Abstract

RAURICH, J.M.  and  IBANEZ, J.. Oxygen cost of breathing in the prediction of successful weaning from mechanical ventilation. Med. Intensiva [online]. 2007, vol.31, n.4, pp.172-178. ISSN 0210-5691.

Objective. To determine whether the oxygen cost of breathing (VO₂ resp) may predict successful weaning from mechanical ventilation. Design. A prospective clinical study. Setting. A polyvalent intensive care unit of a teaching hospital. Patients. Thirty non-consecutive mechanically ventilated patients ready to wean. Successful weaning was considered when reintubation was not needed for 48 h after extubation. Interventions. 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 ≤ 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. Conclusion. The oxygen cost of breathing has no clinical utility in predicting weaning outcome.

Keywords : mechanical ventilation; weaning; oxygen cost of breathing.