This randomised, double-blind, placebo-controlled
study was designed to assess the homodynamic effects of
administered i.v. magnesium sulphate technique of
hypotensive anaesthesia as well as its effect on duration
of surgery and the amount of blood loss during FESS.
forty patients 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
and15mg 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.In the magnesium
group,there was a reduction in surgical time 60.2 ±15
min vs. 88.1 ±10 min , although the anesthetic time was
12 min longer and thus presuming a prolongation in
anaesthetic emergence.There was a significant reduction
of blood loss 160 ±19 ml vs. 270 ±25 ml in magnesium
group.. The preanesthetic and preoperative MAP were
not significantly different between the groups (p= 0.102
and (p=0.716) respectively, but at 5,10,15,30 and 60 min
and at end of surgery they were significantly lower in the
magnesium group (p