title: Minimal effects on ex vivo coagulation during mild therapeutic hypothermia in post cardiac arrest patients.
abstract: OBJECTIVE
  Mild therapeutic hypothermia (MTH) is being used to improve neurological outcome and survival in patients successfully resuscitated after cardiac arrest. The impact on coagulation may be difficult to assess since most coagulation parameters are measured at 37°C and not at actual body core temperature. Therefore we investigated the effects of MTH both at body core (target) temperature of 32°C and at 37°C.
  
  
  METHODS
  Patients admitted at the ICU after cardiac arrest treated with MTH. Baseline blood samples, measured at 37°C were taken directly at arrival. The second and third samples were drawn within 1h and 24h after reaching target temperature and were measured at 32°C and 37°C. A final sample was drawn when the patient returned to normotemperature (measured at 37°C). Clotting time (CT) and maximum clotting formation (MCF) were measured with thromboelastometry.
  
  
  RESULTS
  Upon reaching target temperature (32°C) Extem and Intem CT were increased compared to baseline with 57s (49-75) to 65s (59-72) and 165s (144-183) to 193s (167-212) respectively (median with IQR; P<0.05), with a further significant increase after 24h of hypothermia with 68s (57-80) and 221s (196-266). Samples analyzed at 32°C showed a significant longer CT of 12s in Extem and 33s in Intem compared to 37°C. MCF was not affected by MTH or adjustment of temperature.
  
  
  CONCLUSIONS
  The mild effect of MTH on coagulation parameters remains unidentified when measured at 37°C. Although measurements at 32°C differ from those at 37°C, this does not appear to be of clinical relevance as all values were still within the reference range.
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Anaesthesiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: A C M
authors.initials: AC
authors.lastname: Brinkman
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: b.tentusscher@vumc.nl.
authors.forename: B L
authors.initials: BL
authors.lastname: Ten Tusscher
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: de Waard
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Anaesthesiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: F R
authors.initials: FR
authors.lastname: de Man
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: A R J
authors.initials: AR
authors.lastname: Girbes
authors.affiliation: Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Intensive Care, Medical Spectrum Twente, Enschede, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Beishuizen
mesh_terms: D001778:Blood Coagulation Disorders / Q000097:blood / Q000209:etiology; D001780:Blood Coagulation Tests; D005260:Female; D006323:Heart Arrest / Q000097:blood* / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
keywords: Cardiac arrest; Coagulopathy; Mild therapeutic hypothermia; Thromboelastometry