Delirium in Adults With COVID-19–Related Acute Respiratory Distress Syndrome: Comparison With Other Etiologies

BACKGROUND AND OBJECTIVES: Neurologic complications have been associated with COVID-19, including delirium. Such complications have been reported to be frequent among intensive care unit (ICU)-admitted patients. We hypothesized that the rate of neurologic complications would be higher in COVID-19 associated acute respiratory distress syndrome (ARDS) than those who develop ARDS from a different cause. METHODS: We conducted a retrospective cohort study in the adult ICU of Lausanne University Hospital, including all consecutive patients fulfilling the Berlin criteria for ARDS hospitalized between December 2017 and June 2021, stratifying exposure between COVID-19 or not. The primary outcome was delirium onset during ICU stay, defined by the confusion assessment method (CAM-ICU). Exploratory outcomes included development of neurologic complications of the central nervous system (stroke, hemorrhage, and vasculitis), critical illness weakness, and 30- and 180-day all-cause mortality. RESULTS: Three hundred eleven patients were included in the study (253 with COVID-19 and 58 with other causes) and CAM-ICU could be assessed in 231 (74.3% in COVID-19 vs 74.1% in non-COVID-19). The proportion of patients developing delirium was similar in patients with COVID-19 and controls in univariate comparison (69.1% vs 60.5%, p = 0.246). Yet, patients with COVID-19 had a higher body mass index, lower ICU severity, longer mechanical ventilation, and higher sedation doses (propofol and dexmedetomidine). After adjusting for these factors in a multivariable analysis, the risk of delirium remained comparable across groups (adjusted OR [95% CI]: 0.86 [0.35–2.1]). Similarly, COVID-19–related ARDS had no effect on all-cause mortality at 30 days (adjusted OR: 0.87 [0.39–1.92]) and 180 days (adjusted OR: 0.67 [0.33–1.35]). Finally, neurologic complications affecting the CNS (adjusted OR: 1.15 [0.25–5.29]) and critical illness weakness (adjusted OR: 2.99 [0.97–9.1]) were not higher in the COVID-19 group. DISCUSSION: Compared with other etiologies, patients with COVID-19 did not have higher incidence of delirium and other neurologic complications, after accounting for underlying disease severity in patients with ARDS. Management of COVID-19–associated ARDS needed longer invasive ventilation and higher sedation, which could explain higher rates of delirium in uncontrolled studies.