The Perioperative Outcome of Epinephrine Infusion and Tranexamic Acid in Knee Arthroplasty Surgery

Patients will be randomly divided into two groups: one receiving intravenous low-dose epinephrine and tranexamic acid, while the other will receive TXA alone as the control. Randomization to be done using a computer-generated table. The study will be done a superiority clinical trial. with an estimated 24 hour blood loss of 300 ml, with standard deviation of 150 ml. a power of 80% and alpha 5%, an estimated sample size of 80 is needed to detect a difference.