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

•The excellent intubating condition was more frequent in the magnesium group.•No difference in onset time was found between magnesium and rocuronium 0.9 groups.•Onset of neuromuscular block was shorter in the magnesium group than residual groups.

Study objectivesWe 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.DesignThis is a prospective, randomized, double-blinded study.SettingThe setting is at an operating room in a university-affiliated hospital.PatientsOne hundred ten patients scheduled for general anesthesia were randomly allocated to the following 5 groups in equal numbers.InterventionsThe 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.MeasurementsIntubating condition (primary outcome), rocuronium onset, rocuronium duration, train-of-four ratio upon intubation, and hemodynamic variables (secondary outcomes) were recorded.Main resultsThe 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.ConclusionsMagnesium 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.