title: Validity of Thromboelastometry for Rapid Assessment of Fibrinogen Levels in Heparinized Samples During Cardiac Surgery: A Retrospective, Single-center, Observational Study.
abstract: OBJECTIVE
  To assess the validity of fibrinogen assay of rotational thromboelastometry (FIBTEM)-derived estimates of fibrinogen in samples collected during cardiopulmonary bypass in cardiac surgical patients by comparison to Clauss method fibrinogen concentration.
  
  
  METHODS
  Retrospective observational study.
  
  
  METHODS
  Single university hospital center.
  
  
  METHODS
  Human participants.
  
  
  METHODS
  Retrospectively obtained laboratory assays including rotational thromboelastometry (ROTEM) and Clauss fibrinogen assay.
  
  
  RESULTS
  A retrospective review was performed of anesthesia records at a single university teaching hospital during a 1-year period. From paired samples taken near the end of cardiopulmonary bypass, fibrinogen concentrations (Clauss method) were compared with FIBTEM-derived measures of maximal clot firmness (MCF) and clot amplitude at 10 minutes (A10) using Spearman's rank correlation, linear regression, and receiver operating characteristic curve analysis. The study included 1,077 patients. Clauss fibrinogen was correlated strongly with FIBTEM amplitudes (r = 0.78 for MCF and A10; p<0.01). The correlation was related inversely to hemoglobin concentration (p<0.01). The area under the receiver operating characteristic curve was 0.95; the optimal FIBTEM A10 cutoff for diagnosis of a fibrinogen concentration of<1.5 g/L was ≤8 mm.
  
  
  CONCLUSIONS
  The FIBTEM was a valid point-of-care method for estimating the fibrinogen concentration during cardiopulmonary bypass and may be used for prediction of hypofibrinogenemia before separation from the extracorporeal circuit.
authors: Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ont. Electronic address: hamish.mace@health.wa.gov.au.
authors: Hamish
authors: H
authors: Mace
authors: Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ont.
authors: Nicholas
authors: N
authors: Lightfoot
authors: Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ont.
authors: Stuart
authors: S
authors: McCluskey
authors: Department of Medicine, Laboratory Medicine Program, University Health Network, Toronto, Ont.
authors: Rita
authors: R
authors: Selby
authors: University of Toronto, Toronto, Ont.
authors: Debashis
authors: D
authors: Roy
authors: Department of Anesthesia, Université Paris-Diderot, Paris, France.
authors: Tarik
authors: T
authors: Timoumi
authors: Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ont.
authors: Keyvan
authors: K
authors: Karkouti
mesh_terms: D000368:Aged; D001780:Blood Coagulation Tests / Q000379:methods / Q000592:standards; D006348:Cardiac Surgical Procedures / Q000379:methods / Q000592:standards*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006493:Heparin / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013916:Thrombelastography / Q000379:methods / Q000592:standards*; D013997:Time Factors
chemical_list: D005340:Fibrinogen; D006493:Heparin
keywords: Clauss method; FIBTEM; ROTEM; cardiac anesthesia; cardiopulmonary bypass; fibrinogen