Impaired vascular function in women with pre-eclampsia observed with orthogonal polarisation spectral imaging

OBJECTIVE: To investigate in vivo the function of the microcirculation of the skin in pregnancy and pregnancy complicated with pre-eclampsia. DESIGN: Case-control study. SETTING: Academic Medical Centre. PARTICIPANTS: A group of 10 women with pre-eclampsia and a healthy control group of 10 pregnant women. METHODS: The microcirculation of the skin of the finger at rest and during venous occlusion was studied with laser Doppler fluxmetry and orthogonal polarisation spectral imaging. By inflating a cuff around the upper arm to a pressure of 50 mmHg, causing venous occlusion, the local sympathetic veno-arteriolar reflex was provoked. With laser Doppler fluxmetry the blood flow of the skin at a depth of 1-2mm was measured at rest and during venous occlusion. Orthogonal polarisation spectral imaging was used to assess red blood cell velocity at rest and during venous occlusion of the nutritive capillaries of the skin. RESULTS: Laser Doppler fluxmetry showed no significant difference between the normotensive group and the group with pre-eclampsia. Using orthogonal polarisation spectral imaging, venous occlusion produced a significantly greater decrease in red blood cell velocity in the control group than in the women with pre-eclampsia: (84% (81-88)(median and interquartile range) vs 58% (45-88), P = 0.0029). No differences in absolute red blood cell velocities were observed between groups either at rest or during venous occlusion. CONCLUSION: This study shows an impaired local veno-arteriolar reflex in pre-eclampsia at the nutritive, but not at the therrmoregulatory, level of the microcirculation of the skin