Venous Blood Flow Velocity: Electrical Foot Stimulation Compared to Intermittent Pneumatic Compression of the Foot

ABSTRACT Background: Venous stasis caused by immobility is an important risk factor for venous thromboembolic disease. This is especially true for orthopedic patients with multiple trauma and those undergoing other orthopedic procedures. A safe and convenient method for reducing venous stasis would be useful for preventing venous thrombosis in patients while in hospital and particularly after discharge during rehabilitation. In a prior study, we demonstrated that electrical stimulation of the foot was a safe and convenient method for counteracting venous stasis. In this study, we compare the effects on venous blood flow of intermittent pneumatic compression, an established method, to electrical stimulation of the foot.

Methods: 40 healthy volunteers aged 50 - 80 were seated for 4 hours during which they received mild electrical stimulation of the sole of the foot (plantar plexus of muscles) or intermittent pneumatic compression. Popliteal and femoral venous blood flow velocities were measured via Doppler ultrasound. Blood flow in the non-stimulated or non-compressed lower extremity served as a simultaneous control. Subjects completed a questionnaire regarding their acceptance and tolerance of both treatments.

INTRODUCTION Venous thrombosis and pulmonary embolism or venous thromboembolism (VTE) are important complications of medical and surgical conditions that are associated with prolonged immobilization. This is especially true for orthopedic patients with multiple trauma and those undergoing other orthopedic procedures. Immobilization is also a major contributor to the increased risk of VTE associated with prolonged air travel.

Despite good evidence that prophylaxis is effective, there is widespread under utilization of prophylaxis for VTE following major surgical procedures as well as medical conditions that produce weakness or prolonged bed rest. There is also good evidence that the risk of VTE continues for weeks after major orthopedic as well as other types of surgery. It is now recognized that VTE occurring in the hospital and outside the hospital setting is a single entity and that extended prophylaxis with anticoagulants reduces the risk.

Anticoagulant prophylaxis after hospital discharge although indicated in certain high risk groups is inconvenient since the recommended methods, LMWH and fondaparinux must be administered by subcutaneous injection and warfarin requires laboratory monitoring.