EFFICACY OF ROCURONIUM PRIMING VERSUS PRE-TREATMENT WITH MAGNESIUM SULPHATE DURING ROCURONIUM INTUBATION FOR ELECTIVE GENERAL SURGICAL CASES. A RANDOMISED, PROSPECTIVE, DOUBLE-BLINDED CONTROLLED TRIAL

BACKGROUND Rocuronium is a non-depolarising muscle relaxant, which has the ability to produce good-to-excellent intubating conditions within 60 - 90 seconds without side effects, but still Succinylcholine only has the advantage of producing excellent intubating conditions in less than 60 seconds. Application of priming principle, pre-treatment with agents like magnesium, sevoflurane, lignocaine, ephedrine etc.; in various randomised clinical trials and proved to be of varying efficacy in reducing the time of onset of rocuronium blockade. In this study, the aim is to determine whether priming dose of rocuronium versus pre-treatment with magnesium sulphate 3 minutes prior to intubating dose of rocuronium produces rapid onset of muscle relaxation and optimal intubating conditions. MATERIALS AND METHODS This is a randomised, double-blinded controlled trial. After Institutional Ethical Committee approval and written informed consent, 75 patients belonging to both genders were randomly taken for this double-blinded, prospective and placebo-controlled study. Patients belonging to ASA I/II, both sexes, aged between 18 - 60 yrs., weighing 40 - 80 kgs, Mallampati grading I/II, posted for elective general surgical cases were taken up for this study. Patients were randomly divided into three groups of 25 each. Group RR: Patients were assigned to receive 0.06 mg/kg of IV rocuronium as priming dose in a volume of 3 mL 3 minutes prior to intubating dose of rocuronium 0.54 mg/kg. Group RM: Patients were assigned to receive 30 mg/kg of IV magnesium sulphate in 100 mL of normal saline 10 minutes prior to induction of general anaesthesia. Group RC: Patients were assigned to receive 100 mL of normal saline 10 minutes before induction and 3 mL of normal saline 3 minutes before intubating dose of rocuronium 0.6 mg/kg IV to ensure blinding. The following parameters were assessed during and after intubation and at specific time points following intubation. Haemodynamic parameters were assessed at baseline, 1 min, 3 mins and 5 mins following intubation, mean onset time of muscle relaxation, mean time taken for laryngoscopy and intubation and intubating conditions were assessed. RESULTS The mean onset time to muscle relaxation was significantly less in the rocuronium priming group and rocuronium with magnesium group when compared to the control group, p < 0.001, statistically significant. 92% (23) of cases in RR group reported excellent intubating conditions, 84% (21) of cases in RM group reported excellent intubating conditions and only 40% (10) of cases in the control group reported excellent intubating conditions. CONCLUSION Interventions like rocuronium priming and/or pre-treatment with magnesium sulphate significantly accelerated the onset time to intubating dose of rocuronium when compared to control group.