title: Rotation thromboelastometry velocity curve predicts blood loss during liver transplantation.
abstract: BACKGROUND
  Patients undergoing liver transplantation (LT) have a high risk of bleeding. The goal of this study was to assess whether the first derivative of the velocity waveform (V-curve) generated by whole blood rotation thromboelastometry (ROTEM®) can predict blood loss during LT.
  
  
  METHODS
  Preoperative V-curve parameters were retrospectively evaluated in 198 patients. Patients were divided into quartiles based on blood loss: low (LBL) in the first quartile and high (HBL) in the higher quartiles. A subgroup analysis was performed with patients stratified according to cirrhosis aetiology. A logistic regression model and receiver operator characteristics (ROC) curve were used to test the capacity of the V-curve, to discriminate between LBL and HBL.
  
  
  RESULTS
  In the HBL group, the V-curve showed a lower maximum velocity of clot generation (MaxVel), a lower area under maximum velocity curve (AUC), and a higher time-to-maximum velocity (t-MaxVel) than in the LBL group. t-MaxVel was the only parameter showing a capacity to discriminate between the two groups, with a ROC area of 0.69 (95% CI; 0.62-0.74). The ROC area was 0.78 (95% CI; 0.75-0.83) for the 148 patients with cirrhosis, 0.73 (0.60-0.82) for patients with viral hepatitis and 0.83 (0.78-0.96) for patients with alcoholic hepatitis, the group that showed the best discriminative capacity. Moderate but significant correlations were found between all parameters of V-curve and BL.
  
  
  CONCLUSIONS
  Pre-transplant V-curve obtained from ROTEM is a promising tool for predicting BL risk during LT, particularly in patients with cirrhosis.
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.
authors.forename: L A
authors.initials: LA
authors.lastname: Tafur
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain ptaura@clinic.ub.es.
authors.forename: P
authors.initials: P
authors.lastname: Taura
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.|Institut d'Investigacions Biomédiques Agustí Pi i Sunyer.
authors.forename: A
authors.initials: A
authors.lastname: Blasi
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Beltran
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.|Department of Surgery, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Martinez-Palli
authors.affiliation: Department of Anaesthesiology, Liver Transplant Unit, Hospital Clinic, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Balust
authors.affiliation: Institut d'Investigacions Biomédiques Agustí Pi i Sunyer.
authors.forename: J C
authors.initials: JC
authors.lastname: Garcia-Valdecasas
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013030:Spain; D013916:Thrombelastography / Q000379:methods* / Q000706:statistics & numerical data*
keywords: clot formation; liver transplantation; thrombin generation; viscoelastic assays