Pneumatic compression hemodynamics in total hip arthroplasty

A crossover study was performed to evaluate the effect of several pneumatic compression devices and active dorsoplantar flexion in 10 patients who und erwent total hip arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5-MHz linear array probe, peak venous velocity and venous volum e were assessed above and below the greater saphenous vein and common femor al vein junction. A computer generated randomization table was used to dete rmine the order of the test conditions. The pneumatic compression devices e valuated included two foot pumps, one foot and calf pump, one calf pump, an d three calf and thigh pumps, Statistical analyses included analysis of var iance and analysis of variance with covariance between devices and patients , The covariates tested were the baseline measurements and the order in whi ch the devices were tested. Differences between devices relate in part to t he frequency and rate of inflation and the location and type of compression , Pulsatile calf and foot and calf pneumatic compression with a rapid infla tion time produced the greatest increase in peak venous velocity, whereas c ompression of the calf and thigh showed the greatest increase in venous vol ume, Because patient and nursing compliance is essential to the success of mechanical prophylaxis for thromboembolic disease, the more simple, yet eff icacious, devices that, are easier to apply and less cumbersome appear to h ave a greater likelihood of success; In the active and alert patient, activ e dorsoplantar flexion should be encouraged.