title: A new formula as a predictive score of post-liver transplantation outcome: postoperative MELD-lactate.
abstract: BACKGROUND
  Liver transplantation (OLT) involves a 5% to 10% 30-day mortality rate. Multiple scores have been used as predictors of early postoperative mortality, such as the original Model for End-stage Liver Disease (MELD) and MELD sodium. Investigations have been conducted over the last 5 years to find new predictors of early post-OLT mortality.
  
  
  OBJECTIVE
  The aim of this study was to develop a new mathematical model to predict the individual chance of 30-day mortality after OLT.
  
  
  METHODS
  The study was conducted on 58 patients submitted to OLT at the University Hospital, between October 2008 and March 2012. The 29 latest survivor and 29 latest nonsurvivor cases were selected. Arterial blood sodium, lactate, international normalized ratio, total bilirubin, and creatinine values were determined 1 hour after the end of surgery. The MELD original equation, MELD sodium, and new MELD lactate were also elaborated. The results were analyzed by the Mann-Whitney and Wilcoxon tests. The level of significance was set at .05.
  
  
  RESULTS
  The new formula elaborated was as follows: MELD lactate = 5.68 × loge (lactate) + 0.64 × (Original MELD) + 2.68. The MELD lactate values were significantly higher than the MELD sodium and original MELD values (P < .05). The area under the receiver operating characteristic curve of MELD lactate in predicting the outcome of patients submitted to OLT was 0.80, as opposed to 0.71 for the original MELD and 0.72 for MELD sodium (P < .05).
  
  
  CONCLUSIONS
  The postoperative MELD lactate score proved to be more specific and sensitive than the original MELD and MELD sodium as a predictive model of the outcome of patients submitted to OLT.
authors.affiliation: Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: N M
authors.initials: NM
authors.lastname: Cardoso
authors.affiliation: Illinois Institute of Technology, Department of Applied Mathematics, Chicago, Illinois, United States.
authors.forename: T
authors.initials: T
authors.lastname: Silva
authors.affiliation: Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Basile-Filho
authors.affiliation: Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: E D
authors.initials: ED
authors.lastname: Mente
authors.affiliation: Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil. Electronic address: orlando@fmrp.usp.br.
authors.forename: O
authors.initials: O
authors.lastname: Castro-e-Silva
mesh_terms: D000328:Adult; D058625:End Stage Liver Disease / Q000601:surgery*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011184:Postoperative Period
chemical_list: D019344:Lactic Acid