L'acide tranexamique en chirurgie cardiaque

Tranexamic acid, a synthetic lysine analogue, is an indirect anti fibrinolytic agent. It acts by plasminogene transformation in inactive plasmin.Usual posology is 10 mg/kg loading dose followed by a continuous perfusion of I mg/kg/min during 10 hours or more simply, with an equivalence of effect, two direct intravenous injections of 15 mg/kg, one before the surgical incision, the other after the injection of prolamine. Four meta analyses compare tranexamic acid with aprotinine in cardiac surgery with cardio pulmonary bypass. One meta analysis studies the effect of the acid tranexamic in off-pump coronary artery bypass grafting. Three observational studies bring back the effects of tranexamic acid use in cardiac surgery. These studies show a fall of the post operative bleeding, with reduction in the blood exposure and a less percentage of patients returning to theatre for exploration for bleeding among patients treated by the acid tranexamic compared to patients untreated by an anti fibrinolytic agent. Compared to these 3 items (bleeding, transfusion, Re immediate operation) the results are equivalent to those obtained with the aprotinine. An increased risk of arterial or venous thrombosis was not shown in these studies. The tranexamic acid does not have an anti inflammatory action. The indirect action of the acid tranexamic does not ensure a maximum effectiveness in the cases which active plasmine is already circulating in pre the operative period (dissection, fissuration, rupture of aorta) Tranexamic acid has very few or no side effect. Its cost is modest. It is effective on the post operative reduction of blood requirements after cardiac surgery.