Older adults admitted to the emergency department (ED) and diagnosed with SARS-CoV-2 infection often presented with delirium and no other COVID-19 symptoms, a multicenter cohort study showed.
About 28% of COVID-19 patients 65 and older presented to the ED with delirium, and delirium was a primary symptom in 16% of these patients, reported Maura Kennedy, MD, MPH, of Massachusetts General Hospital in Boston, and co-authors.
More than a third (37%) of patients with delirium did not present with typical COVID-19 signs like fever or shortness of breath, they wrote in JAMA Network Open.
Delirium was the sixth most common presenting symptom in older adults. “Other atypical symptoms also were common; 11% of patients reported a fall and 9% reported dizziness or fainting,” Kennedy said.
“Typical symptoms of COVID-19 were absent in many older patients in this study. Only 56% of patients reported fever and 50% reported cough,” she told MedPage Today.
“Delirium is often a barometer of health for older adults, meaning it can be a very sensitive indicator when something is going wrong,” noted co-author Sharon Inouye, MD, MPH, of Harvard Medical School. It serves as an atypical presentation of many diseases “and it is not surprising it is also a common presentation for COVID-19 infection in older adults to the emergency department,” she noted.
“What is surprising is how often delirium continues to be overlooked,” Inouye told MedPage Today. While the CDC lists “new confusion” as an emergency warning sign of COVID-19 on its website, delirium is not on the agency’s case report form or the core symptom checklist many sites use to determine who gets tested, Inouye said. This means some cases of COVID-19 in older patients may be missed, she pointed out.
“Some experts have argued that this omission may have contributed to the large number of deaths seen in nursing homes,” she said. “Older adults may have been sent back without testing — since COVID-19 was not suspected when they ‘just’ had delirium — and went on to spread infections at their facilities.”
Delirium has been linked with COVID-19 in other research. A prospective study showed that encephalopathy was the most common new-onset neurologic manifestation seen in hospitalized COVID-19 patients, affecting 6.8%. Retrospective reports have shown an even higher prevalence of delirium or encephalopathy, though some have not teased apart the roles sedation or pre-existing conditions may play.
In this analysis, Kennedy and colleagues studied 817 older adults with COVID-19 who presented at one of seven ED sites in the U.S. on or after March 13, 2020. COVID-19 was diagnosed either by positive nasal swab polymerase chain reaction (PCR) test for SARS-CoV-2 (99% of cases) or chest X-ray or CT scan showing classic COVID-19 appearance and distribution of ground-glass opacities (1%). Delirium was identified by medical record review, with uncertain cases adjudicated by at least two clinical experts. Some sites routinely used delirium screening tools.
About half (47%) of study participants were men. Most (62%) were white, 27% were Black, and 7% were Hispanic or Latinx. Mean age was about 78.
The most common presenting symptoms in the ED were fever (56%), shortness of breath (51%), cough (50%), hypoxia (40%), and weakness (30%), followed by delirium (28%), fatigue (26%), diarrhea (16%), and anorexia (15%). Occurrence of delirium was higher than what typically had been reported in ED studies before COVID-19, which ranged from 7% to 20%, the researchers noted.
Delirium symptoms included impaired consciousness (54%), disorientation (43%), hypoactive delirium symptoms (20%), and agitation or hyperactive delirium symptoms (16%).
Factors associated with delirium risk included age older than 75, prior psychoactive medication use, assisted living or skilled nursing facility residence, vision or hearing impairment, stroke, and Parkinson’s disease. (Dementia and mental health conditions were removed from this analysis because of multicollinearity.) Delirium at presentation was significantly associated with increased risk for poor hospital outcomes, including ICU stay, discharge to a rehabilitation facility, and death.
The findings echoed what providers witnessed in the early days of the pandemic, observed Jennifer Frontera, MD, of NYU Langone Health, who wasn’t involved with the study.
“A lot of older people waited to come to the hospital,” Frontera told MedPage Today. “They were delayed until they were in really bad shape, or they were confused and that’s when the family brought them in.”
The research had several limitations, Kennedy and co-authors noted. Most EDs do not routinely screen for delirium and research staff were not allowed in EDs due to infection control policies, so prevalence may be underreported. A large proportion of patients were from assisted living facilities or nursing homes (36%) or previously had been diagnosed with dementia (30%) and findings may not apply to other populations. Because the study focused on delirium as a presenting symptom, it did not have data on factors that could prevent it during hospitalization.
This work was supported in part by a grant from the National Institute on Aging and a grant from the MSTP Training Program at the University of Massachusetts Medical School.
Researchers reported relationships with the National Institute of General Medical Sciences, National Center for Advancing Translational Sciences, and the Robert E. Leet and Clara Guthrie Patterson Trust.