Daytime Bright Light, Circadian Abnormalities, and Delirium in Medical ICU Patients

Study Overview
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Brief Summary
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To determine if daytime bright light will promote circadian alignment and shorten or prevent delirium.

Detailed Description
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To determine if daytime bright light will promote circadian alignment and shorten or prevent delirium. The objective is to conduct a randomized controlled trial to determine if a circadian entrainment intervention, daytime bright light, will promote circadian alignment and reduce days of delirium

Official Title
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Daytime Bright Light, Circadian Abnormalities, and Delirium in Medical ICU Patients

Conditions
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Circadian Rhythm Disorders

Intervention / Treatment
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* Device: Daytime Bright Light
* Device: Usual Light


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Hospital admission ≤30 hours at noon on enrollment day Expected to say in the Medical Intensive Care Unit (MICU) ≥24 hours after enrollment Age ≥50 years Exclusion Criteria: At significant risk for pre-existing circadian abnormalities: Severe chronic brain injury (Injury greater than 30 days ago resulting in the inability to live independently) Acute brain injury of any severity (Injury less than 30 days ago including acute intracranial bleed, traumatic brain injury, central nervous system infection, tumor) Documented circadian disorder or blind/disease of the optic nerve Current history of substance abuse including alcohol (use in last 30 days) 3. Transferred from an outside hospital. 4. History of bipolar disease 5. Paralyzed (due to injury, disease or medications) Enrolled patients who do not stay in the MICU through 13:00 of Study Day 2 will be excluded; patients transferred from the MICU to the floor between 22:00 and 05:00 on subsequent study nights will continue in the study but be excluded from the primary analysis (estimated 10% of patients).

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomized controlled trial with 2 cohorts
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Bright Light<br>Intervention: Daytime Bright Light Patients will be eligible if they were admitted within 30 hours of noon on enrollment day (e.g. at or after 06:00 on the prior calendar day). Enrollment will occur before noon, and the day of enrollment is termed study day 1. Patients will undergo monitoring (light levels, circadian alignment), starting on study day 1. Patients will be exposed to bright light from 09:00 to 13:00 starting on study day 2 and continuing through study day 5 or MICU discharge whichever is longer up to 30 days. Bright light exposure will occur in the Intensive Care Unit (ICU) and on the floor, if the patient is transferred (prior to study day 5). Feasibility metrics will also be collected. | Device: Daytime Bright Light<br>* Daytime Bright Light (DBL) will be delivered by a free-standing apparatus set to deliver 10,000 lux. The device will be placed at the bedside within 36 inches of the patient's head and is expected to provide at least 1,250 lux at the angle of gaze. To remain in the study, the patient must be in the Intensive Care Unit (ICU) through 13:00 on day 2 (e.g., the first day of potential intervention). After day 2, DBL and other study activities will continue if the patient is transferred out of the ICU to the general medical floor.<br>|
| Active Comparator: Usual Light<br>Intervention: Usual Care Patients will be eligible if they were admitted within 30 hours of noon on enrollment day (e.g. at or after 06:00 on the prior calendar day). Enrollment will occur before noon, and the day of enrollment is termed study day 1. Patients will undergo monitoring (light levels, circadian alignment), but otherwise, have usual care. | Device: Usual Light<br>* Usual care lighting in ICU. To remain in the study usual care patients must also remain in the MICU through 13:00 on day 2.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circadian Alignment | The primary circadian outcome will be the proportion of daytime activity out of total activity (daytime proportion). Rest-activity patterns will be measured with the Actiwatch Spectrum (Philips Healthcare, Netherlands) set at 30-second epochs and placed on the patient's wrist. Enrolled patients who do not stay in the MICU through 13:00 of Study Day 2 will be excluded from all analysis. | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Days of Delirium | The approach is to measure days of delirium in our patient cohort. After enrollment, the investigators will check patients daily for delirium until hospital discharge or day 30. | Study Day 1-30 (patients will be censored at hospital discharge) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circadian Alignment, Secondary Measures, Body surface temperature gradient | The investigators will include additional measures of circadian alignment in our analysis: continuous body surface temperature gradient. | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Circadian Alignment, Secondary Measures, Continous Heart Rate | The investigators will include additional measures of circadian alignment in our analysis: continuous heart rate. | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Circadian Alignment, Secondary Measures, urinary 6-sulfatoxymelatonin. | The investigators will include additional measures of circadian alignment in our analysis: urinary 6-sulfatoxymelatonin (for patients making sufficient urine and with an indwelling urinary catheter). | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Feasibility, Patient Acceptance | Percent of patients/surrogates who agree to bright light when initially described to them. | Study Day 1 | 
| Feasibility, Patient Tolerance Time | Percent of intended treatment hours that patient continues with the delivery of bright light once exposed to bright light. | Study Day 2-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Feasibility, Patient Tolerance Symptoms | Percent of patients who develop eyestrain, headache or visual disturbance (combined outcome). | Study Day 2-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Feasibility, Intervention Fidelity | Percent of time per day that device delivers the planned dose of light. | Study Day 2-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Feasibility, Intervention Sustainability | Percent of intended intervention days that the device is used. For this metric, days that the patient refuses bright light will not be included in intended intervention days. | Study Day 2-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Total Sleep | The investigators will measure (and control for) the total amount of sleep (sleep quantity) via actigraphy. | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 
| Sleep Efficiency | The investigators will measure (and control for) overnight sleep efficiency (sleep quality) via actigraphy. | Study Day 1-30 (to study day 5 or MICU discharge whichever is longer, patients will be censored at hospital discharge). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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circadian misalignment, bright light, entrainment, zeitgeber, critical illness, delirium, actigraphy