[Occult fibrin production during surgery in cyanotic congenital heart defects and extracorporeal circulation].

In 10 patients with complex cyanotic congenital defects detailed coagulation examinations were made at the beginning and end of the extracorporeal circulation after neutralization of heparin by protamine and the results were compared with a control examination, made before general heparinization, after introduction into general anaesthesia. The authors examined the activated period of blood (ACT) by means of testing tubes with a celite activator (Hemochron) as well as the HR-ACT test with a kaolin activator (Medtronic) for comparison of the results. The authors assessed quantitatively plasma levels of heparin, antithrombin III and fibrinopeptide A which is a sensitive indicator of intravascular coagulation.