The effects of intermittent pneumatic compression on systemic and local fibrinolysis

Intermittent pneumatic compression (IPC) is effective in deep venous thrombosis prophylaxis. IPC prevents venous stasis by collapsing the peripheral venous plexus in an extremity leading to increased venous return. It has been suggested that IPC has an additional effect of enhancing fibrinolysis. This study was designed to evaluate the effect of IPC on both systemic and local fibrinolysis in normal volunteers by measuring the activity of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-type 1 (PAI-1). In addition, tissue factor pathway inhibitor (TFPI) was measured to assess changes in the extrinsic coagulation cascade. IPC was applied in the foot and calf of 10 healthy subjects and blood was drawn from the antecubital fossa to determine systemic fibrinolytic activity. Local fibrinolysis was assessed in 15 healthy subjects by placing an IPC cuff on the forearm and drawing blood 2 cm above the cuff The IPC maximum inflation pressure was 120 mm Hg lasting for 3 seconds at three cycles per minute. Blood samples were taken at rest, on the 10th minute of active IPC, and 5 minutes after cessation of IPC for both systemic and local measurements. The plasma was analyzed for TFPI, t-PA, and PAI-1 antigen by use of enzyme-linked immunosorbent assays. There were no significant changes in systemic or local fibrinolytic activity before, during, or after application of IPC. TFPI systemic activity before, during, and after was 111 +/- 24, 118 +/- 18, and 116 +/- 22, respectively. Local TFPI activity was 91 +/- 32, 93 +/- 36, and 91 +/- 24, respectively. The t-PA systemic activity before, during, and after was 4.1 +/- 1.9, 4.7 +/- 2.3, and 5 +/- 2.8, respectively. Local t-PA activity was 4.5 +/- 1.3, 4.5 +/- 1.4, and 4.2 +/- 1.4, respectively. Systemic PAI-1 activity was 11 +/- 9.2, 17 +/- 19, and 17 +/- 31, respectively. Local PAI-1 activity was 3.7 +/- 3.1, 3 +/- 1, and 2.8 +/- 1, respectively, p > 0.38 for all comparisons in both groups. No evidence was found that IPC enhances systemic and local fibrinolysis or TFPI release. Irrespective of the length of IPC application or the inflation pressure, several studies have reported increased fibrinolysis, whereas others have not found any changes. Although, according to the literature, there is a trend toward increased fibrinolytic activity, further controlled studies with adequate sample size should be performed to provide an answer to this controversial topic.