Which injured patients with moderate fibrinogen deficit need fibrinogen supplementation?

BACKGROUND: In severely injured patients, fibrinogen supplementation is recommended when fibrinogenemia is < 1.5 g L-1, but some teams have suggested to use higher thresholds (fibrinogenemia < 2.0 g L-1 or FIBTEM clot amplitude at 5 min (A5) values < 11 mm). The goal of this study was to specify in patients with a moderate fibrinogen deficit (MFD) whether some admission characteristics would be associated with fibrinogen administration at 24 h. METHODS: Prospective analysis of retrospectively collected data from a trauma registry (01/2011-12/2019). MFD-C was defined by a fibrinogenemia 1.51-1.99 g L-1 or the corresponding FIBTEM-A5 values (MFD-A5) that were determined from linear regression and ROC curve analysis. Administration of fibrinogen were described according to the following admission parameters: shock index (SI) > 1, hemoglobin level < 110 g L-1 (HemoCue®), and base deficit > 5 mEq L-1. Data are expressed as count (%), median [IQR]. RESULTS: 1076 patients were included in the study and 266 (27%) had MFD-C, among them, 122/266 (46%) received fibrinogen. Patients with MFD-C who received fibrinogen were more severely injured (ISS: 27 [19-36] vs. 24 [17-29]) and had more impaired vital signs (base deficit: 5.4 [3.6-7.8] vs. 3.8 [2.0-6.0]). Linear regression analysis found a positive correlation between fibrinogen level and FIBTEM-A5 (r: 0.805). For a fibrinogen level < 1.5 g L-1 and < 2.0 g L-1, FIBTEM-A5 thresholds were 6 mm (sensitivity 85%, specificity 83%, AUC: 0.934) and 9 mm (sensitivity 84%, specificity 69%, AUC: 0.874), respectively. MFD-A5 values (185 (27%) patients) were defined as a FIBTEM-A5 between 7 and 9 mm. More than 50% of MFD-C patients presenting a SI > 1, a hemoglobin level < 110 g L-1, or a base deficit > 5.0 mEq L-1 received fibrinogen. The relative risk [95% CI] for fibrinogen administration (SI > 1) were 1.39 [1.06-1.82] for MFD-C, and 2.17 [1.48-3.19] for MFD-A5. Results were not modified after adjustment on the ISS. CONCLUSIONS: We have shown in this study an association between shock parameters and fibrinogen administration. Further studies are needed to determine how these parameters may be used to guide fibrinogen administration in trauma patients with MFD.

Diagnostic performance of thromboelastometry in trauma-induced coagulopathy: a comparison between two level I trauma centres using two different devices.

PURPOSE: The implementation of a ROTEM®-based algorithm requires reliable thresholds to mirror a prothrombin time (PT) ratio > 1.2 and/or a fibrinogen concentration < 1.5 g l-1. Our goal was to compare the diagnostic performances of two devices (ROTEM® Sigma and Delta, IL Werfen, Munich, Germany) in two level-I trauma centres for the diagnostic of post-traumatic coagulopathy. METHODS: We conducted a retrospective analysis of two registries across two periods of time: from September 2014 to December 2015 in Lyon-Sud university trauma centre and from April 2016 to January 2018 in the Grenoble Alps Trauma Centre. Accuracies of EXTEM and FIBTEM assays to detect patients with coagulation disorders were tested for each device using receiver operating characteristic (ROC) analyses. RESULTS: Within the study period, 74 trauma patients in the Grenoble cohort and 75 trauma patients in the Lyon cohort had concomitant ROTEM® and standard coagulation testing on admission. No statistically significant difference was found between the two ROC curves for FIBTEM amplitude at 5 min (A5), FIBTEM maximum clot firmness, EXTEM clotting time (CT) and EXTEM A5 for ROTEM® Sigma and Delta to diagnose post-traumatic coagulation disorders. The best threshold for FIBTEM A5 to predict low fibrinogen concentration was 7 mm for each device. EXTEM CT thresholds to diagnose PT ratio > 1.2 were 78 s and 74 s for ROTEM® Sigma and Delta, respectively. CONCLUSIONS: These results suggest that ROTEM®-based algorithms may be transposed from one trauma centre to another independently of the setting and the ROTEM® device in use.

Fibrinolytic shutdown diagnosed with rotational thromboelastometry represents a moderate form of coagulopathy associated with transfusion requirement and mortality: A retrospective analysis.

BACKGROUND: Viscoelastic techniques have made it possible to describe specific fibrinolytic phenotypes (physiological, hyperfibrinolysis and shutdown) and to establish a relationship of these phenotypes with outcome. However, there remains a debate as to whether shutdown is a state of hypercoagulability or rather a coagulopathy with moderate fibrinolysis and fibrinogen consumption. OBJECTIVES: Our objectives were to describe the relationship between fibrinolytic phenotypes and outcomes, and to report the effects of tranexamic acid (TXA) administration. DESIGN: This was a retrospective analysis of prospectively acquired data from a trauma registry. SETTING: An academic level 1 trauma centre in the Lyon Region, from March 2011 to December 2016. PATIENTS: We included all injured patients who had a rotational thromboelastometry analysis at admission. Fibrinolytic phenotypes were determined according to the maximum lysis: shutdown less than 3%, physiological 3 to 15%, hyperfibrinolysis more than 15%. MAIN OUTCOME MEASURE: Mortality at 24 h and at hospital discharge. RESULTS: During the study period, 473 patients were included with the following phenotypes: physiological (344 patients, 73%), shutdown (107 patients, 23%) and hyperfibrinolysis (22 patients, 5%). There was an increase in injury severity, prothrombin time ratio, fibrin degradation products and transfusion requirements from the physiological to the shutdown and hyperfibrinolysis phenotypes. Prehospital TXA administration increased the rate of shutdown and decreased the maximum lysis value at admission. After adjustment, multivariate analysis showed that fibrinolytic phenotypes, but not TXA, were independently associated with an increased risk of early death and death before hospital discharge: shutdown [odds ratio (95% confidence interval)] 2.4 (1.2 to 4.8) and hyperfibrinolysis 67.9 (7.4 to 624.2). CONCLUSION: The results of the current study suggest that shutdown, which is associated with injury severity and mortality, probably reflects a moderate form of coagulopathy and fibrinolysis rather than a hypercoagulopathy. Therefore, the observation of shutdown fibrinolysis on thromboelastography/rotational thromboelastometry should not lead to withholding but rather to the administration of TXA.