Factors associated with a persistent delirium in the intensive care unit: A retrospective cohort study

Purpose: To explore differences between ICU patients with persistent delirium (PD), non-persistent delirium (NPD) and no delirium (ND), and to determine factors associated with PD. Materials and methods: Retrospective cohort study including all ICU adults admitted for >_12 h (January 2015- February 2020), assessable for delirium and followed during their entire hospitalization. PD was defined as >_14 days of delirium. Factors associated with PD were determined using multivariable logistic regression analysis. Results: Out of 10,295 patients, 3138 (30.5%) had delirium, and 284 (2.8%) had PD. As compared to NPD (n = 2854, 27.7%) and ND (n = 7157, 69.5%), PD patients were older, sicker, more physically restrained, longer comatose and mechanically ventilated, had a longer ICU and hospital stay, more ICU readmissions and a higher mortality rate. Factors associated with PD were age (adjusted odds ratio [aOR] 1.03; 95% confidence interval [CI] 1.02-1.04); emergency surgical (aOR 1.84; 95%CI 1.26-2.68) and medical (aOR 1.57; 95%CI 1.12-2.21) referral, mean Sequential Organ Failure Assessment (SOFA) score before delirium onset (aOR 1.18; 95%CI 1.13-1.24) and use of physical restraints (aOR 5.02; 95%CI 3.09-8.15). Conclusions: Patients with persistent delirium differ in several characteristics and had worse short-term outcomes. Physical restraints were the most strongly associated with PD. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).