BACKGROUND: Remifentanil is an opioid agonist with rapid onset and ultra-short duration of action. Rocuronium bromide can elicit a high incidence of pain when intravenous injection. In this study, the quantitative effect of remifentanil pretreatment on the injection pain of rocuronium and cardiovascular response during anesthetic induction were evaluated.

METHODS: Eighty adult female patients undergoing gynecological procedures with general anesthesia were analyzed for this study. Patients were randomly allocated to one of four groups. Patients received 2 ml of normal saline (n = 20), 2 ml (40 mg) of 2% lidocaine (n = 20), 2 ml of remifentanil 0.5 µg/kg (n = 20) or 2 ml of remifentanil 1 µg/kg (n = 20) 60 seconds prior to administration of rocuronium 0.7 mg/kg. Pain was assessed after rocuronium injection. Systolic and diastolic arterial blood pressure and heart rates were measured before and during anesthetic induction.

RESULTS: Both remifentanil and lidocaine have the good effect in minimizing the rocuronium injection pain. But, only 1 µg/kg of remifentanil blunts the hypertension after endotracheal intubation.

CONCLUSIONS: A bolus dose (1 µg/kg) of remifentanil may be used for minimizing the rocuronium injection pain and blunting the hypertension after endotracheal intubation.