Subclinical Pulmonary Edema with Hypobaric Hypoxia
Clinical pulmonary edema is a known but uncommon complication of exposure to high altitude (8,9). In a recent report by Hackett et al. (8) only 7 of 278 subjects exposed to an altitude of 5400 m developed clinical pulmonary edema. However, since clinical signs and symptoms are a late manifestation of an increase in lung water, it is possible that there is in fact a greater incidence of high altitude pulmonary edema (HAPE) than is suggested by the literature, but of a severity insufficient to cause clinical signs and symptoms. There is evidence to suggest that this is so. Gray (7) measured the washout of a single breath of nitrogen in 17 subjects during one week of exposure to 17,600 ft on Mount Logan, Yukon, Canada. There was a significant increase in the slope of the alveolar plateau in these subjects.
KeywordsAttenuation Helium Respiration Iodide Resis
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