Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1999-6-14
pubmed:abstractText
It is controversial whether obstructive sleep apnea (OSA) causes pulmonary hypertension (PH) in the absence of hypoxemic lung disease. To investigate this further we measured awake pulmonary hemodynamics, pulmonary gas exchange, and small airways function in 32 patients with OSA (apnea- hypopnea index, mean +/- SE, 46.2 +/- 3. 9/h) who had normal screening lung function. Pulmonary artery pressure (Ppa) and cardiac output were measured by Doppler echocardiography at three levels of inspired oxygen (FIO2 0.50, 0.21, and 0.11) and during incremental increases in pulmonary blood flow (10, 20, and 30 microgram/kg/min dobutamine infusions) while breathing 50% oxygen. Eleven patients had PH (mean Ppa >/= 20 mm Hg, Group I). They did not differ from patients without PH (Group II) in lung function, severity of sleep-disordered breathing, age, or body mass. Compared with Group II, Group I patients had increased small airways closure during tidal breathing (FRC-closing capacity: Group I, -0.16 +/- 0.11; Group II, 0.27 +/- 0.09 L; p < 0.05), more ventilation-perfusion inequality (AaPO2: 23.8 +/- 2.8; 19.8 +/- 1.4 mm Hg; p = 0.08), a greater pulmonary artery pressor response to hypoxia (DeltaPpa FIO2, 0.50 to 0.11: 16.4 +/- 1.93; 6.4 +/- 0.77 mm Hg; p < 0.05) and a marked rise in Ppa during increased pulmonary blood flow. We conclude that PH may develop in some patients with OSA without lung disease and that it is associated with small airways closure during tidal breathing and heightened pulmonary pressor responses to hypoxia and during increased pulmonary blood flow. Such changes are consistent with remodeling of the pulmonary vascular bed in affected patients with OSA, seemingly unrelated to severity of sleep-disordered breathing.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1073-449X
pubmed:author
pubmed:issnType
Print
pubmed:volume
159
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1518-26
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10228120-Anoxia, pubmed-meshheading:10228120-Blood Pressure, pubmed-meshheading:10228120-Circadian Rhythm, pubmed-meshheading:10228120-Female, pubmed-meshheading:10228120-Hemodynamics, pubmed-meshheading:10228120-Humans, pubmed-meshheading:10228120-Hypertension, Pulmonary, pubmed-meshheading:10228120-Lung, pubmed-meshheading:10228120-Male, pubmed-meshheading:10228120-Middle Aged, pubmed-meshheading:10228120-Polysomnography, pubmed-meshheading:10228120-Pulmonary Artery, pubmed-meshheading:10228120-Pulmonary Circulation, pubmed-meshheading:10228120-Pulmonary Gas Exchange, pubmed-meshheading:10228120-Respiratory Function Tests, pubmed-meshheading:10228120-Respiratory System, pubmed-meshheading:10228120-Sleep Apnea Syndromes, pubmed-meshheading:10228120-Ventilation-Perfusion Ratio
pubmed:year
1999
pubmed:articleTitle
Daytime pulmonary hemodynamics in patients with obstructive sleep apnea without lung disease.
pubmed:affiliation
Sleep Disorders Unit and Department of Cardiology, Repatriation General Hospital, Daw Park, School of Medicine, Flinders University, Bedford Park, Adelaide, South Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't