The history of transcutaneous oxygen partial pressure measurement
The first oxygen partial pressure measurements were performed around 60-70 years ago using a phosphate buffer solution into which you would place your finger until an equilibrium (balance) between the PO2 of the blood and of the solution was reached.
Since the oxygen partial pressure in solution adapted to that of the blood, it was possible to indirectly determine the PO2 level.
In 1962, Clark Leland successfully measured the oxygen partial pressure in the blood transcutaneously. This new, polarographic method involves a gold cathode which is connected via an electrolyte solution to a silver anode with a polarisation voltage of around -0.8 V.
When an oxygen molecule diffuses through the oxygen-permeable membrane to the electrodes, the number of oxygen atoms reduces. The resulting reduction current (nA) is proportional to the number of reduced oxygen molecules and therefore also to the oxygen partial pressure.
Cathode: O2 + 2 e− + 2 H2O → H2O2 + 2 OH− und H2O2 + 2 e− → 2 OH−
Anode: 4 Ag → 4 Ag+ + 4e− und 4 Ag+ + 4Cl− → 4 AgCl
Use in medicine:
Transcutaneous oxygen partial pressure measurement is a non-invasive method of indirectly determining the oxygen partial pressure (PO2) on the skin’s surface, as well as of indirectly measuring the systemic, arterial PO2.
Transcutaneous measurement documents the availability of oxygen in the skin tissue at the end of the organism’s oxygen transport chain and depends on the arterial oxygenation and microcirculation at the measurement site.
To increase the O2 diffusion and capillary perfusion of the skin surface, these PO2 sensors are heated to a constant temperature of between 40 and 45 °C.
Originally, transcutaneous oxygen partial pressure measurement was developed as a non-invasive means of measuring blood gases in new-born babies. In recent years, however, the range of applications of this method has increasingly expanded to include cutaneous parameters, for example to investigate peripheral, arterial occlusive disease and chronic venous insufficiency. Other areas of application include progressive, systemic scleroderma or even diabetes mellitus.
OMT (Oxygen Multistep Therapy):
Oxygen multistep therapy is a scientifically-based and effective method of preventative oxygen treatment. Unlike pure oxygen inhalation, this method involves three stages of treatment.
1st stage: Vital nutrient preparations are intended to stimulate the body to use oxygen more efficiently.
2nd stage: 90% pure oxygen is breathed in for between 30 and 120 minutes.
3rd stage: Physical exertion during, before or after the oxygen inhalation causes the increased oxygen to travel from the blood into the tissues.