ABSTRACT
BACKGROUND: Delirium may be one of the presenting symptoms of COVID-19, complicating diagnosis and care of elderly patients with dementia. We aim to identify the prevalence and prognostic significance of delirium as the sole onset manifestation of COVID-19. METHODS: This is a retrospective single-centre study based on review of medical charts, conducted during the outbreak peak (March 27-April 18, 2020) in a Lombard dementia facility, including 59 elderly subjects with dementia and laboratory-confirmed COVID-19. FINDINGS: Of the 59 residents, 57 (96â 6%) tested positive (mean age: 82â 8; women: 66â 7%). Comorbidities were present in all participants, with 18/57 (31â 6%) having three or more concomitant diseases. Delirium-Onset COVID-19 (DOC) was observed in 21/57 (36â 8%) subjects who were chiefly older (mean age: 85â 4 y/o) and with multiple comorbidities. Eleven/21 DOC patients (52â 4%) had hypoactive delirium, while hyperactive delirium occurred in ten/21 (47â 6%). Lymphopenia was present in almost all subjects (median: 1â 3 × 109/L). Overall mortality rate was 24â 6% (14/57) and dementia severity per se had no impact on short-term mortality due to COVID-19. DOC was strongly associated with higher mortality (p<0â 001). Also, DOC and male gender were independently associated with increased risk of mortality (OR: 17â 0, 95% CI: 2â 8-102â 7, p = 0â 002 and 13â 6, 95% CI: 2â 3-79â 2, p = 0â 001 respectively). INTERPRETATION: Delirium occurrence in the elderly with dementia may represent a prodromal phase of COVID-19, and thus deserves special attention, especially in the presence of lymphopenia. Hypoxia and a severe inflammatory state may develop subsequently. DOC cases have higher short-term mortality rate. FUNDING: None.