Effect of Prophylactic Vasopressin on Hemodynamic Parameters after Coronary Artery Bypass Graft Surgery

Background: As common complications of Coronary artery bypass grafting (CABG), low vascular resistance and hypotension could be life threatening . The aim of present study was to investigate the effect of low-dose vasopressin on hemodynamics in CABG patients.Material &Methods: In this randomized double-blinded clinical trial, 80 patients undergoing selective CABG were randomly divided into two equal case and control groups (n=40). Case group was received vasopressin 0.03 IU/min 30 minute before the end of cardio-pulmonary bypass (CPB) until one hour after that. Control group was received normal saline in the same manner. Dopamine?requirement, ICU stay, heart rate (HR), mean arterial blood pressure (MAP), central venues pressure (CVP) and atrial blood acidity (PH) were recorded and compared between groups ?in 5 phases ( 0,30,60,90,120 min) after separation of CPB.Results: There was no significant difference between two groups in number of patients with severe hypotension (11 vs. 12 patients in case and control group respectively). CVP was corrected and then dopamine administration was compared in both group. In vasopressin and placebo group, 3 vs 11 patients need to dopamine administration immediately after separation from CPB (p= 0.018) and 4 vs 12 patients later in ICU (p=0.024) respectively. The mean needed dose of dopamine in vasopressin and placebo group immediately after separation from CPB were 7.63?3.42 vs 9.21?2.08 ?g/kg/min (p=0.031) and later in ICU were 7.42?2.02 vs 8.66?4.08 ?g/kg/min (p=0.045) respectively, which was significantly lower in vasopressin group in comparison with placebo group.Conclusion: Based on our results low-dose vasopressin administration significantly reduced the mean needed dose of required dopamine, 24 hours urinary output, Duration of mechanical ventilation and patient?s heart rate.