title: Early thromboelastometry variables predict maximum clot firmness in children undergoing cardiac and non-cardiac surgery.
abstract: BACKGROUND
  Early clot amplitudes measured on thromboelastometry (ROTEM®) predict maximum clot firmness (MCF) in adults. In this multicentre, retrospective study, we aimed to confirm the suspected relationship between early ROTEM® variables and MCF, in children undergoing cardiac or non-cardiac surgery.
  
  
  METHODS
  4762 ROTEM® tests (e.g. EXTEM, INTEM, FIBTEM, APTEM, and HEPTEM) performed in children undergoing cardiac or non-cardiac surgery at three University hospitals between January 2011 and June 2014 were reviewed. To assess the correlation between clot amplitudes measured after 5, 10 and 15 min and MCF, each variable was compared with the corresponding MCF by calculating Spearman's correlation coefficient.
  
  
  RESULTS
  For the EXTEM® test, we observed that amplitude measured after 5 min (A5: r=0.91, P<0.001), 10 min (A10: r=0.95, P<0.001) and 15 min (A15: r=0.96, P<0.001) were strongly correlated to MCF. The same correlations were observed for INTEM® test (A5: r=0.93, P<0.001; A10: r=0.97, P<0.001; A15: r=0.97, P<0.001), and FIBTEM® test (A5: r=0.93, P<0.001; A10: r=0.94, P<0.001; A15: r=0.96, P<0.001). In addition, the amplitudes measured after five, 10 and 15 min were also strongly correlated with MCF in the APTEM® and the HEPTEM® tests. Receiver operating characteristics (ROC) analysis confirmed that A5, A10, A15 strongly predicted decreased MCF on all ROTEM® tests.
  
  
  CONCLUSIONS
  This study confirmed that early values of clot amplitudes measured as soon as five, 10 or 15 min after clotting time could be used to predict maximum clot firmness in all ROTEM® tests.
authors.affiliation: Department of Anaesthesiology, La Paz University Hospital, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Perez-Ferrer
authors.affiliation: Department of Anaesthesiology, La Paz University Hospital, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Vicente-Sanchez
authors.affiliation: Department of Anaesthesiology, University Hospital Virgen de la Arrixaca, Murcia, Spain.
authors.forename: M D
authors.initials: MD
authors.lastname: Carceles-Baron
authors.affiliation: Department of Anaesthesiology, Centre Hospitalier Universitaire Brugmann - Queen Fabiola Children University Hospital, Free University of Brussels, Brussels, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Van der Linden
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, USA david.faraoni@childrens.harvard.edu.
authors.forename: D
authors.initials: D
authors.lastname: Faraoni
mesh_terms: D000293:Adolescent; D001777:Blood Coagulation / Q000502:physiology; D001778:Blood Coagulation Disorders / Q000175:diagnosis*; D001780:Blood Coagulation Tests / Q000379:methods; D006348:Cardiac Surgical Procedures; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007430:Intraoperative Care / Q000379:methods*; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013916:Thrombelastography / Q000379:methods*; D013997:Time Factors
keywords: blood coagulation; blood transfusion; children; measurement techniques; thromboelastometry; transfusion algorithm