Non-invasive Assessment of Swallowing and Respiration Coordination for the OSA Patient

Chin-Man Wang, Hsueh-Yu Li, Li- Ang Lee, Wann-Yun Shieh, Shih-Wei Lin

The objectives of this study are to investigate swallowing and its coordination with respiration in patients with obstructive sleep apnea (OSA). This is a prospective cohort study conducted in a tertiary referred Medical Center. A non-invasive method of assessing swallowing was used to detect the oropharyngeal swallowing parameters and the coordination with respiration during swallowing. The system used to assess swallowing detected: (1) movement of the larynx using a force-sensing resistor; (2) submental muscle activity using surface electromyography; and (3) coordination with respiration by measuring nasal airflow. Five sizes of water boluses (maximum 20 mL) were swallowed three times, and the data recorded and analyzed for each participant. Thirty-nine normal controls and 35 patients with OSA who fulfilled the inclusion criteria were recruited. The oropharyngeal swallowing parameters of the patients differed from the controls, including longer total excursion duration and shorter duration of submental muscles contraction. A longer swallowing respiratory pause (SRP), temporary coordination with respiration during swallowing, was demonstrated in the patients compared with the controls. The frequency of non-expiratory/expiratory pre- and postswallowing respiratory phase patterns of the patients was similar with the controls. There was significantly more piecemeal deglutition in OSA patients when clumping 10- and 20-mL water boluses swallowing together (p = 0.048). Oropharyngeal swallowing and coordination with respiration affected patients with OSA, and it could be detected using a non-invasive method. The results of this study may serve as a baseline for further research and help advance research methods in obstructive sleep apnea swallowing studies.