Evaluation of intermittent pneumatic compression devices.

Venous blood flow rate in the lower extremity after applying different pneumatic compression devices was evaluated. Five healthy individuals, aged 21-35, were recruited for this study. The ability of six different pneumatic compression devices to increase femoral venous blood flow velocity was analyzed and compared to that of active and passive foot dorsiflexion. Baseline venous blood flow velocity was measured using an ATL Duplex Doppler before leg compression. Venous blood flow velocity was then monitored before, during, and after each compression cycle. Average peak venous velocity increased >200% on dorsiflexion of the ankle. Among the investigated devices, the increase in venous velocity varied significantly. Design of compression chambers enabling compression on the lateral and medial aspects of the calf produced an increase in venous velocity closest to active foot dorsiflexion. Foot compression devices produced the smallest increase in venous velocity. The relative effectiveness of pneumatic compression devices, particularly with respect to increasing venous blood flow in the lower extremity, may correlate well with how closely the device simulates the physiologic contraction of the calf muscles. Clinical trials are needed to further compare the effectiveness of these devices, as other less readily measured factors play a role in thromboprophylaxis.