Sedative drugs, curb on family visits may increase risk of acute brain dysfunction in Covid-19 ICU patients

Many COVID-19 ICU patients experienced acute brain dysfunction that lasted for an average of 12 days, which is double what is seen in non-COVID ICU patients, finds a new study.

Covid-19 patients admitted to intensive care unit (ICU) are at increased risk of acute brain dysfunction, revealed a new study. They experienced a higher burden of delirium and coma than those hospitalised with acute respiratory failure, said the research published in The Lancet Respiratory Medicine journal.

The study, believed to be the largest of its kind to date, is led by scientists at Vanderbilt University Medical Center (VUMC) in the US. It tracked the incidence of delirium and coma in over 2,000 Covid-19 patients admitted to 69 adult ICUs across 14 countries before April 28, 2020. Nearly 82 per cent of these patients remained comatose for a median of 10 days, and 55 per cent were delirious for a median of three days. The acute brain dysfunction lasted for an average of 12 days, which is double what is seen in non-Covid ICU patients, noted study co-author Brenda Pun from VUMC.

According to the scientists, ICU delirium can not only lead to higher medical costs but is associated greater risk of death and long-term ICU-related dementia.

Causes of acute brain dysfunction inCovid-19 ICU patients

While COVID-19 infection could predispose patients to a higher risk of acute brain dysfunction, patient care factors also appear to have played a significant role, said the researchers. They suspect that the choice of sedative medications and curbs on family visits also contributed to the increased risk of acute brain dysfunction in these patients.

It was found that many ICUs reverted to sedation practices that are not in line with best practice guidelines, leaving the scientists to speculate on the causes.

"Early reports of Covid-19 suggested that the lung dysfunction seen required unique management techniques including deep sedation. In the process, key preventive measures against acute brain dysfunction went somewhat by the boards," news agency PTI quoted Pun as saying.

According to the study authors:

• About 90 per cent of patients tracked in the study were invasively mechanical ventilated at some point during hospitalisation, and 67 per cent on the day of ICU admission.
• Patients receiving benzodiazepine sedative infusions were at 59 per cent higher risk of developing delirium.
• Patients who received family visitation were at 30 per cent lower risk of delirium

Senior author Pratik Pandharipande noted that these prolonged periods of acute brain dysfunction are largely avoidable if ICU teams return to lighter levels of sedation for these patients, along with frequent awakening and breathing trials, mobilisation and safe in-person or virtual visitation.

Covid-19 infection may cause irreversible brain damage

In the early months of the Covid-19 pandemic, doctors mainly focused on treating damage to the lungs and circulatory system of the patients. But they also noticed that some people hospitalized with severe Covid-19 experienced delirium, making them confused, disorientated and agitated. Later, several studies confirmed that infection with the novel coronavirus can cause damage to the brain as well and lead to neurological symptoms.

In April, a group of scientists in Japan published the first report of a Covid-19 patient who had swelling and inflammation in brain tissues. Another report described a Covid-19 patient with deterioration of myelin, a fatty coating that protects neurons.

A report published in Seizure: European Journal of Epilepsy in October 2020 also warned that infection with the novel coronavirus could lead to permanent brain damage. About one-third of Covid-19 patients studied had abnormalities in the frontal lobe of the brain, which researchers said might not be repaired after recovering from the disease.

With inputs from PTI