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Published on: August 19, 2020
Prediction of hyperbilirubinemia in near-term and term infants
D K Stevenson1, A A Fanaroff, M J Maisels
1Department of Pediatrics, Lucile Salter Packard Children's Hospital, Stanford, CA 94305-5208, USA.
Insights
Measuring end-tidal carbon monoxide (ETCOc) and serum total bilirubin (STB) can help predict newborn jaundice. While ETCOc offers insight, STB alone is more effective for predicting hyperbilirubinemia risk in infants.
Area of Science:
- Neonatal Medicine
- Pediatric Gastroenterology
- Clinical Chemistry
Background:
- Hyperbilirubinemia is a common condition in newborns, necessitating accurate prediction methods.
- Early identification of infants at risk for hyperbilirubinemia is crucial to prevent potential complications.
- Current prediction methods often rely on serum total bilirubin (STB) measurements, but their predictive accuracy can be limited.
Purpose of the Study:
- To evaluate the predictive value of end-tidal carbon monoxide (ETCOc) corrected for ambient CO, alone and in combination with STB, for hyperbilirubinemia in neonates.
- To assess if ETCOc measurements can enhance the prediction of hyperbilirubinemia beyond STB alone.
- To determine the utility of these markers in identifying infants needing closer monitoring for jaundice.
Main Methods:
- A prospective cohort study involving 1370 neonates across nine multinational clinical sites.
- Measurements of ETCOc and STB were taken at 30+/-6 hours of life.
- STB was also measured at 96+/-12 hours and as needed, with hyperbilirubinemia defined as STB at or above the 95th percentile for age.
Main Results:
- 8.8% of infants developed hyperbilirubinemia.
- Mean ETCOc at 30+/-6 hours was higher in hyperbilirubinemic infants (1.81 ppm) compared to non-hyperbilirubinemic infants (1.45 ppm).
- ETCOc > population mean had a 13.0% PPV and 95.8% NPV. STB at 30+/-6 hours (excluding early high levels) had a 16.7% PPV and 98.1% NPV. The combination yielded a 6.4% PPV and 99.0% NPV.
Conclusions:
- STB measurement before discharge aids in predicting hyperbilirubinemia risk.
- ETCOc provides insight into bilirubin production/elimination but does not significantly improve STB's predictive ability for hyperbilirubinemia.
- Combining STB and ETCOc may identify infants at risk for increased bilirubin production or decreased elimination, guiding early follow-up for jaundice and related issues.
Objective:
The purpose of this study was to determine whether end-tidal carbon monoxide (CO) corrected for ambient CO (ETCOc), as a single measurement or in combination with serum total bilirubin (STB) measurements, can predict the development of hyperbilirubinemia during the first 7 days of life.
Methods:
From nine multinational clinical sites, 1370 neonates completed this cohort study from February 20, 1998 through February 22, 1999. Measurements of both ETCOc and STB were performed at 30+/-6 hours of life; STB also was measured at 96+/-12 hours and subsequently following a flow diagram based on a table of hours of age-specific STB. An infant was defined as hyperbilirubinemic if the hours of age-specific STB was greater than or equal to the 95th percentile as defined by the table at any time during the study.
Results:
A total of 120 (8.8%) of the enrolled infants became hyperbilirubinemic. Mean STB in breast-fed infants was 8.92+/-4.37 mg/dl at 96 hours versus 7.63+/-3.58 mg/dl in those fed formula only. The mean ETCOc at 30+/-6 hours for the total population was 1.48+/-0.49 ppm, whereas those of nonhyperbilirubinemic and hyperbilirubinemic infants were 1.45+/-0.47 and 1.81+/-0.59 ppm, respectively. Seventy-six percent (92 of 120) of hyperbilirubinemic infants had ETCOc greater than the population mean. An ETCOc greater than the population mean at 30+/-6 hours yielded a 13.0% positive predictive value (PPV) and a 95.8% negative predictive value (NPV) for STB > or =95th percentile. When infants with STB > or =95th percentile at <36 hours of age were excluded, the STB at 30+/-6 hours yielded a 16.7% PPV and a 98.1% NPV for STB >75th percentile. The combination of these two measurements at 30+/-6 hours (either ETCOc more than the population mean or STB >75th percentile) had a 6.4% PPV with a 99.0% NPV.
Conclusions:
This prospective cohort study supports previous observations that measuring STB before discharge may provide some assistance in predicting an infant's risk for developing hyperbilirubinemia. The addition of an ETCOc measurement provides insight into the processes that contribute to the condition but does not materially improve the predictive ability of an hours of age-specific STB in this study population. The combination of STB and ETCOc as early as 30+/-6 hours may identify infants with increased bilirubin production (eg, hemolysis) or decreased elimination (conjugation defects) as well as infants who require early follow-up after discharge for jaundice or other clinical problems such as late anemia. Depending on the incidence of hyperbilirubinemia within an institution, the criteria for decision making should vary according to its unique population.
