Weaning and noninvasive mechanical ventilation

Weaning processes conceived as successful liberation from mechanical ventilation (MV) and extubation could represent 40% of the total time of MV, with large differences between patients with different diseases. The process of discontinuation from MV being close to 50% or even past this limit in patients affected by chronic obstructive pulmonary disease (COPD), cardiac failure and neurological problems. Conversely, weaning failure has a significant independent association with increased risk for death, prolonged intensive care unit (ICU) stay, and transfer to a long-term care or rehabilitation facility. Endotracheal intubation and prolonged invasive MV are often accompanied by complications that carry their own morbidity and mortality and, may, per se, explain why the so called "difficult to wean" patients have such a poor prognosis. Therefore intubation should be avoided, or, if it is needed, reducing the duration of invasive ventilation, should be the most important goals especially in selected populations like COPD patients. It was stated that the use of standardized protocol for weaning gives better results in terms of outcome, and costs and, probably, the method employed is less important than the confidence and familiarity with the technique adopted. Noninvasive ventilatory techniques may be useful to avoid intubation in an ICU setting in about 50% of COPD patients, but it was also shown that using noninvasive ventilation (NIV) as a weaning technique in a selected group of COPD patients, the likelihood of weaning success increased, while the duration of MV and ICU stay decreased. This application of NIV, however, needs appropriate environments with a dedicated and experienced team of physicians, nurses and respiratory therapists. The application of NIV in other situations such as postextubation failure, may be an attractive strategy that deserves future study.