Transcutaneous PO2 and laser Doppler blood flow measurements in 40 patients with venous leg ulcers

Abstract

The study included 40 patients with clinically venous leg ulcer(s) in one leg only and with a systolic toe blood pressure above 50 mmHg in both legs. Transcutaneous oxygen tension was measured on both lower legs at equivalent sites, on the affected leg immediately proximal to the ulcer(s). Similarly, skin blood flow was measured in both legs at a skin temperature of 32 degrees C and 44 degrees C by means of laser Doppler velocimetry, and for each leg the index of blood flow 44 degrees C/flow 32 degrees C was calculated to express the degree of blood flow increment following local hyperthermia. Transcutaneous oxygen tension measurements were significantly lower on affected legs (p less than 0.01) as was flow increment (p less than 0.01), mainly due to a high flow measurement at 32 degrees C on affected legs rather than to a low measurement at 44 degrees C. The results of our flow measurements suggest a state of (relative) hyperemia in the vicinity of venous leg ulcers, also confirmed by the clinical findings. This could be interpreted as an arteriolar response to lowered oxygen tension or (it could) be part of reactive reparative processes leading to increased O2 consumption in the tissues.