title: Evaluation of TEG(®) and RoTEM(®) inter-changeability in trauma patients.
abstract: BACKGROUND
  Massive haemorrhage is a leading cause of preventable deaths in trauma. Traumatic coagulopathy is frequently present early after trauma, and is associated with increased mortality. A number of recent trials suggest that viscoelastic haemostatic assays (VHA), such as thromboelastography and thromboelastometry, are useful tools in guiding transfusion. Treatment algorithms exist for the use of VHAs but are not validated in traumatic haemorrhage. In this study we examined the inter-changeability of two commonly used VHAs, TEG(®) and RoTEM(®).
  
  
  METHODS
  A total of 184 trauma patients over the age of 18, requiring full trauma team activation, were included at three different hospitals in three different countries (Copenhagen, Denmark, San Francisco, CA, USA and Oslo, Norway). Blood samples were drawn immediately upon arrival, and TEG(®) and RoTEM(®) analyzed simultaneously. Correlations were calculated using. Spearman's rank correlation coefficient. Agreement was evaluated by Bland-Altman plots and calculation of limits of agreement.
  
  
  RESULTS
  The mean ISS in the total population was 17, and the mortality was 16.5%. Mean base excess was -2.8 (SD: 4.2). The correlation coefficient for corresponding values for the two devices was 0.24 for the R-time vs CT in all centres combined. For the K-time vs CFT the correlation was 0.48, for the α-angleTEG vs α-angleRoTEM 0.44, and for MA vs MCF 0.76. Limits of agreement exceeded the preset clinically acceptable deviation of 10% for all variables in all centres except for MA/MCF in one centre (Copenhagen). Generally, correlation coefficients were lower and agreement poorer in the one centre (Oslo) where measurements were performed bedside by clinicians.
  
  
  CONCLUSIONS
  Inter-changeability between TEG(®) and RoTEM(®) is limited in the trauma setting. Agreement seems poorer when clinicians operate the devices. Development and validation of separate treatment algorithms for the two devices is required.
authors.affiliation: Department of Research, Norwegian Air Ambulance, Drøbak, Norway. jostein.hagemo@snla.no
authors.forename: Jostein S
authors.initials: JS
authors.lastname: Hagemo
authors.forename: Paal A
authors.initials: PA
authors.lastname: Næss
authors.forename: Pär
authors.initials: P
authors.lastname: Johansson
authors.forename: Nis A
authors.initials: NA
authors.lastname: Windeløv
authors.forename: Mitchell Jay
authors.initials: MJ
authors.lastname: Cohen
authors.forename: Jo
authors.initials: J
authors.lastname: Røislien
authors.forename: Karim
authors.initials: K
authors.lastname: Brohi
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Heier
authors.forename: Morten
authors.initials: M
authors.lastname: Hestnes
authors.forename: Christine
authors.initials: C
authors.lastname: Gaarder
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001778:Blood Coagulation Disorders / Q000097:blood* / Q000209:etiology / Q000235:genetics / Q000628:therapy; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006470:Hemorrhage / Q000097:blood* / Q000175:diagnosis / Q000628:therapy; D006487:Hemostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D015203:Reproducibility of Results; D012495:San Francisco / Q000453:epidemiology; D013916:Thrombelastography / Q000295:instrumentation / Q000379:methods; D014193:Trauma Centers; D014914:Whole Blood Coagulation Time; D014947:Wounds and Injuries / Q000097:blood* / Q000150:complications / Q000628:therapy