The effects of magnesium sulphate-pretreatment on suxamethonium-induced complications during induction of general endotracheal anaesthesia.

To determine the effects of Magnesium-Sulphate-pretreatment on Suxamethonium-induced complications (serum potassium rise, fasciculations and apnea). Eighty-four adult patients were selected and randomly allocated into two study groups during induction of general endotracheal anaesthesia. Endotracheal intubation was facilitated with suxamethonium in group A, while in group B magnesium sulphate pretreatment and suxamethonium. Blood sample for serum potassium estimation was taken before induction and at 5 min after induction. Degree of fasciculations and duration of apnea were assessed clinically. Anaesthetic technique and monitoring of patient was standardized. This study showed statistically significant increase in serum potassium of Group A patients {average 0.34 mmol/L} from baseline value p value 0.00. Magnesium sulphate pretreatment significantly reduced suxamethonium-induced hyperkalaemia by an average of 0.3 mmol/L (p-value 0.01). The severity of fasciculations was also significantly reduced (p-value 0.00). There was no significant effect of magnesium pretreatment on duration of apnea during endotracheal intubation (p-value 0.41). Fourteen point six percent (14.6%) of patients that received magnesium pretreatment complained of feeling of heat or warmth but there was no life threatening dysrrhythmias observed in any of the eighteen patients that had continuous ECG monitoring. The study shows that magnesium sulphate pretreatment has significantly reduced suxamethonium-induced hyperkalaemia and severity of fasciculations during induction of general endotracheal anaesthesia, however there was no significant effect on the duration of apnea. The average of 0.034 mmol/L in Group B was not significant {p value 0.06}. We advocate the use of magnesium pretreatment in all patients at risk of these complications.