Background and Goal of Study: Anti Fibrinolytics have shown to reduce blood loss, transfusion requirements and Re- explorations in cardiac surgery. BART trial [ 1] led to withdrawal of aprotinin for cardiac surgery. This has led to different regimes of tranexamic acid. There is no consensus on the ideal dose. Our goal was to compare the different regimes of tranexamic acid used at castle hill hospital against blood loss, transfusion requirements and re exploration rates.
Materials and Methods: This was a prospective observational study. 97 consecutive patients having various types of cardiac surgery were included. All the data were collected as per agreed standardised format. The different regimes were compared against re-exploration rates, blood loss and transfusion requirements.
Results and Discussion:
Tranexamic acid acts by binding to the lysine binding site of plasminogen. Tranexamic acid concentration of 20 microgram/ml inhibits fibrinolysis in vitro .Fiechtner et al have recommended 10mg/kg followed by 1mg/kg/hr consistently provides plasma values of 20 microgram/ml. Murkin et al have shown convulsions in patients who have had greater than 60 mg/kg. Our study shows that 1.5 gm bolus followed by 200mg/hr for less than 10 hrs meets the recommended plasma levels, does not cross toxic range and produces maximum clinical benefit.
Conclusion(s): Tranexamic acid1.5 gm with 200mg/hr gives the best result.
1. Ferguson et al; A comparison of Aprotinin and lysine analogues in high risk cardiac surgery: NEJM; 2008; 358; 2319-2331.
2.Fiechtner et al:Plasma concentration of tranexamic acid on CP bypass; Anesthesia and Analgesia; Dec 2000
3.Murkin et al; High dose tranexamic acid associated with clinical seizures; Anesthesia and Analgesia;Aug 2010; 580-581