A new study supports earlier evidence that older patients admitted to the emergency department (ED) and subsequently diagnosed with coronavirus disease 2019 (COVID-19) often present with delirium when they have no other typical symptoms, such as fever and cough.

The authors noted that adults aged 65 years and older are at the greatest risk of severe COVID-19, hospitalization, intensive care, and death. Although individuals older than 65 years of age represent just 16% of the US population, the authors said they have accounted for more than 80% of deaths due to COVID-19.

Delirium is characterized by an acute state of confusion, an altered level of consciousness, disorientation, inattention, and other cognitive disturbances. Beyond COVID-19, the authors said it is known to be a common symptom in older adults with severe disease in the ED and is associated with longer hospitalizations as well as increased morbidity and mortality. Despite this threat, delirium goes undetected in two-thirds of patients.

In the study, investigators examined 817 patients aged 65 years or older who were admitted to the ED and who were diagnosed with COVID-19. According to a press release, almost one-third of the patients had delirium at the time they were seen in the ED, and the delirium diagnosis was the main presenting symptom for 16% of those patients. Furthermore, 37% had no typical COVID-19 symptoms.

Delirium was the sixth most common presenting symptom in all patients, suggesting the clinical importance of including delirium on checklists of presenting signs and symptoms for COVID-19. The authors said these checklists are essential to guiding screenings, testing, and evaluations, and that awareness of delirium as a symptom could result in earlier diagnoses.

“This study demonstrates that delirium is not only a common symptom of COVID-19, but also may be the leading and possibly sole symptom in older persons,” said senior author Sharon K. Inouye, MD, MPH, in the press release. “Thus, delirium should be considered an important presenting symptom of COVID-19.”

Study shows delirium can signal presence of COVID-19 in asymptomatic older patients in ED [news release]. EurekAlert; November 19, 2020. https://www.eurekalert.org/pub_releases/2020-11/hsha-ssd111920.php. Accessed December 4, 2020.