Oxygen Transport on Mount Everest: The Effects of Increased Hematocrit on Maximal O2 Transport

  • Paolo Cerretelli
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 75)


Maximal oxygen consumption (V̇O2 max) urateirgoes a progressive reduction in hypoxia, both acute and chronic. Such decrease, for a pressure drop of half an athmosphere corresponding to a climb to about 5500 meters a.s.l., ranges, according to various Authors (1), between 30% and 45% and is apparently independent of the degree of acclimation (Fig. 1). Possible thoracic causes for the observed V̇O2 max limitation in subjects exposed to low oxygen are:
  1. 1)

    the decreased arterial O2 pressure (PaO2) and blood O2 percent saturation (O2aHb%) of which, however, the latter may be more than compensated for in the acclimated, by the increased RBC and blood hemoglobin (Hb) concentration;

  2. 2)

    hypoxia of the myocardium, that may reduce maximal cardiac output (Q̇max) both in acute and chronic hypoxia;

  3. 3)

    limited to the acclimated, the effects on Q̇max of the increased blood relative viscosity (frem 5 to 11, according to personal measurements by the Ostwald viscometer) brought about by the high increase in the hematocrit (Hot).



Cardiac Output Oxygen Transport Mixed Venous Blood Italy Introduction Diac Output 
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Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • Paolo Cerretelli
    • 1
  1. 1.Centro Studi di Fisiologia del Lavoro Muscolare del C.N.R.University of MilanoMilanoItaly

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