Virtual Reality-based Sensory Stimulation for Delirium Prevention in Intensive Care Units

The goal of this clinical trial is to evaluate whether virtual reality (VR)-based sensory stimulation can help prevent delirium in adult intensive care unit (ICU) patients, compared with an active control condition delivering the same nature-based audiovisual content via a tablet. The main questions it aims to answer are: 1. Does VR-based sensory stimulation delay the time to the first delirium event during ICU stay? 2. Does VR-based sensory stimulation reduce delirium incidence, duration, and severity? 3. What are the effects of the intervention on ICU length of stay, duration of mechanical ventilation, cognitive function at 3 months after ICU discharge, and health-related quality of life? Researchers will compare immersive VR-based sensory stimulation with a non-immersive tablet-based active control to assess the added value of immersion beyond the effects of sensory content alone. Participants will: 1. Receive either immersive VR-based sensory stimulation or tablet-based sensory stimulation 2. Receive one 20-minute session per day for up to 3 days during ICU stay Undergo twice-daily delirium assessments during ICU stay Complete follow-up assessments of cognitive function and health-related quality of life at 3 months after ICU discharge

Inclusion Criteria: * Age 18 years or older * Admitted to the ICU * Undergoing or expected to require mechanical ventilation * Expected ICU stay of at least 48 hours * Awake or lightly sedated, defined as a Richmond Agitation-Sedation Scale - (RASS) score between -1 and +1 * Able to understand and follow instructions * Provided informed consent \[or surrogate consent, if applicable\] Exclusion Criteria: * Pre-existing cognitive impairment or dementia * Acute psychiatric illness at admission * Delirium at enrollment as assessed by CAM-ICU * Terminal-stage cancer * APACHE II score \> 20 * Severe uncorrectable hearing or visual impairment * Traumatic brain injury or intracranial drainage tubes that make use of the VR headset impractical