Transcutaneous Po2Electrode

Abstract

Measurements of pO₂ on the skin surface (tc-pO₂) by means of a conventional Clark electrode have under normal conditions (i.e., without producing hyperaemia) shown low tc-pO₂ values and thereby indicated only a small exchange of oxygen through the skin. By using a heated Clark electrode specially designed for application on the surface of the skin, it is, however, possible to perform continuous, non-invasive monitoring of tc-pO₂ which is highly correlated to the arterial pO₂ (pO₂ (aB)) and which responds rapidly to changes in the inspired oxygen concentration (pO₂ (I)). The tc-pO₂ electrode developed by Radiometer and based on the above mentioned principles, viz.: - the use of a Clark oxygen electrode - the application of hyperthermia to produce local hyperaemia is described together with the Radiometer TCMI TC OXYGEN MONITOR. The in vitro calibration of the electrode is performed at 43 deg;C using water saturated with atmospheric air as high calibrating standard, and a sulphite solution as zero standard. The response time of the electrode lies within the range 12-18 sec for 95% response when using a 25 μ Teflon (FEP) membrane. If the calibration is performed as described, the electrode will respond almost linearly to pO₂ values up to 700 mmHg.