Exclusively breast-fed infants are at risk for exaggerated physiologic jaundice due to a relative caloric deprivation during the first few days of life Decreased volume and frequency of feeds may result in a mild dehydration, as well as increased enterohepatic circulation This is mitigated by increasing the frequency of feedings, improving latch and positioning, and occasionally by supplementing with formula in order to improve caloric intake Pyloric stenosis, duodenal atresia, malrotation with volvulus, meconium ileus, and Hirschsprung disease may present with jaundice along with other clinical signs of gastrointestinal (GI) obstruction In neonates, obstruction can increase enterohepatic circulation resulting in unconjugated hyperbilirubinemia Older children with jaundice in the setting of GI obstruction generally have a conjugated hyperbilirubinemia (see Chapter 44 Jaundice: Conjugated Hyperbilirubinemia ) Jaundice may be evident in cases of serious infection, such as sepsis and the congenital TORCH (Toxoplasmosis, Other [e.g., syphilis, parvovirus], Rubella, Cytomegalovirus, Herpes simplex virus) infections Bacterial endotoxins reduce bile flow, thereby impairing its excretion and leading to hyperbilirubinemia Sepsis is exceedingly rare among well-appearing jaundiced neonates who have no additional signs or symptoms Intrauterine or breast milk exposure to certain drugs or toxins may also lead to impaired excretion of bilirubin in the neonate EVALUATION Evaluation should always begin with a detailed history and physical examination It is imperative to know the serum bilirubin level early in the course of evaluation The need for additional studies—laboratory testing, imaging studies— is guided by the findings on history and physical examination History Certain features of the birth history are critical in the evaluation of a neonate who presents with jaundice and concern for hyperbilirubinemia: gestational age, date and time of birth, birth weight, details of delivery (e.g., use of instrumentation such as forceps or vacuum), and maternal blood type and Rh status, as well as maternal exposure to infections such as syphilis The history should also include a detailed feeding history, including type of milk and quantity, duration, and frequency of feeds Urine output and character of stool should be elicited Additionally, the presence or absence of other features that may indicate etiology (e.g., fever, emesis, lethargy) should be established Exposures and previous bilirubin levels and the results of Coombs test should be reviewed, if applicable Pertinent family history includes the presence of a first-degree relative with history of jaundice or anemia, and racial or ethnic origin associated with a hematologic disorder Physical Examination The general appearance and vital signs of the patient will help guide the clinician as to the likelihood of a serious underlying condition such as bacterial sepsis Hydration status should be ascertained Hepatomegaly may indicate underlying liver dysfunction Splenomegaly may be found in hypersplenic states or patients with hemolytic anemia Neurologic examination should include evaluation for signs of ABE: hypotonia, irritability, retrocollis, opisthotonos, high-pitched cry, and coma Pallor may indicate concomitant anemia Presence of a cephalohematoma or large areas of ecchymosis may suggest extravascular hemolysis as the cause of hyperbilirubinemia Clinical examination of jaundice involves close inspection of the sclera and skin under adequate light, applying gentle pressure with one finger to facilitate examination of color In neonates, jaundice progresses in a cephalocaudal direction from the face to the trunk and extremities, and finally to the palms and soles In neonates, visual assessment of jaundice has been found to correlate poorly with serum bilirubin measurement, with great interobserver variability noted The acute neurologic manifestations of the neurotoxic effects of bilirubin are known as ABE, the term recommended by the American Academy of Pediatrics (AAP) ABE may be reversible if identified in the early phase, when clinical findings may be subtle and include sleepiness, hypotonia, and/or a high-pitched cry Later phases include lethargy, irritability, retrocollis, opisthotonos, seizures, apnea, and coma Death is typically due to respiratory failure or intractable seizures Additional Studies The total and fractionated (direct and indirect) serum bilirubin level should always be measured, as visual inspection alone is an unreliable indicator Many times, these are the only laboratory studies indicated in the ED evaluation of a child who presents with jaundice; indication for other laboratory studies will be reviewed here Occasionally, imaging studies are indicated in the evaluation of a child with jaundice or hyperbilirubinemia Laboratory Testing Bilirubin Measurement Transcutaneous measurements of bilirubin are correlated with serum bilirubin; however, they are inaccurate at higher levels (greater than 12 to 15 mg/dL), and thus are best used as a screen A TSB should always be obtained when therapeutic intervention is being considered Nearly all published data regarding the correlation of TSB levels to kernicterus or developmental outcome are based on capillary blood Data on the relationship between capillary and venous sampling are conflicting Capillary sampling is endorsed by the AAP; a confirmatory venous sample is not required In neonates, it may be important to determine the rate of rise of TSB with serial measurements It is imperative to note that many clinical laboratories require the total and fractionated bilirubin to be ordered separately, as the total bilirubin reported on the hepatic function or comprehensive metabolic panels is unreliable in infants under month of age The ED clinician should be familiar with the accuracy of his or her laboratory assay in order to minimize error in the evaluation and management of neonates with suspected hyperbilirubinemia Other Laboratory Studies If the TSB level is below 12 mg/dL, rises slowly, and resolves before days of age, one can diagnose physiologic hyperbilirubinemia without further laboratory studies When these conditions are not met, further testing is required to determine the etiology of elevated serum bilirubin A complete blood cell count should be obtained to evaluate for anemia A peripheral blood smear should be examined microscopically for clues as to the etiology of the anemia: characteristic abnormal morphology, such as sickle cells, spherocytes, or elliptocytes, may be identified; helmet and fragmented cells are diagnostic of a microangiopathic hemolytic anemia; malarial ring forms may be apparent The reticulocyte count may be elevated in the setting of hemolysis Patients with anemia or hemolysis should also have a Coombs test performed to look for evidence of autoimmune hemolysis In patients with a TSB level above threshold for exchange transfusion, a serum albumin should be obtained, and ratio of bilirubin to albumin should be calculated End-tidal carbon monoxide concentration (ETCOc) provides a noninvasive assessment of bilirubin production, and may be utilized to aid in confirmation of active hemolysis The child with fever, hypothermia, or ill appearance should be evaluated for serious bacterial infection, including blood, urine, and cerebrospinal fluid cultures as indicated Serum electrolytes should be obtained in patients with clinical signs of dehydration, and those with a history of emesis or excessive stool output Hepatic function should be assessed in patients with hepatomegaly or in those with hyperbilirubinemia in the absence of anemia Neonates with symptoms or newborn screen suggestive of congenital hypothyroidism should have a free T4 level obtained, along with TSH Imaging Studies If clinical signs of obstruction are present, the patient should undergo appropriate imaging studies such as abdominal radiographs, ultrasound, or upper GI series with contrast MANAGEMENT The goal of neonatal hyperbilirubinemia management is to prevent BIND The jaundiced newborn needs to be kept well hydrated, and enteral feeding should be encouraged to promote bilirubin excretion When bilirubin levels rise significantly, phototherapy and exchange transfusion may be indicated Phototherapy Indications for phototherapy vary according to the age of the neonate; in the term neonate who develops jaundice and has no evidence of hemolysis, indications for phototherapy as recommended by the AAP Subcommittee on Hyperbilirubinemia are shown in Figure 45.1 When there is evidence of isoimmune hemolysis, phototherapy should be started immediately and a neonatologist should be consulted regardless of TSB level Phototherapy may be delivered by an overhead bank of lights or via a fiberoptic light source in a blanket and should be initiated in the ED if an alternate site is not available quickly The mechanism of phototherapy involves wavelengths of light that alter the unconjugated bilirubin in the skin, and convert it to less toxic, water-soluble photoisomers that may be excreted in the bile and urine without conjugation TSB levels decline by to mg/dL within to hours using conventional phototherapy During phototherapy, the baby should be undressed to maximize the exposed surface area of the skin The infant must wear an eye shield when using overhead lights in order to prevent retinal damage Other risks of phototherapy include temperature instability, loose stools, rash, and interruption of breast-feeding Studies suggest an association with phototherapy and subsequent development of long-term complications such as seizures and childhood cancers; although risks are modest and uncertain, they highlight the pitfalls of overtreatment and unnecessary exposure to phototherapy Phototherapy is relatively contraindicated ... neurotoxic effects of bilirubin are known as ABE, the term recommended by the American Academy of Pediatrics (AAP) ABE may be reversible if identified in the early phase, when clinical findings