Mos t patients who require invasive mechanical ventilation (MV) can be liberated quickly from the ventilator after resolution of the acute precipitating illness,<sup>15 Capdevila X., Perrigault P.F., Ramonatxo M. , e al. Changes in breathing pattern and respiratory muscle performance parameters during difficult weaning Crit Care Med 1998 ;  26 : 79-87  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 39 Fiastro J.F., Habib M.P., Shon B.Y. , e al. Comparison of standard weaning parameters and the mechanical work of breathing in mechanically ventilated patients Chest 1988 ;  94 : 232-238  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> but a significant population fails multiple weaning attempts and requires prolonged mechanical ventilation (PMV). Often, these are patients with underlying obstructive lung disease, but patients with severe chest wall deformities, neuromuscular disease, or requiring prolonged acute hospitalization for multiorgan system failure or postoperative complications are also at risk for requiring long-term ventilator care. In this article, the authors discuss the patient populations prone to develop ventilator dependence and investigate predictors of weaning based on the pathophysiology of chronic weaning failure. Given the paucity of randomized, controlled trials studying these patients, the authors attempt to glean insight from the larger body of work describing patients requiring shorter terms of MV. The authors address techniques used to wean patients from PMV as supported by current literature and explore possible directions for future studies.