22: Care of the Extremely Low Birth Weight (ELBW) Infant

CHAPTER 22


Care of the Extremely Low Birth Weight (ELBW) Infant


Jan Sherman



OVERVIEW


Care of premature infants with birth weights between 1000 and 1500 g has become almost routine in most neonatal intensive care units (NICUs) in the United States. The most recent challenge in neonatology is the care of ELBW infants (birth weight < 1000 g). Although they represent a small percentage of overall births and NICU admissions, ELBW infants are often the most critically ill and at the highest risk for mortality and long-term morbidity of any NICU patient. They remain hospitalized for long periods of time, suffer the most acute and long-term complications of neonatal intensive care, and consume a disproportionate number of hospital days. The purpose of this chapter is to provide an overview of topics related to care of the ELBW infant. Detailed information on resuscitation, thermoregulation, ventilation, and fluids and electrolytes can be found in those specific chapters.


EPIDEMIOLOGY (CENTERS FOR DISEASE CONTROL AND PREVENTION [CDC], 2013; MARCH OF DIMES, 2013)


A. The premature birth rate has risen by 36% over the last 25 years and affects nearly 500,000 babies per year (1 of every 9 infants) born in the United States (Centers for Disease Control and Prevention [CDC]).


B. Pretermrelated causes of death together accounted for 35% of all infant deaths in 2008, more than any other single cause. Preterm birth is also a leading cause of long-term neurologic disabilities in children.


C. Preterm birth costs the U.S. health care system more than $26 billion each year (CDC, 2013). Women who are at increased risk of having a premature baby include African American women, women younger than 17, and women older than 35, as well as women who have a low income.


D. Births at the threshold of viability, early preterm birth, or birth of an ELBW infantespecially those weighing less than 750 g or less than 26 weeks of gestation, pose a variety of complex medical, social, and ethical considerations.


E. The effect of such births on the infants, their families, the health care system, and society are profound. Although the prevalence of such births is less than 1%, they account for nearly one half of all cases of perinatal mortality (American Academy of Pediatrics [AAP] and American College of Obstetricians and Gynecologists [ACOG], 2012).


MORTALITY AND MORBIDITY (AAP AND ACOG, 2012)


A. Mortality and survival with major neonatal morbidity for infants 501 to 1500 g decreased between 2000 and 2009. Infants weighing 501 to 750 g had the greatest decrease in mortality but the least change in survival with major morbidity.


B. In 2009, nearly half of all infants 501 to 1500 g and 89% of those weighing 501 to 750 g either died or survived after experiencing ≥ 1 major morbidity during their initial hospital stay, highlighting the continuing challenges facing these vulnerable patients, their families, and the health professionals who care for them.


C. There has been a dramatic increase in the number of multiple births in the United States over the past two decades, largely due to artificial reproductive technology and fertilityinducing drugs.


D. Perinatal risks that may be associated with assisted reproductive therapy include highorder multiple pregnancy, prematurity, low birth weight, small for gestational age, perinatal mortality, cesarean delivery, placenta previa, placental abruption, preeclampsia, and birth defects.


E. Recent studies have shown that triplet or higherorder births are associated with an increased risk of death or neurodevelopmental impairment at 18 to 22 monthscorrected age when compared with ELBW singleton infants (Wadhawan et al., 2011).


Table 22-1 details the rates for mortality and morbidity for 2000 and 2009 (Horbar et al., 2012).



PERINATAL MANAGEMENT (AAP AND ACOG, 2012)


A. Neonates born to women transported during the antepartum period have better survival rates and decreased risks of longterm sequelae than those transferred after birth.


B. Because ELBW and/or very preterm infants are at increased risk of predischarge mortality, they should be delivered at a level III facility unless this is precluded by the mothers medical condition or geographic constraints (Committee on Fetus and Newborn, 2012).


C. Antepartum transport avoids separation of mother and infant in the immediate postpartum period, allows mothers to communicate directly with NICU health care providers, and supports the goal of familycentered health care.


PERINATAL CONSULTATION (AAP AND ACOG, 2012)


A. In general, parents of extremely preterm fetuses can be counseled that infants delivered before 24 weeks of gestation are less likely to survive and those who do are not likely to survive intact.


B. Whenever possible, data specific to the age, weight, and gender of the fetus should be used to aid management decisions made by obstetricians and parents of fetuses at risk of preterm delivery before 26 completed weeks of gestation. This information may be developed by each institution and should indicate the population used in determining estimates of survivability.


C. The Eunice Kennedy Shriver National Institute for Child Health and Development (NICHD) Neonatal Research Networks Extremely Preterm Birth Outcome Data website provides a calculator to estimate infant outcomes based on birth weight, gestational age, gender, and antenatal corticosteroid administration. The calculator is available at www.nichd.nih.gov/about/org/der/branches/ppb/programs/epbo/pages/epbo_case.aspx.


D. If the physicians involved believe that there is no chance of survival, resuscitation is not indicated and should not be initiated. If the physicians consider a good outcome to be very unlikely, then parents should be given the choice of whether resuscitation should be initiated and physicians should respect their preference.


E. When the physiciansjudgment is that a good outcome is reasonably likely, physicians should initiate resuscitation and, together with the parents, continually evaluate whether intensive care should be continued.


ANTENATAL STEROIDS


Enhancement of fetal pulmonary function with the use of antenatal steroids lessens the prevalence and severity of neonatal respiratory distress syndrome. Current recommendations in the Guidelines for Perinatal Care (AAP and ACOG, 2012) include:


A. A single course of corticosteroids (betamethasone or dexamethasone) is recommended for pregnant women between 24 weeks and 34 weeks of gestation who are at risk of preterm delivery within 7 days.


B. A single course of antenatal corticosteroids should be administered to women with premature rupture of membranes (PROM) before 32 weeks of gestation to reduce the risks of respiratory distress syndrome, perinatal mortality, and other morbidities.


C. The efficacy of corticosteroid use at 32 to 33 completed weeks of gestation for preterm PROM is unclear, but treatment may be beneficial, particularly if pulmonary immaturity is documented. Sparse data exist on the efficacy of corticosteroid use before fetal age of viability, and such use is not recommended.


D. A single rescue course of antenatal corticosteroids may be considered if the antecedent treatment was given more than 2 weeks prior, the gestational age is less than 326/7 weeks, and the woman is judged by the physician to be likely to give birth within the next week. However, regularly scheduled repeat courses or multiple courses (more than two) are not recommended.


TIMING OF UMBILICAL CORD CLAMPING AFTER BIRTH (AAP, 2013)


A. Evidence supports delayed umbilical cord clamping in preterm infants. As with term infants, delaying umbilical cord clamping to 30 to 60 seconds after birth with the infant at a level below the placenta is associated with neonatal benefits, including improved transitional circulation, better establishment of red blood cell volume, and decreased need for blood transfusion.


B. The single most important clinical benefit for preterm infants is the possibility for a nearly 50% reduction of intraventricular hemorrhage (IVH). It is important to note that the timing of umbilical cord clamping should not be altered for the purpose of collecting umbilical cord blood for banking.


DELIVERY ROOM CARE SPECIFIC TO ELBW INFANTS


A. Careful adherence to details in the delivery room and during the first few hours after birth is essential to help avoid immediate and longterm complications of the ELBW infant. NICUs should have a consistent approach to the initial care of the ELBW infant in the delivery room and upon admission to the NICU (Table 22-2).



TABLE 22-2


Treatment Guidelines for Initial Management of Extremely Low Birth Weight Infants







































Delivery Room and NICU Admission
Delivery room Immediately place into polyethylene wrap or food-grade plastic bag up to the neck
Ensure good thermoregulation
“Gentle” ventilation as required
Avoid hyperventilation and hyperoxia
Administer surfactant (if prophylaxis approach)
Initiate NCPAP (if early CPAP approach)
NICU admission Obtain weight measurement
Administer surfactant within first hour (if rescue approach)
Establish vascular access:
 Peripheral intravenous catheter
 Umbilical arterial catheter
 Umbilical venous catheter (central, double-lumen)
Start intravenous fluids as soon as possible with dextrose and amino acid solution
Limit evaporative water losses (humidified incubator)
Minimize stimulation
Avoid hyperventilation and hyperoxia
Maintain target oxygen saturations
Obtain specimens for complete blood count with differential, blood culture, blood glucose measurement
Give antibiotics as indicated
Give parents information about their child
First 24 to 48 Hours
Cardiovascular Monitor blood pressure, give vasopressors as required
Maintain vigilance for presence of patent ductus arteriosus
Obtain echocardiogram as indicated
Respiratory Give additional surfactant doses as indicated
Maintain low tidal volume ventilation
Avoid hyperventilation and hyperoxia
Extubate infant and start on CPAP when possible
Fluid management Obtain weight every 12 to 24 hours
Monitor serum electrolyte, blood glucose, and calcium concentrations every 4 to 12 hours
Use of humidity
Limit evaporative water losses
Administer skin care
Hematologic Obtain second blood count
Administer transfusion support as indicated
Monitor bilirubin, begin phototherapy as indicated
Infection Consider discontinuing antibiotics if blood culture results are negative at 48 hours
Nutrition Start parenteral nutrition
Discuss trophic feedings
Neurologic Minimize stimulation
Perform screening head ultrasonography
Social Provide daily updates to the family
Arrange to meet with family


t0015


From Eichenwald, E.C.: Care of the extremely low-birthweight infant. In C.A. Gleason and S.U. Devaskar (Eds.): Averys diseases of the newborn (9th ed.). Philadelphia, 2012, Elsevier Saunders, pp. 390-404.


CPAP, continuous positive airway pressure; NCPAP, nasal continuous positive airway pressure; NICU, neonatal intensive care unit.


B. All neonatal resuscitations and delivery room management should follow the guidelines found in the Textbook of Neonatal Resuscitation, 6th edition (American Academy of Pediatrics and American Heart Association 2011). Also please see Chapter 5.


THERMOREGULATION (SEE CHAPTER 6) (AAP AND ACOG, 2012)


A. Very low birth weight (< 1500g) preterm babies are likely to become hypothermic despite the use of traditional techniques for decreasing heat loss. Because infants younger than 28 weeks of gestation may become hypothermic while being dried, they should be immediately covered up to their necks in polyethylene wrap or a food-grade plastic bag and placed under a radiant warmer.


B. The infants temperature must be monitored closely because overheating has been described when plastic wrap is used in combination with an exothermic mattress. The goal should be an axillary temperature of approximately 36.5° C (97.7° F).


VENTILATORY PRACTICES IN THE DELIVERY ROOM (AAP AND ACOG, 2012)


A. Administration of supplemental oxygen in the delivery room.


1. Current practice recommends supplemental oxygen administration be based on objective monitoring of oxygenation. It is recommended that pulse oximetry be used when resuscitation can be anticipated, supplemental oxygen is administered, positive pressure is administered for more than a few breaths, or cyanosis appears to persist.


2. Because many babies born at less than 32 weeks of gestation will not reach target saturations when resuscitated with air, blended oxygen may be used. If blended oxygen is not available, resuscitation should be initiated with air.


3. The use of room air for resuscitation of these infants has been proposed to protect from hyperoxia and damage to the lungs by oxygen free radicals. Many NICUs have developed their own policies regarding starting values of blended oxygen in the delivery room (Eichenwald, 2012).


B. Assisted ventilation in the delivery room.


1. If positive pressure ventilation is required, it should be provided with low inspiratory pressure to prevent overdistention of the lungs, which can result in air leak and other lung injury. Adequate positive end-expiratory pressure (PEEP) will help to maintain lung volume (Eichenwald, 2012).


C. Surfactant administration in the delivery room.


1. There continues to be uncertainty as to whether to give surfactant in the first few minutes of life to an ELBW newborn, apply nasal continuous positive airway pressure (NCPAP) without surfactant, or intubate giving surfactant and then extubate to CPAP. The potential benefits and risks of these strategies are still under study (Goldsmith and Karotkin, 2011).


2. No matter the timing of the surfactant administration, it is only given after endotracheal tube position is confirmed (AAP and ACOG, 2012).


3. Novel methods of surfactant administration are currently being studied. Klebermass-Schrehof et al. (2013) have described a new mode of surfactant administration without intubation, known as less invasive surfactant administration. CPAP is administered by a nasopharyngeal tube after delivery. At 20 to 30 minutes after birth, a thin catheter (1.3 mm diameter) is inserted into the trachea. Surfactant is then administered over 2 to 5 minutes via this catheter while the infant is breathing spontaneously. About 65% of the extremely premature infants (23 to 25 weeks postmenstrual age) could be managed without mechanical ventilation (MV) during the first week of life, and 41% without any MV during the entire hospital stay. The authors found significantly higher survival rates (especially for the most immature infants), and less IVH, cystic periventricular leukomalacia (PVL), need for supplementary oxygen at day 28, and duration of MV compared to historical controls.


ADMISSION TO THE NEONATAL INTENSIVE CARE UNIT


A. General care.


1. All infants should be weighed upon admission; frequent determination of subsequent weights is a valuable tool in managing fluid and electrolyte balance. In many centers, ELBW infants are initially placed under a radiant warmer for easier access (i.e., for surfactant administration and catheter placement).


2. Because of the high transepidermal fluid losses in these infants, intravenous (IV) fluids containing 5% to 10% dextrose should be started as quickly as possible after admission and efforts should be made to reduce evaporative water losses by increasing the relative humidity surrounding the infant.


B. Ambient humidity.


1. High humidity decreases transepidermal water loss (TEWL) and heat loss. Humidity also decreases fluid requirements and electrolyte imbalances.


2. 70% or higher humidity in the first week of life is needed to affect a difference in TEWL.


C. Oxygen saturation range.


1. The optimal range for oxygen saturation continues to be controversial.


2. The SUPPORT trial found that the risk of death during the initial hospitalization was increased among neonates randomly assigned to the lower-oxygen-saturation (85% to 89%) group as compared with those assigned to the higher-oxygen-saturation (91% to 95%) group. The authors state that lower oxygen saturation targets cannot be recommended in these extremely preterm infants (Vaucher et al., 2012).


3. In general, oxygen is given for saturations less than 85% and weaned for saturations greater than 95%.


VASCULAR ACCESS (SEE CHAPTER 15)


A. Umbilical arterial catheter (UAC).


1. Close monitoring of blood pressure, arterial blood gases, and serum chemistries during the first few days after birth is necessary for high risk ELBW infants. Insertion of a UAC allows for reliable arterial access in critically ill infants. For infants greater than 1200 g, a 5 F catheter should be used. Infants less than 1200 g require a 3.5 F catheter (MacDonald and Ramasethu, 2007).


B. Umbilical venous catheter (UVC).


1. Placement of a UVC at the same time the UAC is placed also provides the clinician with reliable venous access for infusion of fluids, medications, and blood products. Use of a double-lumen UVC helps to preserve IV sites and skin integrity.


C. Percutaneous central venous catheter.


1. Before the UVC is removed, it is advisable to insert a PICC for infusion of parenteral nutrition and medications. PICC line sizes include 1.2 F, 1.9 F (single or double lumen), 2 F, and 3 F. The size PICC to be inserted should be determined by the size of the vein being used for cannulation.


SKIN CARE (SEE CHAPTER 36)


A. Gestational age is strongly linked to epidermal barrier function. Poor epidermal barrier function in the extremely preterm infant leads to disturbances in temperature regulation and water balance. The skin barrier of premature infants is injured easily and can serve as a portal of entry for agents, causing serious bacterial infections (Telofski et al., 2012).


B. Because of these risks, preservation of skin integrity should be incorporated into the care of the extremely preterm infant. Objective tools such as the Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN) Neonatal Skin Condition Score Tool can facilitate assessment of neonatal skin conditions (Lund et al., 2013).


C. Limited use of adhesives and extreme care upon their removal, frequent repositioning of the infant to avoid pressure points on the skin, and use of soft bedding or a water mattress are the minimum requirements (Eichenwald, 2012).


D. Assessment of the overall skin condition involves evaluating all skin surfaces, headtotoe, daily or more frequently. Risk factors for skin injury include less than 32 weeks of gestation, edema, and adhesives applied to the skin to secure tubes, lines, and monitoring equipment.


E. Turning the infant a minimum of every 4 hours is necessary, along with careful inspection of skin surfaces. Even when turning side-to-side is not feasible, lifting the head, shoulders, and hips and supporting these areas with pressure-reducing surfaces is helpful (Harris et al., 2003; Lund, 2011; Telofski et al., 2012).


ASSISTED VENTILATION (SEE CHAPTER 26)


A. Noninvasive respiratory support (NRS).


1. NRS is becoming increasingly popular as a method of respiratory support in sick newborn infants. This support consists primarily of CPAP and noninvasive positive-pressure ventilation (NIPPV).


2. A variety of CDP devices available today allow breaths to be delivered above the baseline CPAP pressure and to be synchronized or nonsynchronized to the infant’s own breaths. The goal of such devices is to enhance CO2 removal and stimulate breathing. Various CDP devices provide an adjunct to weaning infants off MV after they have been extubated and also help manage apnea of prematurity (Wiswell and Courtney, 2011).


3. Marked bowel distention (“CPAP belly”) is frequently seen. The air from the CPAP easily passes into the esophagus and is swallowed. Increased abdominal girth and visibly dilated intestinal loops may be seen. An increased risk of gastric perforation has been reported. An orogastric tube should always be placed whenever CPAP is used (Wiswell and Courtney, 2011).


B. Mechanical ventilation.


1. MV is indicated when the ELBW infant is not exchanging gases sufficiently, or is acidotic, apneic, or bradycardic. In the first few days of life, surfactant administration is commonly needed.


2. A variety of devices are now available for use: synchronized intermittent mandatory ventilation (SIMV), assist–control ventilation, volume-controlled ventilation, high-frequency jet ventilation (HFJV), and high-frequency oscillatory ventilation (HFOV).


C. Methylxanthines.


1. Caffeine has been found to decrease the frequency of apnea of prematurity as well as decrease the need for MV.


2. The Caffeine for Apnea of Prematurity Trial Group (Schmidt et al., 2007) reported on the short- and long-term effects of caffeine at 18 to 21 months in infants with very low birth weight. The study found a decreased rate of BPD, decreased death, less cerebral palsy, and decreased incidence of severe ROP in the treatment group.


NUTRITIONAL MANAGEMENT (SEE CHAPTERS 8 AND 10) (DELL, 2011)


A. ELBW infants are born with limited nutrient reserves, immature pathways for nutrient absorption and metabolism, and higher nutrient demands. Medical conditions associated with extreme prematurity may complicate the adequate delivery of nutrients.


B. All infants have a physiologic weight loss that is a reduction in extracellular water. In very premature infants, the loss of extracellular fluid can be 15%.


C. Fluid requirements.


1. Initial fluid therapy should be aimed at allowing a normal physiologic weight loss while preventing dehydration and electrolyte imbalances.


2. Maintenance fluids required during the first week of life are displayed in Table 22-3. Fluids should be adjusted based upon the infant’s clinical condition and any factors that may alter the fluid requirements.


Oct 29, 2016 | Posted by in NURSING | Comments Off on 22: Care of the Extremely Low Birth Weight (ELBW) Infant
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