Improving the Sleep and Circadian Rhythms of Mechanically Ventilated Patients

Study Overview
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Brief Summary
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The goal of this project is to determine whether the sleep and circadian rhythms of critically ill patients undergoing mechanical ventilation can be improved through practical strategies that can be employed at the bedside.

Detailed Description
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Nearly 1 million patients develop respiratory failure annually in the United States; yet, the sleep of patients undergoing mechanical ventilation has received little attention. This project is designed to characterize sleep and circadian rhythmicity in critically ill patients and to explore the efficacy of a non-pharmacological intervention to improve sleep and normalize circadian phase. The study will examine the effect of a protocol employing noise reduction and enforcement of a robust light-dark cycle on sleep quality and circadian rhythmicity. A secondary analysis will examine the relationship between delirium and sleep disruption and loss of circadian rhythmicity. Circadian rhythmicity will be characterized through the measurement of urinary 6-sulfatoxymelatonin levels at frequent intervals, while sleep will be assessed using continuous polysomnography.

Official Title
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Improving the Sleep and Circadian Rhythms of Mechanically Ventilated Patients

Conditions
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Critical Illness, Sleep Deprivation, Respiratory Failure, Sleep Disorders, Circadian Rhythm

Intervention / Treatment
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* Behavioral: Sleep and circadian rhythm promotion
* Behavioral: Usual care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 years or older Receiving mechanical ventilation and intravenous sedation Exclusion Criteria: Debilitating central nervous system disease or degenerative disorder Active seizures Persistent coma Renal failure requiring dialysis Expected to be extubated within 24 hours Currently receiving neuromuscular blocker

Ages Eligible for Study
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Minimum Age: 18 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sleep promotion protocol<br>Behavioral: 48 hours of sleep and circadian rhythm promotion including timed light exposure. | Behavioral: Sleep and circadian rhythm promotion<br>* This multifaceted intervention attempts to enhance sleep and circadian rhythmicity through improved scheduling of nursing procedures, enforcement of a day/night routine, increased light exposure during the day, and decreased light and sound exposure during the night. The intervention began the morning after enrollment and enforced a specific period of enhanced light exposure from 9:00 a.m. to noon. The initial target of 5,000 lux administered by light box (Sunsation, SunBox Co.) was reduced to 400-700 lux after the first 10 subjects were enrolled in the study.<br>|
| Active Comparator: Usual care<br>Behavioral: 48 hours of usual care. | Behavioral: Usual care<br>* Usual care.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circadian Timing | The magnitude of the phase change in 6-sulfatoxymelatonin excretion between Day 1 and Day 3 will be compared between the intervention and usual care groups. This is done by comparing, for each group, the timing of the best-fit maximum on Day 1 with the timing of the best-fit maximum on Day 3. The result is expressed in hours. A positive value represents a phase advance from Day 1 to Day 3 (e.g. an earlier occurrence of maximum excretion on Day 3 when compared with Day 1), while a negative value represents a phase delay from Day 1 to Day 3 (e.g. a later occurrence of maximum excretion on Day 3 when compared with Day 1). | Day 1 to Day 3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Normal Circadian Timing | The percentage of subjects who exhibit normal circadian timing of 6-sulfatoxymelatonin excretion on Day 3 will be compared between the intervention and usual care groups. | Day 3 | 
| Circadian Amplitude | The amplitude (e.g. one half the value from peak to trough of the fitted cosine curve) of the circadian rhythm of 6-sulfatoxymelatonin on Day 3 will be compared between the usual care and intervention groups. | Day 3 | 
| Spectral Edge Frequency 95% | The difference between the polysomnographically derived daytime and nocturnal spectral edge frequency 95% parameter will be used as a measure of increased diurnal sleep/wake activity. This parameter will be compared between the usual care and intervention groups. | Day 2 | 
| Delirium | The percentage of patients who are delirious at the conclusion at the study will be compared between the intervention and usual care groups. | Day 3 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Critical illness, Sleep, Polysomnography, Respiratory failure, Circadian rhythm, Sedation