title: Hemostatic changes after crystalloid or colloid fluid administration during major orthopedic surgery: the role of fibrinogen administration.
abstract: BACKGROUND
  To explore whether disturbed fibrin polymerization is the main problem underlying dilutional coagulopathy and can be reversed by fibrinogen administration, we conducted a prospective study using modified thrombelastography (ROTEM).
  
  
  METHODS
  Sixty-six orthopedic patients randomly received modified gelatin solution, hydroxyethyl starch 130/0.4, or exclusively Ringer lactate solution. ROTEM analysis was performed, concentrations of coagulation factors and markers of thrombin generation were measured. Fibrinogen concentrate (Hemocomplettan) was administered (30 mg/kg) when thrombelastographically measured fibrinogen polymerization was critically decreased.
  
  
  RESULTS
  The alpha angle, clot firmness, and fibrinogen polymerization (median [min to max]) significantly decreased in the patients receiving hydroxyethyl starch (area under the curve minus baseline (-5 [-9 to -2]), followed by gelatin solution (-3 [-8 to 0]), with the least reductions seen for Ringer lactate solution (-2 [- 4 to 1]) (colloids versus Ringer lactate P < 0.0001). Thirteen patients in the colloid groups but none in the Ringer lactate group needed fibrinogen concentrate to maintain borderline clot firmness. Activity of FVII, FVIII, FIX, and von Willebrand ristocetin activity decreased significantly with colloids. Thrombelastographically measured coagulation time, molecular markers of thrombin generation, and activity of all other coagulation factors were comparable in all groups.
  
  
  CONCLUSIONS
  Disturbance of fibrinogen/fibrin polymerization is the primary problem triggering dilutional coagulopathy during major orthopedic surgery. The magnitude of clot firmness reduction is determined by the type of fluid used, with hydroxyethyl starch showing the most pronounced effects. These undesirable effects of intravascular volume therapy can be reversed by increasing fibrinogen concentration by administering fibrinogen concentrate, even during continuing blood loss and intravascular volume replacement.
authors: Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria. markus.mittermayr@i-med.ac.at
authors: Markus
authors: M
authors: Mittermayr
authors: Werner
authors: W
authors: Streif
authors: Thorsten
authors: T
authors: Haas
authors: Dietmar
authors: D
authors: Fries
authors: Corinna
authors: C
authors: Velik-Salchner
authors: Anton
authors: A
authors: Klingler
authors: Elgar
authors: E
authors: Oswald
authors: Christian
authors: C
authors: Bach
authors: Mirjam
authors: M
authors: Schnapka-Koepf
authors: Petra
authors: P
authors: Innerhofer
mesh_terms: D000328:Adult; D000368:Aged; D001778:Blood Coagulation Disorders / Q000209:etiology / Q000628:therapy; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D003102:Colloids / Q000008:administration & dosage; D000077324:Crystalloid Solutions; D005340:Fibrinogen / Q000627:therapeutic use*; D005780:Gelatin / Q000008:administration & dosage; D006438:Hemodilution / Q000009:adverse effects; D006487:Hemostasis; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage*; D007552:Isotonic Solutions / Q000008:administration & dosage*; D008875:Middle Aged; D019637:Orthopedic Procedures; D010952:Plasma Substitutes / Q000008:administration & dosage*; D000077325:Ringer's Lactate; D013131:Spine / Q000601:surgery; D013916:Thrombelastography
chemical_list: D003102:Colloids; D000077324:Crystalloid Solutions; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D000077325:Ringer's Lactate; D005780:Gelatin; D005340:Fibrinogen