Efficacy of Low‑dose Suxamethonium in Reducing Induction Dose of Propofol for Laryngeal Mask Airway Insertion in Nigerian Adults

Abstract

Background: Propofol is commonly used as a sole induction agent during laryngeal mask airway (LMA)  insertion, and additional doses are often required with systemic consequences.

Objective: Our study evaluated the effect of 0.1 mg/kg suxamethonium on the dose of induction of propofol when used during insertion of LMA.

Methodology: Eighty patients aged between 18 and 60 years were included in this prospective study. Patients undergoing elective  procedures under general anaesthesia with LMA and spontaneous ventilation were randomized into two groups. Patients in both groups were induced with an initial dose of 2.5 mg/kg of propofol; the control group (group P) and the second group (group S) received 5 ml of normal saline and 0.1 mg/kg of suxamethonium made up to 5 ml, respectively. The need for additional doses of propofol following  insertion of LMA was then assessed based on insertion conditions (ease of insertion, severity of airway response in terms of coughing, gagging, laryngospasm, and patient movement). The total dose of propofol required before successful insertion was recorded, as well as the incidence and duration of apnea post-induction. The pulse rate (PR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were assessed at 0, 1, 3 and 5 min after insertion of LMA for each group.

Results: The total dose of propofol required for successful LMA insertion was significantly lower in group S (2.82 ± 0.39 mg/kg) compared to group P (3.13 ± 0.49 mg/kg), P = 0.002. Haemodynamic parameters (SBP, DBP, MAP, PR, and SpO2) were well-controlled post-LMA insertion and were comparable between the two groups. Furthermore, no incidence of hypotension or bradycardia requiring intervention was observed at different time intervals, throughout the study period, in both groups.

Conclusion: The dose of propofol is lesser when low‑dose suxamethonium (0.1 mg/kg) precedes its use for induction during LMA insertion, and there is a reduction in the duration of apnea; however, it causes a higher apnea incidence. Vital signs were similar in the two study groups.