Effect of arterial and venous pressures on transcutaneous oxygen tension

The effect of changes in arterial and venous pressures on transcutaneous oxygen tension (tcPO2) were studied in ten young subjects. The tcPo2 electrode was mounted on the foot, and changes in blood pressures were induced by elevating and lowering the foot and by inflating a cuff around the thigh. tcPo2 decreased gradually during elevation at a rate of 1% per mmHg reduction in arterial pressure. tcPo2 increased during dependency and venous stasis, at a rate of 0.5% per mmHg increase in venous pressure. We propose that tcPo2 is a function of the blood flow under the electrode, and that normal blood flow regulation is abolished in the heated tissue under the electrode.