Comparison of Regional Cerebral Oxygen Saturation (rSO2) and Central Venous Oxygen Saturation (ScvO2) as Predictors of Outcome in Off Pump Coronary Artery Bypass Graft (OPCABG) Surgery Patients

Abstract

Objectives: Aim of the study was to compare central venous oxygen saturation (ScvO2) and regional cerebral oxygen saturation (rSO2) to see which of the two is better predictor of prognosis of patients undergoing off–pump coronary artery bypass grafting (OPCABG). Heart rate (HR), invasive blood pressures, and partial pressure of oxygen (pO2) have also been recorded to see if they are independent predictors of prognosis in OPCABG patients. Materials and Methods: A total of 56 patients undergoing OPCABG were included in the study. Baseline values and intraoperative values of ScvO2, rSO2, HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP), pO2 at different time periods were recorded. Post-operatively the patients were shifted to Intensive care unit (ICU) on elective ventilation, and time to extubation since shifting to ICU were noted. Results:The ScvO2 values after sternal closure (correlation coefficient r= -0.4821, P=0.0002), and on shifting to ICU (correlation coefficient r= -0.4575, P=0.0004) showed strong correlation with time to extubation. Similarly the rSO2 values after sternal closure (correlation coefficient r=-0.5198, P<0.0001) and on shifting to ICU (correlation coefficient r = -o.5498, P<0.0001) showed strong correlation with time to extubation. HR SBP, DBP, MAP, pO2 individually didn’t show any correlation with time to extubation (P>0.05). Conclusion:ScvO2 and rSO2 both have strong correlation with time to extubation and are capable of predicting prognosis in OPCABG patients.