thromboplastin and Heart-Defects--Congenital

Topics: Adolescent; Adult; Blood Coagulation; Blood Coagulation Disorders; Child; Disseminated Intravascular Coagulation; Embolism, Fat; Endotoxins; Fatty Acids; Female; Fibrinolysis; Heart Defects, Congenital; Hemangioma; Hemolysis; Humans; Leukemia; Male; Middle Aged; Mononuclear Phagocyte System; Neoplasms; Pregnancy; Pregnancy Complications; Purpura, Thrombocytopenic; Skin Neoplasms; Thromboplastin

Activation of clotting with tissue factor (TF) allows rapid evaluation of thromboelastograms but alters the values of thromboelastogram variables. We have performed TF-activated thromboelastograms in 250 children <2 yr old undergoing cardiac surgery to establish baseline values. Five groups were distinguished to evaluate the effects of quantitative deficiencies in coagulation factor levels during infancy: <30 days, 1-3 mo, 3-6 mo, 6-12 mo, and 12-24 mo. Activation of clotting (R and K values) was similar among groups. Infants 1-3 mo of age demonstrated increased clot strength compared with the other groups, a finding similar to previous evaluation of native thromboelastograms. The alpha and maximum amplitude values were numerically almost identical in each age group, a unique finding in activated thromboelastograms. Fibrinolysis was similar among groups. We believe that knowledge of baseline TF-activated thromboelastogram variables in young children will be useful in interpreting these thromboelastograms in clinical scenarios, in using these thromboelastograms as part of coagulopathy treatment algorithms, and during the application of more specific thromboelastogram modifiers. Additionally, the similarity of alpha and maximum amplitude values in each age group will allow even faster interpretation of thromboelastogram data.. Baseline values for tissue factor-activated thromboelastograms in young children undergoing cardiac surgery have been established and will permit accurate use and interpretation of this thromboelastogram modification in evaluating and managing coagulopathies.

Topics: Algorithms; Blood Coagulation; Cardiac Surgical Procedures; Female; Heart Defects, Congenital; Hemostatics; Heparin Lyase; Humans; Infant; Infant, Newborn; Male; Platelet Glycoprotein GPIIb-IIIa Complex; Thrombelastography; Thromboplastin

Procoagulant activity after cardiopulmonary bypass (CPB) in infants may predispose to thrombotic and bleeding complications. The induction of tissue factor and prothrombinase activity on endothelial cell membranes is a primary step in the activation of the extrinsic clotting cascade. The purpose of this study is to characterize the fibrinolytic and endothelial procoagulant state in infants undergoing congenital cardiac repairs with and without CPB.. Fourteen infants (aged 1 to 12 weeks) underwent repair of congenital cardiac defects. Two patients had closed procedures (controls) and 12 had open cardiac procedures. Serum samples were taken before and after CPB, 1, 4, and 24 hours after CPB. Tissue plasminogen activator, plasminogen activator inhibitor-1, interleukin-1beta, interleukin-6, plasma tissue factor, and factor V levels were measured. Human umbilical vein endothelial cell cultures were incubated with serum taken from the above time points and assayed for induction of tissue factor and prothrombinase activity.. Control patients had no change from preoperative values in any of the parameters examined. In experimental patients, tissue plasminogen activator levels peaked at 1 hour after CPB and then decreased to normal by 24 hours. Plasminogen activator inhibitor-1 levels peaked at 4 hours after CPB and returned to baseline by 24 hours. The plasma of all patients had no intrinsic tissue factor activity. Induction of tissue factor activity on umbilical vein endothelial cells peaked immediately and again at 24 hours, whereas prothrombinase activity peaked early and stayed elevated. Serum factor V levels were significantly reduced after CPB, but returned to near baseline levels by 24 hours.. Cardiopulmonary bypass is associated with derangement of the coagulation and fibrinolytic systems in infants. The serum of these patients promotes the induction of endothelial procoagulant activity, suggesting that there may be a hypercoagulable state in the postbypass period.

Topics: Blood Coagulation Factors; Cardiopulmonary Bypass; Endothelium, Vascular; Female; Fibrinolysis; Heart Defects, Congenital; Hemostasis; Humans; Infant; Infant, Newborn; Male; Postoperative Hemorrhage; Reference Values; Risk Factors; Thrombophilia; Thromboplastin