Effects of cardiopulmonary bypass on the accuracy of non-invasive hemoglobin measurement by pulse co-oximetry.

A non-invasive continuous measurement of hemoglobin (Hb) by pulse co-oximetry (SpHb) using Radical-7® (Masimo Corporation, CA, USA) is a newly developed method of measuring total Hb concentration. Previously, the accuracy of SpHb in clinical settings was reported (1). However, it has been also reported that SpHb has poor correlation with arterial Hb after cardiac surgery (2). Here we examined the accuracy of SpHb measured by New Radical-7®, which has new software version for measurement of total Hb, in cardiac surgery patients using cardiopulmonary bypass (CPB).