Keywords

electrode equilibration, peripheral vascular disease, tissue oxygenation, tissue viability, transcutaneous oximetry, transcutaneous partial pressure of carbon dioxide, transcutaneous partial pressure of oxygen

Authors

1. Chiang, Nathaniel MBChB
2. Jain, Jitendra K. MBBS, BMedSc
3. Sleigh, Jamie MBChB, MD, FANZCA
4. Vasudevan, Thodur MD, FRACS

ABSTRACT

OBJECTIVE: The transcutaneous oxygenation measurement (TCOM) system is useful in assessing tissue viability. There are no clear recommendations regarding the duration required for the electrode to equilibrate and reliably evaluate tissue oxygenation values. The objective of this study was to validate the duration required to achieve electrode equilibration in a clinical setting.

METHODS: Minute-by-minute recordings using TCOM (TCOM3; Radiometer Medical ApS, Bronshoj, Copenhagen) were obtained for 82 limbs in 50 participants. Twenty-five limbs were in patients with peripheral vascular disease; 30 were in patients with no known peripheral vascular disease; and 27 were in healthy volunteers. Transcutaneous partial pressure of oxygen and carbon dioxide (TcPO₂ and TcPCO₂) were recorded over a 15-minute period.

RESULTS: Participants' TcPO₂ decreased and TcPCO₂ increased over time. Both changed in a nonlinear fashion, eventually settling at an "equilibrium" where the measurements became stable. The difference in proportional change of TcPO₂ between minutes 14 and 15 was 0.8%, and for TcPCO₂was 2.9%. Changes in TCOM measurements over time were similar among the 3 groups.

CONCLUSIONS: This is the first study to target minute-by-minute variation in TcPO₂ and TcPCO₂ measurements. Recording for a minimum of 15 minutes allows a reliable period for the TCOM electrode to equilibrate to record absolute values and determine wound healing potential.