title: Magnesium sulphate as a technique of hypotensive anaesthesia.
abstract: BACKGROUND
  This randomized, double-blind, placebo-controlled study was designed to assess the effect of perioperatively administered i.v. magnesium sulphate as a technique of hypotensive anaesthesia.
  
  
  METHODS
  Sixty patients (25 female) undergoing functional endoscopic sinus surgery were included in two parallel groups. The magnesium group received magnesium sulphate 40 mg kg(-1) i.v. as a bolus before induction of anaesthesia and 15 mg kg(-1) h(-1) by continuous i.v. infusion during the operation. The same volume of isotonic solution was administered to the control group. Intraoperative bleeding was evaluated using a quality scale.
  
  
  RESULTS
  In the magnesium group, there was a reduction in surgical time [68.1 (15.6) min vs 88.1 (10.7) min], although the anaesthetic time was 10 min longer and thus presuming a prolongation in anaesthetic emergence. There was a significant reduction of blood loss [165 (19) ml vs 257 (21) ml]. The anaesthetic requirements (fentanyl, vercuronium and sevoflurane), mean arterial blood pressure (P<0.005) and heart rate (P<0.005) were also significantly reduced.
  
  
  CONCLUSIONS
  Magnesium sulphate led to a reduction in arterial pressure, heart rate, blood loss and duration of surgery. Furthermore, magnesium infusion alters anaesthetic dose requirements and emergence time.
authors: Department of Anesthesiology and Intensive Care, Faculty of Medicine, Ain-shams University, Cairo, Egypt. nmelsharhnouby@hotmail.com
authors: N M
authors: NM
authors: Elsharnouby
authors: M M
authors: MM
authors: Elsharnouby