title: A calcium-containing electrolyte-balanced hydroxyethyl starch (HES) solution is associated with higher factor VIII activity than is a non-balanced HES solution, but does not affect von Willebrand factor function or thromboelastometric measurements--results of a model of in vitro haemodilution.
abstract: BACKGROUND
  Hydroxyethyl starch (HES) is known to impair blood coagulation. The impact of calcium-containing, balanced carrier solutions of HES on coagulation is controversial. We investigated the effects of increasing degrees of haemodilution with modern 6%, electrolyte-balanced HES vs non-balanced HES on coagulation in vitro, and compared the balanced HES to a balanced crystalloid solution for an internal control.
  
  
  METHODS
  Blood samples from ten healthy volunteers were diluted in vitro by 20%, 40% and 60% with either calcium-containing balanced 130/0.42 HES, non-balanced 130/0.4 HES or balanced crystalloid. In all samples, blood counts, prothrombin time ratio, activated partial thromboplastin time, ionized calcium, factor VIII activity, von Willebrand factor antigen, von Willebrand factor collagen binding activity, and von Willebrand factor activity were determined, and activated rotational thromboelastometry (EXTEM and FIBTEM assays) was performed.
  
  
  RESULTS
  Haemodilution impaired coagulation in a dilution-dependent manner as determined by both conventional laboratory assays and thromboelastometry. Ionized calcium increased with balanced HES (p≤0.004), but decreased with non-balanced HES (p≤0.004). Prothrombin time ratio (p≤0.002) and factor VIII levels (p=0.001) were better preserved with balanced HES than with non-balanced HES in dilutions ≥40%. Thromboelastometry showed no differences between values in blood diluted with the balanced or non-balanced HES.
  
  
  CONCLUSIONS
  In vitro, a balanced calcium-containing carrier solution of 6% HES 130/0.42 preserved coagulation better than did non-balanced HES 130/0.4 as quantified by conventional coagulation assays, but not in activated thromboelastometry. One explanation could be the increased ionized calcium levels after dilution with calcium-containing carrier solutions.
authors: Department of Anaesthesiology and Intensive Care Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Juliane
authors: J
authors: Rau
authors: Department of Anaesthesiology and Intensive Care Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Christoph
authors: C
authors: Rosenthal
authors: Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Elisabeth
authors: E
authors: Langer
authors: Department of Anaesthesiology and Intensive Care Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Michael
authors: M
authors: Sander
authors: Department of Anaesthesiology and Intensive Care Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Erika
authors: E
authors: Schulte
authors: Institute for Medical Diagnostics Oderland, Frankfurt, Germany.
authors: Michael
authors: M
authors: Schuster
authors: Department of Anaesthesiology and Intensive Care Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-University Medicine Berlin, Berlin, Germany.
authors: Christian
authors: C
authors: von Heymann
mesh_terms: D000328:Adult; D002118:Calcium / Q000494:pharmacology*; D000077324:Crystalloid Solutions; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D006438:Hemodilution; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D007552:Isotonic Solutions / Q000494:pharmacology; D008297:Male; D010952:Plasma Substitutes / Q000494:pharmacology*; D013916:Thrombelastography; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D000077324:Crystalloid Solutions; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D014841:von Willebrand Factor; C078147:F8 protein, human; D005169:Factor VIII; D002118:Calcium