| Dexamethasone but not tadalafil improves exercise capacity in adults prone to high-altitude pulmonary edema. | |
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MedLine Citation:
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PMID: 19520908 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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RATIONALE: Whether pulmonary hypertension at high altitude limits exercise capacity remains uncertain. OBJECTIVES: To gain further insight into the pathophysiology of hypoxia induced pulmonary hypertension and the resulting reduction in exercise capacity, we investigated if the reduction in hypoxic pulmonary vasoconstrictive response with corticosteroids or phosphodiesterase-5 inhibition improves exercise capacity. METHODS: A cardiopulmonary exercise test and echocardiography to estimate systolic pulmonary artery pressure were performed in 23 subjects with previous history of high altitude pulmonary edema, known to be associated with enhanced hypoxic vasoconstriction. Subjects were randomized to dexamethasone 8 mg twice a day, tadalafil 10 mg twice a day, or placebo (double-blinded), starting the day before ascent. MEASUREMENTS AND MAIN RESULTS: Measurements were performed at low and high (i.e., 4,559 m) altitude. Altitude exposure decreased maximum oxygen uptake and oxygen saturation, increased pulmonary artery pressure, and altered oxygen uptake kinetics. Compared with placebo, dexamethasone improved maximum oxygen uptake (% predicted 74 +/- 13%; tadalafil 63 +/- 13%, placebo 61 +/- 11%; P < 0.05), oxygen kinetics (mean response time 41 +/- 13 s; tadalafil 46 +/- 6 s, placebo 45 +/- 10 s; P < 0.05), and reduced the ventilatory equivalent for CO(2) (42 +/- 4; tadalafil 49 +/- 4, placebo 50 +/- 5; P < 0.01). Peak oxygen saturation did not differ significantly between the three groups (dexamethasone 66 +/- 7%, placebo 62 +/- 7%, tadalafil 69 +/- 5%; P = 0.08). During echocardiography at low-intensity exercise (40% of peak power), dexamethasone compared with placebo resulted in lower pulmonary artery pressure (47 +/- 9 mm Hg; tadalafil 57 +/- 11 mm Hg, placebo 68 +/- 23 mm Hg; P = 0.05) and higher oxygen saturation (74 +/- 7%; tadalafil 67 +/- 3%, placebo 61 +/- 20; P < 0.02). CONCLUSIONS: Corticosteroids, but not phosphodiesterase-5 inhibition, partially prevented the limitation of exercise capacity in subjects with intense hypoxic pulmonary vasoconstriction at high altitude. |
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Authors:
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Manuel Fischler; Marco Maggiorini; Lorenz Dorschner; Johann Debrunner; Alain Bernheim; Stephanie Kiencke; Heimo Mairbäurl; Konrad E Bloch; Robert Naeije; Hans Peter Brunner-La Rocca |
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Publication Detail:
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Type: Comparative Study; Journal Article; Randomized Controlled Trial Date: 2009-06-11 |
Journal Detail:
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Title: American journal of respiratory and critical care medicine Volume: 180 ISSN: 1535-4970 ISO Abbreviation: Am. J. Respir. Crit. Care Med. Publication Date: 2009 Aug |
Date Detail:
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Created Date: 2009-08-07 Completed Date: 2009-08-24 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9421642 Medline TA: Am J Respir Crit Care Med Country: United States |
Other Details:
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Languages: eng Pagination: 346-52 Citation Subset: AIM; IM |
Affiliation:
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Intensive Care Unit, Department of Internal Medicine, University Hospital Zürich, Raemistrasse 100, CH-8091 Zürich, Switzerland. manuel.fischler@usz.ch |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Altitude Sickness / drug therapy* Anti-Inflammatory Agents / adverse effects, therapeutic use* Carbolines / adverse effects, therapeutic use* Carbon Dioxide / blood Dexamethasone / adverse effects, therapeutic use* Double-Blind Method Echocardiography Exercise Test / drug effects* Female Humans Hypertension, Pulmonary / drug therapy Lung / blood supply Male Middle Aged Oxygen / blood Phosphodiesterase Inhibitors / adverse effects, therapeutic use* Pulmonary Edema / drug therapy* Pulmonary Wedge Pressure / drug effects Vasoconstriction / drug effects |
| Chemical | |
Reg. No./Substance:
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0/Anti-Inflammatory Agents; 0/Carbolines; 0/Phosphodiesterase Inhibitors; 0/tadalafil; 124-38-9/Carbon Dioxide; 50-02-2/Dexamethasone; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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