K Dua1, E Bardan, J Ren, Z Sui, R Shaker. 1. MCW Dysphagia Institute, Department of Medicine, Medical College of Wisconsin and Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, USA. dua@mcw.edu
Abstract
BACKGROUND: Injection of water into the pharynx at a threshold volume induces vocal cord adduction--the pharyngoglottal closure reflex (PGCR). This reflex together with other supraoesophageal reflexes may be helpful in preventing aspiration. Cigarette smoking has an adverse affect on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow. The effect of smoking on PGCR has not been studied previously. AIMS: To elucidate the effect of chronic and acute cigarette smoking on PGCR. SUBJECTS: We studied 10 chronic smokers and 10 non-smokers before and after real/simulated smoking, respectively. METHODS: Using concurrent recordings, glottal function was monitored by video endoscopy, swallowing by electromyography, and PGCR was triggered by rapid and slow pharyngeal water injections. RESULTS: The threshold volume to trigger PGCR during rapid injection was significantly higher in chronic smokers (non-smoker 0.20 (SEM 0.02) ml, smoker 0.36 (0.02) ml; p<0.001). In six of 10 smokers, acute smoking abolished this reflex during slow water injection. CONCLUSIONS: Smoking adversely affects stimulation of PGCR. This finding may have implications in the development of reflux related respiratory complications in smokers.
BACKGROUND: Injection of water into the pharynx at a threshold volume induces vocal cord adduction--the pharyngoglottal closure reflex (PGCR). This reflex together with other supraoesophageal reflexes may be helpful in preventing aspiration. Cigarette smoking has an adverse affect on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow. The effect of smoking on PGCR has not been studied previously. AIMS: To elucidate the effect of chronic and acute cigarette smoking on PGCR. SUBJECTS: We studied 10 chronic smokers and 10 non-smokers before and after real/simulated smoking, respectively. METHODS: Using concurrent recordings, glottal function was monitored by video endoscopy, swallowing by electromyography, and PGCR was triggered by rapid and slow pharyngeal water injections. RESULTS: The threshold volume to trigger PGCR during rapid injection was significantly higher in chronic smokers (non-smoker 0.20 (SEM 0.02) ml, smoker 0.36 (0.02) ml; p<0.001). In six of 10 smokers, acute smoking abolished this reflex during slow water injection. CONCLUSIONS: Smoking adversely affects stimulation of PGCR. This finding may have implications in the development of reflux related respiratory complications in smokers.
Authors: J F Hunt; K Fang; R Malik; A Snyder; N Malhotra; T A Platts-Mills; B Gaston Journal: Am J Respir Crit Care Med Date: 2000-03 Impact factor: 21.405