Weaning from mechanical ventilation is the process of abruptly or gradually withdrawing ventilatory support when the cause of the acute respiratory failure is under resolution. For many patients, resuming spontaneous unassisted breathing is accomplished easily. In others, the weaning process induces important changes in respiratory and nonrespiratory parameters and may be associated with complications and failure.<sup>28 Esteban A., Alia I., Iban˜ez J. , e al. Modes of mechanical ventilation and weaning. A national survey of Spanish hospitals Chest 1994 ;  106 : 1188-1193  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> Such patients require more gradual withdrawal of their ventilatory support, especially those who are recovering from a prolonged episode of respiratory failure or patients with chronic obstructive pulmonary disease (COPD), severe heart failure, or severe central neurologic disorders. For those patients, the weaning period may account for more than 40% of the time spent on mechanical ventilation (Figure 1).<sup>28 Esteban A., Alia I., Iban˜ez J. , e al. Modes of mechanical ventilation and weaning. A national survey of Spanish hospitals Chest 1994 ;  106 : 1188-1193  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> In addition, adaptation of several physiologic systems to the new breathing conditions is necessary for the success of this process.

This article reviews the criteria used to determine whether the patient is ready for weaning from ventilatory support, the causes of difficult weaning, the methods of weaning, and the management of the difficult-to-wean patient.