Sir.—I read with interest the response by Eidelman and Schimmel1 to the article by Leslie et al2 on the differences between capillary and venous bilirubin levels. It is always interesting when two studies reach the opposite conclusions. Leslie et al and co-workers found that venous bilirubin levels were generally higher than capillary levels, whereas Eidelman and Schimmel found the opposite. Leslie and coworkers suggested that, because capillary levels appear to "underestimate venous bilirubin levels," it is "prudent to measure venous rather than capillary bilirubin levels when the total serum bilirubin level exceeds 170 μmol/L (10 mg/dL)," whereas Eidelman and Schimmel opined that "further studies are... needed... to ascertain the relationship of sample site and laboratory technique."
Both of these statements require comment. The fact is that virtually every bilirubin level in the literature (on which we base current practice with regard to phototherapy and exchange transfusion for