ACTIVATION OF THE FIBRINOLYTIC, COAGULATION AND PLASMA KALLIKREIN-KININ SYSTEMS DURING AND AFTER OPEN-HEART-SURGERY IN CHILDREN

Activation of the fibrinolytic, coagulation and plasma kallikrein-kini n systems may be responsible for some of the coagulation disorders and inflammatory sequelae seen after extracorporeal circulation. The acti vation pattern of these systems was studied in 10 children undergoing open heart surgery with extracorporeal circulation. Blood samples were drawn serially before, during and up to 48 h after surgery. The hepar in injection induced a significant elevation of plasmin (PL) (p<0.05) which stayed elevated during extracorporeal circulation. Antiplasmin ( AP) values were reduced at wound closure, while the levels were signif icantly elevated 48 h postoperatively (p<0.05). alpha(2)-antiplasmin-p lasmin (APP) increased significantly perioperatively peaking 10 min af ter the initiation of cardiopulmonary bypass (p<0.05). The coagulation markers thrombin-antithrombin (TAT) and the prothrombin fragment F1+2 increased significantly, peaking at wound closure and at termination of bypass respectively (p<0.05). Plasma kallikrein (KK) values increas ed significantly with subsequent decreased levels of prekallikrein (PK K) and kallikrein inhibitor (KKI) after heparin injection. The KK leve l stayed elevated during cardiopulmonary bypass (CPB). The proenzyme f unctional inhibition index (PFI index), defined as the sum of deviatio ns from the control values for proenzyme and functional inhibition val ues of the coagulation, fibrinolytic and plasma kallikrein-kinin syste ms, correlated significantly to the duration of cardiopulmonary bypass (p<0.05). We conclude that open heart surgery in children activates t he fibrinolytic, coagulation and plasma kallikrein-kinin systems.