The use of mini-dose suxamethonium to facilitate the insertion of a laryngeal mask airway

The use of mini-dose suxamethonium to facilitate the insertion of a larynge al mask airway was investigated. Sixty patients were assigned randomly in a double-blind manner to receive 0.9% sodium chloride or suxamethonium 0.1mg .kg(-1) intravenously, following intravenous induction with propofol 2.5 mg .kg(-1). The laryngeal mask was inserted after the first attempt in 87% of patients. Mini-dose suxamethonium improved the correct positioning of the l aryngeal mask during the first attempt (93 vs. 67%, p < 0.02), decreased th e incidence of swallowing (p < 0.001), gagging (p < 0.001) and head or limb movement (p < 0.05). Laryngeal mask insertion was graded as easy in 93% of patients who had mini-dose suxamethonium, compared with 60% in the placebo group (p < 0.01). The duration of apnoea between the two groups was not si gnificantly different (0.54 vs. 0.61 min, p = 0.46). The total dose of prop ofol needed to insert the laryngeal mask was lower in the suxamethonium gro up (2.57 vs. 3.25 mg.kg(-1), p < 0.01) and was associated with less hypoten sion (p < 0.05). Fasciculation (17%) and mild myalgia (23%) were common des pite the small dose of suxamethonium used. In conclusion, mini-dose suxamet honium facilitates laryngeal mask insertion. Myalgia is common and the tech nique is not recommended for patients who are prone to suxamethonium myalgi a.