Delirium in the ICU means badness as delirious ICU patients are associated with longer stay and higher mortality. While medications are not proven to prevent delirium, certain environmental interventions such as window access, light and sound levels have been recognized as legit interventions to prevent ICU delirium.

Settings: This is a retrospective study at Massachusetts General Hospital 
Participants: 3527 patients admitted to a surgical ICU between 2020 and 2023.
Outcome measurement: This study hypothesized that patients in a windowed ICU room will have lower rates of delirium, decreased ICU length of stay, hospital LOS. Multivariable logistic regressions were performed for the association of clinical variables and the presence of delirium.
Study Results: 
Delirium was observed in 460 patients (21%) of the windowed rooms group and 206 patients (16%) of the nonwindowed rooms group. Multivariable logistic regression showed that patients in windowed rooms were associated with higher odds of delirium (aOR, 1.29; 95% CI, 1.07–1.56; p = 0.008), although they were not associated with longer ICU LOS or longer HLOS
Discussion:
The study’s findings added to the literature that natural lighting might not be the effective prevention of delirium. The presence of windows might not be the answer. 
In this study, all the windows were facing another building, and there was no view of other natural scenes, with a limited view of the sky. Therefore, the authors suggested that the overall quality of the windows would be more important.

Conclusion: 
The ICU environment is more important for patients’ delirium than just the presence of windows.

References

Anderson DC, Warner PE, Smith MR, Albanese ML, Mueller AL, Messervy J, Renne BC, Smith SJ. Windows in the ICU and Postoperative Delirium: A Retrospective Cohort Study. Crit Care Med. 2025 Jan 13. doi: 10.1097/CCM.0000000000006557. Epub ahead of print. PMID: 39791968.