title: Thromboelastography is a suboptimal test for determination of the underlying cause of bleeding associated with cardiopulmonary bypass and may not predict a hypercoagulable state.
abstract: OBJECTIVE
  Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) are at risk of bleeding. The goal of this investigation was to compare thromboelastography (TEG) with standard coagulation tests (prothrombin time [PT], partial thromboplastin time [PTT], fibrinogen, and D-dimer) in patients with active bleeding.
  
  
  METHODS
  A retrospective study of patients who underwent cardiac surgery with CPB was performed. A second analysis was performed to determine if a shortened TEG R time is associated with thrombosis.
  
  
  RESULTS
  Paired TEG and standard coagulation tests were available from 21 bleeding patients; of the 15 patients with normal TEG values and three with a shortened R time, all had abnormalities of standard coagulation tests. Eighteen of 67 patients who underwent surgery with CPB had an episode of postoperative bleeding. The TEG R time and coagulation index, PT, and PTT collected after CPB were associated with postoperative bleeding in the univariate analysis, but only PT was independently associated with postoperative bleeding in the multivariate analysis. In the second analysis, three of 38 patients with a normal TEG and four of 43 patients with a shortened R time had a thrombotic event during hospitalization (P = 1.00).
  
  
  CONCLUSIONS
  TEG had limited utility in identifying the underlying cause of bleeding and was not predictive of postoperative bleeding associated with cardiac surgery compared with conventional coagulation tests. A shortened TEG R time may not represent a hypercoagulable state.
authors.affiliation: From the Department of Pathology and Laboratory Medicine, University of Texas at Houston.
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Welsh
authors.affiliation: From the Department of Pathology and Laboratory Medicine, University of Texas at Houston.
authors.forename: Angelica
authors.initials: A
authors.lastname: Padilla
authors.affiliation: From the Department of Pathology and Laboratory Medicine, University of Texas at Houston.
authors.forename: Amitava
authors.initials: A
authors.lastname: Dasgupta
authors.affiliation: From the Department of Pathology and Laboratory Medicine, University of Texas at Houston.
authors.forename: Andy N D
authors.initials: AN
authors.lastname: Nguyen
authors.affiliation: From the Department of Pathology and Laboratory Medicine, University of Texas at Houston. Md.A.Wahed@uth.tmc.edu.
authors.forename: Amer
authors.initials: A
authors.lastname: Wahed
mesh_terms: D000368:Aged; D001777:Blood Coagulation; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006470:Hemorrhage / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000097:blood / Q000209:etiology; D012189:Retrospective Studies; D013916:Thrombelastography; D019851:Thrombophilia / Q000097:blood* / Q000209:etiology; D013997:Time Factors
keywords: Bleeding; Cardiopulmonary bypass; Coagulopathy; Thromboelastography