Delis KT, Azizi ZA, Stevens RJ, Wolfe JH, Nicolaides AN.
Optimum intermittent pneumatic compression stimulus for lower-limb venous
emptying.
Eur J Vasc Endovasc 2000 Mar ;19(3):261-9

Irvine Laboratory for Cardiovascular Investigation and Research Academic Vascular
Surgery, Imperial College School of Medicine, London, UK.

OBJECTIVE: intermittent pneumatic compression (IPC) of the foot (IPC(foot)), calf
(IPC(calf)) or both (IPC(foot+calf)) augments calf inflow, and improves the
walking ability and peripheral haemodynamics of claudicants (IPC(foot),
IPC(foot+calf)), largely due to venous outflow enhancement. This cohort study,
using direct pressure measurements in healthy limbs, determines the optimal
combination of frequency (2-4 impulses/minute), applied pressure (60-140 mmHg),
mode (IPC(foot)-IPC(calf)-IPC(foot+calf)) and delay time of calf-to-foot impulse
(0 s-0.5 s-1 s) that enables IPC to generate an almost complete and sustained
decrease in venous pressure. RESULTS: (a) IPC(foot)at 120 and 80 mmHg generated
lower venous pressure than that with 100 and 60 mmHg (p=0.036) respectively, for
2-4 impulses/minute; venous pressure differences between applied pressures of 140
and 120 mmHg or between 80 and 100 mmHg were insignificant. (b) Venous pressure
with IPC(calf)at 80 mmHg was lower than that with 60 mmHg (p=0.036) (2-4
cycles/minute); differences in venous pressure between applied pressures of 140
and 100 mmHg or between 120 and 80 mmHg were insignificant. (c) At applied
pressures 60-140 mmHg, IPC(foot+calf)with one-second delay generated lower venous
pressure than that with half-second delay (p=0.036), the latter being more
efficient than zero delay; increasing applied pressures produced lower venous
pressure, but differences were small. Venous pressure decreased with increasing
IPC frequency (from 2 to 3-4/minute), at applied pressures 60-140 mmHg.
CONCLUSIONS: IPC(foot+calf)at applied 120-140 mmHg, a frequency of 3-4
impulses/minute and one-second delay, provided the optimum intermittent pneumatic
stimulus.