Serum lactate as a prognostic factor in coronary artery bypass graft operation by on pump method

Background: Lactic acidosis in cardiac surgical patients is a manifestation of systemic inflammation and excess pro-inflammatory cytokine production. This investigation was designed to integrate basic concepts about lactate acidosis with a clinically used of serum lactate in patients under coronary artery bypass surgery (CABG) by on pump method. Methods: From August to September 2012, 15 patients scheduled for routine cardiac surgery entered to our sample and followed up two weeks. Lactate concentration in arterial blood sample was studied. Method of surgery duration of cardiopulmonary bypass, aorta cross clamp timing, hemodynamic parameters, inotrope dosage and patient outcome were documented. The data were collected and analyzed. Results: The mean age of the patients was 62±14 years. The patients with a poor outcome had significantly higher lactate levels in ABG samples (p < 0.001). ABG lactate levels did not correlate with the magnitude of intra-operative bleeding or volume of packed cell transfusion (p > 0.05). The PH of ABG samples did not generally correlate with the ABG lactate concentration (r=0.116, p=0.68). Increased lactate concentration was reliably associated with patient hemodynamic parameters, inotrope dosage, duration of on pump time and aorta cross clamp time. Conclusion: This study demonstrates a correlation between serum lactate levels and patient prognosis after CABG surgery by on pump method.