Effect of the thigh-cuffs on the carotid artery diameter jugular vein section and facial skin edema: HDT study.

Objective: To evaluate the distal arterial, venous and skin changes in a gr oup using thigh cuffs during daytime and in a control group. Method: Cardia c, arterial, venous parameters were measured by echography and Doppler. Ski n thickness was measured by high frequency echography. Results & discussion : Head down position induced plasma volume reduction, increased cerebral re sistance, reduced lower limb resistance. The jugular vein increased whereas the femoral and popliteal veins decreased. All these changes were already observed in previous HDT. Common carotid diameter decreased, Front head ski n thickness increased and Tibial skin thickness decreased. Eight hours with thigh cuffs increased the cardiac and carotid sizes which is in agreement with the plasma volume increase. Conversely they reduced the cerebral vascu lar resistance, jugular section and front head edema which may explain the sensation of comfort reported by the subjects. At the lower limb level the thigh cuffs restored the skin thickness to pre-HDT level but enlarged marke dly the femoral and popliteal veins. HR, BP, CO, TPR did not change. (C) 20 01 Elsevier Science Ltd. All rights reserved.