The Effects of Bright Light Exposure on ICU Nurses

NCT03331822 | Completed

• 1 other identifier: PRO17010109
• Study Type: interventional
• Target: 31
• Locations: 1 country
• Sites: 1

Brief Summary

In the majority of intensive care units, nurses work 12 hour shifts that consist of days and nights. Shift work outside of 6am-6pm has been reported to cause fatigue, induce sleep disorders, and cause metabolic disturbances. This shift to a nocturnal 'day' rather than diurnal, can result in reduced work performance, processing errors, accidents at work, absenteeism, and reduced quality of life. More chronically, those working at night have been shown to experience higher risks of heart disease, cancer and shorter median durations of life span. Much of this elevated risk is thought to be due to altered exposure to light, the dominant environmental cue regulating our circadian rhythms. As diurnal organisms much of our biology is regulated by the solar day. Acutely, bright light exposure (i.e., sun) regulates the phase of the biological clock principally through the suppression of melatonin, which biologically mediates increased alertness and in essence, 'our daytime alertness'. During the night melatonin gradually increases and induces tiredness and ultimately sleep. This, in part, is biology behind the use of melatonin in those with sleep disturbances or to mitigate jet lag, with cross-continental or transoceanic flights. In this study, the investigators will randomize nurses in the hospital to receive either high intensity white light (3,000 lux) or standard ambient white fluorescent (\~400 lx) light for 10 hours during their night shift. This high illuminance light, rich in blue spectrum, is what diurnal creatures, like humans, are exposed to during the day. The lights may subsequently be equipped with blue filters (442 nm) to heighten the exposure to the rich blue spectrum light. Exposure will commence at the beginning of the night shift (\~7pm) and continue for 10 hours. The rationale for terminating exposure prior to shift end is to foster an onset of sleep biology. At the end of each shift, the nurses will complete the Stanford Sleepiness Scale and the Psychomotor Vigilance Task (PVT). Saliva samples will be collected for melatonin level analysis and the nurses will complete sleep diaries at home. The investigators hypothesize that exposure to high intensity lighting during night shifts will reduce fatigue and enhance alertness and computational capacity that correlates with reduced melatonin.

Conditions

Circadian Rhythm Disorders; Sleep

Keywords

circadian; light therapy; ICU nurse

Outcome Measures

Primary Outcomes (2)

• Psychomotor Vigilance Task

  This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded.

  Immediately at the end of the night shift worked.

• Stanford Sleepiness Scale

  It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials.

  Immediately at the end of the night shift worked.

Secondary Outcomes (2)

• Consensus Sleep Diary

  Throughout the course of the study for the night immediately following the night shift worked.

• Salivary melatonin concentration

  Immediately at teh end of the night shift worked.

Study Arms (2)

Light

EXPERIMENTAL

High illuminance ,white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux.

Other: Bright Light

No Light

NO INTERVENTION

Ambient, standard white fluorescent environmental light will serve as control.

Interventions

Bright Light OTHER

high illuminance white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux. To achieve this illuminance, a Day\*Light Classic Light will be positioned at each nursing station in the ICU hallway.

Light

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• All ICU nurses working at the University of Pittsburgh Trauma ICU.

You may not qualify if:

• Not working nights

Sponsors & Collaborators

• University of Pittsburgh: lead

Study Sites (1)

Matthew R. Rosengart

Pittsburgh, Pennsylvania, 15217, United States

Location

Related Publications (1)

• Griepentrog JE, Labiner HE, Gunn SR, Rosengart MR. Bright environmental light improves the sleepiness of nightshift ICU nurses. Crit Care. 2018 Nov 13;22(1):295. doi: 10.1186/s13054-018-2233-4.

  PMID: 30424793 DERIVED

MeSH Terms

Conditions

Chronobiology Disorders

Condition Hierarchy (Ancestors)

Nervous System Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: This is randomized crossover trial, in which each nursing subject will serve as his or her own control: i.e., matched. The subjects will be nurses from the 6FG Trauma Intensive Care Unit at UPMC Presbyterian hospital.

Study Record Dates

• First Submitted: November 1, 2017
• First Posted: November 6, 2017
• Study Start: October 15, 2017
• Primary Completion: December 1, 2017
• Study Completion: December 31, 2017
• Last Updated: December 14, 2018

Record last verified: 2018-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)