Pharyngeal airflow during sleep.
This study was conducted to investigate the effects of sleep and nasal resistance on pharyngeal airflow in a group of healthy male adults without complaint of habitual snoring. Twelve subjects aged 21 to 60 years were studied in a sleep laboratory during exclusive nasal breathing. Nasal and pharyngeal airflow variables were measured concomitantly at different stages of sleep. Awake pharyngeal resistance averaged 0.02-0.03 Pa/cm3/s in recumbency. In stage 2 sleep and quiet breathing resistance increased by a factor of 3-4 and by a factor of 7-8 during snoring. Increased nasal loading did not increase pharyngeal resistance further or induce snoring. Mostly, increased pharyngeal resistances were of similar magnitude in both phases of respiration, but in a few instances inspiratory resistance exceeded that in expiration, and in a similar number the reverse was found. Overall, compliance of the pharyngeal airway was not a prominent feature in this group of subjects. The relationship between transpharyngeal pressure and resistance should be studied further in order to simplify future studies of airflow during sleep.
Miljeteig
H
H
Department of Otolaryngology, St. Michael's Hospital, Toronto, Ontario, Canada.
Hirschberg
A
A
Cole
P
P
Haight
J S
JS
Mateika
S
S
Hoffstein
V
V
D000328:Adult; D006801:Humans; D008297:Male; D008875:Middle Aged; D015508:Nasal Obstruction; D010614:Pharynx / Q000502:physiology*; D017286:Polysomnography; D012123:Pulmonary Ventilation; D012894:Sleep Stages; D012895:Sleep, REM; D012913:Snoring; D014851:Wakefulness