Plasma levels of lidocaine following nebulized aerosol administration.

The venous (plasma) levels of lidocaine were measured in five subjects following nebulization of a 280-mg dose via intermittent positive pressure breathing (IPPB) and nebulization of a 400-mg dose via ultrasound. Even though a lower dose of lidocaine was given by IPPB, this system of delivery produced higher plasma concentrations of the drug than ultrasound and also was more effective in eliminating the gag reflex. In the entire study, plasma concentrations of lidocaine did not exceed 1.1 mug/ml, which is far below toxic levels. Aerosolized lidocaine, administered by IPPB, is a safe and effective topical anesthetic agent which may be useful for instrumentation of the upper airway.