Anemia of Prematurity - Portal Neonatal

Lab Studies:
WORKUP Section 5 of 11
• Bilirubin
o Transcutaneous bilirubinometry can be performed using handheld devices that
incorporate sophisticated optical algorithms to filter out most of the unreflected light
from the bilirubin molecules.
o In infants with mild jaundice, transcutaneous bilirubinometry may be all that is needed
to assure that total bilirubin levels are safely below those requiring intervention.
o In infants with moderate jaundice, transcutaneous bilirubinometry may be useful in
selecting patients who require phlebotomy for serum bilirubin measurement.
o Usually, a total serum bilirubin level is the only testing required in a moderately
jaundiced infant who presents on the typical second or third day of life without a
history and physical findings suggestive of a pathologic process.
• Additional studies may be indicated in the following situations:
o Infants who present with jaundice on the first or after the third day of life
o Infants who are anemic at birth
o Infants who otherwise appear ill
o Infants in whom serum bilirubin levels are very elevated
o Infants in whom significant jaundice persists beyond the first 2 weeks of life
o Infants in whom family, maternal, pregnancy, or case histories suggest the possibility
of a pathologic process
o Infants in whom physical examination reveals findings not explained by simple
physiologic hyperbilirubinemia
• In addition to total serum bilirubin levels, other suggested studies may include the following:
o Blood type and Rh determination in mother and infant
o Direct Coombs testing in the infant
o Hemoglobin and hematocrit values
o Serum albumin levels: This may be a useful adjunct in evaluating risk of toxicity levels,
since albumin binds bilirubin in a ratio of 1:1 at the primary high-affinity binding site.
o Nomogram for hour-specific bilirubin values: This may be a useful tool for predicting,
either before or at the time of hospital discharge, which infants are likely to develop
high serum bilirubin values. These infants require close follow-up monitoring and
repeated bilirubin measurements. The predictive ability has been shown both for
bilirubin values measured in serum and for values measured transcutaneously.
o Measurement of end-tidal carbon monoxide in breath (ETCO): ETCO may be used as
an index of bilirubin production. Measurement of ETCO may assist in identifying
individuals with increased bilirubin production and, thus, at increased risk of
developing high bilirubin levels. An apparatus has been developed that makes
measuring ETCO simple (CO-Stat End Tidal Breath Analyzer, Natus Medical Inc).
o Peripheral blood film for erythrocyte morphology
o Reticulocyte count
o Conjugated bilirubin: Note that direct bilirubin measurements are often inaccurate, are
subject to significant interlaboratory and intralaboratory variation, and generally are
not a sensitive tool for diagnosing cholestasis.
o Liver function tests: Aspartate aminotransferase (ASAT or SGOT) and alanine
aminotransferase (ALAT or SGPT) levels are elevated in hepatocellular disease.
Alkaline phosphatase and γ-glutamyltransferase (GGT) levels often are elevated in
cholestatic disease. A GGT/ALAT ratio greater than 1 is strongly suggestive of biliary
obstruction.