A research team led by Massachusetts General Hospital scientists found that, of 817 COVID-19 patients 65 and older arriving at EDs, 226 (28%) had delirium, which was the sixth most common of all signs and symptoms. Delirium was a primary symptom in 37 (16%) of patients with delirium. Eighty-four patients with delirium (37%) had no typical COVID-19 symptoms, such as fever or shortness of breath. (Older adults are less likely than younger people to respond to infection with a fever.)

Patients most likely to have delirium were older than 75 years (adjusted risk ratio [aRR], 1.51), lived in a nursing home or assisted living facility (aRR, 1.23), had previously used psychoactive medications such as antidepressants or sleep medications (aRR, 1.42), and had impaired vision (aRR, 1.98), hearing problems (aRR, 1.10), or a history of stroke (aRR, 1.47) or Parkinson's disease (aRR, 1.88). Those with 4 or more of 14 common underlying diseases were at 1.58 times the risk for delirium.

The authors noted that although people older than 65 years make up only 16% of the US population, they have accounted for more than 80% of US COVID-19 deaths. They said that the rate of delirium in their study was much higher than that the 7% to 20% usually reported in studies in the ED setting before COVID-19, even though the risk factors for delirium are comparable to those reported in ED and hospitalized patients before the pandemic.

"Our study demonstrates that clinicians must include COVID-19 in the differential diagnosis of delirium among older adults, regardless of whether they have other symptoms of COVID-19 infection," the authors wrote. "This is important to avoid missing diagnoses altogether and to better identify severe cases of COVID-19 at high risk for poor outcomes and death."

And because current Centers for Disease Control and Prevention (CDC) guidance includes new-onset confusion as only a warning sign, not a symptom, of COVID-19, the authors called for the agency to immediately revise its guidance to include delirium as an importance coronavirus symptom.

"Many centers use the CDC guidance to prioritize screening, testing, and evaluation of presenting patients," they said. "By continuing to exclude delirium as a known presenting symptom of COVID-19, many cases will be missed or diagnoses delayed, as is already happening on a wide scale, particularly in older adults."

Identifying delirium as a Covid-19 symptom in patients before they are admitted to a hospital could be important to protect others from infection. It could also be critical for their care because in general, patients with delirium from any cause are more likely to fare worse than other patients. They suffer more severe disease, they stay in the hospital longer, and they are more likely to die. If they survive, they are more likely to need care in a rehabilitation facility or a nursing home after their hospitalization.

Regards
Rutherford
Managing Editor
Journal of Pharmacy Practice and Education