Micro-mobile foot compression device compared with pneumatic compression device.

Abstract

A combination mechanical-pharmacologic regimen is an accepted prophylactic treatment against symptomatic venous thromboembolism for patients undergoing total hip and knee arthroplasties. Foot pumps have been recognized as effective mechanical devices. Research suggests pharmacologic prophylaxis for venous thromboembolism is associated with complications and foot pumps offer an adjunct or alternative approach. Presumably the effectiveness of foot pumps relate to enhancement of venous flow. We compared an established foot pump system with a new mobile foot pump for their ability to influence mean peak venous velocity in the common femoral, popliteal, and posterior tibial veins. We evaluated 60 healthy subjects with the established and the novel foot-pump systems. Ultrasonography was used to measure baseline and peak venous velocity with mechanical compression. We constructed 95% confidence intervals (CI) on the mean differences between the two devices to establish equivalence limits. We compared ratios of peak velocity to resting velocity. Subjects subjectively rated the two foot pumps with respect to size, fit, and comfort. The 95% CI test for equivalence of the mean differences between the two devices was inconclusive. The novel device augmented the venous velocity 11 times greater than the resting velocity in the posterior tibial vein and three times greater than the resting velocity in the popliteal vein. The established foot pump augmented the venous velocity 15 times greater than the resting velocity in the posterior tibial vein and four times greater than the resting velocity in the popliteal vein. The novel device rated better for size, fit, and comfort when compared with the established device. The established foot pump tended to be associated with greater peak velocities; the novel device produced more consistent mean peak venous velocities and may be more acceptable to patients and caregivers.