| Chronic mountain sickness: recent studies of the relationship between hemoglobin concentration and oxygen transport. | |
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MedLine Citation:
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PMID: 15265336 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Although an increase in hemoglobin concentration [Hb] in high altitude residents assists oxygen transport, excessive polycythemia ([Hb] > or = 21 g/100 mL) may cause the syndrome of chronic mountain sickness (CMS). A recent theoretical analysis has suggested that increasing [Hb] above 18 g/100 mL provides no further benefit in oxygen transport at rest. To test this hypothesis, we examined oxygen transport at rest for given arterial oxygen saturations (Sa(O2), in classes at intervals of 5%) as reported in 206 residents of various altitudes. For Sa(O2) of 97% versus 87%, [Hb] and a-v oxygen content difference increased (respectively, 14.5 to 17.5 g/100 mL and 4.11 to 5.03 volume %). As Sa(O2) fell further to 66%, a-v progressively decreased to 3.77 volume %, despite an increase in [Hb] to 24.2 g/100 mL. Over the Sa(O2) range of 97% to 66%, the a-v difference changed little (-8%) compared to other subjects made acutely hypoxic (-33%), for Sa(O2) change from 97% to 75%. The results suggest that increasing [Hb] allows greater oxygen extraction (a cardiac output sparing effect), which is maximal at Sa(O2) of 87% and a [Hb] of 17.5 g/100 mL. For more severe hypoxemia, even to Sa(O2) of 66%, both increasing [Hb] and increasing output are utilized for oxygen transport. |
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Authors:
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John T Reeves; Fabiola Leon-Velarde |
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Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.; Review |
Journal Detail:
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Title: High altitude medicine & biology Volume: 5 ISSN: 1527-0297 ISO Abbreviation: High Alt. Med. Biol. Publication Date: 2004 |
Date Detail:
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Created Date: 2004-07-21 Completed Date: 2004-10-05 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 100901183 Medline TA: High Alt Med Biol Country: United States |
Other Details:
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Languages: eng Pagination: 147-55 Citation Subset: IM; S |
Affiliation:
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University of Colorado Health Sciences Center, Denver, 80262, USA. john.reeves@uchsc.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Altitude Sickness
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blood* Anoxia / metabolism Cardiac Output / physiology Chronic Disease Hemoglobins / metabolism* Humans Oxygen / blood* Oxygen Consumption / physiology Reference Values |
| Grant Support | |
ID/Acronym/Agency:
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HL 14985/HL/NHLBI NIH HHS; HL 57144/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Hemoglobins; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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