Changes in blood coagulation after colloid administration in patients undergoing total hip arthroplasty: comparison between pentastarch and tetrastarches, a randomized trial

BACKGROUND Hydroxyethyl starch (HES) solutions are used as plasma expanders for correcting hypovolemia, but can lead to impaired coagulation. We evaluated the changes in hematological and hemostatic profiles with three types of HES. METHODS Patients were randomized to receive volume replacement with 10% pentastarch 260/0.45 in 0.9% saline (Group-PEN, n = 25), 6% tetrastarch 130/0.4 in 0.9% saline (Group-TETS, n = 25), or 6% tetrastarch 130/0.4 in a balanced electrolyte solution (Group-TETB, n = 25). Coagulation was assessed using rotational thromboelastometry (ROTEM®) and other laboratory tests were performed, including measurements of hematological and hemostatic parameters and electrolytes. RESULTS Post-operative ROTEM® parameters changed toward hypocoagulable states in all groups. The post-operative parameters of EXTEM and FIBTEM were more impaired in Group-PEN than in Group-TETB. The percentage change in INTEM clot formation time (P = 0.004) and α-angle (P = 0.003) were smaller in Group-TETS and Group-TETB than in Group-PEN. The percentage change in the FIBTEM maximum clot firmness was greatest in Group-PEN (P = 0.011). The international normalized ratio of prothrombin time (P < 0.001) and the activated partial thromboplastin time (P < 0.001) were significantly prolonged in Group-PEN compared to those of Group-TETB. CONCLUSIONS The 6% HES 130/0.4 in a balanced electrolyte solution seemed to have less of an impact on blood coagulation than the 10% HES 260/0.45. No differences in hemostatic profile were observed between the balanced electrolyte and saline-based 6% HES 130/0.4.