Transcutaneous Oximetry

Oxygen plays a complex and vital role in wound healing. However, not every non-healing wound will benefit from HBO therapy. Transcutaneous oxygen measurement (TCOM) is a technology that has been developed to non-invasively measure the amount of oxygen in certain bodily tissues. By using these oxygen measurements, we are better able to determine which wounds are in need of extra oxygen in order to heal, and therefore decide which patients will benefit from hyperbaric oxygen therapy.

In order to measure oxygen levels transcutaneously, or through the skin, a specialized adhesive ring is placed on the skin and then attached to a sensor. The temperature is increased slightly in this ring (it will be warm but not hot), which allows oxygen to pass through a gas permeable membrane and be measured.

Several sites are usually selected for the transcutaneous oxygen measurements when evaluating a wound. The first is a control site, usually on the left mid chest. Several sites around the edge of the wound are then selected. In the case of wounds on the lower legs, oxygen levels will be measured at sites above the wound as well.

Once a site has been selected, it needs to be prepared. First, the area is shaved, and then cleaned with an alcohol swab. Finally, adhesive tape is used to remove the loose, unattached outer skin. The adhesive ring is then applied, followed by a special solution, and then the sensor. None of these steps is uncomfortable or painful.

Measurements are taken while the patient is breathing room air. A facemask supplying 100% oxygen is then applied and repeat measurements are taken at 1,2,3,4,5, and 10 minutes after the oxygen is started. These measurements are all recorded on a data sheet and provided to the doctor so that she can make a more informed decision about the value of hyperbaric oxygen therapy in that particular patient.