Impact of Inspiratory Effort and Patient-Ventilator Interaction During the Transition Phase

The goal of this observational study is to learn whether breathing effort and patient-ventilator asynchrony (PVA) during the transition phase are associated with clinical outcomes in mechanically ventilated adults.The main questions it aims to answer are: * Is the level and change in breathing effort associated with successful liberation from mechanical ventilation? * How often does PVA occur during the transition phase? * Are breathing effort and PVA associated with patient outcomes? These questions will be assessed using physiological and clinical data collected during the transition phase of mechanical ventilation. Breathing effort will be measured twice daily using a non-invasive airway pressure measurement, while ventilator waveforms will be continuously monitored to detect PVA. Participants will be followed up at day 28 and day 90.

Inclusion Criteria: * Adult patients (\>=18 years) intubated and receiving invasive mechanical ventilation delivered through an endotracheal tube within the first 48 hours from initiation of ventilation. * No immediate plan for extubation within the next 48 hours, a determined by the treating clinical team. * Patients clinically stable entering the transition phase of mechanical ventilation \* For prospective enrollment and initiation of active monitoring, the transition phase will be identified clinically. A patient will be considered to be entering the transition phase when there is improvement or partial resolution of the acute phase and the treating team initiates at least one clinical action indicating an intention to allow greater spontaneous respiratory participation. These actions may include: reducing or discontinuing sedation, decreasing the set respiratory rate, changing to a ventilatory mode allowing greater patient participation, decision to assess spontaneous breathing or advance liberation from mechanical ventilation. For the final analysis, the physiological onset of the transition phase will be determined retrospectively from the continuous ventilator waveform recordings. It will be defined as the first sustained 30-minute period during which at least 50% of ventilator-delivered breaths are triggered by the patient. This physiological criterion will be used to align individual trajectories and define the analytical onset of transition\* Exclusion Criteria: * Pre-existing neurological or muscular conditions (e.g., subarachnoid hemorrhage, diaphragm paralysis) * History of recovered cardiocirculatory arrest * Extra-corporeal membrane oxygenation (ECMO) * Current pregnancy * Documented intellectual or psychiatric disability prior to hospitalization * A decision to withhold or withdraw life-sustaining treatment * Patients undergoing a second episode of mechanical ventilation during the same hospitalization