Impact of Dexmedetomidine on Hemodynamic Changes during and after Coronary Artery Bypass Grafting

Objective: To determine the effect of dexmedetomidine (Dex) on hemodynamic changes during cardiopulmonary pump and postoperative period in coronary artery bypass grafting (CABG). Methods and Design: This study is designed as a double-blinded, randomized clinical trial. Setting: University hospital and single center. Participants: patients candidate for elective CABG. Intervention: Dex 0.5 mg/kg/h or placebo was infused from the initiation of anesthesia up to extubation in Intensive Care Unit (ICU). Measurements: Heart rate (HR) and blood pressure (BP), pain score, and total morphine dose requirement were monitored and compared during cardiac pump up to 12 h postoperative in ICU. Results: Mean arterial pressure was significantly higher in Dex group in postoperation period at 1 (P = 0.010) and 2 h (P = 0.002) compared to control group. HR was significantly lower in Dex group in postcardiopulmonary bypass (CPB) time at 0 h (P = 0.001), 1 h (P = 0.0016), and 2 h (P = 0.001), and then in postoperative period in ICU at 1 h (P = 0.025), 2 h (P = 0.0012), and 4 h (P = 0.0025) compared to control group. Postoperative pain score was significantly lower during 12 h after surgery. Conclusion: Dex could effectively blunt hemodynamic response to surgical stress, particularly during CPB pump and afterward. Infusion of Dex maintains BP at higher range and HR at lower range compared to placebo.