The effect of magnesium sulphate on intubating condition for rapid-sequence intubation: a randomized controlled trial.

STUDY OBJECTIVES

We compared magnesium sulphate with control, ketamine, rocuronium prime, and large-dose rocuronium (0.9 mg/kg) with regard to intubation conditions during rapid-sequence induction.

DESIGN

This is a prospective, randomized, double-blinded study.

SETTING

The setting is at an operating room in a university-affiliated hospital.

PATIENTS

One hundred ten patients scheduled for general anesthesia were randomly allocated to the following 5 groups in equal numbers.

INTERVENTIONS

The control and rocuronium 0.9 groups received rocuronium 0.6 and 0.9 mg/kg, respectively; the ketamine group was given 0.5 mg/kg ketamine 2 minutes before 0.6 mg/kg rocuronium; the rocuronium prime group received 0.06 mg/kg rocuronium 3 minutes before 0.54 mg/kg rocuronium; and the magnesium group received 50 mg/kg magnesium sulphate. Intubation was initiated 50 seconds after the rocuronium injection.

MEASUREMENTS

Intubating condition (primary outcome), rocuronium onset, rocuronium duration, train-of-four ratio upon intubation, and hemodynamic variables (secondary outcomes) were recorded.

MAIN RESULTS

The excellent intubating condition was more frequent in the magnesium group (P < .05). Onset of neuromuscular block was shorter in the magnesium group than in the control, ketamine, and rocuronium prime groups (P < .05). No difference in onset time was found between the magnesium and rocuronium 0.9 groups. Block duration was longest in the rocuronium 0.9 group. The train-of-four ratio on intubation was lowest in the rocuronium prime group. The only adverse event was a burning or heat sensation reported by 5 patients in the magnesium group.

CONCLUSIONS

Magnesium sulphate pretreatment was most likely to provide excellent intubating condition for rapid-sequence intubation compared with the control, ketamine pretreatment, rocuronium prime, and large-dose rocuronium. However, magnesium sulphate administration is associated with a burning or heat sensation.