Rationale and objectives: The authors evaluated the coordination of swallowing and respiration in dysphagic patients.
Materials and methods: Video fluoroscopy and respirometry were performed simultaneously during 98 swallows in 33 patients (18 women, 15 men) with a median age of 70 years (interquartile range, 52-78 years). Pharyngeal transit time, deglutition apnea, and the ratio between the two (swallowing safety index) were calculated. Presence of a misdirected swallow (aspiration or penetration) was indicated.
Results: Pharyngeal transit time was not associated with deglutition apnea. Misdirected swallow was associated with a slightly prolonged pharyngeal transit time, a slightly shorter deglutition apnea, and a significantly lower swallowing safety index (1.8 [1.0-4.2] vs 4.5 [2.4-6.7]; P < .001) compared with normally directed swallow. The association between misdirected swallow and lower swallowing safety index was independent of pharyngeal transit time.
Conclusion: Assessment of respiration is important in the evaluation of dysphagia. Aspiration, especially in elderly dysphagic patients, may be a consequence of primarily disturbed respiration. A low swallowing safety index may indicate risk of misdirected swallow.