Ex-vivo response to blood products and haemostatic agents after paediatric cardiac surgery

Bleeding complications after cardiac surgery are of particular importance in children because they are more prone to volume overload. To optimize haemostatic intervention, the coagulopathy has to be characterized, and knowledge about the effect of blood products and haemostatic agents is needed. The aims of the present study were to investigate changes in coagulation profiles after paediatric cardiac surgery and the effect after ex-vivo addition of blood products and haemostatic agents. Coagulation profiles were evaluated by thromboelastometry (ROTEM) in 54 children before and immediately after cardiac surgery. The haemostatic potential of various factor concentrates (fibrinogen concentrate, recombinant factor VIIa and factor XIII), fresh frozen plasma (FFP), pooled platelets and tranexamic acid was investigated. After surgery, the coagulation profiles revealed significantly prolonged clotting time (P=0.008), and reduced clot propagation (P<0.001) as well as reduced whole blood clot stability (P<0.001). Ex-vivo addition of pooled platelets fully reversed the postoperative coagulopathy; this was also seen after addition of recombinant factor VIIa although less pronounced. Finally, addition of fibrinogen concentrate, FFP or tranexamic acid improved clot stability significantly. Whole blood coagulation was significantly impaired after cardiac surgery in children. Ex-vivo studies showed a total reversal of the coagulopathy after addition of pooled platelets and significantly improved clot stability after addition of fibrinogen concentrate, FFP and tranexamic acid, respectively.