The impact of light adjustment versus tuneable white mode on ICU staff’s circadian rhythms

The significance of lighting design in intensive care units (ICUs) for healthcare professionals’ demanding work and its profound impact on health, visual comfort and overall well-being cannot be overstated. This study investigates the potential of controlling luminous flux and spectral characteristics to enhance ICU lighting environments. It aims to determine whether modifying the lighting spectrum positively affects health without compromising visual comfort and colour discrimination. Two distinct LED lighting configurations were tested. The first adjusted only light levels, providing insights into staff responses. The second used tuneable white lighting, allowing changes in spectral content and colour temperature throughout shifts, resembling natural light variations. Effects were assessed via subjective perception surveys and objective colour rendering tests. Physiological impacts were evaluated through urine and blood samples, analysing melatonin suppression and cortisol levels, crucial for regulating rhythms and stress. Results offer valuable insights into lighting’s impact on ICU occupants’ well-being, highlighting the potential benefits of spectral adjustments while maintaining visual comfort and colour discrimination. This holistic approach to lighting design in critical care settings emphasizes the importance of balancing health benefits with lighting quality.