The present study is a multi-center randomized prospective placebo-controlled non-inferiority trial. The study's primary objective is to compare the amounts of postoperative bleeding using two different TXA administration strategies: empirical TXA administration vs. viscoelastic test-based Goal-directed vs Preemptive Tranexamic Acid Administration in total hip arthroplasty. The secondary objectives include comparing the incidents of hyper-fibrinolysis, thromboembolic complications, and postoperative seizures. Researchers assumed that goal-directed tranexamic acid (TXA) administration using viscoelastic field tests would not be inferior to the empirical TXA administration strategy in reducing postoperative bleeding and hyper-fibrinolysis. It also would be beneficial in lowering TXA-induced thromboembolic complications and seizures.

Inclusion Criteria:

Inclusion Criteria patients undergoing following surgery

- total hip arthroplasty

Exclusion Criteria:

• pregnancy
• refusal of allogenic blood transfusion
• taking thrombin
• history of thromboembolic and familial hypercoagulability disease
• recent history of myocardial infarction or ischemic cerebral infarction (within 90 days)
• hypersensitive to TXA
• histroy of convulsion or epilepsy
• taking hemodialysis
• history of Heparin-induced thrombocytopenia