Linked Life Data

10503750

Source:http://linkedlifedata.com/resource/pubmed/id/10503750

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-10-21
pubmed:abstractText
The ventilatory effects of a 5-cm H2O positive end expiratory pressure (PEEP) and its influence on the breathing pattern during short hypoxic exposure both at rest and during physical exercise were studied. There were 22 healthy subjects who were submitted to normoxia and to 4-h of hypoxia in a hypobaric chamber (4500 m, PB = 589 hPa) both at rest and during an 8-min cycle ergometer exercise (100 W) without and with a 5 cm H2O PEEP. The results show that hypoxia compared with normoxia induces increases in tidal volume (VT) (+28.5%, p < 0.05 at rest; and +19.4%, p < 0.01 at 100 W) and in respiratory frequency (f) at 100 W (p < 0.05), and significant decreases in inspiratory (tI) (p < 0.05 at rest and at 100 W), and expiratory (tE) durations (p < 0.05 at 100 W). However, the breathing pattern expressed as duty cycle (tI/tt) is unchanged, whereas an increased mean inspiratory flow (VT/tI) is observed (p < 0.01 at rest and at 100 W). This study also demonstrates that PEEP during a 4-h hypobaric hypoxia significantly increases VT (+22.2% p < 0.01 at rest, +8.9% p < 0.05 at 100 W), tI, and tE at rest (p < 0.05), but not during exercise and tends to decrease f (p = 0.06 at rest and at 100 W). However, PEEP does not alter the breathing pattern in hypoxia since VT/tI and tI/tt are unchanged. Heart rate and arterial O2 saturation are also unaffected by PEEP. In conclusion, this study shows that a 4-h hypoxia modifies ventilatory parameters and mean inspiratory flow (VT/tI) at rest and during exercise (100 W), whereas a 5-cm H2O PEEP does not alter the breathing pattern despite changes in ventilatory parameters are observed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0095-6562
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
863-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Short hypobaric hypoxia and breathing pattern: effect of positive end expiratory pressure.
pubmed:affiliation
Unité de Thermophysiologie, Centre de Recherches du Service de Santé des Armées, La Tronche, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't