Colloid solution is generally used to maintain intravascular volume. It is reported to impair blood coagulation in vivo and in vitro more than crystalloid does by prolonging coagulation time and decreasing clot strength. The formed fibrin clot is more vulnerable for fibrinolysis in a case of using colloid. Dilution of plasmin in vitro with colloid enhances fibrinolysis primarily by diminishing α2-antiplasmin-plasmin interaction.

Tranexamic acid is an antifibrinolytics that competitively inhibits the activation of plasminogen, by binding to specific site of both plasminogen and plasmin, a molecule responsible for the degradation of fibrin, a protein that forms the framework of blood clot. It is used to treat or prevent excessive blood loss during surgery and in other medical conditions. Gastrointestinal effect, dizziness, fatigue, headache, hypersensitivity reaction, or potential risk of thrombosis is reported as the adverse effect of tranexamic acid.

We hypothesized that inhibition of plasmin by tranexamic acid after colloid administration can improve the colloid-induced clot strength impairment.

Inclusion Criteria:

• Patients undergoing total hip replacement arthroplasty, who are diagnosed with the avascular necrosis of femoral head or degenerative arthritis of hip
• American Society of Anesthesiologist I or II

Exclusion Criteria:

• Patients receiving an intraoperative transfusion
• Patients receiving thrombin
• Patients having venous thromboembolism
• Patients having renal or hepatic disease
• Patients having coagulopathy
• Patient having heart failure