The goal of this clinical trial is to establish the feasibility of conducting a large trial to determine the optimal timing of intravenous tranexamic acid administration in cardiac surgery. The main questions it aims to answer are:
* Is it feasible to conduct a larger definitive trial? * Can we measure the systemic tranexamic acid concentration and fibrinolytic potential in the blood samples?
Researchers will compare intravenous tranexamic acid administered before cardiopulmonary bypass versus after cardiopulmonary bypass to see if the systemic tranexamic acid concentration and fibrinolytic potential are similar or better.
Participants will:
* Provide written informed consent * Receive tranexamic acid during surgery * Provide blood samples at 5 time points: before surgery, on arrival in intensive care unit, 3 hours after arrival, 6 hours after arrival, and on the next morning.
≥18 years of age
Undergoing a cardiac surgical procedure (i.e., isolated CABG, isolated single cardiac valve surgery or a combination of both or isolated ascending aorta replacement) with the use of cardiopulmonary bypass
Provide written informed consent
Allergy to tranexamic acid
Estimated glomerular filtration rate <30 mL/min (CKD-EPI equation) or on dialysis
Pre-operative hemoglobin >170 g/L
Expected circulatory arrest