The influence of local skin heating and reactive hyperaemia on skin blood flow abnormalities in patients with reflex sympathetic dystrophy (RSD).

Skin blood flow in reflex sympathetic dystrophy (RSD) patients has been reported to develop from an increase at an early stage to a decrease at later stages. So far, it remains unclear whether these abnormalities are solely of microcirculatory origin, and result from functional vasospasm or structural vessel wall changes. Eighty-seven RSD patients were categorized as follows: stage I in case of a stationary warmth sensation; stage II in case of an intermittent warmth and cold sensation; and stage III in case of a stationary cold sensation. Laser Doppler flowmetry (LDF) was used as a measure of total skin blood flow and transcutaneous oximetry (TCPO2) as a measure of vascular reactivity in the more superficial skin layers. Local skin heating and reactive hyperaemia were used to study the relative reserve capacity of skin microvessels. Finapres was used to assess digital arterial pressures. As compared to healthy volunteers (n = 16), LDF under control conditions demonstrated an increase in skin blood flow at stage I (P < 0.01). A decrease in skin blood flow under control conditions was seen at stages II (P < 0.05) and III (P < 0.05), but the relative flow reserve capacity, as measured with LDF, was not impaired at these stages. Regression analysis did not show a relation between LDF parameters and duration of the syndrome. TCPO2 revealed no differences between patient groups and controls. Regression analysis did not demonstrate a relation between TCPO2 parameters and duration of the syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)