This study provides important contributions to the literature by clarifying normal variability within a wide range of swallowing behaviors and by providing normative data from which to compare disordered populations.

on behalf of the CHEST Expert Cough Panel * BACKGROUND: Cough characteristics vary between patients, and this can impact clinical diagnosis and care. The purpose of part two of this state-of-the-art review is to update the American College of Chest Physicians (CHEST) 2006 guideline on global physiology and pathophysiology of cough. STUDY DESIGN AND METHODS:A review of the literature was conducted using PubMed and MEDLINE databases from 1951 to 2019 using prespecified search terms. RESULTS:We describe the demographics of typical patients with cough in the clinical setting, including how cough characteristics change across age. We summarize the effect of common clinical conditions impacting cough mechanics and the physical properties of mucus on airway clearance.INTERPRETATION: This is the second of a two-part update to the 2006 CHEST cough guideline; it complements part one on basic phenomenology of cough by providing an extended clinical picture of cough along with the factors that alter cough mechanics and efficiency in patients. A greater understanding of the physiology and pathophysiology of cough will improve clinical management.

Purpose The timing of laryngeal vestibule closure (LVC) is important for airway protection during swallowing. However, it is unknown whether the extent of LVC contributes to airway protection. The goal of this study is to validate the extent of LVC via a measure called laryngeal constriction ratio (LCR). Methods A retrospective analysis of videofluoroscopic swallows was conducted on 38 stroke participants and 40 healthy controls. The LCR was calculated by deriving a size‐normalized area of airspace from a 1) maximum closed laryngeal vestibule and a 2) maximum open laryngeal airspace (at rest). Airway invasion severity was derived via the Penetration–Aspiration Scale score. Results Six hundred forty‐nine videofluoroscopic swallows were analyzed. A mixed model analysis revealed a statistically significant mean difference between the normalized laryngeal constriction ratios of healthy individuals (mean (m) = 0.003) versus older dysphagic patients (m = .026) (P = 0.001), quantifying less closure in older patients with dysphagia. Additionally, swallows with airway compromise had a statistically worse LCR when compared to swallows without airway compromise (P = 0.001). Conclusion The normalized LCR might be a valid fluoroscopic surrogate measure for LVC and, furthermore, airway compromise during swallowing. By investigating spatial measurements in the laryngeal vestibule during safe and unsafe swallows, the LCR provides a direction for further research to allow for critical examination of the physiology relating to closure degree in order to precisely detect and treat abnormalities during swallowing. Level of Evidence 4 Laryngoscope, 130:E190–E198, 2020