Changes in haemostatic system after application of a tourniquet

Area of Science:

• Orthopaedic Surgery
• Vascular Biology
• Haematology

Background:

• Deep-vein thrombosis (DVT) is a significant risk following orthopaedic surgery.
• Current prophylactic measures like heparin have associated risks.
• The role of surgical tourniquets in modulating systemic fibrinolysis is not well understood.

Purpose of the Study:

• To investigate the effect of occlusive tourniquets on systemic fibrinolytic activity in patients undergoing orthopaedic surgery.
• To compare the fibrinolytic response to tourniquet application versus simple venous occlusion.
• To assess changes in coagulation factors and platelet count during tourniquet use.

Main Methods:

• 35 patients undergoing routine orthopaedic operations were studied.
• Systemic fibrinolytic activity was measured before, during, and after tourniquet application.
• Venous occlusion was used as a control.
• Coagulation factors (V, VIII), fibrinogen, and platelet counts were monitored.

Main Results:

• A pronounced rise in systemic fibrinolytic activity was observed for at least 15 minutes after tourniquet release, regardless of limb operated on.
• No significant increase in fibrinolytic activity was associated with venous occlusion alone.
• Tourniquet application or venous occlusion did not alter factors V, VIII, fibrinogen, or platelet counts.

Conclusions:

• Occlusive tourniquet use during orthopaedic surgery induces a transient but significant increase in systemic fibrinolysis.
• This tourniquet-induced hyperfibrinolysis may represent a novel, simple prophylactic strategy against deep-vein thrombosis.
• This method could potentially avoid the complications associated with anticoagulant therapies such as heparin.