopathic thrombocytopenic purpura; RBC, red blood cell; SCD, sickle cell disease.


Consequences of Anemia


The basic physiologic defect caused by anemia is a decrease in the oxygen-carrying capacity of blood and consequently a reduction in the amount of oxygen available to the cells. When the anemia has developed slowly, the child usually adapts to the declining Hgb level.


The effects of anemia on the circulatory system can be profound. Because the viscosity of blood depends almost entirely on the concentration of RBCs, the resulting hemodilution of severe anemia decreases peripheral resistance, causing greater quantities of blood to return to the heart. The increased circulation and turbulence within the heart may produce a murmur. Because the cardiac workload is greatly increased, especially during exercise, infection, or emotional stress, cardiac failure may ensue.


Children seem to have a remarkable ability to function well despite low levels of Hgb. Cyanosis (the result of the quantity of deoxygenated Hgb in arterial blood) is typically not evident. Growth retardation, resulting from decreased cellular metabolism and coexisting anorexia, is a common finding in chronic severe anemia and is frequently accompanied by delayed sexual maturation in the older child.





Care Management


The assessment of anemia includes the basic techniques that are applicable to any condition. The age of the infant or child provides some clues regarding the possible etiology of the anemia. For example, iron deficiency anemia occurs more frequently in toddlers between 12 and 36 months of age and during the growth spurt of adolescence.


Racial or ethnic background is significant. For example, the anemias related to abnormal Hgb levels are found in Southeast Asians and persons of African or Mediterranean ancestry. These same groups may be genetically deficient in the enzyme lactase after the period of infancy. Affected individuals are unable to tolerate lactose in the diet, with consequent intestinal irritation and chronic blood loss.


Special emphasis is placed on a careful history to elicit any information that might help identify the cause of the anemia. For example, a statement such as: “My child drinks lots of milk” is a frequent finding in toddlers with iron deficiency anemia. An episode of diarrhea may have precipitated temporary lactose intolerance in a young child.


Stool examination for occult (microscopic) blood (Hemoccult test) can identify chronic intestinal bleeding that results from a primary or secondary lactase deficiency. It is also important to understand the significance of various blood tests (see Table 43-1).





Prepare the Child and Family for Laboratory Tests.

Usually, several blood tests are ordered, but because they are generally done sequentially rather than at one time, the child is subjected to multiple finger or heel punctures or venipunctures. Laboratory technicians frequently are not aware of the trauma that repeated punctures represent to a child. However, these invasive procedures need not be painful (see Blood Specimens, Chapter 39). For example, the topical application of EMLA (an eutectic mix of lidocaine and prilocaine) or 4% lidocaine (Ela-Max or LMX) before needle punctures can eliminate pain (see Pain Management, Chapter 30). Therefore the nurse is responsible for preparing the child and family for the tests by:



Older children may appreciate the opportunity to observe the blood cells under a microscope or in photographs. This experience is especially important if a serious blood disorder, such as leukemia, is suspected because it serves as a foundation for explaining the pathophysiology of the disorder.


Bone marrow aspiration is not a routine hematologic test but is essential for definitive diagnosis of the leukemias, lymphomas, and certain anemias.



image Nursing Alert


The following are suggested explanations for teaching children about blood components:




Decrease Tissue Oxygen Needs.

Because the basic pathologic process in anemia is a decrease in oxygen-carrying capacity, an important nursing responsibility is to assess the child’s energy level and minimize excess demands. The child’s level of tolerance for activities of daily living and play is assessed, and adjustments are made to allow as much self-care as possible without undue exertion. During periods of rest, the nurse takes vital signs and observes behavior to establish a baseline of nonexertion energy expenditure. During periods of activity, the nurse repeats these measurements and observations to compare them with resting values.



image Nursing Alert


Signs of exertion include tachycardia, palpitations, tachypnea, dyspnea, shortness of breath, hyperpnea, breathlessness, dizziness, lightheadedness, diaphoresis, and change in skin color. The child looks fatigued (sagging, limp posture; slow, strained movements; inability to tolerate additional activity; difficulty sucking in infants).




Iron Deficiency Anemia


Anemia caused by an inadequate supply of dietary iron is the most prevalent nutritional disorder in the United States and the most preventable mineral disturbance. The prevalence of iron deficiency anemia has decreased during infancy in the United States, probably in part because of families’ participation in the Women, Infants, and Children (WIC) program, which provides iron-fortified formula for the first year of life and routine screening of Hgb levels during early childhood (Baker, Greer, and Committee on Nutrition American Academy of Pediatrics [AAP], 2010; Cusick, Mei, Freedman, et al., 2008). Preterm infants are especially at risk because of their reduced fetal iron supply. Children 12 to 36 months of age are at risk for anemia as a result of primarily cow’s milk intake and not eating an adequate amount of iron-containing food (Andrews, Ullrich, and Fleming, 2009; Baker, Greer, and Committee on Nutrition AAP, 2010; Richardson, 2007). Adolescents are also at risk because of their rapid growth rate combined with poor eating habits, menses, obesity, or strenuous activities.



Pathophysiology


Iron deficiency anemia can be caused by any number of factors that decrease the supply of iron, impair its absorption, increase the body’s need for iron, or affect the synthesis of Hgb. Although the clinical manifestations and diagnostic evaluation are similar regardless of the cause, the therapeutic and nursing care management depend on the specific reason for the iron deficiency. The following discussion is limited to iron deficiency anemia resulting from inadequate iron in the diet.


During the last trimester of pregnancy, iron is transferred from the mother to the fetus. Most of the iron is stored in the circulating erythrocytes of the fetus, with the remainder stored in the fetal liver, spleen, and bone marrow. These iron stores are usually adequate for the first 5 to 6 months in a full-term infant but for only 2 to 3 months in preterm infants and multiple births. If dietary iron is not supplied to meet the infant’s growth demands after the fetal iron stores are depleted, iron deficiency anemia results. Physiologic anemia should not be confused with iron deficiency anemia resulting from nutritional causes.


Although most toddlers with iron deficiency anemia are underweight, many infants are overweight because of excessive milk ingestion (known as milk babies). These children become anemic for two reasons: milk, a poor source of iron, is given almost to the exclusion of solid foods; and 50% of iron deficient infants fed cow’s milk have an increased fecal loss of blood.



Therapeutic Management


After the diagnosis of iron deficiency anemia is made, therapeutic management focuses on increasing the amount of supplemental iron the child receives. This is usually done through dietary counseling and the administration of oral iron supplements.


In formula-fed infants, the most convenient and best sources of supplemental iron are iron-fortified commercial formula and iron-fortified infant cereal. Iron-fortified formula provides a relatively constant and predictable amount of iron and is not associated with an increased incidence of gastrointestinal (GI) symptoms, such as colic, diarrhea, or constipation. Infants younger than 12 months should not be given fresh cow’s milk because it may increase the risk for GI blood loss occurring from exposure to a heat-labile protein in cow’s milk or cow’s milk–induced GI mucosal damage resulting from a lack of cytochrome iron (heme protein) (Glader, 2007; Richardson, 2007). If GI bleeding is suspected, the child’s stool should be guaiac tested on at least four or five occasions to identify any intermittent blood loss.


Dietary addition of iron-rich foods is usually inadequate as the sole treatment of iron deficiency anemia because the iron is poorly absorbed and thus provides insufficient supplemental quantities of iron. If dietary sources of iron cannot replace body stores, oral iron supplements are prescribed for approximately 3 months. Ferrous iron, more readily absorbed than ferric iron, results in higher Hgb levels. Ascorbic acid (vitamin C) appears to facilitate absorption of iron and may be given as vitamin C–enriched foods and juices with the iron preparation.


If the Hgb level fails to rise after 1 month of oral therapy, it is important to assess for persistent bleeding, iron malabsorption, noncompliance, improper iron administration, or other causes of the anemia. Parenteral (IV or intramuscular [IM]) iron administration is safe and effective but painful, expensive, and occasionally associated with regional lymphadenopathy, transient arthralgias, or serious allergic reaction (Andrews, Ullrich, and Fleming, 2009; Glader, 2007; McKenzie, 2004). Therefore parenteral iron is reserved for children who have iron malabsorption or chronic hemoglobinuria. Transfusions are indicated for the most severe anemia and in cases of serious infection, cardiac dysfunction, or surgical emergency when anesthesia is required. Packed RBCs (2-3 mL/kg), not whole blood, are used to minimize the chance of circulatory overload. Supplemental oxygen is administered when tissue hypoxia is severe.




Care Management


An essential nursing responsibility is instructing parents in the administration of iron. Oral iron should be given as prescribed in two divided doses between meals, when the presence of free hydrochloric acid is greatest, because more iron is absorbed in the acidic environment of the upper GI tract. A citrus fruit or juice taken with the medication aids in absorption.



image Medication Alert


Cow’s milk contains substances that bind the iron and interfere with absorption. Iron supplements should not be administered with milk or milk products (Carley, 2003).


An adequate dosage of oral iron turns the stools a tarry green color. The nurse advises parents of this normally expected change and inquires about its occurrence on follow-up visits. Absence of the greenish black stool may be a clue to poor administration of iron, either in schedule or in dosage. Vomiting or diarrhea can occur with iron therapy. If the parents report these symptoms, the iron can be given with meals and the dosage reduced and then gradually increased until tolerated.



image Medication Alert


Liquid preparations of iron may temporarily stain the teeth. If possible, the medication should be taken through a straw or given through a syringe or medicine dropper placed toward the back of the mouth. Brushing the teeth after administration of the drug lessens the discoloration. Because iron ingestion in excessive quantities is toxic or even fatal, parents should be instructed to keep no more than a month’s supply in the home and store it safely away from the reach of children.


If parenteral iron preparations are prescribed, iron dextran must be injected deeply into a large muscle mass using the Z-track method. The injection site is not massaged after injection to minimize skin staining and irritation. Because no more than 1 mL should be given in one site, the IV route should be considered to avoid multiple injections. Careful observation is required because of the risk for adverse reactions, such as anaphylaxis, with IV administration. A test dose is recommended before routine use. Recently, a new IV iron preparation (ferumoxytol) was approved in the United States that shows promise in complete replacement of iron with little toxicity (Auerbach, 2011).





Diet.

A primary nursing objective is to prevent nutritional anemia through family education. Because breast milk is a low iron source, the nurse must reinforce the importance of administering iron supplementation to exclusively breastfed infants by 4 months of age (Baker, Greer, and Committee on Nutrition AAP, 2010; Lokeshwar, Mehta, Mehta, et al., 2011). The American Academy of Pediatrics (AAP) recommends preterm, marginally low–birth-weight and low-birth-weight infants or infants with inadequate iron stores at birth receive iron supplements at approximately 2 months of age (Berglund, Westrup, and Domellof, 2010).


In formula-fed infants, the nurse discusses with parents the importance of using iron-fortified formula and introducing solid foods at the appropriate age during the first year of life. Traditionally, cereals are one of the first semisolid foods to be introduced into the infant’s diet at approximately 6 months of age (Baker, Greer, and Committee on Nutrition AAP, 2010; Glader, 2007; Lokeshwar, Mehta, Mehta, et al., 2011). The best solid-food source of iron is commercial iron-fortified cereals. It may be difficult at first to teach the infant to accept foods other than milk. The same principles are applied as those for introducing new foods (see Nutrition, Chapter 31), especially feeding the solid food before the milk. Predominantly milk-fed infants rebel against solid foods, and parents are cautioned about this and the need to be firm in not relinquishing control to the child. It may require intense problem solving on the part of both the family and the nurse to overcome the child’s resistance.


A difficulty encountered in discouraging the parents from feeding milk to the exclusion of other foods is dispelling the popular myth that milk is a “perfect food.” Many parents believe that milk is best for infants and equate weight gain with a “healthy child” and “good mothering.” The nurse can also stress that overweight is not synonymous with good health.


Diet education of teenagers is especially difficult, especially because teenage girls are particularly prone to following weight-reduction diets. Emphasizing the effect of anemia on appearance (pallor) and energy level (difficulty maintaining popular activities) may be useful.



Sickle Cell Anemia


Sickle cell anemia (SCA) is one of a group of diseases collectively termed hemoglobinopathies in which normal adult Hgb (Hgb A [HbA]) is partly or completely replaced by abnormal sickle Hgb (HbS). Sickle cell disease (SCD) includes all those hereditary disorders whose clinical, hematologic, and pathologic features are related to the presence of HbS. Even though the term SCD is sometimes used to refer to SCA, this use is incorrect. Other correct terms for SCA are SS and homozygous SCD.


The following are the most common forms of SCD in the United States:



Of the SCDs, SCA is the most common form in African-Americans, followed by sickle cell–C disease and sickle thalassemia. Sickle syndromes exist when the HbS is paired with other mutant globins.


Sickle cell disease is one of the most common genetic diseases worldwide. SCD affects approximately 90,000 Americans, primarily African-American, followed by Hispanics, with a lower incidence in the other ethnic groups (Driscoll, 2007). The incidence of the disease varies in different geographic locations. Among African-Americans, the incidence of sickle cell trait is about 9%. In West Africa, the incidence is reported to be as high as 40% among native Africans. The high incidence of sickle cell trait in West Africans is believed by some to be the result of selective protection afforded trait carriers against one type of malaria.


The gene that determines the production of HbS is situated on an autosome and, when present, is always detectable and therefore dominant. Heterozygous persons who have both normal HbA and abnormal HbS are said to have sickle cell trait. Persons who are homozygous have predominantly HbS and have SCA. The inheritance pattern is essentially that of an autosomal recessive disorder. Therefore, when both parents have sickle cell trait, there is a 25% chance with each pregnancy of producing an offspring with SCA.


Although the defect is inherited, the sickling phenomenon is usually not apparent until later in infancy because of the presence of fetal Hbg (HbF). As long as the child has predominantly HbF, sickling does not occur because there is less HbS. Newborns with SCA are generally asymptomatic because of the protective effect of HbF (60%-80% HbF), but this rapidly decreases during the first year, so these children are at risk for sickle cell–related complications (Driscoll, 2007; Heeney and Dover, 2009).



Pathophysiology


The clinical features of SCA are primarily the result of (1) obstruction caused by the sickled RBCs, (2) vascular inflammation, and (3) increased RBC destruction (Fig. 43-2). The abnormal adhesion, entanglement, and enmeshing of rigid sickle-shaped cells accompanied by the inflammatory process intermittently block the microcirculation, causing vasoocclusion (Fig. 43-3). The resultant absence of blood flow to adjacent tissues causes local hypoxia, leading to tissue ischemia and infarction (cellular death). Most of the complications seen in SCA can be traced to this process and its impact on various organs of the body (Box 43-2).



Box 43-2   Clinical Manifestations of Sickle Cell Anemia






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FIG 43-2 Clinical features of sickle cell anemia from red blood cell obstruction and destruction. CVA, Cerebrovascular accident.

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FIG 43-3 A, Normal red blood cells (RBCs) flowing freely in a blood vessel. The inset shows a cross section of a normal RBC with normal hemoglobin. B, Abnormal, sickled RBCs clumping and blocking blood flow in a blood vessel. (Other cells also may play a role in this clumping process.) The inset shows a cross section of a sickle cell with abnormal hemoglobin. (From National Heart, Lung, and Blood Institute: What is sickle cell anemia? Bethesda, MD, August 2008, Author.)

The clinical manifestations of SCA vary greatly in severity and frequency. The most acute symptoms of the disease occur during periods of exacerbation called crises. There are several types of episodic crises, including vasoocclusive, acute splenic sequestration, aplastic, hyperhemolytic, cerebrovascular accident, chest syndrome, and infection. The crises may occur individually or concomitantly with one or more other crises. The vasoocclusive crisis (VOC), preferably called a “painful episode,” is characterized by ischemia causing mild to severe pain that may last from minutes to days. Sequestration crisis is a pooling of a large amount of blood—usually in the spleen and infrequently in the liver—that causes a decreased blood volume and ultimately shock. Aplastic crisis is diminished RBC production usually caused by viral infection that may result in profound anemia. Hyperhemolytic crisis is an accelerated rate of RBC destruction characterized by anemia, jaundice, and reticulocytosis.


Another serious complication is acute chest syndrome (ACS), which is clinically similar to pneumonia. It is the presence of a new pulmonary infiltrate and may be associated with chest pain, fever, cough, tachypnea, wheezing, and hypoxia. A cerebrovascular accident (CVA, stroke) is a sudden and severe complication, often with no related illnesses. Sickled cells block the major blood vessels in the brain, resulting in cerebral infarction, which causes variable degrees of neurologic impairment. The current treatment for SCD children who have experienced a stroke is chronic transfusion therapy. Repeat CVAs causing progressively greater brain damage occur in approximately 70% of untreated children who have experienced one stroke (Heeney and Dover, 2009).



Diagnostic Evaluation


Newborn screening for SCA is mandatory in most of the United States so that infants can be identified before symptoms occur. At birth, infants have up to 80% of HbF, which does not carry the defect. Because levels of HbS are low at birth, Hgb electrophoresis or other tests that measure Hgb concentrations are indicated. Early diagnosis (before 3 months of age) enables initiation of appropriate interventions to minimize complications. The family is taught to administer prophylactic antibiotics and identify early signs of infection and to seek medical therapy as soon as possible.


If SCA is not diagnosed in early infancy, it is likely to manifest symptoms during the toddler and preschool years. SCA is occasionally first diagnosed during a crisis that follows an acute respiratory tract or GI infection. Routine hematologic tests are done to evaluate the anemia. Several specific tests detect the presence of the abnormal Hgb in the heterozygote or the homozygote. For screening purposes, the sickle-turbidity test (Sickledex) is frequently used because it can be performed on blood from a fingerstick and yields accurate results in 3 minutes. However, if the test result is positive, Hgb electrophoresis is necessary to distinguish between children with the trait and those with the disease. Hemoglobin electrophoresis (“fingerprinting” of the protein) is an accurate, rapid, and specific test for detecting the homozygous and heterozygous forms of the disease, as well as the percentages of the various types of Hgb.



Therapeutic Management


The aims of therapy are to (1) prevent the sickling phenomena, which are responsible for the pathologic sequelae, and (2) treat the medical emergencies of sickle cell crisis. The successful achievement of the aims depends on prompt nursing interventions, medical therapies, patient and family preventive measures, and use of innovative treatments.


Medical management of a crisis is usually directed toward supportive and symptomatic treatment. The main objectives are to provide (1) rest to minimize energy expenditure and to improve oxygen utilization; (2) hydration through oral and IV therapy; (3) electrolyte replacement because hypoxia results in metabolic acidosis, which also promotes sickling; (4) analgesia for the severe pain from vasoocclusion; (5) blood replacement to treat anemia and to reduce the viscosity of the sickled blood; and (6) antibiotics to treat any existing infection.


Administration of pneumococcal and meningococcal vaccines is recommended for these children because of their susceptibility to infection as a result of functional asplenia. In addition to routine immunizations, children with SCD should receive a yearly influenza vaccination (see Immunizations, Chapter 31). Oral penicillin prophylaxis is also recommended by 2 months of age to reduce the chance of pneumococcal sepsis (see Evidence-Based Practice box) (AAP Committee on Infectious Diseases, 2009; Hirst and Owusu-Ofori, 2010; National Institutes of Health, 2002; Pack-Mabien and Haynes, 2009).



Evidence-Based Practice


Sickle Cell Anemia and Penicillin Prophylaxis





Critically Analyze the Evidence




• Hirst and Owusu-Ofori (2010) conducted an updated systematic Cochrane review of three trials that showed a reduced rate of infection in children with SCD receiving penicillin preventatively. Two trials looked at whether treatment was effective. The third trial followed from one of the early trials and looked at when it was safe to stop treatment. Adverse drug effects were rare and minor. Penicillin given preventatively reduces the rate of pneumococcal infections in children with SCD younger than 5 years.


• Researchers combined the clinical experiences of three sickle cell programs in the eastern United States in an attempt to determine the age and disease-specific risk for Streptococcus pneumoniae bacteremia and meningitis in children with SCD at a time when penicillin prophylaxis was routine. Forty-seven pneumococcal infections (44 bacteremia; 3 meningitis) among 40 patients with SCD were observed. Most children in whom infections developed were taking prophylactic penicillin and received Pneumovax at 24 months of age. The observed severe pneumococcal infection rate in HgbSS children younger than 5 years was less than that reported before penicillin prophylaxis in this specific population (Hord, Byrd, Stowe, et al., 2002).


• Administration of oral prophylactic penicillin was compared with the 14-valent pneumococcal vaccine in preventing pneumococcal infection in 242 children between the ages of 6 months and 3 years with HgbSS. In the first 5 years of the trial, there were 11 pneumococcal infections in the pneumococcal vaccine group and higher infection rates in those given the vaccine before 1 year of age. No pneumococcal isolates were found in the group receiving penicillin, although 4 pneumococcal isolates were found in this group within 1 year of stopping the penicillin prophylaxis at age 3 years. This study supported the use of penicillin prophylaxis to prevent pneumococcal infection in children younger than 3 years (John, Ramlal, Jackson, et al., 1984).


• In a multicenter, randomized, double-blind, placebo-controlled clinical trial, 105 children received penicillin twice daily; a control group of 110 children received a placebo twice daily. The trial was terminated 8 months early when an 84% reduction in the incidence of pneumococcal infections was observed in the group treated with penicillin compared with the placebo group. There were no deaths in the penicillin group, but three deaths from infection occurred in the placebo group. Researchers stressed the importance of screening children during the neonatal period and prescribing prophylactic penicillin to decrease the morbidity and mortality associated with pneumococcal infection (Gaston, Verter, Woods, et al., 1986).


• Zarkowsky, Gallagher, Gill, et al. (1986) conducted a retrospective analysis of 178 episodes of bacteremia in children with sickle hemoglobinopathies that occurred during 13,771 patient-years of follow-up (n = 3451). The predominant pathogen in patients younger than 6 years was S. pneumoniae (66%), and gram-negative organisms were responsible for 50% of the bacteremias in patients 6 years and older. The incidence of pneumococcal bacteremia in children with SCA younger than 3 years was 6.1 events per 100 patient-years. The results of this study supported prophylactic administration of penicillin for prevention of pneumococcal bacteremia in children younger than 3 years.


• A cohort study of 315 patients with HgbSS who lived in Jamaica was conducted between June 1973 and December 1981. The patients were divided into three groups to determine whether interventions such as penicillin prophylaxis, parental education in early diagnosis of acute splenic sequestration, and close monitoring in a sickle cell clinic improved survival. A significant decline in deaths from acute splenic sequestration and pneumococcal septicemia and meningitis was found. The research indicated that early detection of SCD and prophylactic measures could significantly reduce deaths associated with HgbSS (Lee, Thomas, Cupidore, et al., 1995).


• Riddington and Owusu-Ofori (2002) conducted a systematic review of randomized controlled trials evaluating the effectiveness of prophylactic antibiotic administration in preventing pneumococcal infection in children with SCD. The review of published research found that penicillin prophylaxis significantly reduced the risk for pneumococcal infection in children with HgbSS with minimal adverse reactions.



Apply the Evidence: Nursing Implications


There is good evidence with strong recommendations (Guyatt, Oxman, Vist, et al., 2008) that demonstrates that penicillin prophylaxis significantly reduces the risk for pneumococcal infection in children with SCA. The epidemiologic studies strongly suggest that all children with SCA should be started on prophylactic penicillin at 2 months of age. Parents and children with SCA should be instructed in the importance of taking the prophylactic penicillin twice daily and seeking medical attention immediately for acute illness, especially if the temperature exceeds 38.3° C (101° F), regardless of the use of prophylaxis.




References



Gaston, MH, Verter, JI, Woods, G, et al. Prophylaxis with oral penicillin in children with sickle cell anemia: a randomized trial. N Engl J Med. 1986; 314(25):1593–1599.


Guyatt, GH, Oxman, AD, Vist, GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008; 336(7650):924–926.


Hirst, C, Owusu-Ofori, S. Prophylactic antibiotics for preventing pneumococcal infection in children with sickle cell disease. Cochrane Database Syst Rev. (11):2010.


Hord, J, Byrd, R, Stowe, L, et al. Streptococcus pneumoniae sepsis and meningitis during the penicillin prophylaxis era in children with sickle cell disease. J Pediatr Hematol Oncol. 2002; 24(6):470–472.


John, AB, Ramlal, A, Jackson, H, et al. Prevention of pneumococcal infection in children with homozygous sickle cell disease. BMJ. 1984; 288(6430):1567–1570.


Lee, A, Thomas, P, Cupidore, L, et al. Improved survival in homozygous sickle cell disease: lessons from cohort study. BMJ. 1995; 311(7020):1600–1602.


Riddington, C, Owusu-Ofori, S. Prophylactic antibiotics for preventing pneumococcal infection in children with sickle cell disease. Cochrane Database Syst Rev. (3):2002.


Zarkowsky, HS, Gallagher, D, Gill, FM, et al. Bacteremia in sickle hemoglobinopathies. J Pediatr. 1986; 109(4):579–585.


*Adapted from the QSEN at www.qsen.org.


Oxygen therapy is of little therapeutic value unless the patient has hypoxia (Heeney and Dover, 2009). Severe hypoxia must be prevented because it causes massive systemic sickling that can be fatal. Oxygen administration is usually not effective in reversing sickling or reducing pain because the oxygen is unable to reach the enmeshed sickled erythrocytes in clogged vessels (Chiocca, 1996). In addition, prolonged administration of oxygen can depress bone marrow, further aggravating the anemia (Khoury and Grimsley, 1995).


Another important component of care is the use of blood transfusions. Exchange RBC transfusion (erythrocytapheresis) is the replacement of sickle cells with normal RBCs. Exchange transfusion is a successful, rapid method of reducing the number of circulating sickle cells and therefore slowing down the vicious circle of hypoxia, thrombosis, tissue ischemia, and injury. The procedure is advocated as a possible technique in preventing reoccurrence of ACS and CVA (Velasquez, Mariscalco, Goldstein, et al., 2009). A transcranial Doppler (TCD) test identifies the child with SCD who is at high risk for developing a CVA by monitoring the intracranial vascular flow (Driscoll, 2007; Kwiatkowski, Yim, Miller, et al., 2011). The TCD test is performed yearly for children from 2 to 16 years of age. The recommended treatment for children with confirmed abnormal TCD is chronic transfusion therapy (Armstrong-Wells, Grimes, Sidney, et al., 2009; Driscoll, 2007; Kwiatkowski, Yim, Miller, et al., 2011). Multiple transfusions carry the risk for transmission of viral infection, hyperviscosity, transfusion reactions, alloimmunization, and hemosiderosis (Driscoll, 2007; Heeney and Dover, 2009). After a CVA, blood transfusions are usually given every 3 to 4 weeks to help prevent a repeat stroke. To reduce iron overload from chronic transfusion therapy, chelation therapy may be started (see p. 1311).


In children with recurrent life-threatening splenic sequestration, splenectomy may be a lifesaving measure. However, the spleen usually atrophies on its own through progressive fibrotic changes (functional asplenia) by 6 years of age in children with SCA. Prophylactic penicillin and pneumococcal vaccines have decreased the incidence of pneumococcal sepsis. Packed RBC transfusions are recommended for treatment of splenic sequestration and stroke and are used preoperatively accompanied with maintenance IV hydration for most surgical procedures in children with SCD.


The most common and debilitating symptom experienced by patients with SCD is VOC, which is accompanied by increasing heath care cost because of prolonged hospitalization associated with pulmonary and GI complications (Driscoll, 2007; Raphael, Mei, Mueller, et al., 2012). The chronic nature of this pain can greatly affect the child’s development. A multidisciplinary team (e.g., physician, psychologist, family, nurse, social worker) approach is best for vasoocclusive pain management that includes pharmacologic treatment, hydration, physical therapy, and complementary treatment (e.g., prayer, spiritual healing, massage, herbs, relaxation, acupuncture, and biofeedback) (Brandow, Weisman, and Panepinto, 2011; Redding-Lallinger and Knoll, 2006). When mild to moderate VOC is reported, nonsteroidal antiinflammatory medication (e.g., ibuprofen, ketorolac) or acetaminophen (Tylenol) is used initially. If these drugs are not effective alone, codeine can be added. The dosages of both drugs are titrated (adjusted) to a therapeutic level. Opioids such as immediate- and sustained-release morphine, oxycodone, hydromorphone (Dilaudid), and methadone are administered intravenously or orally for severe pain and are given around the clock. In conjunction with the opioid, IV ketorolac for a maximum of a 5-day course is commonly used to enhance the pain management effect. Patient-controlled analgesia (PCA) has been used successfully for sickle cell–related pain. PCA reinforces the patient’s role and responsibility in managing the pain and provides flexibility in dealing with pain, which may vary in severity over time (see Pain Management, Chapter 30).



image Medication Alert


Meperidine (Demerol) is not recommended. Normeperidine, a metabolite of meperidine, is a central nervous system (CNS) stimulant that produces anxiety, tremors, myoclonus, and generalized seizures when it accumulates with repetitive dosing. Patients with SCD are particularly at risk for normeperidine-induced seizures (Howard and Davies, 2007; National Institutes of Health, 2002).



Prognosis.

The prognosis varies, but most patients live into the fifth decade. Most of the time, children are without symptoms and participate in normal activities without restrictions. The greatest risk is usually in children younger than 5 years, and the majority of deaths in these children are caused by overwhelming infection. Consequently, SCA is a chronic illness with a potentially terminal outcome. Physical and sexual maturation are delayed in adolescents with SCA. Although adults achieve normal height, weight, and sexual function, the delay may present problems to adolescents (Heeney and Dover, 2009; Redding-Lallinger and Knoll, 2006).


Individuals with SCD who have higher levels of HbF tend to have a milder disease with fewer complications than those with lower levels (Anderson, 2006; Driscoll, 2007). Hydroxyurea is a U.S. Food and Drug Administration–approved medication that increases the production of HbF, reduces endothelial adhesion of sickle cells, improves the sickle cell hydration, increases nitric oxide production (a vasodilator), and lowers leukocyte and reticulocyte counts (McGann and Ware, 2011; National Institutes of Health, 2002). Long-term follow-up of patients taking hydroxyurea alone revealed a 40% reduction in mortality and decreased frequency of VOC, ACS, hospital admissions, and need for transfusions, thus making SCD crises milder (Anderson, 2006; Strouse, Lanzkron, Beach, et al., 2008). Pediatric studies have shown that hydroxyurea can be safely used in children (Wang, Ware, Miller, et al., 2011; Zimmerman, Schultz, Davis, et al., 2004).


Hematopoietic stem cell transplantation (HSCT) offers a curative approach for some children with SCD with event-free survival of 95% (Driscoll, 2007; Haining, Duncan, and Lehmann, 2009) (see p. 1389).



Care Management





Educate the Family and Child.

Family education begins with an explanation of the disease and its consequences. After this explanation, the most important issues to teach the family are to (1) seek early intervention for problems, such as fever of 38.5° C (101.3° F) or greater; (2) give penicillin as ordered; (3) recognize signs and symptoms of splenic sequestration, as well as respiratory problems that can lead to hypoxia; and (4) treat the child normally. The nurse tells the family that the child is normal but can get sick in ways that other children cannot.


The nurse emphasizes the importance of adequate hydration to prevent sickling and to delay the adhesion-stasis-thrombosis-ischemia cycle. It is not sufficient to advise parents to “force fluids” or “encourage drinking.” They need specific instructions on how many glasses or bottles of fluid are required daily. Many foods are also a source of fluid, particularly soups, flavored ice pops, ice cream, sherbet, gelatin, and puddings.


Increased fluids combined with impaired kidney function result in the problem of enuresis. Parents who are unaware of this fact frequently use the usual measures to discourage bedwetting, such as limiting fluids at night, and may resort to punishment and shame to force bladder control. To alleviate parental pressure on the child, enuresis should be considered a complication of the disease just as joint pain or some other symptom is regarded.



Promote Supportive Therapies During Crises.

The success of many of the medical therapies relies heavily on nursing implementation. Management of pain is an especially difficult problem and often involves experimenting with various analgesics, including opioids, and schedules before relief is achieved. Unfortunately, these children tend to be undermedicated, resulting in their “clock watching” and demands for additional doses sooner than might be expected. Often this incorrectly raises suspicions of drug addiction, when in fact the problem is one of improper dosage (see Family-Centered Care box). In choosing and scheduling analgesics, the goal should be prevention of pain.



image Family-Centered Care


Fear of Addiction


Although the pain during a sickle cell crisis is usually severe and opioids are needed, many families fear that their child will become addicted to the narcotic. Unfortunately, misinformed health care professionals may foster this unfounded fear, which results in needless suffering. Extremely few children who receive opioids for severe pain become behaviorally addicted to the drug (American Pain Society, 1999; Howard and Davies, 2007; National Institutes of Health, 2002). Families and older children, especially adolescents, need to be reassured that opioids are medically indicated, high doses may be needed, and children rarely become addicted.



image Nursing Alert


Advise parents to be particularly alert to situations in which dehydration may be a possibility, such as hot weather, and to recognize early signs of reduced intake, such as decreased urinary output (e.g., fewer wet diapers) and increased thirst.


Any pain program should be combined with psychologic support to help the child deal with the depression, anxiety, and fear that may accompany the disease. This includes regular visits with the child to discuss any concerns during the hospitalization and positive reinforcement of coping skills, such as successful methods of dealing with the pain and compliance with treatment prescriptions. To reduce the negative connotation associated with the term crisis, it is best to say pain episode.


If blood transfusions or exchange transfusions are given, the nurse has the responsibility of observing for signs of transfusion reaction. Because hypervolemia from too-rapid transfusion can increase the workload of the heart, the nurse also is alert to signs of cardiac failure.


In splenic sequestration, the size of the spleen is gently measured by abdominal palpation (see Abdomen, Chapter 29). The nurse should be aware of spleen size because increasing splenomegaly is an ominous sign. A decreasing spleen size denotes response to therapy. Vital signs and blood pressure are also closely monitored for impending shock. Anemia is typically not a presenting complication in vasoocclusive crises but is a critical problem in other types of crises. The nurse monitors for evidence of increasing anemia and institutes appropriate nursing interventions. Oxygen is not beneficial in vasoocclusive episodes unless hypoxemia is present (Heeney and Dover, 2009). It does not reverse sickled RBCs, and if used in a nonhypoxic patient, it will decrease erythropoiesis (Vichinsky and Styles, 1996). Because prolonged use of oxygen can aggravate the anemia, signs of lack of therapeutic benefit, such as restlessness, increased pallor, and continued pain, are reported.


Record intake, especially of IV fluids, and output. The child’s weight should be taken on admission to serve as a baseline for evaluating hydration. Because diuresis can result in electrolyte loss, the nurse also observes for signs of hypokalemia and should be familiar with normal serum electrolyte values to report changes.




Support the Family.

Families need the opportunity to discuss their feelings regarding transmitting a potentially fatal, chronic illness to their child. Because of the widely publicized prognosis for children with SCA, many parents express their prevalent fear of the child’s death. Three manifestations of SCD that may appear in the first 2 years of life (dactylitis, severe anemia, leukocytosis) can be predictors of disease severity (DeBaun and Vichinsky, 2007; Ohls and Christensen, 2007). The nurse should care for the family as for any family with a child who has a chronic and life-threatening illness and consider the siblings’ reactions, the stress on the marital relationship, and the childrearing attitudes displayed toward the child. Several resources are available to families with a sickling disorder.*


The nurse advises parents to inform all treating personnel of the child’s condition. The use of medical identification, such as a bracelet, is another way of ensuring awareness of the disease.


If family members have the SCD trait or SCA, genetic counseling is necessary. A primary consideration in genetic counseling is informing parents of the 25% chance with each pregnancy of having a child with the disease when both parents carry the trait.




β-Thalassemia (Cooley Anemia)


Worldwide, thalassemia is a common genetic disorder, affecting as many as 15 million people (Yaish, 2010). The term thalassemia, which is derived from the Greek word thalassa, meaning “sea,” is applied to a variety of inherited blood disorders characterized by deficiencies in the rate of production of specific globin chains in Hgb. The name appropriately refers to descendants of or people living near the Mediterranean Sea, who have the highest incidence of the disease, namely Italians, Greeks, and Syrians. Evidence suggests that the high incidence of the disorders among these groups is a result of the selective advantage the trait confers in relation to malaria, as is postulated in SCD. However, the disorder has a wide geographic distribution, probably as a result of genetic migration through intermarriage or possibly as a result of spontaneous mutation.


β-Thalassemia is the most common of the thalassemias and occurs in four forms:





Diagnostic Evaluation


The onset of thalassemia major may be insidious and not recognized until the latter half of infancy. The clinical effects of thalassemia major are primarily attributable to (1) defective synthesis of HbA, (2) structurally impaired RBCs, and (3) shortened life span of erythrocytes (Box 43-3).



Box 43-3   Clinical Manifestations of β-Thalassemia








Related posts:

  1. 21st Century Pediatric Nursing
  2. Family-Centered Care of the Child During Illness and Hospitalization
  3. The High Risk Newborn
  4. Newborn Nutrition and Feeding

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Sep 16, 2016 | Posted by in NURSING | Comments Off on Hematologic and Immunologic Dysfunction

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