title: Effects of colloid and crystalloid solutions on endogenous activation of fibrinolysis and resistance of polymerized fibrin to recombinant tissue plasminogen activator added ex vivo.
abstract: BACKGROUND
  The study was conducted to explore the effects of colloid and crystalloid solutions on activation of fibrinolysis during orthopaedic surgery and to determine whether fluids facilitate clot dissolution at a particular fibrinolytic activity.
  
  
  METHODS
  Tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were measured in plasma samples of 66 orthopaedic patients randomly receiving gelatin solution, hydroxyethyl starch (HES) (130/0.4), or exclusively Ringer's lactate solution. Plasma obtained before induction of anaesthesia (undiluted) and at the end of surgery (diluted) was exposed to recombinant tissue plasminogen activator (r-tPA) in vitro and analysed by modified thrombelastography (ROTEM).
  
  
  RESULTS
  There were similar changes in t-PA and PAI-1 concentrations in the gelatin, HES, and Ringer's lactate groups. When compared with the effect of r-tPA on undiluted plasma samples, the presence of colloids prompted faster clot dissolution than did Ringer's lactate solution. Lysis index at 30 min decreased significantly [median (min/max); P vs Ringer's lactate solution] to 43 (1/82)% (P=0.007), 14 (3/70)% (P<0.001), and 91 (34/97)%, lysis onset time decreased to 1269 (1054/1743) s (P=0.007), 972 (490/1565) s (P<0.001), and 1970 (1260/2165) s, and lysis time to 2469 (1586/3303) s (P=0.019), 2002 (1569/3600) s (P=0.006), and 3012 (2017/3600) s in the gelatin, HES, and Ringer's lactate groups, respectively.
  
  
  CONCLUSIONS
  The type of i.v. fluid used does not influence endogenously occurring fibrinolytic activity in patients undergoing major orthopaedic surgery. However, during hyperfibrinolysis, the presence of HES or gelatin solution facilitates clot disintegration to a greater extent than Ringer's lactate solution, because the weaker clots formed with colloids dissolve faster.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. markus.mittermayr@i-med.ac.at
authors.forename: M
authors.initials: M
authors.lastname: Mittermayr
authors.forename: W
authors.initials: W
authors.lastname: Streif
authors.forename: T
authors.initials: T
authors.lastname: Haas
authors.forename: D
authors.initials: D
authors.lastname: Fries
authors.forename: C
authors.initials: C
authors.lastname: Velik-Salchner
authors.forename: A
authors.initials: A
authors.lastname: Klingler
authors.forename: P
authors.initials: P
authors.lastname: Innerhofer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005337:Fibrin / Q000378:metabolism*; D005342:Fibrinolysis / Q000187:drug effects*; D005780:Gelatin / Q000494:pharmacology*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D007430:Intraoperative Care / Q000379:methods; D007552:Isotonic Solutions / Q000494:pharmacology; D008875:Middle Aged; D019637:Orthopedic Procedures; D010952:Plasma Substitutes / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D000077325:Ringer's Lactate; D013916:Thrombelastography; D010959:Tissue Plasminogen Activator / Q000097:blood / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D017395:Plasminogen Activator Inhibitor 1; D000077325:Ringer's Lactate; C051321:SERPINE1 protein, human; D005780:Gelatin; D005337:Fibrin; D010959:Tissue Plasminogen Activator