Protective role of aerodigestive reflexes against XXXX : study on subjects with impaired and preserved reflexes.

@entity7552 @entity1173
BACKGROUND _ AIMS: Direct evidence to support the airway protective function of aerodigestive reflexes triggered by pharyngeal stimulation was previously demonstrated by abolishing these reflexes by topical pharyngeal anesthesia in normal subjects. Studies have also shown that these reflexes deteriorate in cigarette smokers. Aim of this study was to determine the influence of defective pharyngeal aerodigestive reflexes on airway protection in cigarette smokers. METHODS: Pharyngoglottal Closure reflex; PGCR, Pharyngo-UES Contractile reflex; PUCR, and Reflexive Pharyngeal Swallow; RPS were studied in 15 healthy non-smokers (24.2  3.3 SD y, 7 males) and 15 healthy chronic smokers (27.3  8.1, 7 males). To elicit these reflexes and to evaluate @entity1173 , colored water was perfused into the hypopharynx at the rate of 1 mL/min. Maximum volume of water that can safely dwell in the hypopharynx before spilling into the larynx (Hypopharyngeal Safe Volume; HPSV) and the threshold volume to elicit PGCR, PUCR, and RPS were determined in smokers and results compared with non-smokers. RESULTS: At baseline, RPS was elicited in all non-smokers (100%) and in only 3 of 15 smokers (20%; P<.001). None of the non-smokers showed evidence of @entity7552 of water, whereas 12 of 15 smokers with absent RPS had @entity7552 . Pharyngeal anesthesia abolished RPS reflex in all non-smokers resulting in @entity7552 . The HPSV was 0.61  0.06 mL and 0.76  0.06 mL in non-smokers and smokers respectively (P=.1). CONCLUSIONS: Deteriorated reflexive pharyngeal swallow in chronic cigarette smokers predispose them to risks of @entity1173 and similarly, abolishing this reflex in non-smokers also results in @entity7552 . These observations directly demonstrate the airway protective function of RPS.
