Delirium During COVID-19 Pandemic: Were We Over-Reporting an Overlooked Syndrome?

Background: Delirium is an overlooked syndrome in Emergency Departments (ED) around the world. Previous studies demonstrated high incidence of Delirium in elderly patients with COVID-19, however, these studies did not compare Delirium incidences in patients admitted for SARS-CoV-2 infection or sepsis for other etiologies. Methods This is an observational study that analyzed elderly patients (> 65 years) from two cohort studies that recruited patients in the ED at Hospital Clínicas da Faculdade de Medicina da Universidade de São Paulo, an urban, academic department in São Paulo, Brazil. The first cohort studied patients with sepsis and was conducted between September 30, 2019, and March 17, 2020. The second cohort studied COVID-19 patients between April 8, 2021, and May 28, 2021. Our primary outcome was incidence of delirium at admission in ED, which we defined using the Confusion Assessment Method (CAM). Additional study information was collected from medical records. Results We included 141 patients in our final analysis, with a median age of 72 (IQR 68-79) years and a predominance of the male sex (58%). We identified delirium at admission in 31 participants (22%), 20 in septic group and 11 in COVID-19 group (p = 0.70). Conclusion This present study does not support that elderly patients with COVID-19 have higher risk for Delirium at admission in Emergency Department when compared to patients hospitalized with sepsis for other etiologies. In spite of sepsis for COVID-19 have had more than 28% mortality, COVID-19 was not associated with higher mortality in elderly than sepsis for other etiologies.