Cardinal Health

Preventing Venous Thromboembolism: A Healthcare Professional Guide to Intervention 21 The SCD™ Addresses Two Components of Virchow's Triad Vessel Wall Damage Coagulation Changes Stasis Virchow’s Triad SCD™ increases femoral vein velocity by 240% over baseline 44 Stimulates endogenous fibrinolytic activity 45 Intermittent Pneumatic Compression (IPC). Mechanism of Action. Intermittent Pneumatic Compression (IPC) refers to compressing a patient’s leg intermittently by using a controller (pump) to pneumatically inflate a garment wrapped around the patient’s limbs. The SCD™ is an IPC device that uses sequential, gradient circumferential compression. 1. Sequential. The leg sleeve is sequential in that there are three separate chambers of inflation that squeeze the leg in a ‘milking action’ Themost distal area (lower calf) inflates/compresses first, and the subsequent chambers followmoving up the leg in the samemanner. 2. Gradient. The SCD™ leg sleeve is gradient in that each of the three chambers inflates at a different compression pattern. The distal at 45mmHg, middle at 40mmHg and proximal at 30mmHg. 3. Circumferential. The SCD™ leg sleeve is circumferential in that it compresses the entire circumference of the leg—front, back and sides. Vascular Refill Detection (VRD). Vascular Refill Detection (VRD) is a proprietary non-invasive method of measuring venous refill time—the time it takes for a vein in a patient’s leg or foot to refill with blood after being compressed. Without VRD, compressions take place on a fixed 60 second cycle time. The SCD with VRD moves more blood over time compared with other IPCs. VRD Technology has been proven to move 76%more blood over time compared with IPC devices without VRD. 42 The Kendall SCD™ system is clinically proven to reduce the risk of both DVT and PE, and to improve survival in stroke patients. 43 Mechanism of Action Stasis Prevents distal trapping and ensures clearance behind valve cusps/ soleal sinuses Increases blood flow velocity Reduces venous stasis Maximises blood flow Coagulation Changes Increases fibrinolytic activity Coagulation Prothrombin Thrombin Fibrinogen Fibrin Thrombus Fibrinolysis Plasminogen Plasmin Fibrin Degradation Products (FDP) Increased Platelet Aggregation Figure 3. Coagulation & Fibrinolysis Cascade Figures 3. identifies the stages where the SCD’s™ mechanism of action plays a role in the coagulation cascade.