Responsive Nature-Driven Imagery to Reduce Delirium After Cardiac Surgery

Hypotheses:

This study will explore: (1) the feasibility of using Mindful Garden-a novel, nature-based digital therapeutic device offering responsive imagery and sound with biofeedback-in patients undergoing cardiac surgery; and (2) whether its use reduces psychotropic medication use, agitation, anxiety, and both the incidence and duration of postoperative delirium.

Rationale:

Delirium is a frequent, serious complication after cardiac surgery, leading to prolonged hospital stays, increased costs, and higher mortality rates. Although medications are often used to manage delirium-related behavior, they can lead to over-sedation and do not reliably prevent or treat delirium. There is an urgent need for safe, effective, non-pharmacological interventions in high-risk groups. Mindful Garden offers a screen-based display of dynamic nature scenes with interactive elements that respond to physiological cues. In prior ICU settings, brief exposure to Mindful Garden reduced agitation and the need for unscheduled medications. However, its effectiveness in preventing or managing delirium specifically in cardiac surgical patients remains unexplored.

Objectives:

The primary goals are to evaluate the feasibility of implementing Mindful Garden (in terms of recruitment, adherence, data completeness), its usage patterns, and patient satisfaction. Secondary aims include assessing the device's impact on delirium incidence and severity, need for psychotropic medications, agitation levels, anxiety, postoperative recovery, and length of hospital stay.

Participants:

This pilot randomized controlled trial will enroll 60 adult patients (aged ≥18 years) undergoing open-heart surgery at St. Paul's Hospital in Vancouver, Canada. Each arm will include 30 patients. Participants must have at least one risk factor for delirium, including being aged 64 or older, a history of delirium, stroke or TIA, cognitive impairment, or depression. Individuals with severe pre-existing cognitive impairments will be excluded.

Intervention:

Participants will be randomized 1:1 to either the Mindful Garden intervention or standard care. Due to the nature of the intervention, blinding is not feasible. In the intervention group, the Mindful Garden device will be made available for up to 7 days postoperatively or until discharge. All participants will receive standard post-operative care, including routine non-drug delirium prevention measures.

Outcomes:

Primary feasibility outcomes include recruitment success, adherence to study protocol, and participant satisfaction. Secondary clinical outcomes involve:

• Frequency of unscheduled psychotropic medication use
• Incidence and severity of delirium (measured via the Intensive Care Delirium Screening Checklist and Confusion Assessment Method)
• Agitation (Richmond Agitation Sedation Scale)
• Anxiety (State Trait Anxiety Inventory)
• Recovery quality (QoR-15 score)
• Presence of Hallucinations (PSYRATS)
• Hospital length of stay

Anticipated Impact:

This pilot trial will assess whether integrating the Mindful Garden device into post-cardiac surgery care is practical and beneficial. Results will inform a larger trial and may support broader implementation of non-pharmacological digital therapeutics to enhance recovery, reduce delirium, and minimize reliance on psychoactive drugs in surgical settings.

Inclusion criteria

• Planned open-heart cardiac surgery (e.g. coronary artery bypass grafting, valve replacement surgery);
• Able to understand study procedures and provide informed consent in English;
• At least one delirium risk factor: 1) Age less than 65yrs; 2) History of delirium; 3) History of stroke/TIA; 4) Known cognitive impairment; 5) Depression requiring medication.

Exclusion criteria

• Severe pre-existing cognitive impairment (Montreal Cognitive Assessment [MOCA6]<10)
• Uncorrected visual impairment;
• Significant impairment from psychiatric disease;
• Enrolment in another clinical trial which may interfere with the study outcome measures.