Abstract 1094

End-tidal breath carbon monoxide (CO) corrected for inhaled CO (ETCOc) correlates with bilirubin production and is therefore useful in assessing the development of hyperbilirubinemia in the newborn. The aim of this study was to assess the distribution of ETCOc measurements in a multi-ethnic population. We prospectively measured ETCOc in 174 healthy term newborns at 24 to 36th of life with the Co-Stat™ End Tidal Breath Analyzer (Natus Medical Inc., San Carlos, CA). Serum total bilirubin (STB) (mean ± SD) was determined within 6h of the ETCOc measurement and repeated at 96 ± 12h of life. Screening was performed for glucose-6-phosphate dehydrogenase (G6PD) activity deficiency in erythrocytes using a colorimetric method. (Table)

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These preliminary data indicate that, while no significant differences were found in STB levels between any of the groups (p > 0.05), ETCOc values were significantly different for two of the ethnic groups. These differences were not explained by the occurrence of G6PD deficiency. The physiological and clinical significance of higher bilirubin production in newborns of certain ethnic groups during the transitional period and its genetic origins requires additional study. However, the influence of ethnic factors must be taken into account when using ETCOc measurements for prediction of hyperbilirubinemia in term newborns.