Correlation of transcutaneous oxygen tension to blood flow in heated skin

Abstract

Blood flow regulation in the foot under a heated (43°C) transcutaneous oxygen tension (tcPo₂) electrode was studied in six young subjects. Blood flow under the electrode was estimated from the electrical power consumption of the thermostatically-controlled heating element in the electrode. Changes in arterial and venous pressures, and thereby in perfusion and transmural pressure and blood flow were induced by elevation and lowering of the foot and by venous stasis. tcPo, was significantly and positively correlated to the blood flow under the electrode, and blood flow neither showed auto regulation nor vasoconstrictor response as judged from the power consumption. In contrast the blood flow in normal unheated skin measured simultaneously by the 133–Xenon technique showed auto regulation as well as vasoconstrictor response. It is concluded that tcPo₂ is a parameter determined by many variables, of which the arterial blood pressure is of particular clinical importance.

Key Words:

• blood circulation
• blood gas analysis
• blood pressure
• oxygen
• regional blood flow
• skin
• skin temperature
• transcutaneous oxygen electrode
• vascular resistance