Evaluation of a point-of-care direct spectrophotometric method for measurement of total serum bilirubin in term and near-term neonates

Abstract

Objective: To evaluate point-of-care (POC) measurement of total serum bilirubin (TSB) in the management of neonatal jaundice.

Study design: TSB was measured by a POC direct spectrophotometric bilirubin method (Unistat (U/TSB)) and a standard diazo clinical laboratory method (Olympus AU640E analyzer (diazo/TSB)). Agreement between U/TSB and diazo/TSB was assessed by correlation coefficient and Bland-Altman analysis. Transcutaneous bilirubin (TcB) was measured using JM-103 (JM).

Results: Correlation between U/TSB and diazo/TSB was 0.99 (n = 120). Maximum difference (U/TSB minus diazo/TSB) was -2.9 mg/dl, and 79% were +/-1 mg/dl; the average difference was -0.37+/-0.70 mg/dl and the average absolute difference was 0.60+/-0.52 mg/dl. Median time to determine U/TSB was 5 min. Correlation between U/TSB and JM was 0.92 (n = 113). Maximum difference (U/TSB minus JM) was 6.3 mg/dl, and 45% were +/-1 mg/dl; the average difference was 0.7+/-1.8 mg/dl and the average absolute difference was 1.4+/-1.2 mg/dl.

Conclusion: Measurement of TSB using Unistat provides excellent agreement with diazo/TSB and rapid turnaround time. This technique may provide reliable POC confirmation of TcB results that are above a screening cutoff value.