Journal of cardiothoracic and vascular anesthesia
-
J. Cardiothorac. Vasc. Anesth. · Aug 1999
Coagulation tests during cardiopulmonary bypass correlate with blood loss in children undergoing cardiac surgery.
To examine whether coagulation tests, sampled before and during cardiopulmonary bypass (CPB), are related to blood loss and blood product transfusion requirements, and to determine what test value(s) provide the best sensitivity and specificity for prediction of excessive hemorrhage. ⋯ During cardiac surgery, coagulation tests (including thromboelastography) drawn pre-CPB and during CPB are useful to identify children at risk for excessive bleeding. Platelet count during CPB was the variable most significantly associated with blood loss.
-
J. Cardiothorac. Vasc. Anesth. · Aug 1999
ReviewAnticoagulation and anticoagulation reversal with cardiac surgery involving cardiopulmonary bypass: an update.
Accelerated thrombin generation is central to the development of hemostatic abnormalities during cardiopulmonary bypass (CPB) that are associated with both thromboembolic complications and serious, abnormal bleeding. Thrombin not only converts fibrinogen to fibrin, but also activates platelets and coagulation factors V, VIII, and XI and causes release of von Willebrand factor from vascular endothelium. Thrombin can also downregulate the hemostatic system by inducing formation of platelet inhibitory agents, such as nitric oxide and prostacyclin, and release of tissue plasminogen activator, facilitating activation of protein C, and releasing tissue factor pathway inhibitor. ⋯ Administration of heparin doses higher than those generally recommended, as guided by predetermined, patient-specific whole blood heparin concentration measurements during bypass, can reduce excessive thrombin-mediated consumption of platelets and coagulation factors as well as post-CPB blood loss and blood component transfusions. New modalities of improving suppression of excess thrombin generation during CPB include use of heparin-bonded CPB circuits, heparin cofactor II or related analogs, supplemental antithrombin III, direct thrombin inhibitors (eg, hirudin, argatroban), and inhibitors of the contact and tissue factor pathways. The safety and efficacy of these approaches remains to be established by additional, appropriately powered, prospective studies.
-
J. Cardiothorac. Vasc. Anesth. · Aug 1999
Do anticoagulation with heparin and protamine reversal alter thrombogenicity of coated and noncoated pulmonary artery catheters?
To clarify the role of anticoagulation with heparin and protamine reversal on the effectiveness of heparin bonding or coating of pulmonary artery catheters in preventing thrombus formation in the Rhesus monkey. ⋯ Anticoagulation of primates with heparin before catheter insertion imparts some protection to non-coated catheters, and protamine reversal of anticoagulation with heparin may partially negate the protective effect seen with heparin-coated pulmonary artery catheters.