A Prospective Randomized Double Blind Controlled Study Evaluating the Effects of Dexmedetomidine on Haemodynamic Status in Patients Undergoing Laparoscopic Assisted Vaginal Hysterectomy

Background: Intraoperative hypertension and tachycardia are common hemodynamic disturbances in patients undergoing laparoscopic assisted vaginal hysterectomy. In addition there is increase in systemic vascular resistance, and is associated with a decrease in cardiac index and metabolic changes. Dexmedetomidine a centrally acting α-2 agonist has been particularly effective in blunting the haemodynamic response to tracheal intubation and pneumoperitoneum. Methodology: Sixty patients, scheduled for elective laparoscopic assisted vaginal hysterectomy belonging to ASA class I and II, in the age group 38 to 55 years were included in the study and they were assigned randomly into two groups.Group D (n=30): received dexmedetomidine as a bolus of 0.6 μg/kg body weight (0.3 ml/kg body weight) over 10 min intravenously, 10 min before induction, followed by infusion at a rate of 0.2 μg/kg/hr(0.1 ml/kg/hr) throughout the surgery. Group C (n=30): received bolus of normal saline at a rate of 0.3 ml/kg body weight in 50 ml syringe over 10 min intravenously, 10 min before induction followed by infusion at a rate of 0.1 ml/kg/hrthroughout the surgery. Results: It was noted that HR, SBP, DBP and MAP in group D were significantly decreased after intubation, throughout the period of pneumoperitoneum and after extubation. In addition dexmedetomidine produced arousable sedation after extubation, decreased the incidence of post operative nausea and vomiting without significant side effects like bradycardia and hypotension. Conclusion: Dexmedetomidine as a single bolus dose of 0.6 μg/kg body weight and continuous infusion at a rate of 0.2 μg/kg/hr was seen to effectively attenuate the haemodynamic response to laryngoscopy and tracheal intubation and also to pneumoperitoneum without any side effects.