Limb perfusion in the lower limb amputee—a comparative study using a laser Doppler flowmeter and a transcutaneous oxygen electrode:

Accurate and objective assessment of amputation level in the lower limb plays an important role in patient management. Laser Doppler flowmetry (LDF) is a new and noninvasive technique for skin blood flow measurement and has been used pre-operatively in 25 patients undergoing amputation for vascular disease and in five normal controls. Baseline flux measurements were made at room temperature on the medial aspect of legs and then again after local heating of the skin for five minutes. Transcutaneous oxygen measurements were made at the same site for comparison and amputation level in patients selected on this basis.Significant differences (p<0.001) in TcPO2 values were found between controls (10.9±0.5kPa), below-knee (BK) amputees (6.0±1.5kPa) and above-knee (AK) amputees (1.5±0.6kPa). Baseline LDF flux did not differ significantly between any group. Heated flux values did however show a significant difference (p<0.005) between controls (52.4±23.5) and both BK (20.6±9.2) and AK groups (8.1±7.7) and also bet...