title: Changes in coagulation during therapeutic hypothermia in cardiac arrest patients.
abstract: OBJECTIVE
  Therapeutic hypothermia improves neurological outcome in patients resuscitated after out-of-hospital cardiac arrest. The aim was to investigate whether therapeutic hypothermia induced impaired coagulation.
  
  
  METHODS
  Changes in coagulation were investigated in 22 out-of-hospital cardiac arrest patients treated with therapeutic hypothermia (33 ± 1 °C). Blood samples were obtained after 22 ± 2h of hypothermia and compared with normothermic samples drawn 48 h later. The coagulation was evaluated with thromboelastometry (ROTEM(®)) using a sensitive low-tissue-factor assay. Leukocytes, haemoglobin, haematocrit, platelet count, activated partial thromboplastin time (aPTT), thrombin time, international normalised ratio (INR) and fibrinogen were also measured. Clinical information including use of anti thrombotic drugs was systematically collected.
  
  
  RESULTS
  No significant changes were found in clotting time (p=0.21), clot formation time (p=0.26), time to maximum velocity (p=0.52) or maximum velocity (p=0.17) when results obtained at hypothermia were compared with results obtained at normothermia. Maximum clot firmness (p<0.01) and fibrinogen levels (p<0.01) were significantly higher in patients at normothermia. However, the fibrinogen levels were within the reference interval for all patients at both hypothermia and normothermia. Values of aPTT, thrombin time and INR at hypothermia and normothermia were not significantly different.
  
  
  CONCLUSIONS
  No substantial difference in coagulation was found in hypothermia compared with normothermia in out-of-hospital cardiac arrest patients. The results indicate that treatment with hypothermia does not impair coagulation.
  
  
  BACKGROUND
  NCT02179021.
authors.affiliation: Centre for Haemophilia and Thrombosis, Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Anne Katrine Wulff
authors.initials: AK
authors.lastname: Nielsen
authors.affiliation: Research Centre for Emergency Medicine, Aarhus University Hospital, Nørrebrogade 44, DK-8200 Aarhus N, Denmark; Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Anni Nørgaard
authors.initials: AN
authors.lastname: Jeppesen
authors.affiliation: Research Centre for Emergency Medicine, Aarhus University Hospital, Nørrebrogade 44, DK-8200 Aarhus N, Denmark; Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Kirkegaard
authors.affiliation: Centre for Haemophilia and Thrombosis, Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus N, Denmark. Electronic address: am.hvas@dadlnet.dk.
authors.forename: Anne-Mette
authors.initials: AM
authors.lastname: Hvas
mesh_terms: D000328:Adult; D000368:Aged; D001778:Blood Coagulation Disorders / Q000628:therapy*; D001780:Blood Coagulation Tests; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D011446:Prospective Studies
keywords: Cardiac arrest; Haemostasis; Therapeutic hypothermia; Thromboelastometry