Objective: The venous pump of the foot assists blood returning to the heart. The aim of this study was to evaluate the effect of mechanical activation of the foot pump on the microcirculation of the skin in patients with peripheral occlusive arterial disease.
Design: Single parallel group comparing patients with arterial disease to normal control subjects.
Setting: Department of Surgery, the University College and Middlesex Hospital, London, U.K.
Subjects and materials: 15 patients with peripheral occlusive arterial disease and 15 control subjects. A pneumatic impulse foot pump was applied to the foot.
Outcome measures: The Laser Doppler flux (LDF) and transcutaneous oxygen tension (tcPO2) were measured on the big toe with the subject supine, before, during and after a 10 min period of foot pumping. The study was repeated with the subject sitting.
Results: On sitting there is a fall in LDF and rise in tcPO2. Application of intermittent pneumatic compression of the foot in the sitting position resulted in an increase in LDF. In patients, the median percentage increase was 57% and the median difference was 82 arbitrary units (AU) (95% CI 60-130, p < 0.001). In controls, the median percentage increase was 66% and the median difference was 124 AU (95% CI 73-275 p < 0.001). There was a corresponding "further" increase in tcPO2 in both groups of subjects. In patients, the median percentage increase was 8%, in controls the median percentage increase was 10% p < 0.01).
Conclusion: We conclude that intermittent pneumatic compression of the foot in the dependent position increases LDF and tcPO2.