Abstract

Measurement of laser Doppler flow on the fingertip was evaluated before and after occlusion of the fingerbase for 5 min by suprasystolic compression in normal control subjects and in patients with several types of Raynaud's phenomenon (RP). Baseline flow values differed significantly (P less than 0.002) between the 24 normals and the 29 primary Raynaud patients but there was a considerable overlap between the primary and the secondary Raynaud group. The postocclusive reactive hyperemia parameters showed an improved discrimination between the patients with primary RP and the 38 patients with secondary RP. The patients with scleroderma and those with arterial obstructive disease of the finger had the lowest increase in flow. Of all the indices analyzed none showed an optimal discrimination among the several subtypes of finger ischemia. The parameters that represent the increase in laser Doppler values after occlusion differentiated best between primary and secondary types (P less than 0.02). Time variables after the peak were more suitable to differentiate scleroderma patients from those with arterial obstructive disease (P less than 0.002). The reproducibility of the laser Doppler-monitored postocclusive response in normals was found to be only moderate (standard error of a single observation varies between 7 and 43% for different parameters). In conclusion postocclusive reactive hyperemia may be useful in determining the degree of obstructive vascular disease in groups of patients presenting with RP. It is not sensitive enough to discriminate adequately among individuals in the several subgroups.