Accuracy and Reliability of Radiometer Gas Analyzer for Neonatal Hyperbilirubinaemia Management

Abstract

Aims
To assess the accuracy of capillary gas bilirubin (Radiometer TBiL) compared to venous total plasma bilirubin (Roche TPB), and to evaluate the reliability of Radiometer TBiL in neonatal hyperbilirubinaemia treatment decisions.

Methods
A prospective study was conducted at a tertiary neonatal centre in Dublin, Ireland between December 2023 and May 2025. Paired Radiometer TBiL and Roche TPB measurements were obtained from 97 neonates requiring bilirubin assessment.

Results
Radiometer TBiL demonstrated high correlation with Roche TPB (r = 0.97, p < 0.0001), although Radiometer TBiL showed an overestimation, especially at bilirubin levels between 150 to 230 μmol/L. Bland-Altman analysis revealed a mean difference of -16.6 μmol/L with wide limits of agreement (-63.6 to 30.4 μmol/L). Kappa analysis (κ = 0.35, 95% CI: 0.14 – 0.55) showed fair agreement in treatment decisions, with a tendency for Radiometer TBiL to overestimate the need for treatment, but there was no significant underestimation.

Discussion
Radiometer TBiL offers a rapid and less invasive alternative for bilirubin screening and risk stratification in neonates, with high correlation to standard laboratory measurements. While a tendency to overestimate bilirubin levels may lead to overtreatment, the absence of significant underestimation suggests Radiometer TBiL is a safe tool for clinical decision-making. Larger studies are warranted to validate these findings and refine clinical thresholds.