1. Diagnostic Medical Sonography Program Vascular Technology
Lecture 10: Transcutaneous Oximetry
(TcPO2)
Holdorf

2. Capabilities Wound heeling and amputation level determination.
Reflects tissue oxygen tension and relies on a balance between oxygen supply and consumption.

3. Limitations
Inability to keep electrode fairly flat on the skin surface
Electrode placement must be on intact skin

4. Patient Positioning
Patient supine, head slightly elevated, room is warm

5. Patient positioning for Transcutaneous Oximetry TcP02

6. Physical Principles Electrode heats skin to 45 Degrees C
Blood flow increases
Lipid layer in fatty tissue melts
More “02” escapes through skin, measured by sensor in electrode
As “02” escapes, a chemical reaction occurs in electrolyte solution, located between the skin and the electrode surface
Electrode converts chemical reaction to a CURRENT reading which is converted to a p02*
reading in mmHg.
* Measure of Oxygen in the blood

7. Technique Skin cleansed with alcohol wipe: air dried
Airtight self-adhesive fixation ring placed on the skin
Few Drops of electrolyte solution put inside ring
Electrode/Sensor is affixed to fixation ring

8. Borderline healing: 30 – 40 mmHg
After manual calibration: it takes approximately 15 – 20 minutes to obtain p02 reading.
Interpretation
Normal values vary in literature and with manufacturer. Healing should occur with p02 reading of mmHg.
Borderline healing: 30 – 40 mmHg
Non-healing (poor values) = mmHg
This number also varies

9. Additional notes: Lecture 10 Transcutaneous Oximetry TcPO2
No other test will do this.
Know the normal values
40-80 mmHg
Non-healing is mmHg

10. Homework
Chapter 11
Pages 115 – 118
SDMS assignments