Delirium in hospitalized patients with COVID-19 pneumonia: a prospective, cross-sectional, cohort study

Delirium is an acute confusional state characterized by altered level of consciousness and attention. Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), can manifest itself with this neuropsychiatric disorder. The endpoints of our study were: the frequency of delirium in subjects with COVID-19 pneumonia; the risk factors that predispose to this condition; and the impact of delirium on mortality. Subjects were consecutively enrolled in a Geriatric Unit from January 5th to March 5th, 2021. Inclusion criteria were: diagnosis of SARS-CoV-2 infection, a radiologically documented pneumonia, and the ability of providing informed consent. Exclusion criteria were: absence of radiological evidence of pneumonia, sepsis, and the need of intensive care unit treatment. All subjects were evaluated by means of Richmond Agitation Sedation Scale (RASS) and Confusion Assessment Method-Intensive Care Unit (CAM-ICU) at least twice per day. In the study cohort (n = 71), twenty patients (28.2%) had delirium. Delirium was present on admission in 11.3%, and occurred during hospitalization in 19.0%. Compared to patients without delirium, patients who developed this neuropsychiatric disorder had a higher mortality rate (35% vs 5.9%) and an increased average hospital length of stay (21 days vs 17 days). In the multivariate analysis delirium was associated with frailty (OR = 2.81; CI = 1.4-5.8) and helmet ventilation (OR = 141.05; CI = 4.3-4663.9). Delirium was an independent predictor of mortality. Nearly a third of subjects (28.2%) had delirium during hospitalization for COVID-19. This finding supports the notion that delirium is a common complication of SARS-CoV2 infection. Since delirium is associated with longer hospital stay, and it is an independent marker of increased mortality, clinicians should assess and prevent it.