Physiologic effects and serum lidocaine concentrations after inhalation of lidocaine from a compressed gas-powered...

The physiologic effects, efficacy, and serum lidocaine concentrations were determined in 10 normal volunteers who inhaled nebulized lidocaine from a compressed gas-powered jet nebulizer. Physiologic variables and serial venous serum lidocaine concentrations were measured during and after lidocaine inhalation. All 10 subjects experienced loss of the gag reflex, which returned to normal at 32 +/- 5.9 min (mean +/- 1 SD), with a range of 20 to 40 min. There were no significant changes in systolic or diastolic blood pressures or heart rates. There were no significant changes from baseline in any of the measured spirometric variables (FVC, FEV1, peak expiratory flow rate, peak inspiratory flow rate). The peak mean serum lidocaine concentration measured at 20 min after beginning lidocaine inhalation was 0.52 microgram/ml, and the highest single value measured was 1.05 micrograms/ml. We conclude that inhalation of lidocaine from a compressed gas-powered jet nebulizer can produce safe and effective oropharyngeal anesthesia with minimal drug absorption.