The goal of this clinical trial is to evaluate the feasibility of using a standardized sleep bundle in adults undergoing cardiac surgery. The main questions it aims to answer are:

1. Can eligible participants be recruited and retained in the study?
2. Can participants follow the study procedures, including using sleep aids and completing daily assessments?
3. Can sleep and other clinical data be reliably collected during the hospital stay? Researchers will compare participants who receive the sleep bundle to participants who receive usual postoperative care.

Participants will:

• Use non-drug sleep aids, including a sleep mask, ear plugs, and a noise machine (sleep bundle group only).
• Take sleep medications if needed, following a stepwise protocol (sleep bundle group only).
• Complete daily sleep assessments using the Richards-Campbell Sleep Questionnaire (RCSQ).
• Wear a Fitbit device at night to track sleep.
• Follow usual postoperative care routines (control group)

The study will also collect and describe data on sleep duration, nighttime awakenings, subjective sleep quality, incidence of postoperative delirium, and hospital length of stay to inform the design of a future larger trial.

This study is a pilot randomized controlled trial designed to evaluate the feasibility and effects of a standardized sleep bundle on sleep quality in patients undergoing cardiac surgery. Adult patients scheduled for non-emergent cardiac surgery at the Saint John Regional Hospital (SJRH) will be screened for eligibility and enrolled after providing informed consent. Participants will be randomized to either usual postoperative care or the sleep bundle group.

The sleep bundle includes non-pharmacological interventions (sleep mask, ear plugs, nightly noise machine) and a stepwise pharmacological approach (melatonin, with trazodone or quetiapine added as needed). Sleep outcomes will be measured objectively using the Fitbit Inspire 3 device and subjectively using the Richards-Campbell Sleep Questionnaire (RCSQ). Feasibility will be assessed based on recruitment, retention, and adherence to the study protocol. Secondary outcomes include total sleep duration, nighttime awakenings, subjective sleep quality, incidence of postoperative delirium, and hospital length of stay.

All study procedures and daily assessments will be conducted by trained research personnel, with data analysis performed by a team member blinded to group allocation. This pilot study will inform the design of a future larger-scale trial.

Inclusion Criteria:

• Adult patients over 19 years old, undergoing non-emergent cardiac surgery with cardiopulmonary bypass at the Saint John Regional Hospital (SJRH).

Exclusion Criteria:

• Emergent surgery.
• Severe renal or hepatic impairment (creatinine clearance (CrCl) <30 mL/min, Chronic Kidney Disease (CKD) stage ≥4, cirrhosis, Alanine Transaminase (ALT) ≥ 3 × upper limit of normal (ULN)).
• Sleep apnea.
• Restless leg syndrome (RLS).
• Insomnia with chronic use of pharmacological sleep aids prior to admission (trazodone, benzodiazepines, zopiclone, mirtazapine, quetiapine, tricyclic antidepressants [nortriptyline, amitriptyline, doxepin]).
• Prior use of a monoamine oxidase inhibitor in the past 14 days.
• Corrected QT Interval (QTc) > 500ms / history of prolonged QTc, Torsade de points or ventricular tachycardia.
• History of dementia, alcohol, or opioid use disorder.
• Documented or previous intolerance to melatonin, trazodone, or quetiapine. Unable to provide informed consent.

Run-in Period Exclusions:

After enrolment and before randomization, participants will be monitored for specific postoperative criteria. Those meeting any of the following criteria will be withdrawn prior to randomization.

• Radial artery harvest required (unable to place Fitbit device on the wrist contralateral to the arterial monitoring line).
• Prolonged intubation or sedation (> 48 hours) post-surgery.
• Major intra- or early postoperative complications (stroke, transient ischemic attach (TIA), major bleeding, need for mechanical/circulatory support, reoperation, open chest, pulmonary embolism, acute renal failure requiring dialysis or other major surgical complications that would inhibit ability to participate).

The decision to share individual participant data has not yet been determined. Plans for data sharing will be considered once the feasibility and outcomes of the pilot study are evaluated.