The use of thromboelastography (TEG) in the evaluation of coagulation in patients on intensive care unit (ICU)

Patients in the intensive care unit are in critical condition which is often accompanied by a coagulation disorder. Sepsis as a leading cause of death in critically ill patients may be associated with both hypercoagulable state with microtrombi formation in microcirculation and with increased production of endogenous heparinoids with inhibitory effects on blood clotting. Central venous catheter and arterial catheter are established in patients for hemodynamic monitoring and these are flushed with heparin to prevent their closure. Both inputs are used for blood sampling for laboratory tests such as blood count and coagulation parameters, including thromboelastography (TEG). In the first step of the work, arterio-venous differences in coagulation parameters were investigated in patients with sepsis. Higher concentration of D-dimers and lower antithrombin activity were found in venous blood. This finding can be explained by increased antithrombin consumption in hypercoagulable state and reactive hyperfibrinolysis. Inconsistency in the site of blood sampling may then lead to misinterpretation of the pathophysiological processes in the body. No significant differences were found in TEG parameters. In the second step of the work we examined how heparin commonly used for catheter flushing affects TEG-assessed..

The use of thromboelastography (TEG) in the evaluation of coagulation in patients on intensive care unit (ICU)

Pacienti na jednotce intenzivní péče jsou v kritickém zdravotním stavu, který je často provázen koagulační poruchou. Sepse jako hlavní příčina smrti u kriticky nemocných pacientů může být provázena jak hyperkoagulačním stavem a tvorbou mikrotrombů v mikrocirkulaci, tak i zvýšenou tvorbou endogenních heparinoidů s inhibičním vlivem na krevní srážlivost. K monitoraci hemodynamiky mají tito pacienti zavedený centrální žilní katetr a arteriální katetr, které jsou proplachovány heparinem jako prevence jejich uzávěru. Oba vstupy jsou používány pro odběr krevního vzorku na vyšetření krevního obrazu a koagulačních parametrů, včetně tromboelastografie (TEG). V prvním kroku práce bylo zjišťováno, zda u pacientů se sepsí můžeme očekávat arteriovenózní rozdíly při interpretaci vyšetření hemokoagulačních parametrů. Tato hypotéza byla potvrzena nálezem vyšší koncentrace D-dimerů a nižší aktivitou antitrombinu ve venózní krvi a zjištění lze vysvětlit zvýšenou konzumpcí antitrombinu při hyperkoagulačním stavu a následnou reaktivní hyperfibrinolýzou. Nekonzistentnost v místě odběru krevního vzorku potom může vést k chybné interpretaci patofyziologických procesů v organizmu. V parametrech TEG signifikantní rozdíly nebyly zjištěny. V druhém kroku práce bylo zkoumáno, jak heparin používaný k proplachu katetrů ovlivňuje srážení...Patients in the intensive care unit are in critical condition which is often accompanied by a coagulation disorder. Sepsis as a leading cause of death in critically ill patients may be associated with both hypercoagulable state with microtrombi formation in microcirculation and with increased production of endogenous heparinoids with inhibitory effects on blood clotting. Central venous catheter and arterial catheter are established in patients for hemodynamic monitoring and these are flushed with heparin to prevent their closure. Both inputs are used for blood sampling for laboratory tests such as blood count and coagulation parameters, including thromboelastography (TEG). In the first step of the work, arterio-venous differences in coagulation parameters were investigated in patients with sepsis. Higher concentration of D-dimers and lower antithrombin activity were found in venous blood. This finding can be explained by increased antithrombin consumption in hypercoagulable state and reactive hyperfibrinolysis. Inconsistency in the site of blood sampling may then lead to misinterpretation of the pathophysiological processes in the body. No significant differences were found in TEG parameters. In the second step of the work we examined how heparin commonly used for catheter flushing affects TEG-assessed...Department of Anaesthesiology and ICMKlinika anesteziologie, resuscitace a intenzivní medicíny2. lékařská fakultaSecond Faculty of Medicin

Role of prothrombin complex concentrate in perioperative coagulation therapy

Prothrombin complex concentrate (PCC) is a term to describe pharmacological products that contain lyophilized, human plasma-derived vitamin K-dependent factors (F), FII, FVII, FIX, FX, and various amounts of proteins C and S. PCCs can be rapidly reconstituted in a small volume (20 ml for about 500 international units (IU)) at bedside and administered regardless of the patient\u27s blood type. PCCs are categorized as 4-factor PCC if they contain therapeutic amounts of FVII, and 3-factor PCC when FVII content is low. In addition, activated PCC which contains activated FVII and FX with prothrombin is available for factor VIII bypassing therapy in hemophilia patients with inhibitors. Currently, 4-factor PCC is approved for the management of bleeding in patients taking warfarin, but there has been increasing use of various PCCs in the treatment of acquired perioperative coagulopathy unrelated to warfarin therapy and in the management of bleeding due to novel oral anticoagulants. There is also an ongoing controversy about plasma transfusion and its potential hazards including transfusion-related lung injury (TRALI). Early fixed ratio plasma transfusion has been implemented in many trauma centers in the USA, whereas fibrinogen concentrate and PCC are preferred over plasma transfusion in some European centers. In this review, the rationales for including PCCs in the perioperative hemostatic management will be discussed in conjunction with plasma transfusion

Evaluation of fibrinogen concentrates and prothrombin complex concentrates on coagulation changes in a hypothermic <i>in vitro</i> model using thromboelastometry and thromboelastography

<p><b><i>Background</i>.</b> Hypothermic coagulopathy is very challenging in bleeding trauma patients. Therefore, we decided to evaluate the efficacy of fibrinogen and prothrombin complex in 30°C hypothermia <i>in vitro</i> to investigate if higher levels of fibrinogen and prothrombin complex concentrate can compensate for the hypothermic effect on coagulation as measured by thromboelastometry/thromboelastography. <b><i>Methods</i>.</b> Blood samples were obtained from 12 healthy volunteers (six men and six women) in our study. Measurements were performed at 37°C and 30°C simultaneously, then at 30°C with adding fibrinogen and prothrombin complex and in the last step samples with added coagulation factors were warmed back to 37°C. <b><i>Results</i>.</b> We found that 30°C hypothermic coagulopathy can be detected both by thromboelastometry and thromboelastography. Hypothermic coagulopathy can be restored by fibrinogen to the point where the results do not significantly differ from 37°C values (<i>p</i> > 0.05). After warming the sample with fibrinogen to 37°C, the thrombodynamic potential index was not significantly different from baseline (<i>p</i> > 0.05), although there was a trend to prothrombotic status. The addition of prothrombin complex concentrate to 30°C hypothermic sample was not able to correct hypothermic coagulopathy <i>in vitro</i>. <b><i>Conclusions</i>.</b> Coagulopathy caused by the 30°C hypothermia <i>in vitro</i> model can be corrected by fibrinogen concentrate compared to prothrombin complex concentrate. In spite of a tendency to prothrombotic status, this was not significant with the use of the recommended dose of fibrinogen even after warming the blood to 37°C. However, measurement performed at 37°C seems to be safer than at 30°C.</p