Overview :

The transcutaneous partial pressure of oxygen (TcpO2, or oxygen tension) is related to cutaneous oxygen delivery. The transcutaneous partial pressure of oxygen can be used to assess potential amputation sites for likelihood of healing.

Measurement sites:

(1) anterior surface of calf at proposed amputation site

(2) posterior surface of calf at proposed amputation site

(3) reference site on arm

TcO2 index =

= (TcpO2 from calf in mm Hg) / (TcpO2 of reference site in mm Hg)

Oishi et al (1988) measured TcpO2 before and after oxygen inhalation.

Interpretation:

• If the TcpO2 is > 20 mm Hg, healing is likely; if it is < 20 mm Hg, then healing is uncertain.

• If the TcpO2 index > 0.2, then healing is likely; if it is < 0.20, then healing is uncertain.

• If the TcpO2 before and after oxygen inhalation was <= 10 mm Hg, then healing was unlikely; if TcpO2 was <= 10 mm Hg before oxygen but > 10 mm Hg after oxygen, then healing at the amputation site was possible.

De Frang RD, Taylor LM Jr, Porter JM. Basic data related to amputations. Ann Vasc Surg. 1991; 5: 202-207.

Katsamouris A, Brewster DC, et al. Transcutaneous oxygen tension in selection of amputation level. Am J Surg. 1984; 147: 510-517.

Kram HB, Appel PL, Shoemaker WC. Multisensor transcutaneous oximetric mapping to predict below-knee amputation wound healing: Use of a critical pO2. J Vasc Surg. 1989; 9: 796-800.

Oishi CS, Fronek A, et al. The role of non-invasive vascular studies in determining levels of amputation. J Bone Joint Surg. 1988; 70-A: 1520-1530.

Ratliff DA, Clyne CAC, et al. Prediction of amputation wound healing: the role of transcutaneous pO2 assessment. Br J Surg. 1984; 71: 219-222.