DVT Pumps are pneumatic compression pumps designed to prevent people from getting deep vein thrombosis (DVT), which can be life-threatening. DVT Compression Pumps deliver pressure to increase blood flow in the venous system of the limbs so that blood does not clot. Those who are especially susceptible to thrombosis are people who recently had surgery or who are immobile or sedentary throughout the day. Prolonged inactive states often cause blood to pool around venous valves slowing circulation. The lack of proper blood flow leads to blot clotting.