Covid: outmoded critical care practices fuelled delirium in ICU patients

Scientists have established that choice of sedatives contributed to the confusion

Acute brain dysfunction lasted for a median of 12 days in the ICU Covid patients studied. AFP

Coronavirus patients admitted to intensive care in the early months of the pandemic were more likely to suffer from delirium and coma as a result of outmoded intensive care practices, according to a new study.

Incidence of acute brain dysfunction were far more prevalent in these Covid patients than is typical in other forms of acute respiratory failure, US and Spanish researchers found.

They tracked the incidence of delirium and coma in 2,088 patients admitted before April 28, 2020, to 69 adult intensive care units in 14 countries.

ICU delirium is associated with higher medical costs, and greater risk of death and long-term intensive care-related dementia.

Seminal studies at the Tennessee’s Vanderbilt University Medical Centre in the past two decades have spurred widespread interest in ICU delirium research, and the resulting body of evidence has come to inform critical care guidelines endorsed by medical societies in several countries.

These guidelines include well-calibrated pain management with prompt discontinuation of analgesics and sedatives, daily spontaneous awakening trials, daily spontaneous breathing trials, delirium assessments throughout the day, early mobility and exercise, and family engagement.

Eighty-two per cent of patients in this observational study were comatose for a median of 10 days, and 55 per cent were delirious for a median of three days. Acute brain dysfunction [coma or delirium] lasted a median of 12 days.

“This is double what is seen in non-Covid ICU patients,” said Brenda Pun of Vanderbilt University, who led the study with Rafael Badenes of the University of Valencia in Spain.

They cite a previous large, multi-site ICU study led by Vanderbilt researchers in which acute brain dysfunction lasted a median of five days, including four days of coma and one day of delirium.

The report recognises that the pathogenesis of Covid could predispose ICU patients to more acute brain dysfunction. But it also links the outcome to the outmoded critical care practices used by healthcare practitioners.

These include deep sedation, widespread infusions of benzodiazepine drugs – a group of nervous system depressants – immobilisation and isolation from families.

The authors assert that Covid led to the apparent widespread abandonment of newer clinical protocols that are proven to help ward off the acute brain dysfunction that stalks many critically ill patients.

“It is clear in our findings that many ICUs reverted to sedation practices that are not in line with best-practice guidelines, and we're left to speculate on the causes,” Ms Pun said.

“Many of the hospitals in our sample reported shortages of ICU providers informed about best practices.

“There were concerns about sedative shortages, and early reports of Covid 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.”

The National reported in April that Italy had retrained thousands of nurses for ICU service. With resources stretched in health services throughout the world, neophyte ICU nurses could be an explanatory factor for the treatment regression.

Using electronic health records, investigators were able to examine closely patient characteristics, care practices and findings from clinical assessments.

Eighty-eight per cent of patients tracked in the study received invasive mechanical ventilation at some point during their hospital stay, 68 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 visits from loved ones, whether in person or remotely, were at 30 per cent lower risk of delirium.

“There's no reason to think that, since the close of our study, the situation for these patients has changed,” said Vanderbilt researcher Pratik Pandharipande, Professor of Anaesthesiology at the university.

“These prolonged periods of acute brain dysfunction are largely avoidable. Our study sounds an alarm. As we enter the second and third waves of Covid-19, ICU teams need, above all, to return to lighter levels of sedation for these patients, frequent awakening and breathing trials, mobilisation and safe in-person or virtual visitation.”

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