The effect on responsivity of the P_tcO₂ electrode by an increased pressure on the electrode membrane

Abstract

At application of the electrode for continuous transcutaneous oxygen monitoring, a superatmospheric pressure may be produced between the skin and the electrode membrane. Such a pressure may change the electrode characteristics resulting in a slower reacting electrode. A superatmospheric pressure may also influence on the subepidermal capillaries and on the oxygen diffusion through the skin. The results in the current in vitro study show that an increase of the pressure between the electrode membrane and the skin results in a slower reacting electrode, only when the pressure also produces an increased diffusion distance from the capillaries to the electrode membrane. Thus, the P_tcO₂ electrode seems rather rough and different P_tcO₂ levels recorded among patients or in the same patient at two applications are not produced by the application procedure per se but by physiological differences in the skin at the electrode application site.

Key Words:

• oxygen electrode characteristics
• PO₂ measurements
• transcutaneous oxygen measurements