Anemia of Prematurity - Portal Neonatal

• A number of guidelines for the management of neonatal jaundice have been published, and
even more appear to be in local use without submission for critical review. In a survey
published in 1996, the author analyzed clinical practices in this field based on responses from
108 neonatal intensive care units (NICUs) worldwide. The survey revealed a significant
disparity in guidelines.
o Image 1 shows a box-and-whisker plot of the range of serum bilirubin values that trigger
phototherapy and exchange transfusion, respectively, in these NICUs. Evidently, an infant
might receive an exchange transfusion in one NICU for a serum bilirubin level that would
not trigger phototherapy in many other NICUs. This disparity illustrates how difficult it has
been to translate clinical data into sensible treatment guidelines.
o In 1994, the American Academy of Pediatrics (AAP) published guidelines for the
management of hyperbilirubinemia in healthy full-term newborns. These guidelines have
been plotted on the graph in Image 1 and represent a significant departure from the
standards applied up to that point.
o The AAP guidelines were controversial at the time of publication and continue to be a
topic of discussion and disagreement among bilirubin experts. Briefly, the objections
raised focused mainly on the fact that the AAP guidelines were untested and unproven. In
addition, it has been noted that the AAP standard refers to "healthy term newborns," a
designation that may be difficult to apply without testing every newborn for congenital
hemolytic disease.
o The above discussion clarifies the finding that therapeutic guidelines for neonatal jaundice
are difficult to substantiate with solid scientific facts. At present, the wisest choice may be
to apply guidelines that have been in local use for a period sufficient to prove that no
cases of kernicterus occurred while the guidelines were followed.
o With this background, and the clear understanding that this is meant only as an example,
Image 2 shows the chart currently in use in the NICU at the author's institution in Oslo.
These guidelines have been in use for a quarter of a century in most of Norway, and no
known cases of kernicterus have occurred in infants in whom serum bilirubin levels were
kept below the stated limits.
o Readers who are working in different ethnic or geographic situations should not apply
these guidelines uncritically to their own populations but must consider factors unique to
their settings. Such factors may include racial characteristics, prevalence of congenital
hemolytic disease, and environmental concerns.
Key points in the practical execution of phototherapy are maximizing energy delivery and the available
surface area.
• The infant should be naked except for diapers (use these only if deemed absolutely necessary
and cut them to minimum workable size), and the eyes should be covered to reduce risk of
retinal damage.
• Check the distance between the infant's skin and the light source. With fluorescent lamps, the
distance should be no greater than 50 cm (20 in). This distance may be reduced if
temperature homeostasis is monitored to reduce the risk of overheating.
• Cover the inside of the bassinet with reflecting material; white linen works well. Hang a white
curtain around the phototherapy unit and bassinet. These simple expedients can multiply
energy delivery by several fold.
• In the well baby unit at the author's institution, energy delivery was measured in the
phototherapy bassinets in the horizontal and vertical planes corresponding to the level of the
infant's back (when prone) and sides, respectively. Then, new fluorescent tubes were
exchanged for the previously used lights and white linen was added as reflecting material in
the bed and as curtains. These changes increased the energy delivered from 7-8 to 17-18
μW/cm 2 /nm in the horizontal plane and from 1 to 10-12 μW/cm 2 /nm in the vertical plane. The
average time infants spent in phototherapy subsequently fell by 5 hours.
• When using spotlights, ensure that the infant is placed at the center of the circle of light, since
photoenergy drops off towards the circle's perimeter. Observe the infant closely to ensure that
the infant doesn't move away from the high-energy area. Spotlights are probably more
appropriate for small premature infants than for larger near-term infants.