Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-10-7
pubmed:abstractText
Based on previous studies, we hypothesized that the pharynx collapses at multiple sites in most patients with obstructive sleep apnea (OSA). The purpose of this study was to document, in a population of apneic subjects, the site(s) of narrowing and closing pressure of the hypotonic pharynx. We endoscopically examined the pharynx in 45 OSA patients during sleep while they received nasal continuous positive airway pressure (CPAP), which produces hypotonia of pharyngeal muscles. Intrapharyngeal images and pressures were obtained at the end of expiration during single-breath tests (SBT). The fractional narrowing (FN) of each pharyngeal segment (nasopharynx, oropharynx, and hypopharynx) was calculated as the relative change in area when nasal airway pressure was reduced from a pressure that held the pharynx fully distended to the pressure at which the airway closed. The frequency distribution of FN for the nasopharynx was skewed toward larger values, and the frequency was relatively evenly distributed for the oropharynx and hypopharynx. A site having FN greater than 0.75 was defined as a site of primary narrowing, and a site showing FN 0.25 to 0.75 was defined as a site of secondary narrowing. The nasopharynx was a site of primary narrowing in 80% of patients, and two or more sites of narrowing were commonly observed (82%). Four categories of combined narrowing were identified: (1) primary narrowing only at the nasopharynx (18%); (2) primary narrowing at the nasopharynx plus other sites of secondary narrowing (40%); (3) primary narrowing at the nasopharynx plus other sites of primary narrowing (22%); and (4) other patterns (20%).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
148
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
606-11
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Pharyngeal narrowing and closing pressures in patients with obstructive sleep apnea.
pubmed:affiliation
Department of Internal Medicine, Faculty of Medicine, University of Calgary, Alberta, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't