title: Direct Oral Anticoagulants in Emergency Trauma Admissions.
abstract: BACKGROUND
  Direct (non-vitamin-K-dependent) oral anticoagulants (DOAC) are given as an alternative to vitamin K antagonists (VKA) to prevent stroke and embolic disease in patients with atrial fibrillation that is not due to pathology of the heart valves. Fatal hemorrhage is rarer when DOACs are given (nonvalvular atrial fibrillation: odds ratio [OR] 0.68; 95% confidence interval [95% CI: 0.48; 0.96], and venous thromboembolism: OR 0.54; [0.22; 1.32]). 48% of emergency trauma patients need an emergency operation or early surgery. Clotting disturbances elevate the mortality of such patients to 43%, compared to 17% in patients without a clotting disturbance. This underscores the impor tance of the proper, targeted treatment of trauma patients who are aking DOAC.
  
  
  METHODS
  This review is based on articles retrieved by a selective search in PubMed and on a summary of expert opinion and the recommendations of the relevant medical specialty societies.
  
  
  RESULTS
  Peak DOAC levels are reached 2-4 hours after the drug is taken. In patients with normal renal and hepatic function, no drug accumulation, and no drug interactions, the plasma level of DOAC 24 hours after administration is generally too low to cause any clinically relevant risk of bleeding. The risk of drug accumulation is higher in patients with renal dysfunction (creatinine clearance [CrCl] of 30 mL/min or less). Dabigatran levels can be estimated from the thrombin time, ecarin clotting time, and diluted thrombin time, while levels of factor Xa inhibitors can be estimated by means of calibrated chromogenic anti-factor Xa activity tests. Routine clotting studies do not reliably reflect the anticoagulant activity of DOAC. Surgery should be postponed, if possible, until at least 24-48 hours after the last dose of DOAC. For patients with mild, non-life threatening hemorrhage, it suffices to discontinue DOAC; for patients with severe hemorrhage, there are special treatment algorithms that should be followed.
  
  
  CONCLUSIONS
  DOACs in the setting of hemorrhage are a clinical challenge in the traumatological emergency room because of the inadequate validity of the relevant laboratory tests. An emergency antidote is now available only for dabigatran.
authors.affiliation: Department of Trauma and Orthopedic Sugery, Cologne-Merheim Medical Center (CMMC), Witten/Herdecke University, Cologne and Institute for Research in Operative Medicine (IFOM), Witten/Herdecke University, Campus Cologne-Merheim, Cologne, Experimental Hemostaseology, Department of Anesthesiology, University Hospital RWTH Aachen, Aachen, Department of Anesthesiology and Intensive Care Medicine, AUVA Emergency Hospital, Salzburg (Austria), Department of Neurosurgery, Ludwigsburg Hospital, Ludwigsburg, Department of Anesthesiology, Ludwig Maximilian University of Munich, Munich, Institute for Transfusion Medicine, Charité University Medicine Berlin, Berlin.
authors.forename: Marc
authors.initials: M
authors.lastname: Maegele
authors.forename: Oliver
authors.initials: O
authors.lastname: Grottke
authors.forename: Herbert
authors.initials: H
authors.lastname: Schöchl
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Sakowitz
authors.forename: Michael
authors.initials: M
authors.lastname: Spannagl
authors.forename: Jürgen
authors.initials: J
authors.lastname: Koscielny
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004632:Emergency Medical Services / Q000592:standards*; D006470:Hemorrhage / Q000139:chemically induced / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D017410:Practice Guidelines as Topic; D020521:Stroke / Q000175:diagnosis / Q000517:prevention & control*; D013923:Thromboembolism / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000150:complications* / Q000628:therapy*
chemical_list: D000925:Anticoagulants