Transforming Intensive Care Unit Environments Through Human-Centred Design: A Mixed-Methods Retrofit Study of Noise and Lighting Interventions

Survival following intensive care unit (ICU) admission continues to improve globally; however, increasing attention has been directed toward the detrimental effects of ICU environments on patients, families, and healthcare staff.Excessive noise, inappropriate lighting, sensory deprivation, and limited opportunities for personalisation contribute to sleep disturbance, delirium, psychological distress, and prolonged recovery.A mixedmethod, multi-stage participatory design approach was undertaken, guided by the action effect method and the Consolidated Framework for Implementation Research.Qualitative interviews with patients, family members, and clinicians were combined with objective environmental assessments and evidence synthesis to identify priority design challenges.Two ICU bedspaces were retrofitted within a live clinical unit through iterative stakeholder consultation, full-scale prototyping, and integration of architectural, technological, and workflow innovations.The redesigned bedspaces incorporated multilayered acoustic treatments, noise-blocking room configurations, bespoke circadian lighting systems, virtual access to nature, enhanced patient engagement technologies, and flexible clinical layouts.Early post-implementation evaluations demonstrated substantial improvements in acoustic performance, reduced perceived alarm noise, and lighting conditions more closely aligned with natural circadian rhythms compared with conventional ICU environments.Optimising ICU bedspace environments through participatory, evidence-informed design is achievable even within retrofit constraints.Improvements in noise and lighting transformed the ICU setting from a passive stressor into an active contributor to care quality.However, findings are based on two retrofitted bedspaces and short-term environmental evaluation, and therefore should be interpreted as exploratory.