Which category includes lack of visible daylight as a risk factor?

• A. Environmental factors
• B. Clinical factors
• C. Devices
• D. Sedation

Answer: (A)

Lack of visible daylight is about the surroundings and how the patient experiences the ICU environment, making it an environmental factor. Daylight helps regulate the body's circadian rhythm, promoting daytime alertness and nighttime sleep through proper melatonin signaling. In the ICU, insufficient daylight or constant artificial lighting disrupts this rhythm, increasing the risk of delirium, sleep disturbance, and reduced participation in mobilization.

Clinical factors refer to the patient’s medical conditions (like infection or organ failure), devices involve lines and monitors, and sedation involves drugs that dull awareness. Since lack of daylight stems from the environment rather than the patient's illness, equipment, or sedation, it fits best under environmental factors.