title: Temperature corrected thromboelastography in hypothermia: is it necessary?
abstract: BACKGROUND
  Hypothermia is known to influence thromboelastography (TEG). TEG reproducibility is generally low.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the rationale of TEG temperature adjustment in patients during hypothermia. We hypothesised that temperature adjustment would not be important because of low TEG reproducibility.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Single-centre, secondary care study performed 01/2009 to 07/2010.
  
  
  METHODS
  Survivors of cardiopulmonary resuscitation in whom therapeutic hypothermia (32 to 34°C) was indicated for 24 h were recruited to the study which lasted 36 h. Four hundred samples from 30 patients (22 men and eight women) were obtained. No specific exclusion criteria were defined.
  
  
  METHODS
  Temperature adjusted and non-adjusted Kaolin-Heparinase and Rapid-TEG were done at 12-h intervals during the first 36 h.
  
  
  RESULTS
  Bland-Altman plots were used for analysis. During hypothermia, the bias of adjusted measurements was greater in clot formation variables for both Kaolin-Heparinase-TEG (from -15 to -19%) and Rapid-TEG (-9 to -25%) compared to normothermia (from -3 to 3% for Kaolin-Heparinase-TEG and -10 to 2% for Rapid-TEG). Bias of clot strength variables was not influenced by temperature adjustment (median -1%). The 95% limits of agreement were wide for clot formation variables and independent of temperature. In Kaolin-Heparinase-TEG (R -42 to 40% normothermia, -47 to 18% hypothermia) and in Rapid-TEG (R -117 to 97% normothermia, -114 to 95% hypothermia). Limits of agreement of clot strength variables were narrower and independent of temperature in Kaolin-Heparinase-TEG (MA -16 to 13% normothermia, -9 to 10% hypothermia) and also in Rapid-TEG (MA -27 to 24% normothermia, -18 to 20% hypothermia).
  
  
  CONCLUSIONS
  Although TEG analysis with temperature adjusted to the in-vivo value during hypothermia yields results with small systematic bias, the importance of temperature adjustment in clinical routine is low because of the precision limits of TEG measurement itself. Therefore, we see no need to perform TEG analysis at the in-vivo temperature.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Masaryk University, St Anna's University Hospital, Brno, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Cundrle
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sramek
authors.forename: Martin
authors.initials: M
authors.lastname: Pavlik
authors.forename: Pavel
authors.initials: P
authors.lastname: Suk
authors.forename: Iveta
authors.initials: I
authors.lastname: Radouskova
authors.forename: Vaclav
authors.initials: V
authors.lastname: Zvonicek
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000592:standards; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000628:therapy; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013916:Thrombelastography / Q000379:methods* / Q000592:standards