Tranexamic Acid for Unilateral Total Knee Arthroplasty

Prevention of Postoperative Blood Loss: Randomised Multicentre Parallel Clinical Trial That Assess the Topical and Intravenous Tranexamic Acid in Surgical Patients With a Total Knee Arthroplasty.

Total knee arthroplasty is often associated with excessive postoperative bleeding due to increased fibrinolysis. Hence, the objective of the proposed of this multicentre study is to determine the peri-operative bleeding comparing the application of topical and intravenous tranexamic acid with the habitual surgical haemostasis.

Objectives:

1. Principal: To assess if the topical and intravenous tranexamic acid reduce less or at least than 20% the blood losses with respect to the habitual haemostasia in patients, after unilateral total knee arthroplasty.
2. Secondary: To assess the treatment safety. To perform a cost- analyses.

Methods: Randomized, multicentre, open and parallel clinical trial with three comparative groups: Topical tranexamic acid, Intravenous tranexamic acid and habitual haemostasia. In all patients, a single drainage of 8mm will be inserted in the joint, and it will remain closed during one hour after the closure of the skin.

Nº of participant centres: 2. Random allocation will be centralised in "Hospital de la Santa Creu i Sant Pau".

Main outcome: Total blood loss (mL) in the post-operative period collected by the habitual drain system ).

Secondary outcomes: Total blood loss (mL)and hidden blood calculated by Nadler's formula. Proportion of patients with blood transfusion, complications of surgery wound, haemoglobin pre and post-operative, units of blood transfused, post-operative mortality, days of hospital stay, safety of interventions assessed.Direct cost analysis.

Substudy: Pharmacokinetic study. The first 24 patients included in "Hospital de la Santa Creu i Sant Pau" for tranexamic acid (12 topical- 12 intravenous) to determine:

1. Plasmatic concentrations of tranexamic acid
2. In topical and intravenous tranexamic acid administration determine the absorption rate and drug bioavailability by these routes: maximum plasma concentration, time to reach Cmax, AUC, and half-life.

Inclusion Criteria:

• Unilateral Total knee arthroplasty
• The patient consent to participate

Exclusion Criteria:

• Antecedent of thromboembolic disease
• Patient with cardiac alterations of the rhythm
• Patients with valvular cardiac prosthesis
• Patients with pro-thrombotic alterations of coagulation
• Treatment with anticonceptive drugs