Systemic haemostasis after intermittent pneumatic compression. Clues for the investigation of DVT prophylaxis and travellers thrombosis

Intermittent pneumatic compression (IPC) is known to provide effective prophylaxis against post-surgical deep-vein thrombosis (DVT), and other procedures based on reducing venous stasis have been promoted recently to minimize the risk of thromboembolism after long-haul travel ('travellers thrombosis'). This study sought to measure the effects of IPC on systemic haemostasis, which are currently disputed. IPC was applied for 120 min on 21 male, non-smoking volunteers ranging in age from 19 to 47 years. IPC promoted a significant increase in global fibrinolytic potential. Levels of urokinase plasminogen activator activity (uPA) measured using an amidolytic assay were raised after IPC. However, enzyme-linked immunosorbent assays (ELISA) of uPA antigen, and the activities of tissue plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI-1) were not statistically different from those in control experiments. IPC led to highly significant falls in factor VIIa, associated with increased levels of tissue factor pathway inhibitor (TFPI). IPC enhances fibrinolysis and suppresses procoagulant activation. Measurements of specific fibrinolytic components do not reflect overall fibrinolytic activity and are highly dependent on the method of assay. The results provide important clues for detailed studies of the effects of haemodynamics on systemic haemostasis.