Effect of Low-Dose Dopamine on Lactate Level in Patients Undergoing Coronary Bypass Surgery

Background: The aim of this study was to study the effect of low-dose Dopamine on the blood lactate levels as a sign of visceral perfusion in coronary artery bypass graft surgery (CABG) patients. Methods: In a double-blinded, randomized clinical trial, 100 adult patients – who were candidate for elective isolated CABG surgery - were divided equally into two groups of low-dose Dopamine group (2 ?g / kg / min) and control group (n=50 in each). Lactate levels, arterial blood gas analyses, blood pressure, and heart rate were recorded intraoperatively at four time points: before the induction of anesthesia; 15 minutes after the beginning of cardiopulmonary bypass (CPB); during CPB at rewarming to 34?C; and 15 minutes after separation from CPB. These biochemical and hemodynamic parameters were compared in these four time points between the two study groups. Results: Arterial blood gas and hemodynamic parameters were similar between the two groups during surgery (p values > 0.05). There were no significant differences between the lactate levels in the Dopamine and control groups at the beginning of CPB (3.1 ± 2.5 vs. 2.6 ± 2.0 mg/dl; p value = 0.453), at the time of rewarming (3.1 ± 2.5 vs. 2.6 ± 2.0 mg/dl; p value =0.510), and after CPB (3.1 ± 2.5 vs. 2.6 ± 2.0 mg/dl; p value = 0.551) - respectively. Conclusions: The use of low-dose Dopamine did not decrease lactate levels in our CABG patients using CPB.