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

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.