Hyperbilirubinemia

in the Newborn

Developed by - Lisa Fikac, MSN, RNC-NIC

Expiration Date - 10/1/17

This continuing education activity is provided by Cape Fear Valley Health System, Training and Development Department, which is an approved provider of Continuing Nursing Education by the North Carolina Nurses Association, an accredited approver by the American Nurses Credentialing Center’s Commission on Accreditation.

1.1 Contact hours will be awarded upon completion of the following criteria:

• Completion of the entire activity • Submission of a completed evaluation form • Completion a post-test with a grade of at least 85%.

The planning committee members and content experts have declared no financial relationships which would influence the planning of this activity.

Microsoft Office Clip Art and Creative Memories are the sources for all graphics unless otherwise noted.

The author would like to thank Stacey Cashwell for her work as original author.

• Discuss the etiology and risk factors for hyperbilirubinemia. • Discuss the clinical presentation, clinical management and outcomes for

hyperbilirubinemia.

Humans produce bilirubin throughout their lifetimes, but during the neonatal period, infants produce greater amounts of bilirubin than any other age group.

• Bilirubin levels of the newborn may be 2-3 times the levels of an adult.

• Neonatal bilirubin production is elevated during the first 24-48 hours of life.

The newborn produces up to 10 mg/kg/day of bilirubin.

• 1 gm of hemoglobin ~ 35 mg of bilirubin. • The majority of bilirubin in the newborn is created from the destruction of

hemoglobin from red blood cells (RBCs).

RBCs have a life span of approximately 120 days in the normal adult.

In newborns, the life span is approximately 70-90 days.

Bilirubin is created from the normal breakdown of circulating erythrocytes and the high turnover of cytochromes.

• The destruction of erythrocytes into heme accounts for about 80-90% of bilirubin production.

• The breakdown of other heme-containing products such as cytochromes and catalase accounts for the remaining 10-20%.

Bilirubin values are expressed as milligrams (mg) per 100 milliliters (mL) of blood.

• e.g. 5 mg/100 mL or 5 mg/dL (deciliter) • It may also be abbreviated as a percent (5 mg%)

Bilirubin metabolism starts in the reticuloendothelial system.

• This is primarily in the liver and spleen. • Old or abnormal RBCs are removed from circulation.

Bilirubin is formed in two steps.

1. The enzyme heme oxygenase (HO), located in the spleen and liver as well as in all nucleated cells, initiates the breakdown of heme.

• This leads to the formation of carbon monoxide (CO) and biliverdin. 2. Biliverdin is then converted to bilirubin by the enzyme biliverdin reductase.

At this point, bilirubin is in its unconjugated form and binds tightly to albumin.

• In the sick or preterm infant, this rate of binding may be much lower.

The bilirubin that is bound with albumin is transported to the liver where a series of chemical reactions change bilirubin from a fat-soluble to a water-soluble product.

Once in a water-soluble form, bilirubin is excreted into the bile system for transport to and excretion from the gastrointestinal (GI) tract and kidneys.

Jaundice, or hyperbilirubinemia, occurs in most newborns.

Bilirubin levels rise after birth because of -

• Excessive bilirubin production AND • An immature liver that cannot properly clear the blood of bilirubin

During the first 24-48 hours of life, bilirubin production is higher due to a higher hematocrit and a more rapid turnover of RBCs.

• Bilirubin conjugation is slower in newborns during the first few hours of life but increases by 24 hours of age.

• Bilirubin conjugation reaches adult levels by 4 days of age in the term infant. • About 50% of term infants will have visible jaundice with an increased total serum

bilirubin (TSB) within the first 3-4 days of life. o This subsides by the 6th day of life.

• Bilirubin elimination is more delayed in the preterm infant.

In the past, the jaundice that occurs in most newborns was referred to as physiologic jaundice since it is due to the normal impairment of neonatal bilirubin clearance.

• Due to the difficulties in defining a specific range of hyperbilirubinemia that constitutes physiologic jaundice, this term is considered no longer applicable.

There are several factors that affect the ability of bilirubin to bind to albumin, leading to hyperbilirubinemia. Those factors include -

• Acidosis decreases binding by decreasing affinity at the binding site and increasing tissue affinity.

• Competitive inhibition of binding at the primary site by - o Hematin

o Free fatty acids o Stabilizers for albumin preparations o X-ray contrast media

• Infection - this mechanism is not fully understood. • Competitive binding at secondary sites caused by certain drugs -

o Sulfa compounds o Sodium salicylate o Phenylbutazone o Ceftriaxone

There are several causes of hyperbilirubinemia in newborns -

• Overproduction of bilirubin • Slow excretion of bilirubin • Combined overproduction and slow excretion of bilirubin • Jaundice associated with breast feeding • Miscellaneous causes

In order to determine the potential cause of severe hyperbilirubinemia, it may be described according to the time of onset.

• Early-onset severe hyperbilirubinemia is usually associated with increased bilirubin production.

• Late-onset severe hyperbilirubinemia is usually associated with delayed bilirubin elimination.

There are several potential reasons why there may be overproduction of bilirubin that leads to hyperbilirubinemia.

Reasons for overproduction of bilirubin include -

• Hemolytic disease of the newborn • Hereditary hemolytic anemias • Polycythemia • Extravascular blood • Increased enterohepatic circulation

HEMOLYTIC DISEASE OF THE NEWBORN

Blood group incompatibilities between a mother and fetus can cause hemolytic diseases of the newborn. Incompatibilities include -

• Rh • ABO • Minor blood groups

The classic example of hemolytic disease of the newborn is Rh compatibility.

• An Rh-negative mother is sensitized to the Rh antigen by one of the following - o Improperly matched blood transfusion o Fetal-maternal blood transfusion that occurs during -

Pregnancy Delivery Abortion Amniocentesis

• This induces maternal antibody production.

Sensitization with the Rh antigen is required for antibody production to occur. For this reason, the first Rh-positive infant usually is not affected.

After sensitization, maternal immunoglobulin G (IgG) crosses the placenta into the fetal circulation.

• IgG reacts with the Rh antigen on fetal erythrocytes. • The spleen recognizes these cells as abnormal and destroys them.

o This creates an increase in hemoglobin that needs to be broken down. o As the erythrocytes are broken down and bilirubin is created, the neonate's ability

to efficiently eliminate the excess bilirubin may be surpassed.

It is recommended that the Rh Negative mother--A, B, and O--have cord blood drawn at delivery and sent for -

• Rh and group • Coombs' test • Bilirubin

o Some facilities will wait for the results of the infant's Rh, grouping, and Coombs' test before drawing the bilirubin.

o If either or both come back positive, a bilirubin is drawn.

Rho(D) immune globulin (RhoGAM®) administration is advised for treatment of Rh sensitization.

• Rho(D) immune globulin has virtually eliminated Rh incompatibility as a complication of pregnancies in most developed countries of the world.

• While it is almost universally administered following delivery, it can be administered before delivery.

• Rho(D) immune globulin suppresses the mother's production of antibodies and protects future fetuses

Due to the widespread use of Rho(D) immune globulin, hemolytic disease of the newborn is now primarily due to ABO blood group incompatibility.

• ABO sensitization occurs when a mother who has type O blood has an infant with either type A or B.

• All people who have type O blood have naturally occurring anti-A and anti-B (IgG) antibodies.

• Hyperbilirubinemia that is due to ABO incompatibility is usually milder than that seen in Rh incompatibility.

HEREDITARY HEMOLYTIC ANEMIAS

Erythrocytes that have abnormal membranes or contain abnormal hemoglobin variants have increased rates of RBC destruction.

There are enzyme defects that make it difficult for RBCs to maintain integrity because of increased osmotic fragility and an increased rate of splenic destruction.

Glucose-6-phosphate dehydrogenase (G6PD) is the most common enzyme defect.

• It occurs most often in Chinese, Greeks, and black people.

Pyruvate kinase deficiency can also be a cause but is less common.

Those with hemoglobinopathies can be diagnosed by hemoglobin electrophoresis, but the cause for hemolysis is difficult to determine in infants.

• Family history is very important in diagnosing and strongly correlates in approximately 80% of cases.

POLYCYTHEMIA

Polycythemia is defined as a central venous hematocrit (Hct) greater than 65.

With polycythemia, there is an increase in RBC mass. When this is combined with the shortened lifespan of RBCs in newborns, the bilirubin load is increased.

The causes of polycythemia include -

• Maternal-fetal transfusion • Twin-to-twin transfusion • Chronic in utero hypoxia

• Delayed cord clamping

EXTRAVASCULAR BLOOD

Extravascular blood is caused when the neonate experiences any enclosed hemorrhage including -

• Cephalohematoma • Subgaleal hemorrhage • Cerebral hemorrhage • Abdominal bleeding • Occult internal bleeding • Extensive bruising

Swallowed maternal blood is another potential source of increased bilirubin load.

With the resolution of any hemorrhage, the trapped RBCs break down and add to bilirubin production.

INCREASED ENTEROHEPATIC CIRCULATION

Meconium contains a fair amount of bilirubin.

• There is approximately 1 mg of bilirubin per 1 gram of meconium. • This translates into a total load of 100-200 mg

Any delay in the passage of meconium increases the load of bilirubin to be metabolized. This can be caused by -

• Decreased motility of prematurity • Bowel obstruction

Hyperbilirubinemia that is evident within the first 24-48 hours of life is rarely due to this cause.

Bilirubinemia can also occur in the infant who has a normal level of bilirubin production, but may be unable to efficiently excrete that bilirubin.

Reasons for slow bilirubin excretion include -

• Decreased hepatic uptake of bilirubin • Decreased bilirubin conjugation • Inadequate transport out of the hepatocyte • Biliary obstruction

DECREASED HEPATIC UPTAKE OF BILIRUBIN

Decreased hepatic uptake of bilirubin can be due to -

• Inadequate perfusion of hepatic sinusoids • Deficient carrier proteins

o Proteins Y and Z • Competitive binding to proteins by -

o Steroid hormones o Free fatty acids o Chloramphenicol

Inadequate perfusion of hepatic sinusoids can be caused by -

• Shunting through the ductus venosus • Extrahepatic portal vein thrombosis • Hyperviscosity • Hypovolemia

DECREASED BILIRUBIN CONJUGATION

Decreased bilirubin conjugation can be due to a deficiency of UDP-glucoronosyltransferase 1 (UDPGT1). This type of deficiency occurs in -

• Crigler-Najjar syndrome • Gilbert syndrome

Crigler-Najjar syndrome is a rare disorder where the enzymatic activity that conjugates bilirubin is either partially or completely impaired.

• Type I involves complete absence of enzymatic activity. o Phototherapy is ineffective in aiding bilirubin conjugation, and liver transplant is

the only cure. • Type II involves partial impairment of enzymatic activity and responds to enzyme

induction with phenobarbital.

Gilbert syndrome is a milder disorder with partial impairment of enzymatic activity.

• This syndrome is more common and usually is diagnosed after the neonatal period. • Bilirubin becomes elevated during times of stress and recurrent illness. • This may be a factor in infants with late-onset severe hyperbilirubinemia.

INADEQUATE TRANSPORT OUT OF THE HEPATOCYTE

Dubin-Johnson and Rotor syndromes are inherited conditions where individuals can conjugate bilirubin normally but cannot excrete it.

• This leads to direct hyperbilirubinemia. • These conditions lead to liver damage and require diagnosis by liver biopsy.

BILIARY OBSTRUCTION

The cause of biliary obstruction can be difficult to determine in the neonate.

• Biliary obstruction can be caused by generalized liver damage or mechanical obstruction.

There are several potential causes of liver damage such as -

• Hepatitis • Galactosemia • Long term use of parenteral nutrition

Causes of mechanical obstruction include -

• Biliary atresia • Choledochal cyst

Bilirubinemia may also be due to a combination of overproduction and slow excretion. Sources for this include -

• Infection • Infant of a diabetic mother (IDM)

INFECTION

Some infections produce toxins that cause increased bilirubin production coupled with decreased hepatic clearance.

• Thrombocytopenia and rash are often present in infants who have these infections.

The types of infections that can cause this include -

• Bacterial infections o Necrotizing enterocolitis (NEC) o Certain strains of E. coli

• Intrauterine infections o Syphilis o TORCH

Toxoplasmosis Rubella Cytomegalovirus (CMV) Herpes simplex virus (HSV)

o Coxsackie B virus

INFANT OF A DIABETIC MOTHER (IDM)

Hyperbilirubinemia in the IDM may have many contributing factors. Potential factors include -

• Prematurity • Poor feeding • Increased bilirubin due to an increased RBC mass • Altered erythrocyte membrane • Macrosomic infants are often bruised during delivery

Breastfed infants who are discharged early and are not adequately followed may develop hyperbilirubinemia because of poor hydration.

• Follow-up with a lactation consultant within 48-72 hours post-discharge can help with feeding evaluation and assistance.

BREASTFEEDING JAUNDICE

Breastfeeding jaundice usually begins within 2-4 days of life and peaks between 3-6 days of life.

Breastfed infants tend to have higher bilirubin levels than bottle fed infants, particularly during the first few days of life. Factors that may contribute to this phenomenon include -

• Decreased caloric and fluid intake from colostrum • Dehydration • Increased enterohepatic circulation due to -

o Low stool output o Breastmilk β-glucuronidase

Breastfeeding jaundice occurs in approximately 10% of breastfed infants.

In the past, glucose water supplementation of breastfed infants after nursing was common practice. This type of supplementation should be avoided because -

• Breastfeeding frequency is reduced. • Maternal milk production is decreased because of fewer feedings. • Glucose water supplementation does not improve intestinal motility.

Breastfeeding infants should begin nursing early and frequently, with a goal of 8-12 feedings per day. This results in increased -

• Caloric intake • Weight gain • Meconium passage which facilitates the passage of bilirubin

in stool

If the baby is unable to feed this frequently, supplementation with expressed breastmilk or formula is preferred.

• This helps to improve maternal milk supply and increase the baby's intestinal motility.

BREASTMILK JAUNDICE

Approximately 1-2% of breastfed infants will have prolonged and exaggerated jaundice.

• This is thought to be related to increased intestinal absorption of bilirubin into the enterohepatic circulation.

• β-glucuronidase activity is higher in breast milk than formula and may play a role in breast milk jaundice.

• Bile salt-stimulated lipase, found in human milk, increases fat absorption, which is believed to be associated with an increased absorption of intestinal bilirubin.

• Breastfed infants have decreased amount of urobilinogen which may also play a role in breast milk jaundice.

• Breastfed infants excrete urobilin in their stools later than formula-fed infants.

Infants with breastmilk jaundice tend to develop hyperbilirubinemia (unconjugated bilirubin > 12 mg/dL) that becomes exaggerated and persists past the first week of life.

• Hyperbilirubinemia may persist for 4-14 days with a slow decline. • Breastfeeding usually does not need to be interrupted, even if the baby needs

phototherapy.

For the infant who has hyperbilirubinemia that is unexplained by overproduction, slow excretion, or breastmilk jaundice, there are other rare causes that can result in hyperbilirubinemia.

Hyperbilirubinemia may be the first sign of these conditions which include -

• Hypothyroidism • Galactosemia

Most states perform newborn screening for these conditions in order to prevent permanent neurological sequelae.

HYPOTHYROIDISM

Although the relationship of hypothyroidism to hyperbilirubinemia is not well understood, some studies suggest that thyroxine is needed for adequate hepatic clearance of bilirubin.

GALACTOSEMIA

Galactosemia is an autosomal recessive disorder of galactose metabolism.

• The enzyme needed to convert galactose to glucose is absent. Therefore, the infant cannot digest lactose.

• The partially metabolized galactose is extremely toxic to the brain, liver, and kidneys, and this leads to the accumulation of hepatotoxic by-products.

Risk factors for hyperbilirubinemia in the neonate include -

• Major risk factors o Pre-discharge total serum bilirubin (TSB) or transcutaneous bilirubin

(TcB) in the high-risk zone* This is based on the infant's postnatal age

*Nomogram for designation of risk in 2840 well newborns at 36 or more weeks of gestational age with birth weight of 2000 g (4.4 pounds) or more, or 35 or more weeks of gestational age and birth weight of 2500 g (5.5 pounds) or more, based on the hour-specific serum bilirubin values.

Nomogram in - Wilson, D. & Hockenberry, M.J. (2012). Wong's Clinical Manual of Pediatric Nursing, 8th Edition. St. Louis: Elsevier. Retrieved August 22, 2014. Used with permission under CFVHS licensure for use of Mosby’s Nursing Consult.

o Observable jaundice within the first 24 hours of life o Documented blood group incompatibility with a positive direct antiglobulin

test o Gestational age 35-36 weeks o Previous sibling who received phototherapy o Cephalohematoma or significant bruising o Exclusive breastfeeding, particularly if -

• Nursing is not going well AND • There is excessive weight loss

o East Asian ethnicity

• Minor risk factors o Pre-discharge TSB or TcB in the high-intermediate risk zone

• This is based on the infant's postnatal age* o Gestational age 37-38 weeks o Observable jaundice prior to discharge o Previous sibling with jaundice o Macrosomic infant of a diabetic mother o Maternal age > 25 years old o Male gender

The following infants have a decreased risk for significant jaundice -

• TSB or TcB in the low-risk zone o This is based on the infant's postnatal age*

• Gestational age > 41 weeks • Exclusive bottle feeding • Black race • Discharge from the hospital after 72 hours of age

Depending on the source of hyperbilirubinemia, there may be a wide variety of symptoms present in the jaundiced infant.

Visual Assessment of Jaundice

All newborns should be routinely assessed for jaundice. Jaundice is usually visible with bilirubin levels of 5-7 mg/dL and is first seen on the head and face and progresses cephalocaudally.

• Jaundice in the extremities is the last area affected.

Photo from - Clinical manifestations of unconjugated hyperbilirubinemia in term and late preterm infants. (2013). In UpToDate 2014. Retrieved August 22, 2014. Used with permission under CFVHS licensure for use of UpToDate.

Physical Assessment

The infant who has or is at risk for hyperbilirubinemia may have -

• Cephalohematoma • Petechiae or purpura - this is suspicious for infection • Congenital anomalies or syndromic appearance

o Jaundice is associated with the trisomies

In addition to jaundice, the infant with hemolytic disease of the newborn may show signs of pallor due to anemia.

• Hepatosplenomegaly may be present.

Laboratory Evaluation

Although jaundice may be evident visually, this type of assessment is very subjective, and the infant should be assessed by either total serum bilirubin (TSB) or transcutaneous bilirubin (TcB).

• The TSB is one of the most commonly performed lab tests performed on newborns.

TcB measurements estimate the TSB by measuring the yellow color of blanched skin and subcutaneous tissue.

• TcB values are plotted on the same nomogram as TSB values. • Several studies have shown close correlation of TcB to TSB within 2-3 mg/dL when the

TSB level is less than 15 mg/dL. o TcB values should be used with caution when approaching 15 mg/dL.

Signs of Bilirubin Toxicity

Hyperbilirubinemia is concerning because of the potential for brain injury.

Acute bilirubin encephalopathy (ABE) describes the effects of hyperbilirubinemia that occurs during the acute episode and immediately following its resolution.

Clinical signs of ABE include -

• Lethargy • Poor feeding • Poor tone • Poor Moro reflex with incomplete flexion of the extremities • High-pitched cry • Opisthonos posturing and retrocollis - later symptoms

As ABE worsens, symptoms include -

• Apnea • Seizures • Coma • Death

Kernicterus occurs with chronic bilirubin encephalopathy.

• It is irreversible and causes devastating brain injury. • There is yellow staining in the deep nuclei of the central nervous system.

Signs of kernicterus include -

• Extrapyramidal movements • Dystonia • Choreoathetoid movements • Auditory disturbances - deafness

o Auditory pathways are most sensitive to bilirubin injury. • Enamel dysplasia of the teeth • Mild cognitive defects

In 2004, the American Academy of Pediatrics (AAP), developed its Clinical Practice Guideline: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation.

The AAP guideline outlines four key areas of focus for reduction of the risk of severe hyperbilirubinemia. These recommendations include -

1. Promotion and support of breastfeeding. 2. Development of nursery protocols to identify hyperbilirubinemia. 3. Use of hyperbilirubinemia risk to determine post-discharge follow-up timeframe with

the infant's pediatrician. 4. Use of phototherapy and/or exchange transfusion to treat infants with

hyperbilirubinemia to prevent severe hyperbilirubinemia, bilirubin encephalopathy, and kernicterus.

BREASTFEEDING

Although exclusive breastfeeding has been identified as a major risk factor for the development of hyperbilirubinemia, the AAP strongly encourages breastfeeding for all infants. This requires lactation support for the mother and infant to establish adequate lactation.

The AAP Guidelines encourage breastfeeding mothers to nurse 8 to 12 times per day for the first 48-72 hours after delivery.

• Although there are no randomized trials to support this practice, frequent nursing increases the number of feeding times which promotes the intake of fluid and calories.

NURSERY PROTOCOLS TO IDENTIFY HYPERBILIRUBINEMIA

Management of hyperbilirubinemia begins with identification of its presence.

Since visual assessment of jaundice is subjective, the AAP Guidelines recommend screening by total serum bilirubin (TSB) or transcutaneous bilirubin (TcB).

• It is suggested that general nursery protocol authorize nurses to order a TSB when hyperbilirubinemia is suspected by either visual observation of jaundice or TcB.

• If jaundice is noted visually, the nurse should obtain a TcB prior to obtaining a TSB since this is an invasive procedure.

• Although evidence supports the correlation of TcB values to TSB values, it cannot be used as a substitute.

Measurement of transcutaneous bilirubin

Photo in - Mosby's Skills.(2014). Bilirubin meter: transcutaneous monitoring. Retrieved August 22, 2014. Used with permission under CFVHS licensure for use of Mosby’s Skills.

Prior to discharge, the infant should be assessed for risk factors for the development of hyperbilirubinemia.

• This especially applies to infants discharged before 72 hours of age.

The AAP also recommends that parents receive discharge teaching and educational materials about jaundice covering -

• Risk factors • Identification • Treatment

POST DISCHARGE FOLLOW-UP

A risk assessment for severe hyperbilirubinemia should be performed on all newborns prior to discharge. This is done by -

• Plotting the TSB or TcB on the bilirubin nomogram AND/OR • Assessment for the presence of major and minor risk factors

For the infant at risk for developing hyperbilirubinemia, the AAP recommends the first outpatient office visit at 2 days after discharge if the infant was discharged < 72 hours after birth.

• If the infant is not at risk and there are no other issues, the first visit can be later. • At the follow-up visit, information about jaundice should be reinforced, and parent

questions should be encouraged.

TREATMENT

Phototherapy is the most commonly used therapy for hyperbilirubinemia.

• With effective phototherapy, bilirubin levels should decrease by 0.5-1 mg% per hour and by 30-40% after 24 hours of treatment.

Phototherapy may be provided by -

• Bank lights • Spot lights • Fiberoptic blankets

Photo from - Patient information: jaundice in babies (The Basics). (2014). In UpToDate 2014. Retrieved August 22, 2014. Used with permission under CFVHS licensure for use of UpToDate.

Photo from - Patient information: jaundice in babies (The Basics). (2014). In UpToDate 2014. Retrieved August 22, 2014. Used with permission under CFVHS licensure for use of UpToDate.

Phototherapy uses light in the blue-green spectrum to alter the shape and structure of bilirubin.

• This converts the bilirubin molecules into a form that is more easily excreted in urine and stool.

Phototherapy efficacy depends on -

• Energy output of the light source • Distance of the light source from the infant • Surface area of the infant exposed

After the initiation of phototherapy, TSBs must be monitored at least every 12-24 hours to monitor bilirubin levels.

• After the discontinuation of phototherapy, TSB levels should be followed for at least 24 hours to rule out the occurrence of rebound hyperbilirubinemia.

There are very few side effects of phototherapy. However, potential side effects include -

• Thermal instability • Increased insensible water loss • Injury to the retina - cover eyes during phototherapy use • Increased bowel movements • Temporary lactose intolerance • Decreased platelet count

Exchange Transfusion

Before phototherapy was discovered, exchange transfusion was the treatment used to reduce serum bilirubin levels and prevent kernicterus.

• With the use of hyperbilirubinemia risk assessment and phototherapy, exchange transfusion has become rarely used.

During an exchange transfusion, twice the infant’s blood volume, ~ 170 mL/kg) is exchanged in small aliquots.

• The aliquots are not to exceed 10% of the total blood volume.

• The aliquots are withdrawn from the infant and replaced with equal aliquots of donor blood.

o Packed RBCs reconstituted with plasma is commonly used. • The procedure is usually performed through two central catheters. • The double volume exchange transfusion replaces

approximately 85% of the infant’s blood volume and reduces bilirubin levels by ~ 40% at the end of the procedure.

• Serum bilirubin levels can rise to 70% to 80% of preexchange levels within 30 minutes of the procedure because of re-equilibration that occurs between the vascular and extravascular compartment.

• When the procedure is performed on an infant with immune-mediated hemolytic disease, it has the added benefits of -

o Removing antibody-coated RBCs o Removing maternal antibodies o Correcting anemia.

The AAP recommends the administration of intravenous gamma globulin for infants with isoimmune hemolytic disease if the TSB level is rising despite intensive phototherapy or the TSB level is within 2 to 3 mg/dL of the exchange level.

Potential complications of exchange transfusion include -

• Thrombocytopenia • Hypocalcemia, • Hypomagnesemia • Hypoglycemia • Arrhythmia • Cardiac arrest • Respiratory or metabolic acidosis • Rebound metabolic alkalosis • Complications associated with blood transfusion • Complications associated with umbilical vessel catheterization

Infants with hemolytic disease and preterm infants should receive phototherapy and exchange transfusion at lower bilirubin levels.

The role of the nurse during an exchange transfusion is to assess the infant, monitor VS, and document the procedure. It is NOT within

the scope of practice for the nurse to perform an exchange transfusion.

Hyperbilirubinemia has been consistently associated with hearing impairment and abnormal brainstem auditory evoked potentials.

For infants who do not develop ABE, there is inconsistent evidence regarding the adverse effects of bilirubin on neurodevelopmental outcome.

Kernicterus occurs with chronic bilirubin encephalopathy.

• It is irreversible and causes devastating brain injury.

Signs of kernicterus include -

• Extrapyramidal movements o Dystonia o Choreoathetoid movements o Auditory disturbances - deafness

Auditory pathways are most sensitive to bilirubin injury. o Enamel dysplasia of the teeth o Mild cognitive defects

Severely affected survivors of kernicterus may exhibit the following in later life -

• Choreoathetosis • Spastic cerebral palsy • Mental handicap • Sensory and perceptual deafness • Visual-motor incoordination

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