Introduction

Delirium is the most frequent psychiatric syndrome in the Intensive Care Unit (ICU). This form of acute brain dysfunction predicts higher mortality rates and is associated with worse global cognition after ICU discharge \cite{Ely2004,Pandharipande2013}.  Therefore, delirium prevention bundles have become an integral part of guideline recommendations. Clinical trials investigating pharmacological strategies have failed to demonstrate consistent results in terms of patient outcomes. Hence, focus has moved towards non-pharmacological approaches. 

Objective

Within an interdisciplinary project, we developed a new ICU room concept . In 2013 we finished the renovation of 2 double ICU rooms (Fig. \ref{435085} and \ref{787204}).  Beside interventions aimed at noise reduction, workflow optimisation and infection control, we developed a new light ceiling that enables clinicians to apply patient individualised light therapy \cite{Luetz2016a,alawi2016}. We hypothesised that the delirium incidence for patients treated in the modified rooms is significantly lower when compared to patients treated in the standard rooms.