| Hypoxia-induced intrapulmonary arteriovenous shunting at rest in healthy humans. | |
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MedLine Citation:
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PMID: 20689088 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Intrapulmonary arteriovenous (IPAV) shunting has been shown to occur at rest in some subjects breathing a hypoxic gas mixture [fraction of inspired oxygen (FI(O(2))) = 0.12] for brief periods of time. In the present study we set out to determine if IPAV shunting could be induced at rest in all subjects exposed to hypoxia for 30 min. Twelve subjects (6 women) breathed four levels of hypoxia (FI(O(2)) = 0.16, 0.14, 0.12, and 0.10) for 30 min each in either an ascending or descending order with a 15-min normoxic break between bouts. Saline contrast echocardiography was used to detect IPAV shunt and a shunt score (0-5) was assigned based on contrast in the left ventricle with a shunt score ≥ 2 considered significant. Pulmonary artery systolic pressure (PASP) was determined using Doppler ultrasound. The total number of subjects demonstrating shunt scores ≥ 2 for FI(O(2)) = 0.16, 0.14, 0.12, and 0.10 was 1/12, 7/12, 9/12, and 12/12, respectively. Shunt scores were variable between subjects but significantly greater than normoxia for FI(O(2)) = 0.12 and 0.10. Shunt scores correlated with peripheral measurements of arterial oxygen saturation (SpO(2)) (r(w) = -0.67) and PASP (r(w) = 0.44), despite an increased shunt score but no increase in PASP while breathing an FI(O(2)) = 0.12. It is unknown how hypoxia induces the opening of IPAV shunts, but these vessels may be controlled via similar mechanisms as systemic vessels that vasodilate in response to hypoxia. Despite intersubject variability our results indicate significant IPAV shunting occurs at rest in all subjects breathing an FI(O(2)) = 0.10 for 30 min. |
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Authors:
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Steven S Laurie; Ximeng Yang; Jonathan E Elliott; Kara M Beasley; Andrew T Lovering |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-08-05 |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 109 ISSN: 1522-1601 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2010 Oct |
Date Detail:
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Created Date: 2010-10-13 Completed Date: 2011-05-23 Revised Date: 2011-07-05 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
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Languages: eng Pagination: 1072-9 Citation Subset: IM |
Affiliation:
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Department of Human Physiology, University of Oregon, Eugene, Oregon 97403, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Anoxia / blood, physiopathology*, ultrasonography Blood Pressure Female Forced Expiratory Volume Humans Lung / physiopathology Male Maximal Midexpiratory Flow Rate Oxygen / blood Peak Expiratory Flow Rate Pulmonary Artery / physiopathology*, ultrasonography Pulmonary Circulation* Pulmonary Veins / physiopathology*, ultrasonography Time Factors Total Lung Capacity Vital Capacity Young Adult |
| Chemical | |
Reg. No./Substance:
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7782-44-7/Oxygen |
| Comments/Corrections | |
Erratum In:
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J Appl Physiol. 2011 May;110(5):1502 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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