title: Analysis of specific pre-operative model to valve surgery and relationship with the length of stay in intensive care unit.
abstract: OBJECTIVE
  The length of stay after prolonged cardiac surgery has been associated with poor immediate outcomes and increased costs. This study aimed to evaluate the predictive power of the Ambler Score to anticipate the length of stay in the intensive care unit.
  
  
  METHODS
  This was a retrospective cohort study based on data collected from 110 patients undergoing valve replacement surgery alone or in combination with other procedures. Additive and logistic Ambler Scores were obtained and their predictive performances calculated using the Receiver Operating Characteristic curve. The normal length stay in the intensive care unit was assumed to be <3 days and prolonged >3 days. The areas under the receiver operating curves for both the additive and logistic models were compared using the Hanley-MacNeil test.
  
  
  RESULTS
  The mean intensive care unit length of stay was 4.2 days. Sixty-three patients were male. The logistic model showed areas under the receiver operating characteristic curve of 0.73 and 0.79 for hospitalization > 3 days and < 3 days, respectively, showing good discriminative power. For the additive model, the areas were 0.63 and 0.59 for hospitalization > 3 days and < 3 days, respectively, a poor discriminative power.
  
  
  CONCLUSIONS
  In our database, prolonged length of stay in the intensive care unit was positively correlated with the logistic Ambler score. The performance of the logistic Ambler Score had good discriminative power for correlation with the intensive care unit length of stay.
authors.affiliation: Unidade de Terapia Intensiva, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Felipe Montes
authors.initials: FM
authors.lastname: Pena
authors.affiliation: Serviço de Hemodinâmica e Cardiologia Intervencionista, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Jamil da Silva
authors.initials: Jda S
authors.lastname: Soares
authors.affiliation: Serviço de Cirurgia Cardiovascular, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Ronald Souza
authors.initials: RS
authors.lastname: Peixoto
authors.affiliation: Serviço de Cirurgia Cardiovascular, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Herbet Rosa
authors.initials: HR
authors.lastname: Pires Júnior
authors.affiliation: Unidade de Terapia Intensiva, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Beatriz Tose Costa
authors.initials: BT
authors.lastname: Paiva
authors.affiliation: Unidade de Terapia Intensiva, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Frederico Vieira Dias
authors.initials: FV
authors.lastname: Moraes
authors.affiliation: Unidade de Terapia Intensiva, Hospital Escola Álvaro Alvim, Rio de Janeiro, RJ, Brasil.
authors.forename: Patricia Chicharo
authors.initials: PC
authors.lastname: Engel
authors.affiliation: Faculdade de Medicina de Campos dos Goytacazes, Rio de Janeiro, RJ, Brasil.
authors.forename: Nayara Campos
authors.initials: NC
authors.lastname: Gomes
authors.forename: Genevania de Souza Areas
authors.initials: Gde S
authors.lastname: Pena