In this in vitro trial, we assessed the effect on blood coagulation of 60% dilution with different colloids and investigated reversibility by replacement of factor XIII (F XIII), fibrinogen, and the combination of fibrinogen and F XIII.Using the blood of 12 volunteers, the following measurements were performed at baseline and after 60% dilution with (hydroxyethyl starch solutions) HES 130/0.42, gelatin, or balanced gelatin solution: blood gas analyses, coagulation factor concentrations (F I, F II, F VII, F VIII, F XIII), impedance aggregometry (Multiplate®), and rotational thromboelastometry (ROTEM). Then F XIII and fibrinogen as well as a combination of both were added, in concentrations corresponding to 6 g fibrinogen and 1250 IU F XIII in adults. ROTEM measurements and determination of factor concentrations were again performed.Colloid dilution led to a significant reduction of fibrinogen polymerization, especially with HES. Platelet function was impaired by all colloids, with gelatin having a significantly greater effect (area under the curve, collagen Test, P ≤ 0.008) than HES and balanced gelatin solution. The substitution of F XIII only did not improve clot formation. Substitution of fibrinogen improved the polymerization of fibrinogen in dilutions with gelatin and balanced gelatin solution (P = 0.002), whereas HES-induced coagulopathy could not be corrected. The combination of fibrinogen and F XIII showed a better effect than the addition of fibrinogen only for certain variables.Coagulation and platelet function are impaired by all 3 colloids. However, in vitro gelatin-induced coagulopathy was significantly more reversible than HES-induced coagulopathy.
