LIGNOCAINE TO AID THE INSERTION OF THE LARYNGEAL MASK AIRWAY WITH THIOPENTONE - A COMPARISON BETWEEN TOPICAL AND INTRAVENOUS ADMINISTRATION

Conditions for insertion of a laryngeal mask airway in 90 unpremedicat ed adult patients were assessed in a randomised, single-blinded trial. Each patient received fentanyl 1 mu g.kg(-1) and thiopentone 5 mg.kg( -1) intravenously (group 2) or 40 mg of topical lignocaine spray to th e posterior pharyngeal wall (group 3). Conditions for laryngeal mask a irway insertion were recorded. The group receiving topical lignocaine had a lower incidence of laryngospasm (p<0.05), required fewer attempt s for successful insertion of the laryngeal mask (p<0.05) and coughed or gagged less frequently than either group receiving lignocaine intra venously (p>0.05). Overall, the conditions for laryngeal mask airway i nsertion were better in the topical group (p<0.05). There were no sign ificant differences in haemodynamic response and apnoea between the th ree groups. Topical lignocaine spray prior to thiopentone provides con ditions for insertion of a laryngeal mask that are superior to those p rovided by lignocaine and thiopentone intravenously.