Articles: thrombin-generation.
-
The new direct-acting anticoagulants such as dabigatran and rivaroxaban are usually not monitored but may be associated with haemorrhage, particularly where renal impairment occurs. They have no effective "antidotes". We studied 17 patients receiving dabigatran 150 mg twice daily for non-valvular atrial fibrillation and 15 patients receiving rivaroxaban 10 mg daily for the prevention of deep venous thrombosis after hip or knee replacement surgery. ⋯ Rivaroxaban did not affect the TEG and ROTEM parameters but did increase the lag time and reduce ETP and peak height of the CAT. For both drugs, these parameters were significantly and meaningfully corrected by PCC and FEIBA and to a lesser but still significant extent by rFVIIa. These results may be useful in devising a reversal strategy in patients but clinical experience will be needed to verify them.
-
Blood dilution after transfusion fluids leads to diminished coagulant activity monitored by rotational thromboelastometry, assessing elastic fibrin clot formation, or by thrombin generation testing. We aimed to determine the contributions of blood cells (platelets, red blood cells) and plasma factors (fibrinogen, prothrombin complex concentrate) to fibrin clot formation under conditions of haemodilution in vitro or in vivo. Whole blood or plasma diluted in vitro was supplemented with platelets, red cells, fibrinogen or prothrombin complex concentrate (PCC). ⋯ Thrombin generation in diluted (patient) plasma was not changed by fibrinogen, but improved markedly by prothrombin complex concentrate. In conclusion, in dilutional coagulopathy, platelets and fibrinogen, but not red blood cells or vitamin K-dependent coagulation factors, independently determine thromboelastometry parameters measured in whole blood and plasma. Clinical decisions for transfusion based on thromboelastometry should take into account the platelet concentration.
-
Thrombosis research · Mar 2014
Measurement of thrombin generation intra-operatively and its association with bleeding tendency after cardiac surgery.
Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) are susceptible to haemostatic disturbances. Monitoring the haemostatic capacity by conventional clotting tests is challenging. ⋯ TG can be determined during CPB despite the high heparinization level, it reflects the haemostatic capacity better than clotting-based assays and might better predict bleeding when performed intraoperatively.
-
Journal of critical care · Feb 2014
Impairment of thrombin generation in the early phases of the host response of sepsis.
The purpose was to investigate the presence of hypercoagulability in the very early phase of the host response to an infection in the clinical course of sepsis and septic shock. ⋯ Patients with sepsis and febrile neutropenia present an impairment in thrombin generation from very early stages of their disease course. These results suggest that the procoagulant in vitro alterations described during sepsis do not necessarily translate into a clinically relevant systemic hypercoagulable state. These findings could help explain why treatment with systemic anticoagulants did not translate to clinical benefits in human sepsis and highlight the need for a better understanding of the hemostatic alterations in sepsis before new treatments targeting coagulation activation are developed.
-
Journal of critical care · Feb 2014
Thrombin generation and fibrin clot formation under hypothermic conditions: An in vitro evaluation of tissue factor initiated whole blood coagulation.
Despite trauma-induced hypothermic coagulopathy being familiar in the clinical setting, empirical experimentation concerning this phenomenon is lacking. In this study, we investigated the effects of hypothermia on thrombin generation, clot formation, and global hemostatic functions in an in vitro environment using a whole blood model and thromboelastography, which can recapitulate hypothermia. ⋯ Induced hypothermic conditions directly affect the rate of thrombin generation and clot formation, whereas global clot stability remains intact.