Estimation of digital circulation and its correlation to clinical signs of ischaemia--a comparative methodological study.

Five different methods were used to evaluate the arterial blood supply to 29 toes from 15 patients with atherosclerotic disease: digital pulse plethysmography, systolic toe blood pressure recording, skin temperature recording, vital capillary microscopy and dynamic fluorescein angiography. An optimal discrimination between legs with and without ischaemic ulcers or gangrene was obtained with the following borderlines: inclination time non-measurable because of very low or no recordable pulse curve, systolic toe blood pressure less than 20 mmHg, skin temperature (after vasodilatation) less than 29 degrees C, capillary stage greater than 3 (indicating the presence of capillary haemorrhages or more advanced changes) and fluorescein appearance time greater than 45 s. The results of the study provide no basis for the opinion that one method is superior to the others in discriminating between arteriosclerotic feet with and without existing skin necrosis.