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

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

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

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

Patient positioning for Transcutaneous Oximetry TcP02

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

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

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 70-80 mmHg. Borderline healing: 30 – 40 mmHg Non-healing (poor values) = 10-15 mmHg This number also varies

Additional notes: Lecture 10 Transcutaneous Oximetry TcPO2   No other test will do this. Know the normal values 40-80 mmHg Non-healing is 10-15 mmHg

Homework Chapter 11 Pages 115 – 118 SDMS assignments