Effects of surface anesthesia on deglutition in man

The importance of sensitivity in the mouth, pharynx and esophagus upon swallowing was studied on 17 healthy volunteers. Intraluminal pressures of the pharynx, pharyngo‐esophageal sphincter and esophagus were synchronously recorded before and after surface anesthesia with lidocaine. Anesthesia of the mucous membrane in sectors of the oral cavity, pharynx or esophagus separately did not cause any objective changes, whereas simultaneous anesthesia of an area consisting of the soft palate, tonsillar pillars, tonsils, base of the tongue and pharynx, caused considerable changes upon swallowing: the coordination between the pharynx and sphincter was disturbed; dysphagia and coughing occurred. Similar dys‐coordinations have been reported earlier from patients with hypopharyn‐geal diverticulum but have not previously been shown experimentally. The changes are probably caused by the mucous membrane's anesthesia inhibiting the discharge of impulses from oropharyngeal receptors.