Comparison of Two Different Fibrinogen Concentrates in an in vitro Model of Dilutional Coagulopathy

Introduction: Fibrinogen concentrates are widely used to restore clot stability in situations of bleeding. Fibrinogen preparations are produced using different production methods, resulting in different compounds. Thus, different preparations might have a distinct impact on blood coagulation. We tested the effect of fibrinogen concentrates Haemocomplettan (R) (CSL Behring, Marburg, Germany) and fibryga (R) (Octapharma GmbH, Langenfeld, Germany) on the impairments induced by 60% dilutional coagulopathy in vitro. Materials and Methods: The influence of the fibrinogen concentrates fibryga (R) and Haemocomplettan (R) on colloid (gelatine, hydroxyethyl starch [HES], albumin)-induced or crystalloid (Ringer's acetate)-induced dilutional coagulopathy was analysed using rotational thromboelastometry (ROTEM (R)) and standard laboratory tests. The following experimental conditions were analysed in vitro: whole blood, 60% dilution (40% blood and 60% diluent) +/- 50 or 100 mg/kg(-1) fibryga (R) or Haemocomplettan (R), respectively. Results: Dilution with either diluent resulted in prolonged clotting time (CT) in an extrinsic activated test (CTEXTEM) and decreased maximum clot firmness (MCFFIBTEM) as expressed, e.g., by gelatine: (59.5 s [62/54.8] vs. 95 s [102.8/86.8]; p < 0.001 and 14 mm [16/10.5] vs. 3 mm [4-3]; p < 0.001). Substitution after 60% dilution with HES resulted in no difference between the preparations, except for shorter thrombin time with fibryga (R) (14 s [15/14] vs. 18 s [18.8/17]; p = 0.0093; low dose). CTEXTEM was higher with Haemocomplettan (R) in a gelatine-induced dilution (51 s [54.5/47.5] vs. 63 s [71/60.3]; p = 0.0202; low dose) whereas thrombin time was lower with fibryga (R) (19.5 s [20.8/19] vs. 27 s [29/25.3]; p = 0.0017). In dilution with albumin, differences in CTEXTEM (69 s [76.5/66] vs. 56 s [57/53.3]; p = 0.0114; low dose) and thrombin time (18 s [18/17] vs. 24.5 s [25.8/24]; p = 0.0202; low dose) were seen. In dilution with crystalloid solution, again differences in CTEXTEM (53.5 s [57.8/53] vs. 45 s [47/43]; p = 0.035; low dose) and thrombin time (17 s [17/16] vs. 23.5 s [24/23]; p = 0.0014; low dose) were seen. Fibrinogen levels were more increased by high-dose substitution of both preparations. Conclusion: Based on this data it can be stated that both fibryga (R) and Haemocomplettan (R) had the same performance in our in vitro model except for CTEXTEM and thrombin time.