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

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. In a double-blinded, randomized clinical trial, 100 adult patients – who were candidated for elective isolated CABG surgery - were divided equally into two groups of low-dose Dopamine group (2 µg / 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. 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. The use of low-dose Dopamine did not decrease lactate levels in our CABG patients using CPB