title: A comparison of fibrinogen measurement methods with fibrin clot elasticity assessed by thromboelastometry, before and after administration of fibrinogen concentrate in cardiac surgery patients.
abstract: BACKGROUND
  Fibrinogen concentrate administration can be guided by measuring fibrinogen concentration or quality of the fibrin-based clot. This study compared different fibrinogen concentration measurement methods with maximum clot firmness (MCF) of the fibrin clot, assessed by thromboelastometry (FIBTEM), in 33 cardiovascular surgery patients receiving fibrinogen concentrate for hemostatic therapy.
  
  
  METHODS
  Blood samples were collected after cardiopulmonary bypass (CPB) and after fibrinogen concentrate administration. FIBTEM MCF was measured using a rotational thromboelastometry device (ROTEM, Tem International). Fibrinogen concentration was measured using photo-optical (CA-7000, Siemens Healthcare Diagnostics), mechanical (KC-10 steel ball, Schnitger and Gross hook, Amelung GmbH), and electromechanical (STA-R, Diagnostica Stago) coagulometers. Assessments included agreement between fibrinogen concentration measurements and correlations between fibrinogen concentration and FIBTEM MCF.
  
  
  RESULTS
  After CPB, correlations were significant (p < 0.001) between FIBTEM MCF and fibrinogen concentration determined by steel ball (r = 0.71), hook (r = 0.73), STA-R (r = 0.81), and CA-7000 (r = 0.82) coagulometers. After fibrinogen concentrate administration, agreement between fibrinogen measurement methods was severely impaired, and correlations with FIBTEM MCF were 0.39 (steel ball), 0.33 (hook), 0.59 (STA-R), and 0.33 (CA-7000).
  
  
  CONCLUSIONS
  Agreement between fibrinogen concentration measurement methods decreased considerably after fibrinogen concentrate administration. All methods correlated acceptably with FIBTEM MCF at the end of CPB, but not after hemostatic therapy. Further investigation is needed to explain these findings.
authors.affiliation: Department of Anaesthesiology and Intensive Care and the Institute of Medical and Chemical Laboratory Diagnostics, Salzburger Landeskliniken SALK, Salzburg, Austria. solomon.cristina@googlemail.com
authors.forename: Cristina
authors.initials: C
authors.lastname: Solomon
authors.forename: Janne
authors.initials: J
authors.lastname: Cadamuro
authors.forename: Bernhard
authors.initials: B
authors.lastname: Ziegler
authors.forename: Herbert
authors.initials: H
authors.lastname: Schöchl
authors.forename: Michael
authors.initials: M
authors.lastname: Varvenne
authors.forename: Benny
authors.initials: B
authors.lastname: Sørensen
authors.forename: Gerald
authors.initials: G
authors.lastname: Hochleitner
authors.forename: Niels
authors.initials: N
authors.lastname: Rahe-Meyer
mesh_terms: D000368:Aged; D001777:Blood Coagulation / Q000502:physiology*; D001780:Blood Coagulation Tests; D016913:Blood Component Transfusion / Q000379:methods; D006348:Cardiac Surgical Procedures / Q000534:rehabilitation; D002315:Cardiopulmonary Bypass; D005260:Female; D005337:Fibrin / Q000032:analysis* / Q000378:metabolism; D005340:Fibrinogen / Q000008:administration & dosage* / Q000032:analysis* / Q000378:metabolism; D006487:Hemostasis / Q000187:drug effects; D006490:Hemostatics / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D013916:Thrombelastography / Q000379:methods
chemical_list: D006490:Hemostatics; D005337:Fibrin; D005340:Fibrinogen