Some Effects of High Altitude and Polycythaemia on Oxygen Delivery

Abstract

The purpose of this project was to investigate by means of mathematical analysis some of the implications of polycythaemia at high altitude on tissue oxygenation with special emphasis on the human cerebral cortex. Experimental data concerning arterial oxygen saturation, haematocrit, and corresponding blood viscosity was collected from the literature and used as input data for the predictive study. Tissue oxygenation of brain cortex was evaluated for a variety of cases using a mathematical model and solution techniques for the mapping of oxygen deficient tissue zones as described in prior publications but specifically in Reneau et al (1970). In addition, the effect of changes in specified variables was analysed in an effort to evaluate the effectiveness of possible protective mechanisms. Specific effects investigated included a rightward shift in the oxygen dissociation curve as found in polycythaemic patients due to hypercapnia, increased capillary density and flow rate accommodation.