A simple and reliable method for determination of skin perfusion pressure in patients with severe occlusive arterial disease

Summary. In an attempt to simplify the pre-operative assessment of amputation level in patients with severe occlusive arterial disease of the legs the skin perfusion pressure (SPP_i) on calf and/or thigh was determined photo-electrically in 38 patients, aged 41–85 years and compared to the pressure values (SPP_i) determined by the widely used but cumbersome isotope washout technique. SPP_i was determined as the minimal external counter pressure (applied by a blood pressure cuff) sufficient to stop the washout from an intracutaneous depot of Na¹³¹I^- mixed with histamine. SPP_P was determined as the minimal external counter pressure required to prevent skin reddening after blanching of the skin. The systolic blood pressure, determined indirectly by strain gauge technique at the same level of the leg, was used for reading the SPP_P as that counter pressure at which the photo-electric tracing moves away from a straight line placed on the tracing through the counter pressure corresponding to the systolic blood pressure. In the studied range 18–88 mmHg there was no significant difference between SPP_P and SPP_i. The total day-to-day variation of SPP_P, determined from ten double determinations in eight patients was 6-6 mmHg (range of SPP_P: 23–80 mmHg). The present results indicate that assessment of amputation level from SPPp using the standardized reading should offer a reliable alternative to the isotope washout method. The photo-electric technique is simple and fast, and gives only negligible discomfort to the patient.