Accession Number:
ADA052564
Title:
Mechanisms of the Changes in Arterial Oxygen Saturation at Altitude,
Descriptive Note:
Corporate Author:
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MASS
Personal Author(s):
Report Date:
1978-02-16
Pagination or Media Count:
15.0
Abstract:
The reasons for the arterial oxygen saturation SaO2 changes during altitude exposure at rest and during exercise are presented and discussed. SaO2 is prevented to show lower values than usually measured due to hyperventilation. Ventilation increases SaO2 through an elevation of P sub O2 and pH. No negative contribution is found with the rightward shift of the oxygen-hemoglobin O2-Hb dissociation curve reported in vitro. The explanation is found on similar P sub 50 in vivo values shown at sea level and at altitude. The SaO2 fall observed during exercise at altitude is fully explained by the metabolic acidosis Bohr effect. However, if additional factors are taken into account, such as temperature increase and left shift of the O2-Hb dissociation curve, no changes are expected to occur in vivo. Author
Descriptors:
Subject Categories:
- Anatomy and Physiology
- Stress Physiology