A method for topical anesthesia by nebulization of local anesthetics.

The number of procedures involving the direct examination of, and the introduction of instruments and materials into, the tubular structures of the respiratory tract is increasing. This increase in endoscopic procedures has been attended by greater efforts to overcome the natural defenses of the entrance to the respiratory passages. The defenses are:1 1) The swallowing reflex, originating chiefly in the posterior pharynx, dorsum of the tongue, and pyriform sinuses. 2) The gag reflex, originating chiefly in the anterior faucial pillars, soft palate, uvula, epiglottis, and posterior pharynx. 3) The cough reflex, originating chiefly in the larynx, trachea, and carina. 4) The anatomic position and structure of the larynx, at right angles with the oral cavity, below the epiglottis, and with the strongly contractile glottis at Its entrance. 5) The patient’s general apprehension concerning instrumentation of the respiratory passages. The most commonly practiced method of reducing the patient’s apprehension is by preliminary sedation and a brief explanation of the necessity for relaxation and cooperation. The reflex defenses are usually attacked by administering a surface anesthetic. The anatomic peculiarities of the larynx constitute a major difficulty in introducing anesthetic solutions as well as instruments and other materials. The conventional technique of obtaining surface anesthesia consists of “boldly squirting 2 or 3 cubic centimeters from a syringe (or atomizer) through the mouth on to the posterior pharyngeal wall; after which the anesthetist side-steps smartly out of the line of the patient’s mouth and relies on the violent gagging and coughing to spread the liquid throughout the pharynx and lar nx.”2 It is usually necessary, in addition, to swab the