Enhancing venous outflow in the lower limb with intermittent pneumatic compression. A comparative haemodynamic analysis on the effect of foot vs. calf vs. foot and calf compression

Objectives: intermittent pneumatic compression (IPC), an established method of deep-vein thrombosis prophylaxis, is also an effective means of leg inf low enhancement, improving the walking capacity and ankle pressure of claud icants, long-term. This study, using duplex ultrasonography, compares the h aemodynamic effect of IPC of the (a) foot (at 120 mmHg [IPCfoot/120 mmHg], and 180 mmHg [IPCfoot/180 mm Hg]), (b) calf (IPCcalf, 120 mmHg) and (c) bot h simultaneously (IPCfoot+calf, 120 mmHg), on the venous outflow of 20 legs of normals and 25 legs of claudicants. Results: the peak and mean velocities, volume flow and pulsatility index in the superficial femoral and popliteal veins of both groups increased signi ficantly with all IPC modes (p<0.001). IPCfoot+calf produced the highest en hancement followed by IPCcalf (p<0.01), which was more effective (p<0.001) than either IPCfoot/180 mmHg or IPCfoot/120 mmHg, The venous volume expelle d with IPCcalf and IPCfoot+calf was 2-2.5 and 3-3.5 times that with IPCfoot /180 mmHg respectively. Velocity enhancement with IPC was similar between g roups and the superficial femoral and popliteal veins, IPCfoot/180 mmHg pro duced higher (p<0.01) flow velocities than IPCfoot/120 mmHg in both groups and veins examined; however, differences were limited. Conclusions: all IPC modes proved effective, IPCfoot+calf generating the hi ghest venous outflow, enhancement. Higher venous volumes expelled with IPCf oot+calf explain its reported superiority on leg inflow, over the other mod es. Increase of applied pressure from 120 to 180 mmHg with IPCfoot, offered only a small outflow improvement. Venous haemodynamics at rest and with IP C in claudicants do not differ significantly from those in healthy subjects .