Controlled Hypotension During Endoscopic Sinus Surgery: A Comparison of Propofol and Magnesium Sulfate

Objective: Controlled hypotension is considered as an effective technique for reducing blood loss and optimizing the surgical field. This study was designed to compare intravenous infusion of propofol and magnesium sulfate for achieving controlled hypotension during elective endoscopic sinus surgery.

Methods: This randomized, double blinded, comparative study was conducted on fifty patients of either sex, aged between 18 and 45 years old underwent elective endoscopic sinus surgery. Patients were randomly categorized into two equal groups (25 patients each). Propofol group: patients were received intravenous infusion 75 mcg/kg/min of propofol for the first 15 minutes post induction and then a maintenance infusion of propofol (50 mcg/kg/min). Magnesium group: before induction of anesthesia, magnesium sulfate intravenous infusion was started at 40 mg/ kg in 100 ml saline over 10 minutes as a loading dose then magnesium sulfate infusion of 167 mcg/kg/min during surgery. Perioperative mean arterial blood pressure and heart rate were recorded. The intra-operative surgical field assessment and surgeon satisfaction score were assessed. The recovery profile was assessed by Ramsay sedation score and modified Aldrete score. Postoperative complications in the terms of postoperative nausea and vomiting and shivering were also recorded.

Results: The intraoperative mean arterial blood pressure was significantly decreased in propofol group at 15, 30, 45, 60 and 75 minutes after induction when compared to magnesium group. However, perioperative heart rate showed no significant changes between both studied groups. No statistical changes between the two studied groups as regard surgeon satisfaction and bleeding scores. Nitroglycerine doses were significantly higher in magnesium group than propofol group (P value<0.001). Postoperative Ramsay sedation scores were statistically significant higher, and the recovery time was significantly longer in magnesium group compared to propofol group (P value <0.001). Postoperatively shivering was significantly higher in propofol group compared to magnesium group while nausea and vomiting showed no significant changes between both groups.

Conclusion: This study concluded that intravenous infusion of propofol provided easily controlled hypotension, while intravenous infusion of magnesium sulfate was associated with a better recovery profile and reducing the incidence of postoperative shivering.

Keywords: Controlled hypotension; Magnesium sulfate; Propofol; Endoscopic sinus surgery