The Effect of a Pre-induction Bolus Dose of Magnesium Sulphate on Emergence Agitation after Sevoflurane Anesthesia in Children Undergoing Adenotonsillectomy.

Background: Magnesium sulphate has been shown to have sedative and antinociceptive effect in animal and human models of chronic pain, opiate detoxification and severe manic agitation. Sevoflurane is associated with a high incidence of emergence agitation in children. In this placebo-controlled study, we examined the effect of IV magnesium sulphate on emergence agitation in children undergoing adenotonsillectomy. Methods: In a double blinded trial, 40 children, ASA I, (age 3-12 years) undergoing an adenotonsillectomy were randomly assigned into one of two groups: they received magnesium sulphate (30 mg/kg IV) or (saline) pre-induction. For induction and maintenance of anesthesia, we used sevoflurane. For analgesia, all children received fentanyl (1μg/kg) just before induction and acetaminophen suppository (15 mg/kg) after intubation. After surgery, the severity of agitation and pain were assessed with (a 5-point agitation scale and objective pain score (OPS) respectively). Results: Severe agitation (a score of 4), and severe pain (a score of 7 or more) were significantly less in the magnesium group (P 0.05). There was no significant difference in the time of surgery, duration till living the recovery room and the occurrence of postoperative complications (e.g. vomiting) between the two groups. Conclusions: We conclude that 30 mg/kg magnesium sulphate IV bolus reduces agitation after sevoflurane anesthesia in children undergoing adenotonsillectomy.