Intensive care unit delirium in patients with severe COVID-19: A prospective observational cohort study

Ryan J. Smith, Christian Lachner, Vijay P. Singh, Rodrigo Cartin-Ceba

Research output: Contribution to journalArticlepeer-review


Background: Delirium is common in patients with severe coronavirus disease-19 (COVID-19). The purpose of our study was to determine whether severe COVID-19 is an independent risk factor for the development of delirium in patients treated in the intensive care unit (ICU). Methods: This prospective observational cohort study involved 162 critically ill patients admitted to a multidisciplinary ICU during 2019 and 2020. A validated screening tool was used to diagnose delirium. Multiple delirium risk factors were collected daily including clinical characteristics, hospital course, lab values, vital signs, surgical exposure, drug exposure, and COVID-19 characteristics. After univariate analysis, a multivariate logistic regression analysis was performed to determine independent risk factors associated with the development of delirium. Results: In our study population, 50 (31%) patients developed delirium. A total of 39 (24.1%) tested positive for COVID-19. Initial analysis showed COVID-19 to be more prevalent in those patients that developed delirium (40% vs. 17%; P = 0.003). Multivariate analysis showed opioid use (odds ratio [OR]: 24 [95% confidence intervals (CI): 16-27]; P ≤ 0.001), benzodiazepine use (OR: 23 [95% CI: 16-63] P = 0.001), and estimated mortality based on acute physiology and chronic health evaluation IV score (OR: 1.04 [95% CI: 1.01-1.07] P = 0.002) to be independently associated with delirium development. COVID-19 (OR: 1.44 [95% CI: 0.13-10.6]; P = 0.7) was not found to be associated with delirium. Conclusion: Delirium is prevalent in critically ill patients admitted to the ICU, including those with COVID-19. However, after adjustment for important covariates, we found in this cohort that COVID-19 was not an independent risk factor for delirium.

Original languageEnglish (US)
Pages (from-to)61-69
Number of pages9
JournalInternational Journal of Critical Illness and Injury Science
Issue number2
StatePublished - Apr 1 2022


  • Coronavirus disease-19
  • delirium
  • encephalopathy
  • intensive care unit
  • neuroinflammation
  • severe acute respiratory syndrome coronavirus 2

ASJC Scopus subject areas

  • Emergency Medicine
  • Public Health, Environmental and Occupational Health
  • Critical Care and Intensive Care Medicine


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