Document Detail


Effect of six days of staging on physiologic adjustments and acute mountain sickness during ascent to 4300 meters.
MedLine Citation:
PMID:  19775215     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study determined the effectiveness of 6 days (d) of staging at 2200 m on physiologic adjustments and acute mountain sickness (AMS) during rapid, high-risk ascent to 4300 m. Eleven sea-level (SL) resident men (means +/- SD; 21 +/- 3 yr; 78 +/- 13 kg) completed resting measures of end-tidal CO(2) (Petco(2)), arterial oxygen saturation (Sao(2)), heart rate (HR), and mean arterial pressure (MAP) at SL and within 1 h of exposure to 4300 m in a hypobaric chamber prior to 6 d of staging at 2200 m (preSTG) and on the summit of Pikes Peak following 6 d of staging at 2200 m (postSTG). Immediately following resting ventilation measures, all performed submaximal exercise ( approximately 55% of altitude-specific maximal oxygen uptake) for approximately 2 h on a bicycle ergometer to induce higher levels of AMS. AMS-C, calculated from the Environmental Symptoms Questionnaire, was measured following 4 h and 8 h of exposure at preSTG and postSTG, and the mean was calculated. Resting Petco(2) (mmHg) was unchanged from SL (39.8 +/- 2.6) to preSTG (39.3 +/- 3.0), but decreased (p < 0.05) from preSTG to postSTG (32.8 +/- 2.6). Resting Sao(2) (%) decreased (p < 0.05) from SL (97 +/- 2) to preSTG (80 +/- 4) and increased (p < 0.05) from preSTG to postSTG (83 +/- 3). Resting HR (bpm) and MAP (mmHg) did not change in any of the test conditions. The incidence and severity of AMS-C decreased (p < 0.05) from preSTG (91 +/- 30%; 1.05 +/- 0.56) to postSTG (45 +/- 53%; 0.59 +/- 0.43), respectively. These results suggest that modest physiologic adjustments induced by staging for 6 d at 2200 m reduced the incidence and severity of AMS during rapid, high-risk ascent to 4300 m.
Authors:
Beth A Beidleman; Charles S Fulco; Stephen R Muza; Paul B Rock; Janet E Staab; Vincent A Forte; Michael D Brothers; Allen Cymerman
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Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  High altitude medicine & biology     Volume:  10     ISSN:  1557-8682     ISO Abbreviation:  High Alt. Med. Biol.     Publication Date:  2009  
Date Detail:
Created Date:  2009-09-24     Completed Date:  2009-12-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901183     Medline TA:  High Alt Med Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  253-60     Citation Subset:  IM; S    
Affiliation:
Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760, USA. beth.beidleman@us.army.mil
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology*
Adult
Altitude*
Altitude Sickness / blood,  physiopathology*
Anoxia / physiopathology*
Blood Pressure / physiology
Carbon Dioxide / blood
Cross-Over Studies
Environment, Controlled*
Exercise Test
Heart Rate / physiology
Humans
Male
Oxygen / blood
Prospective Studies
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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