To TCOM or Not to TCOM!
Transcutaneous oximetry (TCOM or PtcO2) has arguably been the gold standard in assessing microvascular flow and predictive wound healing using hyperbaric oxygen therapy.
In the 1950s, the relationship between skin oxygen levels and arterial blood oxygenation was investigated, which initiated the later development of tools to measure transcutaneous oxygen levels. (Schmid, H. 1959).
As the technology improved, enhancements such as heated electrodes were introduced to improve accuracy, and the devices were eventually introduced into clinical practice, particularly when assessing patients with peripheral vascular disease and diabetes and measuring wound healing and tissue viability.
As the use of hyperbaric medicine in wound healing increased, TCOM was a natural choice for obtaining measurements to predict the success of healing with hyperbaric oxygen and measure the progress of improvement in vascularity by measuring the level of oxygen in interstitial fluids.
The National Board of Diving & Hyperbaric Medical Technology (NBDHMT) pioneered the certification of hyperbaric medical provider competency. It incorporated the application and interpretation of TCOM results into its certification competency to assure that the individual being “certified” was competent in administering TCOM testing. That testing included attending the didactic portion of the theory and skills and performing three proctored TCOM procedures under the supervision of a skilled technologist, physician, or nurse. This has been the standard of care since the early 1990s.
In September 2024, it was announced that the NBDHMT would no longer require the performance of three proctored tests to qualify for the certification examination. This was in recognition of the evolution of vascular testing that included the development of many different technologies to assess vascular patency and the increased cost of the TCOM devices with a concomitant low reimbursement for the procedure.
Even though proctored testing is no longer required, the competency of staff remains the responsibility of the facility leadership and should not be ignored with this change of policy. Regardless of the modality used to assess vascular patency, the facility is still responsible for the accuracy and clinical application of the chosen modality.
References:
H. Schmid, "Transcutaneous oxygen and carbon dioxide tension," *Archives of Surgery*, 1959.