title: [Oxygen cost of breathing in the prediction of successful weaning from mechanical ventilation].
abstract: OBJECTIVE
  To determine whether the oxygen cost of breathing (VO2 resp) may predict successful weaning from mechanical ventilation.
  
  
  METHODS
  A prospective clinical study.
  
  
  METHODS
  A polyvalent intensive care unit of a teaching hospital.
  
  
  METHODS
  Thirty non-consecutive mechanically ventilated patients ready to wean. Successful weaning was considered when reintubation was not needed for 48 h after extubation.
  
  
  METHODS
  Spontaneous breathing test with a t-tube. VO2 resp was measured with the Douglas bag method.
  
  
  RESULTS
  Successful weaning was present in 20 (67%) of 30 patients. No patient with successful weaning needed tracheal reintubation. A cut-off value for VO2 resp <or= 10% had the highest value for the ROC curve (0.96 +/- 0.03) and +LR (9.5; 95% CI: 1.5 - 61) and -LR (0.1; 95% CI: 0.01 - 0.4) to distinguish between success or failure of weaning. A misclassification error of 7% was present to predict successful weaning.
  
  
  CONCLUSIONS
  The oxygen cost of breathing has no clinical utility in predicting weaning outcome.
authors.affiliation: Hospital Son Dureta, Palma de Mallorca, Islas Baleares, España. jmraurich@hsd.es
authors.forename: J M
authors.initials: JM
authors.lastname: Raurich
authors.forename: J
authors.initials: J
authors.lastname: Ibáñez
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011446:Prospective Studies; D012119:Respiration; D012131:Respiratory Insufficiency / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D015300:Ventilator Weaning