Continuous noninvasive monitoring of the hemoglobin during cardiac surgery and comparative analysis with existing technique

Abstract

Hemoglobin (Hb) concentration monitoring is the most required analysis during surgery and critical care treatment to make proper decision regarding blood transfusion. Blood gas analysis is required invasive intermittent blood sampling. Various non-invasive Hb monitoring techniques are under research for better real time patients’ management. Masimo rainbow® Pulse CO-Oximeter® is to monitor continuous and noninvasive hemoglobin (SpHb) whereas blood samples give intermittent results. Recently, disposable SpHb sensor has been updated. We evaluate the SpHb sensor compared with total Hemoglobin(tHb) in patients undergoing cardiac surgery using cardiopulmonary bypass (CPB). A total of 272 SpHb and tHb paired data samples from 60 patients. To analyze the tHb, the patients’ blood samples were drawn intermittently by the radial arterial line and blood gas analyzer ABL 90 (Radiometer corp., Denmark) as per anesthesiologist decision. SpHb sensors (RD rainbow SET-2 Adt sensor, Masimo Corp., USA) were attached to the patients’ ring finger connected to Root® with Radical-7®. Reliability and trending ability between the SpHb and tHb were analyzed by the regression analysis, Bland-Altman analysis, four quadrant plots and polar plot. Limits of agreement between SpHb and tHb is calculated to be -2.01 to 2.2 g/dL with a bias of 0.13 g/dL. The correlation coefficient (r) of SpHb and tHb were 0.8036. Concordance ratio of four quadrant and polar plots were 93% and 91%, respectively. Both Absolute and trend accuracy of SpHb with the latest version are clinically acceptable in patients undergo cardiac surgery using CPB.