Study Reveals Impact of Light and Noise on ICU Work Environments

A recent study conducted in an intensive care unit (ICU) in Tokyo, Japan, highlights the critical role of environmental factors like lighting and noise in influencing healthcare workers’ productivity and satisfaction. The three-month investigation, led by Assistant Professor Wataru Umishio at Science Tokyo, found that inadequate natural light and excessive ambient noise significantly detracted from the work experience of ICU staff.

The findings suggest that enhancing the design of ICUs to incorporate more natural light and effective noise reduction could improve not only employee satisfaction but also the quality of patient care. The research aligns with broader efforts, including reforms initiated by the Japanese Ministry of Health, Labor, and Welfare, aimed at improving healthcare worker well-being and reducing exhaustion related to overwork.

ICU environments are often characterized by high noise levels due to life-support machines and the rapid movement of healthcare staff. These elements contribute to a stressful atmosphere, which can lead to diminished productivity and increased risk of errors. The study emphasizes that addressing these environmental challenges is essential for enhancing both worker performance and patient outcomes.

Since April 2024, the Ministry has focused on capping work hours for physicians. However, improving indoor environmental quality (IEQ) is equally crucial in addressing healthcare workers’ fatigue. The Japanese Society of Intensive Care Medicine (JSICM) has established guidelines aimed at minimizing patient discomfort, which could also alleviate stress for healthcare professionals in ICUs. These guidelines set minimum levels for lighting, maximum ambient noise levels, and acceptable ranges for temperature and humidity.

The research team conducted field measurements across four IEQ domains—thermal, lighting, acoustic, and air quality—while also collecting subjective feedback through questionnaires from ICU staff. The study, which took place from July to September 2023, revealed that while air quality metrics for CO2 and particulate matter (PM 2.5) remained within recommended limits, other factors fell short of expectations.

The light illuminance exceeded the JSICM’s recommended minimum, but there was significant variability between areas with sufficient natural daylight and those lacking it. Conversely, noise levels were found to be consistently above the recommended guideline range, and temperatures in single-bed rooms were approximately 3 °C below what is deemed comfortable.

Survey responses reflected these findings, with over 60% of healthcare professionals expressing dissatisfaction with the ICU’s overall IEQ. Specifically, satisfaction levels related to thermal, lighting, and acoustic environments were notably low. Alarmingly, none of the respondents reported positive feelings about the acoustic environment, with approximately 75% indicating dissatisfaction, particularly with noise from medical equipment and insufficient natural light.

The implications of these findings are significant. They point to a need for thoughtful ICU design that prioritizes aspects such as daylight access and effective acoustic treatment. As Umishio notes, “Prioritizing daylight/circadian-supportive lighting and robust acoustic mitigation—implemented through coordinated efforts between architectural environmental engineering and critical care teams—offers a practical pathway to enhance staff experience and productivity while maintaining patient-centered care.”

The full study is detailed in the journal Intensive and Critical Care Nursing. These insights may help guide future designs and policies aimed at creating more supportive environments for healthcare workers in ICUs, ultimately benefiting both staff and patients alike.