title: The effects of colloid solutions on hemostasis.
abstract: OBJECTIVE
  Colloid solutions are widely used to prevent or to correct hypovolemia in surgical patients. Although more efficacious than crystalloids, they are more expensive and can be associated with adverse effects, in particular when they interfere with the hemostatic system.
  
  
  METHODS
  This narrative review focuses on the effects of albumin and synthetic colloids on the biological markers of coagulation and their clinical consequences.
  
  
  RESULTS
  All colloidal plasma substitutes interfere with the physiological mechanisms of hemostasis either through a non-specific effect correlated to the degree of hemodilution or through specific actions of these macromolecules on platelet function, coagulation proteins, and the fibrinolytic system. Albumin has the least effect, while high molecular weight (Mw) dextrans and hydroxyethyl starches (HES) have the most significant effects. Gelatins and medium Mw HES with a low molar substitution ratio have moderate and, probably, comparable effects. The use of dextrans and high in vivo Mw HES may be associated with increased bleeding, while gelatins and low in vivo Mw HES are unlikely to have such an effect.
  
  
  CONCLUSIONS
  In most cases, the clinical consequences of the biological effects of colloids on hemostasis are limited, provided that safety considerations are observed (maximum daily dosage, duration of treatment, patient's hemostatic status, clinical conditions). The implications may be different in patients with hemostatic disorders, either inherited or related to preoperative antiplatelet or anticoagulant treatment. In these patients, crystalloids, gelatins or even albumin solutions should be preferred when hemodilution exceeds 30% of the circulating blood volume.
authors.affiliation: Department of Anesthesiology, CHU Brugmann - HUDERF, 4 Place Van Gehuchten, B-1020 Brussels, Belgium. philippe.vanderlinden@chu-brugmann.be
authors.forename: Philippe
authors.initials: P
authors.lastname: Van der Linden
authors.forename: Brigitte E
authors.initials: BE
authors.lastname: Ickx
mesh_terms: D000818:Animals; D003102:Colloids / Q000008:administration & dosage / Q000627:therapeutic use*; D003911:Dextrans / Q000627:therapeutic use; D005780:Gelatin / Q000627:therapeutic use; D006487:Hemostasis / Q000187:drug effects*; D006490:Hemostatics / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use; D010952:Plasma Substitutes / Q000009:adverse effects / Q000627:therapeutic use; D012709:Serum Albumin / Q000627:therapeutic use
chemical_list: D003102:Colloids; D003911:Dextrans; D006490:Hemostatics; D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes; D012709:Serum Albumin; D005780:Gelatin