The effect of intravenous lidocaine on laryngeal and respiratory reflex responses in anaesthetised children*

Abstract

We studied the effect of intravenous lidocaine on laryngeal and respiratory reflex responses in children anaesthetised with sevoflurane. We tested the hypothesis that the incidence of laryngospasm evoked by laryngeal stimulation is temporarily diminished after the administration of lidocaine. Forty children, aged between 25 and 84months, were anaesthetised with sevoflurane and breathed spontaneously through a laryngeal mask airway. Respiratory reflex responses were elicited by spraying distilled water onto the laryngeal mucosa at three time intervals: (i) before lidocaine was administered (baseline); (ii) at 2min and (iii) at 10min following the intravenous administration of a bolus of lidocaine 2mg.kg(-1) . A blinded reviewer assessed the evoked responses. The incidence of laryngospasm was reduced from 38% at baseline to 15% 2min after lidocaine administration (p<0.02) and 18% 10min after lidocaine administration (p=0.10). We conclude that intravenous lidocaine significantly reduced the incidence of laryngospasm but that the effect was short-lived.