title: Evaluation of fibrinogen concentrates and prothrombin complex concentrates on coagulation changes in a hypothermic in vitro model using thromboelastometry and thromboelastography.
abstract: BACKGROUND
  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 in vitro to investigate if higher levels of fibrinogen and prothrombin complex concentrate can compensate for the hypothermic effect on coagulation as measured by thromboelastometry/thromboelastography.
  
  
  METHODS
  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.
  
  
  RESULTS
  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 (p > 0.05). After warming the sample with fibrinogen to 37°C, the thrombodynamic potential index was not significantly different from baseline (p > 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 in vitro.
  
  
  CONCLUSIONS
  Coagulopathy caused by the 30°C hypothermia in vitro 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.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Second Faculty of Medicine, Charles University in Prague, Motol University Hospital , Prague , Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Durila
authors.forename: Pavel
authors.initials: P
authors.lastname: Lukáš
authors.forename: Marta
authors.initials: M
authors.lastname: Astraverkhava
authors.forename: Tomáš
authors.initials: T
authors.lastname: Vymazal
mesh_terms: D000328:Adult; D001777:Blood Coagulation / Q000187:drug effects*; D001779:Blood Coagulation Factors / Q000494:pharmacology*; D005260:Female; D005340:Fibrinogen / Q000494:pharmacology*; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008954:Models, Biological; D012399:Rotation; D013916:Thrombelastography / Q000379:methods*
chemical_list: D001779:Blood Coagulation Factors; C025667:prothrombin complex concentrates; D005340:Fibrinogen
keywords: Thromboelastometry; coagulation; fibrinogen; hypothermia; temperature; thromboelastography; thrombosis