Correlation of Blood Lactate and Mixed Venous Oxygen Saturation in Off-Pump CABG

Aim: To evaluate the correlation of blood lactate and mixed venous oxygen saturation to predict outcome in off-pump coronary artery bypass grafting. Method: This is a randomized study including 30 patients. Blood lactate and mixed venous oxygen saturation were measured in 4 groups of patients—number of grafts, presence or absence of left main coronary artery disease, ejection fraction and serum creatinine. Blood samples were taken before induction, after grafting, on intensive care unit admission, 24 hours and 48 hours after surgery. The measured blood lactate and mixed venous oxygen saturation are compared to assess the outcomes in terms of duration of ventilation and intensive care unit stay. Results: The blood lactate and mixed venous oxygen saturation values increased post operatively but no statistically significant difference in three groups— number of grafts, left main coronary artery disease and ejection fraction. In serum creatinine group, the blood lactate value was found to be statistically significant after grafting in patients with creatinine <1.5 mg/dl, however, there was a significant disparity in numbers. Conclusion: Mixed venous oxygen saturation is a better predictor of morbidity than blood lactate in terms of intensive care unit stay in patients undergoing off pump coronary artery bypass grafting.