Infants with greater than 20% of their bilirubin in the direct form have cholestasis or obstruction to bile flow. The first step in evaluation of prolonged jaundice is to measure total and fractional bilirubin concentrations
Infants with greater than 20% of their bilirubin in the direct form have cholestasis or obstruction to bile flow. The first step in evaluation of prolonged jaundice is to measure total and fractional bilirubin concentrations: Excerpt from Avoiding Common Pediatric Errors
Author:
Yolanda Lewis-Ragland, MD
What to Do - Gather Appropriate Data
Jaundice is derived from the French word jaune, which means yellow, and
is the term used to describe the yellowish discoloration caused by an excess
amount of bilirubin in skin. Bilirubin is a yellowish-red pigment that is the
result of red blood cell (RBC) breakdown in the natural RBC aging process,
and is normally found in small amounts in the blood. Its appearance in
newborns is primarily due to the immaturity of the newborn's liver, which
cannot effectively metabolize the bilirubin and prepare it for excretion into
the urine.
When too much bilirubin is made, the excess is dumped into the bloodstream and deposited in tissues for temporary storage. Most jaundice in
newborn babies is a normal event and is not critical. In most cases, this jaundice appears between the second and fifth days of life and clears with time,
often without treatment. Also, once this type of jaundice disappears, there is
no evidence that it will appear again or that it has any lasting effects on the
baby.
Physiologic Jaundice
Physiologic jaundice in healthy term newborns follows a typical pattern. The
average total serum bilirubin level usually peaks at 5 to 6 mg/dL (86–103
µmol/L)on the third to fourth day of life and declines over the first week after
birth. Bilirubin elevations of up to 12 mg/dL, with <2 mg/dL (34 µmol/L)
of the conjugated form, can sometimes occur. Infants with multiple risk
factors may develop an exaggerated form of physiologic jaundice in which
the total serum bilirubin level may rise as high as 17 mg/dL (291 µmol/L)
(Table 8.1).
Other factors that contribute to the development of physiologic hyperbilirubinemia in the neonate include an increased bilirubin load because of relative polycythemia, a shortened erythrocyte life span (80 days
compared with the adult 120 days), immature hepatic uptake and conjugation processes, and decreased enterohepatic circulation.
Breast Milk Jaundice
Breastfeeding jaundice is recognized in two phases: early-onset and late-
onset.
Early Onset Breastfeeding Jaundice. Breastfed newborns may be at increased risk for early onset exaggerated physiologic jaundice because of relative caloric deprivation in the first few days of life. Decreased volume and
frequency of feedings may result in mild dehydration and the delayed passage of meconium. Compared with formula-fed newborns, breastfed infants
are 3 to 6 times more likely to experience moderate jaundice (total serum
bilirubin level >12 mg/dL) or severe jaundice (total serum bilirubin level
>15 mg/dL [257 µmol/L]).
Late-Onset Breast Milk Jaundice. Breast milk jaundice occurs later in
the newborn period, with the bilirubin level usually peaking between
days 6 and 14 of life. This late-onset jaundice may develop in up to one
third of healthy breastfed infants. Total serum bilirubin levels vary from
12 to 20 mg/dL (340 µmol/L) and are nonpathologic. The underlying cause
of breast milk jaundice is not entirely understood. Substances in maternal
milk, such as ß-glucuronidases, and nonesterified fatty acids, may inhibit
normal bilirubin metabolism. The bilirubin level usually falls continually
after the infant is 2 weeks old, but it may remain persistently elevated for
1 to 3 months.
Pathologic Jaundice
All etiologies of jaundice beyond physiologic and breastfeeding or breast
milk jaundice are considered pathologic. Features of pathologic jaundice
include the appearance of jaundice within 24 hours after birth, a rapidly
rising total serum bilirubin concentration (increase of more than 5
mg/dL/day), and a total serum bilirubin level >17 mg/dL in a full-term
newborn. Other features of concern include prolonged jaundice, evidence
of underlying illness, and elevation of the serum conjugated bilirubin
level to >2 mg/dL or >20% of the total serum bilirubin concentration.
Pathologic causes include disorders such as sepsis, rubella, toxoplasmosis,
occult hemorrhage, and erythroblastosis fetalis.
Laboratory Evaluation
The initial evaluation of jaundice depends on the age of the newborn. If the
serum conjugated bilirubin level is >2mg/dL,the infant should be evaluated
for possible hepatocellular disease orbiliary obstruction. Using the following
algorithm, clinicians are able to systematically evaluate the most likely cause
of hyperbilirubinemia in a baby and initiate appropriate therapy (Fig. 8.1).
Suggested Readings
HansenTWR.Jaundice,neonatal. 2006, eMedicine. www.emedicine.com/PED/topic1061.htm.
Accessed December 17, 2007.
MedlinePlus Medical Encyclopedia: Newborn jaundice. 2007. www.nlm.nih.gov/medlineplus/
ency/article/001559.htm. Accessed. Newborn jaundice. 2005. www.emedicinehealth.com/
newborn jaundice/article em.htm. Accessed December 17, 2007.
Pictures
>
Book Source Details
- Book Title: Avoiding Common Pediatric Errors
- Author(s): Anthony D Slonim MD, DrPH; Lisa Marcucci MD
- Year of Publication: 2008
- Copyright Details: Avoiding Common Pediatric Errors, Copyright © 2008 Lippincott Williams & Wilkins.
More About Cholestasis
More Medical Textbooks Online about Cholestasis
Review other book chapters online related to Cholestasis:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
|
|
More About This Book:
Title: Avoiding Common Pediatric Errors
Authors: Anthony D Slonim MD, DrPH; Lisa Marcucci MD
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7489-6
|
|
» Next page: The vomiting of bile-stained fluid in the first few days of life should be considered intestinal obstruction until proven otherwise (Avoiding Common Pediatric Errors)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
