Delirium as a Presenting Symptom of COVID-19.

BACKGROUND: Delirium is a common neurologic manifestation of coronavirus disease 2019 (COVID-19) in older adults who present to the emergency department (ED). OBJECTIVE: To investigate clinical characteristics associated with delirium as a presenting symptom of COVID-19 in older adults and develop a logistic regression to predict the likelihood of delirium. METHOD: We compared clinical characteristics in an age- and gender-matched sample of 68 delirious individuals with 68 nondelirious individuals (Mage = 78) who presented to the ED with COVID-19. RESULTS: The delirious group was more likely to have neurologic, psychiatric, and cardiovascular comorbidities; a prior history of delirium; and deliriogenic medications in their medication list. They were less likely to present with respiratory symptoms and more likely to present with sepsis, hypoxia, higher heart rate, and higher sodium. The delirious group had higher mortality (51%) than the nondelirious group (32%). Delirium developed within an average of 2 days of initial COVID-19 symptom onset, with symptom onset to ED within an average of 4 days and symptom onset to death within an average of 11 days. Logistic regression based on five delirium predictors correctly predicted 80% of those with delirium (75% sensitivity at 86% specificity). CONCLUSION: Our results are largely consistent with prior studies and suggest that delirium is a common, early occurring, and lethal manifestation of COVID-19 in older adults presenting to the ED, in most cases causing acute on chronic neurocognitive dysfunction strongly influenced by inflammatory and hypoxic-ischemic mechanisms.