× You are not currently logged in. To receive all the benefits our site has to offer, we encourage you to log in now.

Lighting, sleep and circadian rhythm: An intervention study in the intensive care unit

Originally Published:
2015
Key Point Summary
Key Point Summary Author(s):
Zborowsky, Terri
Share
Key Concepts/Context

Regular daylight and night darkness provided over 24 hours is important for human health in supporting the body’s circadian rhythm. Intensive care unit (ICU) patients are not exposed to this naturally occurring cycle and as result can suffer from sleep deprivation and are at risk for ICU delirium. As these patients are at their most vulnerable in a hospital, it is important that the environment support a restorative process.

Objectives

The objective of this paper was to study ICU patient environment with regard to sleep, rest, and circadian rhythms.

Methods

This study was part 2 of study that had an explorative and descriptive design based on data derived from 19 interviews, subjected to qualitative and quantitative content analysis. The study was conducted in an eight-bed general ICU in a regional hospital in Sweden in which a new cycled lighting intervention was designed to promote circadian rhythm and health. The system was installed and used in a modified two-bed patient room (intervention room). An identical two-bed patient room was left untouched for comparison (ordinary room). Patients were randomly assigned to the rooms. The lighting in the intervention room ranged from 2 to 615 lux—cycled throughout the day to mimic daylight and nighttime darkness. The lighting in the control room ranged from 0.07 to 810 lux and was dependent on the lighting fixture activated at any given moment. Part 1 of the study was a comparative, descriptive study using a questionnaire. Part 2 was an explorative and descriptive study based on data analyzed from 19 patient interviews that were subjected to qualitative and quantitative analysis.

Design Implications
How light impacts and entrains our circadian rhythms is a relatively new area of study that has enormous implications for healthcare designers. This population studied in this paper is one of the most vulnerable in the hospital. There may be ways to affect their outcomes based on this research. Designers should consider how their designs may be used to enable the best access to daylight and darkness, as well as how artificial light can mimic this natural cycle of life.
Findings

Patients’ experience of lighting/light in the intervention room was grouped into four major  categories. ‘A dynamic lighting environment’ was described as experiences such as pleasantness, levels of lightings, and variation. The ‘impact of lighting on patients’ sleep’ was described as experiences of sleep and how light is related to sleep. Patients emphasized the importance of sleep for recovering and regaining health. The‘impact of lighting/lights on the circadian rhythm was described as patients’ experiences concerning circadian rhythm and its relationship to light. The patients had diverse perceptions of the regularity of day and night. ‘The lighting calms’ was described as how the lighting clarified the environment and how anxiety was alleviated by light.

Limitations

This study represents an exploratory study with a small sample population (n=19) and therefore the results cannot be generalized to another population.

Environmental Condition Category
Lighting
Key Point Summary Author(s):
Zborowsky, Terri
Primary Author
Engwall, M.