title: An in vitro study comparing the effects of Hextend, Hespan, normal saline, and lactated ringer's solution on thrombelastography and the activated partial thromboplastin time.
abstract: OBJECTIVE
  The purpose of this study was to determine if 6% HES 450/0.7 (hydroxyethyl starch 450/0.7) in normal saline (Hespan) and 6% HES 450/0.7 in lactated Ringer's solution (Hextend) have the same inhibition of the intrinsic coagulation pathway and platelet function. Multiple studies have suggested that 6% Hespan inhibits coagulation and increases chest tube drainage and transfusion requirements in cardiac surgical patients. There have been few studies of the effects of 6% Hextend, a relatively new plasma volume expander, on coagulation and the results thus far have been mixed.
  
  
  METHODS
  A prospective in vitro study.
  
  
  METHODS
  A large academic medical center.
  
  
  METHODS
  Blood was collected from 30 healthy volunteers. Interventions : The blood was fractionated and diluted by 30% with Hextend, Hespan, normal saline, and lactated Ringer's solutions, with a native sample for a control.
  
  
  RESULTS
  Primary outcome measures were thromboelastography and activated partial thromboplastin time (APTT). For each of the TEG parameters, there was no difference between samples diluted with Hextend compared with Hespan (p > or = 0.112 in all cases). APTT did not differ significantly between samples diluted with Hextend compared with Hespan (p = 0.562).
  
  
  CONCLUSIONS
  This prospective in vitro study suggests that Hextend and Hespan, hydroxyethyl starch 450/0.7 in different base solutions, exhibit the same effect on platelet function as measured by the TEG.
authors.affiliation: Mayo School of Health Sciences, Rochester, MN 55905, USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Dailey
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Dysart
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Langan
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Slye
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Nuttall
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Schrader
authors.forename: Brent A
authors.initials: BA
authors.lastname: Williams
authors.forename: William C
authors.initials: WC
authors.lastname: Oliver
mesh_terms: D000328:Adult; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects; D005260:Female; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D007552:Isotonic Solutions / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time / Q000379:methods; D010952:Plasma Substitutes / Q000494:pharmacology*; D011446:Prospective Studies; D012016:Reference Values; D000077325:Ringer's Lactate; D012965:Sodium Chloride / Q000494:pharmacology*; D013916:Thrombelastography / Q000187:drug effects*
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D000077325:Ringer's Lactate; D012965:Sodium Chloride