Effect of bright light on shift work nurses in hospitals

Area of Science:

• Chronobiology
• Occupational Health
• Light Therapy

Background:

• Shift work disrupts circadian rhythms, impacting health and performance.
• Hospital settings present unique challenges for shift worker well-being.
• Understanding interventions to mitigate shift work's negative effects is crucial.

Purpose of the Study:

• To evaluate the impact of Bright Light (BL) exposure on physiological and subjective measures in hospital nurses.
• To assess BL's effects on body temperature, melatonin, cortisol, and alertness during night shifts.

Main Methods:

• 34 healthy nurses participated in a four-week study involving controlled BL exposure (4500 lux) during night shifts.
• Measurements included plasma melatonin and cortisol at 3-hour intervals, body temperature, and subjective alertness (Karolinska Sleepiness Scale, Visual Analog Scale).

Main Results:

• Bright Light (BL) significantly suppressed nighttime melatonin levels.
• BL exposure showed a trend towards increased cortisol levels and body temperature.
• Subjective alertness was significantly improved during night shifts with BL intervention.

Conclusions:

• Photic stimulation, specifically Bright Light (BL), can effectively influence circadian system adjustment in a hospital environment.
• BL therapy offers a potential strategy to improve shift worker adaptation and well-being.