An End-Tidal Carbon Monoxide Nomogram for Term and Late-Preterm Chinese Newborns

Area of Science:

• Neonatal Medicine
• Biomedical Engineering
• Pediatric Pulmonology

Background:

• Hyperbilirubinemia is a common condition in newborns, potentially leading to serious complications if untreated.
• Current methods for assessing hyperbilirubinemia risk have limitations.
• End-tidal CO corrected for ambient CO (ETCOc) is a non-invasive marker that may aid in early detection.

Purpose of the Study:

• To develop a reference nomogram for ETCOc levels in Chinese term and late-preterm newborns.
• To evaluate the efficacy of this nomogram in identifying hemolytic hyperbilirubinemia.
• To assess ETCOc's predictive value for phototherapy and readmission.

Main Methods:

• A prospective study measured ETCOc and bilirubin levels (TSB or TcB) in 455 newborns.
• A reference nomogram was constructed using ETCOc percentiles at various postnatal ages (12-120 hours).
• The nomogram's ability to predict hyperbilirubinemia and readmission was analyzed.

Main Results:

• The nomogram showed a stable trend within the first 3 postnatal days, followed by a decline.
• ETCOc and TSB/TcB ≥75th percentile identified hemolytic hyperbilirubinemia (12-72 hours) with an AUC of 0.741.
• ETCOc ≥1.7 ppm (96-120 hours) identified hemolytic hyperbilirubinemia with an AUC of 0.816; 90.5% of readmitted infants had ETCOc ≥75th percentile.

Conclusions:

• A reference ETCOc nomogram for newborns can effectively identify hemolytic hyperbilirubinemia.
• The nomogram aids in predicting the need for phototherapy and late postnatal readmission.
• ETCOc serves as a valuable non-invasive tool for neonatal jaundice management.