Effect of Dexmedetomidine on Stress-Induced Changes in Hemodynamic and Left Ventricular Function in Coronary Artery Bypass Grafting Surgery: A Randomized Controlled Trial

Background: Dexmedetomidine is a highly selective central adrenoceptor agonist with a short half-life, making it an ideal intravenous drug for blunting the stress response. Objectives: The present study aimed to determine the effect of dexmedetomidine on left ventricular function and its ability to attenuate the hemodynamic response to skin incision, sternotomy, and the postoperative period in coronary artery bypass graft (CABG) surgery. Methods: This randomized controlled clinical trial included 64 patients of both sexes who underwent elective CABG surgery. They were randomly assigned to two equal groups: Group D received a continuous infusion of dexmedetomidine (0.5 µg/kg/h) one hour before the induction of anesthesia until immediately before transfer to the intensive care unit (ICU), while group C received a continuous infusion of 0.9% saline at a rate of 10 mL/h. Results: The heart rate (HR) and mean arterial blood pressure in group D exhibited significant differences starting 3 minutes following skin incision and continuing for 4 hours (P < 0.05). Although they changed postoperatively, the pre- and post-bypass ejection fraction (EF) did not change significantly between the two groups. The need for inotropic support was significantly higher in group D. Additionally, the incidence of new-onset atrial fibrillation was significantly lower in group D. Conversely, both groups showed no significant differences in serum lactate levels, the incidence of bleeding and reopening, pacemaker usage, mechanical ventilation, ventricular fibrillation, and bradycardia. Conclusions: Using a 0.5 µg/kg/h dexmedetomidine infusion as pretreatment is a secure and effective method for decreasing stress-induced reactions and improving hemodynamic stability, without any noticeable adverse effects.