Mapping the waking brain: how ICU patients emerge from sedation

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Adult critically ill patients with acute respiratory failure or requiring invasive mechanical ventilation in the context of critical illness will be consecutively enrolled. Eligible participants must meet all of the following criteria: * Age ≥18 years. * Receiving invasive mechanical ventilation for ≥24 hours. * Prior exposure to continuous analgosedation before undergoing a first valid Structured Awakening Evaluation (SAE) during the ICU stay, as defined by the study's operational criteria. * Availability of sufficient clinical information to identify the baseline time point (t0) and characterize the first valid Structured Awakening Evaluation according to the study's operational definitions. * Provision of informed consent for participation in the study. Exclusion Criteria: 1. Acute primary structural brain injury in which the level of consciousness is primarily determined by the neurological condition or constitutes a therapeutic target, including but not limited to: * Moderate or severe traumatic brain injury. * Subarachnoid hemorrhage. * Ischemic or hemorrhagic stroke. * Central nervous system infections. * Other structural brain injuries requiring therapeutic sedation or goal-directed intensive neurological monitoring. 2. Ongoing therapeutic sedation for neurological indications at the time of the first valid Structured Awakening Evaluation (SAE), including: * Intracranial hypertension management. * Status epilepticus. * Other neuroprotective strategies requiring deep sedation. 3. ICU admission following cardiac arrest with return of spontaneous circulation and suspected hypoxic-ischemic brain injury or the need for targeted therapeutic sedation. 4. Insufficient clinical information to accurately identify the baseline time point (t0) and characterize the architecture of the first valid Structured Awakening Evaluation. 5. Patients receiving extracorporeal life support (ECLS/ECMO), in whom assessment of hemodynamic and respiratory stability before initiation of awakening and liberation from invasive mechanical ventilation is substantially more complex.