Differences between intracutaneous and transcutaneous skin oxygen tension in chronic venous insufficiency

Data obtained from transcutaneously measured PO2 (tcPO2) were taken as an indication for a decreased oxygen supply to the skin in patients with chronic venous insufficiency III. Direct (invasive) measurements in LDS have not yet been performed. We therefore measured the intracutaneous PO2 (icPO2) in healthy skin and LDS (8 healthy volunteers and 18 patients with CVI III) with needle probes (250 microns tip diameter). The icPO2 values were compared with data of tcPO2 (37 degrees C and 44 degrees C electrode temperature). In healthy skin the mean icPO2 was about 50 mmHg and no steep PO2 gradients were found. In LDS (ulcer edge) mean PO2 values were lower than in healthy skin, however, no hypoxia or anoxia was observed. At the same site most tcPO2 (44 degrees C) values were between 0 and 5 mmHg. The mean icPO2 values from ulcer edges of different patients ranged from 6 mmHg to 42 mmHg (mean 22 mmHg). In LDS very different PO2 profiles were seen. There was no correlation between tcPO2 and icPO2 data. Our present results may suggest that skin damage in patients with CVI is not necessary associated with hypoxia.