Non-Invasive Measurement of Venous Muscle Pump Function in the Supine Position
Objective: A new non-invasive procedure for testing venous muscle pump function in the horizontal position is presented. Design: The test is based on an indirect method we use for measuring ambulatory venous pressure by means of strain-gauge plethysmography. Setting: University Hospital Nijmegen, The Netherlands. Patients: The results of 28 limbs of 20 patients with deep venous insufficiency are compared with 32 limbs of 16 healthy volunteers. Interventions: The same test is performed in all patients and volunteers: in the supine position a raised venous pressure in the limb is induced by venous congestion. The reduction in venous volume after standardized leg movements is measured by strain-gauge plethysmography and, with an additionally obtained pressure-volume relation, this volume reduction is converted into a pressure reduction. Main outcome measure: The reduction by standardized leg movements of an increased venous pressure is a measure for calf muscle pump function. Results: The mean pressure reduction in the patient group was 47% (standard deviation (SD) = 8%), in the healthy group 77% (SD = 6%). Conclusions: The new ‘supine venous pump function test’ is a promising method for measuring the function of the deep veins. Since the whole procedure is performed in the horizontal positon, the method offers several important advantages.