Conventional Weaning Parameters Do Not Predict Extubation Outcome in Intubated Subjects Requiring Prolonged Mechanical Ventilation

BACKGROUND: Approaches to respiratory care of patients needing prolonged mechanical ventilation (PMV) might be varied. In this study we assessed the predictive value of usual variables for extubation outcome in PMV patients. METHODS: From 2005 to 2007, intubated patients who were admitted to the intermediate respiratory care unit, had been on mechanical ventilation for ≥ 21 days at the time of admission, and underwent extubation after successful spontaneous breathing trials were included. Comparisons between subjects with successful extubation and failed extubation in terms of weaning parameters and clinical predictors of extubation outcome were performed. Also, 1-year survival of subjects with regard to extubation outcome was analyzed. RESULTS: Twenty-seven (23.7%) of 119 PMV subjects required reintubation within 7 days. Multivariate logistic regression analysis demonstrated that the only variable associated with extubation failure was ineffective cough (P < .001). Possessing 2 or more acceptable weaning parameters was not helpful in predicting extubation outcome. Subjects with failed extubation had worse 1-year survival (hazard ratio 0.49, 95% CI 0.28-0.87, P = .02) compared with those with successful extubation. CONCLUSIONS: In PMV subjects who tolerated spontaneous breathing trials and were ready to extubate, ineffective cough was the best predictor of extubation failure. Furthermore, extubation failure was associated with future mortality; thus, different management strategies need to be developed for improving patient outcome.