[On some experimental conditions possibly influencing the correct measurement of venous pressure by Doppler method]

Measurement of venous pressure by means of the Doppler method applied to the posterior tibial vein and to the internal and external saphenous veins is subject to error which depends on the observer's technique. We have therefore sought to ascertain whether and how differences in measurement techniques could affect the results of venous pressure determination in 50 subjects. We have observed that: --Measured pressure are higher when the duration of the test is prolonged, probably because the cuff remains inflated too long. --Of several consecutive determinations, the first and second yield generally higher values, that decrease and remain stable thereafter through the 5th measurement, following the initial loss of venous tone. --Venous pressure is lower as the measurement site is moved more proximally, as predicted by the expected pressure gradient along the venous circulation; the decrease could also be affected by local changes of vein compliance.