Maize- or potato-derived hydroxyethyl starches: is there any thromboelastometric difference?

Hydroxyethyl starches (HES) could differ with regard to the origin, and the influence on the coagulation of the raw material is unknown. This study compared the effects of a new potato-derived HES with a maize-derived HES and two crystalloid solutions.

Whole blood from 10 healthy individuals was diluted by 20% and 40% using either non-balanced potato-derived HES 130/0.42/6:1, non-balanced maize-derived HES 130/0.4/9:1, isotonic saline or Ringer's lactate solution. Samples were analysed by thromboelastometry ROTEM(®) : Coagulation was initiated by acid ellagic [intrinsic thromboelastometry (INTEM)] or tissue factor (extrinsic thromboelastometry) with and without cytochalasin to determine the functional component of fibrinogen [cytochalasin-d-modified thromboelastometry (FIBTEM)]. Platelet count and fibrinogen activity were measured.

No effect of raw material was found as no difference was detected among the HES solutions. Whatever the solution, progressive haemodilution impaired haemostasis in a dose-dependant manner: For INTEM, the clot formation time was increased up to 308% and the maximum clot firmness (MCF) was decreased down to 49%. As dilution increased, initiation of coagulation was also impaired. Thromboelastometric alterations were more severe with HES than with crystalloids, especially regarding fibrin polymerization explorations: MCF of FIBTEM was considerably reduced from 12[10-14] to 2[2-3] mm (P<0.05). Fibrinogen activity and platelet count were reduced by dilution in a dose-dependant manner and decreased similarly in all groups.

Maize- and potato-derived HES have similar effects on coagulation. Both the starch preparations tested lead to more severe haemostatic defects than crystalloids, and impairment of fibrin polymerization appears to be a leading determinant of this coagulopathy.