title: Sleep Stage Coordination of Respiration and Swallowing: A Preliminary Study.
abstract: Swallowing is an important physiological response that protects the airway. Although aspiration during sleep may cause aspiration pneumonia, the mechanisms responsible have not yet been elucidated. We evaluated the coordination between respiration and swallowing by infusing water into the pharynx of healthy young adults during each sleep stage. Seven normal subjects participated in the study. During polysomnography recordings, to elicit a swallow we injected distilled water into the pharynx during the awake state and each sleep stage through a nasal catheter. We assessed swallow latency, swallow apnea time, the respiratory phase during a swallow, the number of swallows, and coughing. A total number of 79 swallows were recorded. The median swallow latency was significantly higher in stage 2 (10.05 s) and stage 3 (44.17 s) when compared to awake state (4.99 s). The swallow latency in stage 3 showed a very wide interquartile range. In two subjects, the result was predominantly prolonged compared to the other subjects. There was no significant difference in the swallow apnea time between sleep stages. The presence of inspiration after swallowing, repetitive swallowing, and coughing after swallowing was more frequent during sleep than when awake. This study suggests that the coordination between respiration and swallowing as a defense mechanism against aspiration was impaired during sleep. Our results supported physiologically the fact that healthy adult individuals aspirate pharyngeal secretions during sleep.
authors.affiliation: Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada. k-okuno@dent.osaka-u.ac.jp.|Division of Functional Oral Neuroscience, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita-City, Osaka, 565-0871, Japan. k-okuno@dent.osaka-u.ac.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Okuno
authors.affiliation: Division of Functional Oral Neuroscience, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita-City, Osaka, 565-0871, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Nohara
authors.affiliation: Division of Functional Oral Neuroscience, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita-City, Osaka, 565-0871, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Takai
authors.affiliation: Division of Functional Oral Neuroscience, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita-City, Osaka, 565-0871, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, University of British Columbia, 2194 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: John A
authors.initials: JA
authors.lastname: Fleetham
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, University of British Columbia, 2194 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: Najib T
authors.initials: NT
authors.lastname: Ayas
authors.affiliation: Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: Alan A
authors.initials: AA
authors.lastname: Lowe
authors.affiliation: Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: Fernanda R
authors.initials: FR
authors.lastname: Almeida
mesh_terms: D000328:Adult; D001049:Apnea; D003371:Cough / Q000503:physiopathology; D003679:Deglutition / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010614:Pharynx / Q000502:physiology; D011015:Pneumonia, Aspiration / Q000503:physiopathology; D012119:Respiration; D012894:Sleep Stages / Q000502:physiology*; D014867:Water / Q000008:administration & dosage
chemical_list: D014867:Water
keywords: Aspiration; Deglutition; Deglutition disorders; Reflex; Sleep; Swallowing