A comparative study between magnesium sulphate and dexmedetomidine for deliberate hypotension during middle ear surgery

AbstractBackgroundThis study was designed to compare magnesium sulphate with dexmedetomidine, regarding their efficiency in inducing deliberate hypotension and providing a better surgical field exposure during middle ear surgery. It also compared the influence of their use on postoperative pain and recovery time.MethodsEighty-eight adult patients undergoing middle ear surgery were included. Patients were randomly divided into two equal groups. Patients were assigned to receive either magnesium sulphate (M group) or dexmedetomidine (D group). Anaesthesia was induced by propofol 2mg/kg iv and fentanyl 1μg/kg. Patients in the M group received an iv bolus of magnesium sulphate 50mg/kg in a total of 100ml saline over 10min followed by infusion of 15mg/kg/h until the end of surgery. Similarly, patients in the D group received dexmedetomidine 1μg/kg over 10min followed by 0.4–0.8μg/kg/h until the end of operation. The target MAP during operation was between 60 and 70mmHg. The surgeon who was blinded of the selected hypotensive agent was asked to assess the quality of the surgical field. In the postanaesthesia care unit (PACU), postoperative pain was assessed and recovery time was recorded.ResultsBoth study drugs succeeded to reach the target MAP. The quality of the surgical field was not different between the two groups. Postoperative pain was not different between the two group and only eight patients in the M group and seven patients in the D group required analgesics. Recovery time was significantly longer for the patients in group D (p