Effect of a Nurse-Led Environmental Stressor Reduction Package on Perceived Stress and Sleep Quality in Intensive Care Unit Patients

This semi-experimental study is designed to investigate the effect of a nurse-led "Environmental Stressor Reduction Package" on patients' perception of environmental stress and their sleep quality in the intensive care unit (ICU).

The intervention package includes five core components:

Noise control: Environmental sound levels will be maintained at ≤45 dB during night hours using a portable sound level meter (Benetech GM1351). Non-critical alarms will be silenced or reduced by 50%, and staff will be reminded to minimize unnecessary conversations at the bedside.

Lighting adjustment: Circadian rhythm-oriented lighting will be supported by turning off unnecessary bedside lights during sleep periods, using curtains to block external light, and providing patients with eye masks when needed.

Thermal comfort: As central air conditioning cannot be individually adjusted, tympanic temperature will be monitored and blankets or portable warmers will be used to ensure comfort.

Visitor regulation: No visitors will be allowed after 22:00, and physicians' or staff communications will be conducted as quietly as possible during patients' rest periods.

Nursing care organization: Routine nursing interventions such as hygiene care or repositioning will be scheduled before 22:00 whenever feasible, to minimize sleep interruption between 22:00 and 06:00.

The structured "Quiet Night Checklist" developed by the research team will be used to monitor the fidelity of the intervention. The checklist will be completed at 22:00, 02:00, and 06:00, covering all intervention domains. Each item is scored on a 3-point Likert scale (1 = not implemented, 2 = partially implemented, 3 = fully implemented).

Data collection will be carried out over a minimum of two and up to five consecutive nights of ICU stay, depending on patients' clinical course. The intervention group will receive the package, while the control group will continue to receive standard ICU care.

The primary outcome will be the change in patients' perceived environmental stress, measured by the Intensive Care Unit Environmental Stressor Scale (ICUESS), a validated 42-item instrument. The secondary outcome will be self-reported sleep quality, measured by the Richards-Campbell Sleep Questionnaire (RCSQ), a validated 5-item visual analogue scale. Both instruments have validated Turkish versions (Toptas et al., 2018; Demir et al., 2021).

It is anticipated that the intervention will reduce patients' stress perception and improve sleep quality compared to standard care. The findings will contribute to evidence-based nursing practices in ICU environments, highlighting the role of structured, nurse-led environmental modifications in improving patient outcomes.

Inclusion criteria

• Adults aged 18 years and older

Patients admitted to the intensive care unit (ICU)

Awake and able to communicate (not under sedation or mechanical ventilation)

Expected to remain in the ICU for at least 2 consecutive nights

Voluntary participation with written informed consent

Exclusion criteria

• Patients under 18 years old

Patients diagnosed with delirium or severe cognitive impairment

Patients with a history of psychiatric illness affecting sleep or stress perception

Patients under continuous sedative or opioid infusion

Patients discharged from the ICU or deceased before completing the intervention period (2-5 nights)