A comparative study of dexmedetomidine, magnesium sulphate, or glyceryl trinitrate in deliberate hypotension during functional endoscopic sinus surgery

Context Induced hypotension to minimize bleeding during functional endoscopic sinus surgery ( FESS) is of vital importance to the surgeon and anesthetist to decrease the risk of complications as well as procedural failure. Aim This study was designed to compare the efficacy of dexmedetomidine, magnesium sulfate, or glyceryl trinitrate in inducing deliberate hypotension during FESS and their effect on postoperative recovery, discharge, and postoperative analgesic requirement. Settings and design This was a randomized prospective single-blind study. Patients and methods Sixty patients of ASA physical status I or II scheduled for FESS were equally randomly assigned into three groups. The glyceryl trinitrate group (the G group) received glyceryl trinitrate infusion of 2–10 μg/kg/min. The dexmedetomidine group (the DEX group) received dexmedetomidine bolus of 1 μg/kg, followed by 0.2–0.7 μg/kg/h infusion for maintenance, and the magnesium sulfate group (the M group) received a bolus of 50 mg/kg magnesium sulfate, followed by infusion of 15 mg/kg/h for maintenance. The target mean arterial pressure was 55–65 mmHg. Hemodynamic parameters, blood lose, surgical field quality, intraoperative atropine, ephedrine or fentanyl use, emergence time, time to achieve an Aldrete score of 9 or greater, sedation score, time of discharge from postanesthesia care unit, and time to first analgesic request were recorded. Results The studied drugs achieved the target mean arterial pressure (55–65 mmHg) with superior hemodynamic stability in the DEX group. Intraoperative blood lose and quality of the surgical field were comparable. Both dexmedetomidine and magnesium sulfate offered the advantage of inherent analgesic and sedative effect, but at the expense of longer recovery of anesthesia and discharge from postanesthesia care unit. Conclusion Dexmedetomidine, magnesium sulfate, or glyceryl trinitrate induced deliberate hypotension, with superior hemodynamic stability in dexmedetomidine. Analgesic and sedative effects were obtained with dexmedetomidine and magnesium sulfate, but with longer recovery and discharge times.