title: The effects of hydroxyethyl starch solutions on thromboelastography in preoperative male patients.
abstract: BACKGROUND
  Hydroxyethyl starches (HES) have been shown to decrease clot strength and to increase coagulation times assessed by thromboelastography (TEG). HES with minimal anticoagulant side-effects is beneficial for plasma volume expansion in the perioperative setting. A comparison of the in vivo effects of high, middle and low molecular weight HES solutions on TEG variables has not been performed so far.
  
  
  METHODS
  Blood was obtained before and after intravenous infusion (10 ml kg-1) of either saline, HES 70/0.5/4 (molecular weight in kDa/degree of substitution/C2:C6 ratio), HES 130/0.4/9, HES 200/0.6/9.4, or HES 450/0.7/4.6 in 50 otherwise healthy patients. Thromboelastography was performed in 360 micro l of 1% celite activated citrated whole blood after recalcification.
  
  
  RESULTS
  HES 450/0.7/4.6 prolonged reaction time indicating impairment of the plasmatic coagulation system. TEG parameters indicative for platelet function, including angle alpha, maximum amplitude and coagulation time, deteriorated after infusion of HES 450/0.7/4.6 and HES 70/0.5/4. HES 200/0.6/9.4 and HES 130/0.4/9 impaired platelet contribution to hemostasis only partially, decreasing two or one TEG platelet parameters, respectively.
  
  
  CONCLUSIONS
  Infusion of HES 450/0.7/4.6 compromises TEG parameters more than the other solutions tested, whereas HES 130/0.4/9 has the smallest effect. Further outcome-related studies are needed in order to assess the clinical relevance of our findings.
authors.affiliation: Department of Anesthesiology and Intensive Care B, University of Vienna, School of Medicine, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Felfernig
authors.forename: A
authors.initials: A
authors.lastname: Franz
authors.forename: P
authors.initials: P
authors.lastname: Bräunlich
authors.forename: C
authors.initials: C
authors.lastname: Fohringer
authors.forename: S A
authors.initials: SA
authors.lastname: Kozek-Langenecker
mesh_terms: D000328:Adult; D001777:Blood Coagulation / Q000187:drug effects; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010952:Plasma Substitutes / Q000494:pharmacology*; D011184:Postoperative Period; D013916:Thrombelastography / Q000187:drug effects*
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes