Threshold and Correlation of Total Serum Bilirubin with Screening Automated Auditory Brainstem Response Among Newborns with Hyperbilirubinemia in National Hospital Abuja

Abstract

Objective To determine the total serum bilirubin (TSB) cut-off value predictive of hearing impairment among newborns with hyperbilirubinemia at the National Hospital Abuja. Setting This was a cross-sectional study conducted in the Special Care Baby Unit (SCBU) and Neonatal Intensive Care Unit (NICU) of National Hospital Abuja between August 2020 and February 2021. Methods A universal sampling of eligible participants was done, and consent was obtained from the parent. Using the TSB and results of hearing screening carried out with the Otoport advance from Otodynamics®, the proportion of automated auditory brainstem response (AABR) screening failure was determined, and the receiver’s operating characteristics (ROC) curve coordinates were used to find the threshold bilirubin level for the risk of hearing loss. The Spearman-Rho correlation assessed the relationship between TSB level and AABR findings. Results 160 newborns below 28 days of age, delivered at 34 weeks gestation and above, who had clinical jaundice were recruited. The prevalence of screening AABR failure in at least one ear was 26.2%. The correlation between TSB and AABR was weakly positive (rs = .189, p = .093) and the TSB cut-off for AABR failure was 16.3 mg/dl (sensitivity 45.5%, specificity 81%, Youden’s-J statistic = 0.265). Conclusion The TSB threshold for AABR screening failure was 16.3 mg/dl, but TSB did not correlate well with screening AABR. Serum bilirubin above 15 mg/dl in late preterm and term neonates should be actively treated with phototherapy and/or exchange blood transfusions where feasible, particularly in resource-poor settings.