Determinants of Successful Decannulation in Difficult-to-wean Patients

The factors of success of decannulation are not well known in the literature and the decision to decannulate is mainly based on clinical judgment. The failure rate of decannulation is between 2 and 25% with a poor prognosis in case of failure. The objective of this study is to determine the factors associated with successful tracheostomy removal in patients hospitalized in a respiratory weaning unit. The secondary objectives are to evaluate in tracheostomized and hospitalized patients in weaning unit: * The prevalence of successful tracheostomy removal; * The prevalence of successful weaning from mechanical ventilation; * Factors associated with successful weaning from mechanical ventilation; * Demographic characteristics of these patients at admission; * Ventilatory characteristics of these patients at admission; * Biological characteristics of these patients at admission; This is a prospective, single-centre, interventional cohort study with an expected duration of 2 years. All patients admitted to the respiratory weaning unit in the Forcilles' hospital, with a tracheostomy and an expected duration of mechanical ventilation \> 48 hours will be consecutively included. All factors potentially associated with successful tracheostomy removal will be prospectively collected: severity factors related to the ICU stay, ventilatory factors, respiratory and extra-respiratory factors.