Fibrinogen in trauma, an evaluation of thrombelastography and rotational thromboelastometry fibrinogen assays

Identifying hypofibrinogenemia in trauma is important. The optimal method of fibrinogen determination is unknown. We therefore evaluated fibrinogen levels determined by two whole blood viscoelastic hemostatic assays, thrombelastography functional fibrinogen (FF) and rotational thromboelastometry FIBTEM in trauma patients and compared these with the plasma-based Clauss method.

Prospective study of consecutive adult trauma patients admitted to a level I trauma center. Levels of fibrinogen were analyzed by Clauss, FF, and FIBTEM on arrival. These methods were compared, and we then investigated whether specific cutoffs of fibrinogen levels were indicative for an increased risk of receiving a transfusion within the initial 6 h.

A total of 182 patients with an Injury Severity Score of 17 (9-26) were enrolled. Functional fibrinogen maximum amplitude (FF MA) and FIBTEM maximum clot firmness (MCF) had identical correlation coefficients when compared with those of Clauss fibrinogen (both ρ = 0.64, P < 0.001), and FF MA and FIBTEM MCF correlated with each other (ρ = 0.71, P < 0.001). By logistic regression, the following cutoffs of fibrinogen levels were associated with increased odds of receiving a transfusion, red blood cell concentrates: Clauss <2.5 g/L, FF MA <14.9 mm, FIBTEM MCF <10 mm; fresh frozen plasma and platelets: Clauss <2.5 g/L, FF MA <16.9 mm, FIBTEM MCF <14 mm.

The viscoelastic hemostatic assays for determining fibrinogen levels, FIBTEM and FF, are both correlated with the Clauss fibrinogen level, and there are no differences in the strength of these correlations. In this study, specific fibrinogen levels at arrival to the emergency department were indicative, although not necessarily causal, of increased odds of receiving a transfusion.