Plasma exchange and Raynaud's phenomenon--its assessment by Doppler ultrasound velocimetry.

In a group of 47 patients with Raynaud's phenomenon, Doppler ultrasound velocimetry was used to establish the severity of the disease by detecting the patency of the digital arteries. In conjunction with small digital occlusion cuffs, digital artery systolic pressure was measured on either side of the finger. A significant variation in systolic pressure was detected in each finger, and on each side of individual fingers. A more sensitive index of the severity of the disease was noted when the digital systolic pressure was compared to the brachial systolic pressure. Plasma exchange, a potent method of lowering whole blood viscosity and plasma fibrinogen, was used to treat 18 of these patients. There was a significant improvement in digital vessel patency at both 21 degrees C and 13 degrees C after plasma exchange. Both the digital artery systolic pressure and the pressure index improved significantly after treatment.