Carboxyhemoglobin Concentration in Fetal Cord Blood

Abstract

In Reply.— Huch et al give very valuable comments about the limitations of the IL 282 Co-oximeter (IL Instrumentation Laboratory) for measurements of carboxyhemoglobin (HbCO) in fetal blood. They mentioned the problems of interference between oxyhemoglobin (HbO2) and HbCO of fetal blood on the multiwavelength analysis of spectrophotometers such as the IL 282 Co-oximeter. For practical purposes the method used overestimates the fetal HbCO but not maternal HbCO and therefore the ratio of fetal/maternal HbCO is falsely increased.