OBJECTIVETo determine the effect of neostigmine on antagonizing atracurium-induced neuromuscular blockage with sulfate magnesium pretreatment.

METHODSForty patients who undertook elective gynecologic laparoscopic examinations and treatments under general anesthesia were randomized into four groups (group A, B, C, and D, group A paired with group C, and group B paired with group D). Before induction of general anesthesia, patients in group A and group C received MgSO4 30 mg/kg in saline intravenously within 5 min, while patients in group B and group D received the same volume of saline. Anesthesia was induced with fentanyl and propofol; subsequently tracheal intubation was performed with 0.5 mg/kg atracurium after stabilization of the electromyography recording, and neostigmine (0.02 mg/kg) and atropine (0.01 mg/kg) were infused in group C and group D when neuromuscular recovery (T1/T(C)) reached 10%. T1/T(C) changes after neostigmine infusion as well as haemodynamic changes and other responses during induction and neostigmine and atropine infusion were recorded.

RESULTSThe neuromuscular recovery speed had no significant difference between group A and group B after the neuromuscular recovery reached 10%, but it was lower in group C than in group D (P < 0.05). Significant difference existed between group AC and group BD (P < 0.05). No haemodynamic changes and other responses were found during induction and neostigmine and atropine infusion.

CONCLUSIONNeostigmine-induced neuromuscular recovery can be attenuated in patients pretreated with magnesium sulfate.