Continuous Infusion Versus Intermittent Bolus Injection of Rocuronium

Inclusion Criteria: * Pediatric patients aged between 2 and 12, undergoing elective noncardiac surgery which requires general anesthesia but does not require intense block, and estimated time of surgery is between 2 and 5 hours Exclusion Criteria: * ASA class 3-6 * BMI \>= 30 * Previous history of hepatic failure, renal failure or neuromuscular disease * Patients taking medicine which interacts with rocuronium bromide, before or during surgery: aminoglycosides, lincosamides, acylamino-penicillin antibiotics, tetracyclines, metronidazole (high dose), diuretics, MAO inhibitors, calcium channel blockers, corticosteroids, phenytoin, carbamazepine, or norepinephrine * Previous history of allergic reaction (including anaphylactic reaction) and/or malignant hyperthermia during general anesthesia * Patients taking medicines which contains magnesium