Circadian Rhythm Disruption in the Hospital Intensive Care Environment

Study Overview
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Brief Summary
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Abrupt changes to one's lifestyle disrupt biorhythms. Acute effects are well known from jet lag where transmeridian travel leads to insomnia, fatigue, irritability, gastrointestinal symptoms and other complaints. Several studies in the hospital environment reported dampened and misaligned biorhythms, suggesting that the inpatient experience is replete with circadian disruptors. However, comprehensive assessments of how circadian clocks are affected in intensive care and how this predicts post-operative recovery and risk are largely missing.

Official Title
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Circadian Rhythm Disruption in the Hospital Intensive Care Environment

Conditions
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Surgery, Cardiovascular Diseases

Intervention / Treatment
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* Other: Observation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults scheduled for cardiac surgery; ≥18 years of age; Capable of giving informed consent; Own a smartphone (Apple devices only). Exclusion Criteria: Taking sleep aids (antihistamines, melatonin, etc.) History of alcohol abuse (more than 2 drinks a day with last drink within the past 3 days) History of substance abuse at risk of postoperative withdrawal; Active diagnosis of alcohol or substance abuse; Recent travel across more than two (2) time zones (within the past month); Planned travel across more than two (2) time zones during the planned study activities; Subjects, who have received an experimental drug, used an experimental medical device within 30 days prior to screening, or who gave a blood donation of ≥ one pint within 8 weeks prior to screening; Subjects without access to WiFi in their or close to home or at work; Patients with hearing aids; Heart transplant patients; Patients in isolation.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Elective cardiac surgery<br> | Other: Observation<br>* No intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep depth | Variance in sleep depth assessed as percent REM sleep of total sleep time (TST) | Up to 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Odds Ratio Product-based sleep depth | Variance in sleep depth assessed as Odds Ratio Product (ORP) which ranges between ORP=0 (deeply asleep) and ORB=2.5 (fully awake). | Up to 48 hours | 
| Cognitive function assessed by the Montreal Cognitive Assessment (MoCA) | Variance in cognitive function | Up to 24 hours | 
| Number of recorded patient visits | Any patient visits by physicians, nurses, maintenance and cleaning staff, family members and friends are documented | 24 hours | 
| Purpose of recorded patient visits | The rationale is documented descriptively for each patient visits by physicians, nurses, maintenance and cleaning staff, family members and friends | 24 hours |