Swallowing transit times and valleculae residue in stable chronic obstructive pulmonary disease

Background: Breathing and swallowing are physiologically linked to ensure effortless gas exchange during oronasal breathing and to prevent aspiration during swallowing. Studies have indicated consistent aspiration in chronic obstructive pulmonary disease, mainly related to delayed swallowing reflex and problems with lingual propulsion and pharyngeal peristalsis as a result of bilateral weakness and incoordination of the related muscles. The purpose of the present study was to evaluate swallowing transit times and valleculae residue characteristics of stable COPD patients who have no swallowing complaints. Methods: Our study population included 20 stable patients with COPD and no swallowing complaints and 20 healthy controls. Swallowing was assessed through videofluoroscopic examination and involved the analysis of the following parameters: (1) pharyngeal stages of deglutition; (2) the duration of bolus movement through the oral cavity and pharynx (i.e. transit times); (3) valleculae residue ratio; (4) penetration/aspiration. Results: Participants of the study did not present any signs of penetration-aspiration for any of the tested consistencies. Patients with COPD presented longer pharyngeal transit times during the ingestion of the liquid consistency and during the ingestion of the paste consistency. Regarding the duration of tongue base contact with the posterior pharyngeal wall, COPD patients also presented longer durations for the liquid and paste consistencies. No significant difference was observed for the distribution of individuals among the different valleculae residue severity levels. Conclusions: Our study suggests that stable COPD patients may present physiological adaptations as a protective swallowing maneuver to avoid aspiration/penetration of pharyngeal contents. Moreover, valleculae residue cannot be seen as an isolated factor when trying to explain swallowing alterations in this population.