Pediatric emergency medicine trisk 223

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 1 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 8 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 1 to 2 mg/dL within 4 to 6 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