Rationale:

Pediatric Adenotonsillectomy is a common procedure of brief performed on a day-case basis, in which rapid recovery with safe airway after extubation is crucial. Sevoflurane is considered the inhaled anesthetic of choice in such procedures, however it has been reported that emergence agitation (EA) is a frequent complication in 30-80% of children receiving sevoflurane general anesthesia. The possible effect of magnesium sulphate on decreasing the incidence of EA in children was not adequately investigated.

Objective:

To assess the possible effects of intraoperative intravenous magnesium sulphate (MgSO4) infusion on the incidence of sevoflurane-induced EA in children undergoing adenotonsillectomy.

Study population and sample size:

Children 4-7 years, ASA physical status I or II, undergoing Adenotonsillectomy under sevoflurane general anesthesia. 64 patients (32/group) is required to detect a significance difference of 40% in the incidence of agitation between two groups, with a power of 80% and alpha error of 5%.

Study design:

A double blind, randomized, placebo controlled study.

Method:

In the placebo group, a normal saline bolus dose 0.3ml/kg will be iv infused followed by a continuous infusion of 0.1 ml/kg/h. In the MgSO4 group, a MgSO4 bolus dose 0.3mL/kg will be iv infused followed by a continuous infusion of 0.1 ml/kg/h. infusion terminated by the end of surgery. Post operative emergence agitation will be assessed by using the Pediatric Anesthesia Emergence Delirium scale.

Possible risks:

Drug side effects such as facial warmth, flushing, dry mouth, and malaise.

Outcome parameters:

The primary outcome: incidence of sevoflurane-induced EA measured using the Pediatric Anesthesia Emergence Delirium (PEAD). Secondary outcome: postoperative pain and rescue analgesic requirements, perioperative hemodynamics, durations of recovery, postoperative complications

Statistical analysis plan:

Student's t-test or Mann Whitney-U and Chi square or Fisher's exact tests will be used as appropriate. The possible relationship between EA and pain scores will be evaluated with the use of Spearman's rank correlation coefficient

Time plan:

6-9 months.

Inclusion Criteria:

Children 4-7 years, ASA physical status I or II, undergoing Adenotonsillectomy will be included in the study.

Exclusion Criteria:

• The study will exclude children with behavioral changes, physical developmental delay and children on treatment with sedative or anticonvulsant. Also children with pre-existing renal disease or cardiovascular diseases will be excluded.