[CONTINUOUS HEMOGLOBIN MONITORING USING PULSE CO-OXIMETRY IN CARDIAC SURGERY.]

The aim: To assess the accuracy ofcontinuous hemoglobin monitoring using pulse co-oximetry and revealfactors affecting the results of the measurements during early postoperative period in cardiac surgery.

Materials and methods: 27 patients undergoing off-pump CABG and 16patients after elective complex (repair or replacement of two or more valves) or combined (valve and coronary artery) cardiac surgery requiring CPB were enrolled into a prospective observational study. Both groups received continuous hemoglobin monitoring using pulse co-oximetry (SpHb). During early postoperative period SpHb was compared with hemoglobin concentration in the arterial blood (Hbart).

Results: Wefoundpositive correlation between SpHb and Hb in both groups (rho =0,29, p < 0,05 u rho=0,34; p<0.005 respectively). The Bland-Altman analysis showed a bias ? limits of agreement (?I.96 SD) between the continuously measured hemoglobin and reference arterial blood hemoglobin concentration of -6,0 ? 41,0 g/l in the off-pump group and 7,7 k 31,0 g/l in the CPB group.

Conclusions: Hemoglobin measurement using pulse co-oximetry does not provide acceptable accuracy during early postoperative period in cardiac surgery. Applicability of this technology is influenced by vascular tone, systemic and regional tissue hypoperfusion.