Transcutaneous measurements of oxygen tension at edges of leg ulcers: preliminary communication.

Using skin-surface sensors, transcutaneous oxygen tension (TcPo2) has been measured at the edges of ulcers and at control sites proximal to wounds on the same legs. TcPo2 at 43 degrees C at the edges of venous ulcers was found to be significantly different (P less than 0.003) from that of arterial and mixed arteriovenous ulcers (P less than 0.05) respectively. TcPo2 on healed skin was higher than at any wound edge. At this temperature TcPo2 was also found to be significantly different (P less than 0.001) on the intact skin of patients with venous disease when compared with measurements at identical sites on healthy controls. In the same group, these TcPo2 values increased with dependency. By contrast, at 37 degrees C TcPo2 was no different between groups (P less than 0.10), nor did it alter with position. This protocol adopted for investigating ulcers enables a quantitative distinction to be made between ulcers of different aetiologies. The differences in TcPo2 between different ulcers and healed skin support the fibrin cuff mechanism which has been suggested as the cause of venous ulceration.