Intermittent pneumatic compression pump settings for the optimum reduction of oedema.

This study investigated the reduction in lower limb oedema achieved when different combinations of intermittent pneumatic compression (IPC) pump settings were used. Twenty-seven individuals aged between 22 and 96 years, with ankle oedema of venous origin, were randomised to either a treatment or control group. Treatment was delivered via a Flowpac pump (Huntleigh Healthcare Ltd, Luton, UK) possessing variable controls. The control group were 'treated' by elevating both lower limbs. The average difference in limb volumes was compared, for each combination of pump setting, to changes in limb volume in the control group. These comparisons revealed that the highest mean reduction in limb volumes was recorded for a pressure of 40 mmHg (p = 0.02), 10 second deflation time (p = 0.0002) and 15 second inflation time (p = 0.0096). Other significant results were obtained by the 30 mmHg pressure (p = 0.017), 35 second deflation time (p = 0.018), and 5 and 45 second inflation times (p = 0.012, 0.013 respectively). For many setting combinations no significant differences were observed between the limb oedema seen in the control and experimental groups. The results should be interpreted with caution because of the large number of tests performed. In addition adverse effects were observed in six out of nine subjects at 70 mmHg pressure and this pressure was discontinued. One subject suffered cramp at 60 mmHg pressure. Lower pressures together with shorter inflation and deflation times appear to be more efficient than higher pressures and long inflation/deflation times. In addition the lack of significant reduction in oedema at pressures above 40 mmHg suggests that the higher pressures cause a tourniquet effect.