Prevention of lidocaine aerosol-induced bronchoconstriction with intravenous lidocaine

Background: Lidocaine applied topically provokes bronchoconstriction in persons with hyperreactive airway disease. The authors questioned whether intravenous lidocaine would prevent lidocaine-aerosol induced bronchoconstriction. They compared the effects of lidocaine administered intravenously and by the aerosol route on baseline airway tone, and on the prevention of histamine-induced bronchoconstriction in five Basenji-Greyhound dogs. Methods: Dogs were pretreated with either intravenous or aerosol lidocaine followed by histamine aerosol challenge. On separate days, dogs were pretreated with intravenous lidocaine, followed by aerosol lidocaine administration at similar doses. Airway caliber was assessed using high- resolution computed tomography. Data were analyzed by two-way analysis of variance. Serum lidocaine concentrations were obtained. Results: Histamine alone decreased the airway area by 32 ± 3%. Lidocaine administered intravenously or by the aerosol route significantly inhibited histamine- induced bronchoconstriction. There was no significant difference between the two routes in preventing histamine-induced bronchoconstriction. At the dose that inhibited histamine-induced bronchoconstriction, lidocaine administered by the aerosol route decreased baseline airway area by 27 ± 3% (P < 0.01), whereas intravenous lidocaine had no effect. Intravenous lidocaine prevented lidocaine aerosol-induced bronchoconstriction, and the combination of intravenous and aerosol lidocaine significantly dilated the airways by 20 ± 5% (P < 0.01 compared with control). Conclusion: An intravenous bolus of lidocaine prevents the initial bronchoconstriction induced by lidocaine when administered as an aerosol.