Can serum albumin level affect the transcutaneous bilirubinometry in term neonates?

Jaundice is the quite common benign condition in neonates, but due to its potential toxicity, neonates must be monitored. This study was aimed to evaluate the effect of serum albumin level on the transcutaneous bilirubin (TcB) measurements in term neonates with unconjugated hyperbilirubinemia.

Serum albumin and total serum bilirubin (TSB) of 252 jaundiced term neonates were estimated and simultaneously TcB was measured over sternum and the effect of serum albumin on TcB measurements was evaluated.

The correlation between TSB and TcB was linear and significant for the entire cohort. When this correlation was studied separately in the groups with different albumin levels, maximum correlation (r = 0.888, R2 linear = 0.789, p < 0.001) was observed in group 1 with hypo-albuminemia followed by in group 2 with normal albumin levels (r = 0.854, R2 linear = 0.729, p < 0.001) and group 3 with higher albumin levels (r = 0.809, R2 linear = 0.689, p < 0.001). Bland-Altman plot analysis of whole study population demonstrate good agreement between TSB and TcB [95% CI = -0.038 to 0.493 mg/dL, 17/252 = 6.75% outside the limits of agreement, Mean difference = 0.227]. This analysis in different groups also show good agreement between TSB and TcB.

The correlation between the TSB and TcB may affected by serum albumin level. Therefore, transcutaneous bilirubinometry is not able to replace invasive TSB measurement. However, in the absence of TSB it could be an alternative to measure the level of bilirubin in term neonates.