title: The modified integrative weaning index as a predictor of extubation failure.
abstract: BACKGROUND
  The extubation period is one of the most challenging aspects for intensive care teams. Timely recognition of the return to spontaneous ventilation is essential for reducing costs, morbidity, and mortality. Several weaning predictors were studied in an attempt to evaluate the outcome of removing ventilatory support. The purpose of this study was to analyze the predictive performance of the modified integrative weaning index (IWI) in the extubation process.
  
  
  METHODS
  A prospective study was performed in an ICU in a public hospital in Porto Alegre, Brazil, with 59 adult medical-surgical beds. The final population of the study comprised 153 patients receiving mechanical ventilation for over 48 h who were extubated during the period from February to November 2011. Demographic data and clinical parameters were collected in addition to extubation predictors, including static compliance of the respiratory system, ratio of breathing frequency to tidal volume, tracheal airway-occlusion pressure 0.1 s after the start of inspiratory flow, and modified IWI.
  
  
  RESULTS
  Extubation failure was observed in 23 of the subjects (15%). Subjects with greater positive fluid balance, lower hemoglobin levels, and lower levels of bicarbonate presented a higher rate of reintubation. The 3 modified IWI values (the first and 30th minute of the spontaneous breathing trial and the difference between them), as well as the other ventilatory parameters and extubation predictors, displayed poor extubation outcome discrimination accuracy. All indexes presented small areas under the receiver operating characteristic curve, and no accurate cutoff point was identified.
  
  
  CONCLUSIONS
  We concluded that modified IWI, similar to other extubation predictors, does not accurately predict extubation failure.
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Viviane M C
authors.initials: VM
authors.lastname: Boniatti
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil. marciobt@terra.com.br.
authors.forename: Márcio M
authors.initials: MM
authors.lastname: Boniatti
authors.affiliation: Thoracic Surgery Department, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Cristiano F
authors.initials: CF
authors.lastname: Andrade
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Crislene C
authors.initials: CC
authors.lastname: Zigiotto
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Kaminski
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Samantha P
authors.initials: SP
authors.lastname: Gomes
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Lippert
authors.affiliation: Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Diego C
authors.initials: DC
authors.lastname: Miguel
authors.affiliation: Anesthesia Department, Hospital de Clínicas de Porto Alegre, Brazil, and the Critical Care Department, Hospital Nossa Senhora da Conceição, Brazil.
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Felix
mesh_terms: D000328:Adult; D000368:Aged; D060666:Airway Extubation; D003422:Critical Care; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012123:Pulmonary Ventilation / Q000502:physiology*; D012372:ROC Curve; D012131:Respiratory Insufficiency / Q000503:physiopathology* / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology; D017211:Treatment Failure; D015300:Ventilator Weaning
keywords: mechanical ventilation; predictive indexes of extubation; weaning