In a study of nearly 150 patients hospitalized for COVID at the beginning of the pandemic, researchers found that 73% had delirium, a serious disturbance in mental state wherein a patient is confused, agitated and unable to think clearly.
Patients with delirium tended to be sicker, with more comorbidities like hypertension and diabetes, and appeared to have more severe COVID-related illness as well, said study author Phillip Vlisides, M.D., of the Department of Anesthesiology at Michigan Medicine.
Using patient medical records and telephone surveys following hospital discharge for a group of patients hospitalized in the intensive care unit between March and May 2020, the study team attempted to identify common threads amongst patients who developed delirium. Several factors are at play, said Vlisides.
The disease itself can lead to reduced oxygen to the brain as well as the development of blood clots and stroke, resulting in cognitive impairment. In addition, inflammatory markers were greatly increased in patients with delirium. Confusion and agitation could be a result of inflammation of the brain.
Adding insult to injury, care teams often were unable to perform standard delirium reduction techniques, such as exercises designed to get a patient moving or allowing visitors or objects from home to orient patients while in the hospital.
Furthermore, there was a correlation between the use of sedatives and delirium—patients with delirium were sedated more often and frequently at higher doses. “It is common to use IV sedatives in the ICU, particular for patients on a ventilator. However, from talking to nurses, we found that patients with severe COVID were inherently more delirious and agitated at baseline, perhaps prompting more sedative use.”
The study also found that cognitive impairment can persist even after discharge. Almost a third of patients did not have their delirium marked as resolved in their chart upon leaving the hospital and 40% of these patients required skilled nursing care. Almost a quarter of patients screened positive for delirium based on assessment by their caretaker. For some patients, these symptoms lasted for months. This can make managing the recovery process after hospitalization that much more difficult.