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

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

Study Overview

• Status: Completed
• Conditions: Circadian Rhythm Disorders
• Intervention / Treatment: Device: Daytime Bright Light; Device: Usual Light

Detailed Description

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

• Study Type: Interventional
• Enrollment (Actual): 68
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06520
      • Yale New Haven Hospital, York Street Campus

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Hospital admission ≤30 hours at noon on enrollment day
2. Expected to say in the Medical Intensive Care Unit (MICU) ≥24 hours after enrollment
3. Age ≥50 years

Exclusion Criteria:

1. 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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bright Light; 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; 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.
Active Comparator: Usual Light; 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; 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.

What is the study measuring?

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).

Collaborators and Investigators

• Sponsor: Yale University
• Investigators: Principal Investigator: Melissa Knauert, MD, PhD, Yale University

Study record dates

Study Major Dates

• Study Start (Actual): July 8, 2019
• Primary Completion (Actual): March 28, 2024
• Study Completion (Actual): March 28, 2024

Study Registration Dates

• First Submitted: June 5, 2018
• First Submitted That Met QC Criteria: September 21, 2018
• First Posted (Actual): September 25, 2018

Study Record Updates

• Last Update Posted (Actual): May 23, 2024
• Last Update Submitted That Met QC Criteria: May 21, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: delirium; critical illness; actigraphy; entrainment; bright light; circadian misalignment; zeitgeber
• Additional Relevant MeSH Terms: Mental Disorders; Nervous System Diseases; Neurologic Manifestations; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Chronobiology Disorders
• Other Study ID Numbers: 2000023033; 000 (Other Identifier: YCTG)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes