ISSN:
1439-6327
Schlagwort(e):
Altitude acclimatization
;
Oxygen transport
;
Ventilation
;
Blood-gases
;
Hemodynamics
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Abstract Key aspects of the oxygen transport system were studied under supine, near-basal conditions in 6 male subjects, initially at low altitude (200 m) and subsequently over a 15-day sojourn on Pikes Peak (4300 m). Certain functions, including cardiac output, heart rate, mean arterial pressure and left ventricular work, were transiently increased with maximum values observed on day 2 of altitude exposure. Others, including arterial PO2, O2 saturation, and O2 content passed through minimal values on the same day and then recovered somewhat as the sojourn progressed. Tidal volume and arterial pH exhibited relatively linear increases over the two-week sojourn while pulmonary minute volume and hemoglobin exhibited progressive increases which were especially pronounced during the first 5 days of exposure. Plasma volume, stroke volume, arterial PCO2, and plasma HCO 3 − concentration decreased progressively, with the more pronounced effects being observed during the first 5 days of exposure. A decrease in stroke volume and cardiac output on day 14 led to diminished arterial O2 delivery. On the basis of the results and complementary data reported by others, it was concluded that altitude acclimatization progresses through three distinct but overlapping stages. Arbitrarily, the states were termed accommodation, acute acclimatization, and chronic acclimatization.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00423054
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