Functional electric stimulation to enhance systemic fibrinolytic activity in spinal cord injury patients

Functional electric stimulation (FES) of muscle has been used to decrease the incidence of postoperative deep vein thrombosis (DVT) in neurologically intact individuals. This study was undertaken in order to determine whether a large-scale trial should be initiated using FES to prevent DVT in spinal cord injury (SCI) patients. The goals of this pilot study were to demonstrate the value of FES of calf musculature in (1) increasing plasma fibrinolytic activity and (2) promoting venous blood flow in the lower extremities. Plasma fibrinolytic activity was monitored in ten SCI patients before, immediately after, and 100 minutes after 60 minutes of calf FES. A significant increase in plasma fibrinolytic activity was noted using whole blood and platelet-rich plasma clot lysis assays. Continuous photoplethysmographic and Doppler ultrasound monitoring of venous flow was attempted during FES in four spinal cord patients, and a mild to moderate increase in flow was achieved. FES was not as successful as manual compression in promoting venous emptying of the lower extremity. FES may be a useful tool in the prevention of DVT in SCI patients due to a significant increase in fibrinolytic activity and a mild to moderate increase in venous blood flow. FES merits full-scale clinical evaluation for this purpose.