Delirium in COVID-19 patients admitted to an infectious diseases intensive care unit

Background and aims: COVID-19 is a respiratory disease caused by SARS-CoV-2. Nevertheless, neurological complications have been described. Delirium, seems frequent, prolonged, and difficult to control. Methods: To evaluate the prevalence and characteristics of delirium in a cohort of critically ill patients with COVID- 19, compared to a historical cohort of critically ill patients with other respiratory infections. Retrospective comparative analysis of demographic, clinical and laboratory data from two cohorts: patients admitted to an Infectious Diseases Intensive Care Unit (IDICU) with COVID-19 and for other respiratory infections in 2018-2019. Olanzapine equivalent dosages of antipsychotics necessary to control delirium was used as a severity marker. Results: We included 114 patients (74 COVID-19 and 40 non-COVID-19). The COVID-19 cohort presented with a statistically significant higher median age of 67 years old and a slight male predominance (56.8%). Previous neurological disease was present in 12.2%. Delirium developed in 45.9% of which, lasted a median of four days and needed a median of 10mg/day of olanzapine equivalents to control. Samples were matched to sex, previous neurological disease and use of benzodiazepines/ antipsychotics. There was no difference in prevalence of delirium or its duration between cohorts (p>0.05). In patients with delirium the univariate analysis demonstrated a difference in the severity of delirium (p=0.045). In a model of multiple logistic regression, COVID-19 was associated with increased severity of delirium (p≤0.001) adjusted for confounding factors. Conclusion: COVID-19 is not associated with higher prevalence or duration of delirium. However, it seems to be associated with severe forms with increasing doses of antipsychotics needed its control.