More than 15 years in the making, the revised AAP Clinical Practice Guideline Revision: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation was released in 2022. A key driving force for this revision was the expanded evidence base regarding monitoring and treatment of newborns 35 or more weeks’ gestation to prevent bilirubin encephalopathy and kernicterus.
Here, we summarize the highlights of the new guidelines and point out practical ways to incorporate these guidelines into daily practice.
What has changed?
If you are familiar with the previous guidelines (2004 or the 2009 update) for the management of newborn jaundice, you’ll note that the treatment graphs for phototherapy and exchange transfusion have been updated with new, slightly higher thresholds.
Bilirubin thresholds for starting phototherapy are about 2 mg/dL higher overall than indicated in previous iterations of the guidelines.
This change reflects new evidence that infants don’t typically develop bilirubin neurotoxicity until the total serum bilirubin (TSB) reaches levels well above the previous exchange transfusion threshold, justifying a narrow increase in the bilirubin level for starting phototherapy. Also, phototherapy treatment thresholds are now risk-adjusted, with separate curves for each gestational age from 35 weeks to > 38 weeks.
To find the applicable phototherapy threshold, use the infant’s gestational age (rounding down) and determine whether the infant has even a single neurotoxicity risk factor other than prematurity. Neurotoxicity risk factors include a low albumin level, isoimmune hemolytic disease, glucose-6-phosphate dehydrogenase (G6PD) deficiency, or other hemolytic conditions; sepsis; or any significant clinical instability in the previous 24 hours.
For example, a 384/7 weeks’ gestation newborn has a TSB of 12 mg/dL at 48 hours of age but no neurotoxicity risk factors. Using the graph Phototherapy Thresholds: No Hyperbilirubinemia Neurotoxicity Risk Factors, should the infant be placed under phototherapy at this time? (Answer: No. The threshold for starting phototherapy on this infant is approximately 16 mg/dL.)
When hyperbilirubinemia becomes a medical emergency
A new term, “escalation of care,” has been adopted to describe actions to take when the newborn’s TSB climbs to within 2 mg/dL of the exchange transfusion threshold – a medical emergency. Instructions on how to ensure intensive phototherapy, and when to initiate an urgent exchange transfusion, are given, including the critical need to maintain intensive phototherapy continuously during infant transport and admission to another facility.
Transcutaneous vs. serum bilirubin
Either a serum TSB or a transcutaneous bilirubin (TcB) should be measured in all infants between 24 and 48 hours after birth or before discharge if that occurs earlier. TcB measurements are valid and reliable when used as a screening test to identify infants who require a TSB measurement. Although the two tests are generally correlated, they are not identical, and treatment decisions should be based on TSB levels. A TSB should be obtained if the TcB exceeds or is within 3 mg/dL of the phototherapy treatment threshold, or if the TcB is ≥ 15 mg/dL.
Following up: When to check another bilirubin level
Prior to these new guidelines, the question of when to get the next bilirubin level was based on Vinod Bhutani, MD’s risk nomogram, which classified newborn bilirubin levels within high-, intermediate-, or low-risk zones for needing phototherapy. A bilirubin level in the high-risk zone indicated the need for earlier follow-up. These risk zones have been replaced with a more specific table that provides recommended postdischarge follow-up based on how close the newborn’s bilirubin level is to the hour-specific threshold for treatment. The closer the latest TSB or TcB level is to the newborn’s risk-based phototherapy threshold, the sooner the follow-up to check another bilirubin level will need to be.
Most infants discharged before 72 hours of age will need follow-up within 2 days. Newborns with TSB levels nearing the level for phototherapy (within 2 mg/dL or less) should remain in the hospital.
Five tips for using the new guidelines
Bilitool.org, a popular and useful app, has already been updated to reflect the changes in the new guidelines, making it easy to apply the new thresholds and create a follow-up plan for each patient.
The guidelines provide recommendations for when to check rebound bilirubin levels after stopping phototherapy (hint: babies with neurotoxic risk factors). A TcB device should not be used while the infant is being treated with phototherapy. However, a TcB can be measured once the baby has been off phototherapy for at least 24 hours.
If you have at least two bilirubin measurements, you can calculate the “rate of rise” in bilirubin level. A rapid rate of rise, which serves as a clinical indicator of hemolysis, is defined as ≥ 0.3 mg/dL per hour in the first 24 hours or ≥ 0.2 mg/dL per hour after the first 24 hours of life. This is especially helpful when hemolysis is suspected even if the newborn’s direct antibody test (DAT) is negative. In this scenario, the infant is considered to have a neurotoxic risk factor.
When you initiate phototherapy, be aware of the infant’s bilirubin level threshold for stopping phototherapy (2 mg/dL below the starting phototherapy threshold), as well as the threshold for escalation of care (2 mg/dL below the exchange transfusion threshold).
Because the thresholds for starting phototherapy and initiating exchange transfusion are slightly higher and specific to gestational age, clinicians can more confidently use less phototherapy.
Other guideline highlights
The neurotoxic risk factors and corresponding thresholds are important. If the newborn has one or more neurotoxic risk factors other than prematurity, the neurotoxic risk threshold graph should be used when assessing the need for treatment. Neurotoxic risk thresholds should also be used for newborns whose bilirubin levels continue rising on phototherapy.
The guidelines emphasize that G6PD is one of the most important causes of hazardous hyperbilirubinemia leading to kernicterus in the United States and worldwide. Overall, 13% of African American males and about 4% of African American females have G6PD deficiency.
Finally, the guidelines remind clinicians that an important way to reduce the chances that phototherapy will be needed is to encourage early and frequent feeding (8-12 times in 24 hours).
The AAP Clinical Practice Guideline Revision: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation contains a great deal more information, but these basic principles should allow practitioners to begin to incorporate these guidelines into daily practice.
Dr. Amaya is associate professor, department of pediatrics, Medical University of South Carolina, Charleston, and medical director, level 1 nursery, department of pediatrics, MUSC general academic pediatrics. She disclosed ties with Medical University of South Carolina. Dr. Balog is clinical associate professor of pediatrics, Medical University of South Carolina, Charleston. She has no relevant financial relationships. Dr. Basco is professor, department of pediatrics, Medical University of South Carolina, Charleston; director, division of general pediatrics, department of pediatrics, MUSC Children’s Hospital. He has disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.