Document Detail

Postural changes in respiratory airflow pressure and resistance in nasal, hypopharyngeal, and pharyngeal airway in normal subjects.
MedLine Citation:
PMID:  8615586     Owner:  NLM     Status:  MEDLINE    
We investigated the effect of posture on nasal and pharyngeal resistance in 12 healthy subjects studied during wakefulness. Airway pressure and airflow were measured with subjects seated and in dorsal and left lateral recumbency, during inspiration and expiration. We found that pharyngeal resistance was approximately four to six times lower than the nasal resistance. Only pharyngeal resistance was significantly increased upon assumption of a supine posture, from 0.02 +/- 0.01 Pa/mL per second when seated to 0.06 +/- 0.05 Pa/mL per second in dorsal recumbency and to 0.05 +/- 0.04 Pa/mL per second in left lateral recumbency. Mean nasal and pharyngeal resistances doubled upon assumption of a supine posture, but this difference was not statistically significant. There was no significant difference in pharyngeal resistance between inspiration and expiration. Finally, there was a strong linear relationship between pharyngeal pressure and pharyngeal resistance (r = .98, p<.0001). We concluded that in normal awake subjects 1) pharyngeal resistance increases with assumption of a supine posture, 2) the walls of the pharynx are not compliant enough to alter their resistance in response to inspiratory and expiratory pressure changes, and 3) it may be possible to infer pharyngeal resistance from measurements of pressure alone, without measurement of airflow.
M Tvinnereim; P Cole; S Mateika; J Haight; V Hoffstein
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Annals of otology, rhinology, and laryngology     Volume:  105     ISSN:  0003-4894     ISO Abbreviation:  Ann. Otol. Rhinol. Laryngol.     Publication Date:  1996 Mar 
Date Detail:
Created Date:  1996-06-06     Completed Date:  1996-06-06     Revised Date:  2006-05-15    
Medline Journal Info:
Nlm Unique ID:  0407300     Medline TA:  Ann Otol Rhinol Laryngol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  218-21     Citation Subset:  AIM; IM; S    
Department of Otolaryngology, St. Michael's Hospital, Toronto, Canada.
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MeSH Terms
Airway Resistance / physiology*
Hypopharynx / physiology*
Middle Aged
Pharynx / physiology*
Posture / physiology*
Pulmonary Ventilation / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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