Risks of Developing Delirium in ICU Patients With COVID-19

The onset of delirium for patients in the intensive care unit (ICU) can really influence what happens to them in the aftermath of their critical illness, and rates of delirium have skyrocketed during the coronavirus disease 2019 (COVID-19) pandemic, said Brenda Truman Pun, DNP, RN, director of data quality at the Vanderbilt Critical Illness, Brain Dysfunction, and Survivorship (CIBDS) Center, during her presentation at CHEST 2020.

Patients who are critically ill have historically had high rates of delirium and coma when they are in the ICU; however, although the rates were between 60% and 80% up until 2015, those rates had come down to 45% to 50% due to changes in care. Now, during COVID-19 pandemic, those rates of delirium are back in the 80% range, and reports from ICUs show that use of benzodiazepines have risen sharply to more than 80%, as well, explained Pun.

The CIBDS Center has started using the mnemonic device of F-COVID to help clinicians think about the causes of delirium during the pandemic and what will put a patient at higher risk of developing delirium in the ICU:

Family (and lack of visitation)

Clotting problems

Oxygenation issues

Virus itself

Immobilization

Drugs (eg, benzodiazepines)

“We can see all of these risk factors that are magnified during COVID are placing our patients at greater risk for delirium, almost creating the perfect delirium factory,” Pun said.

The solutions for dealing with delirium follow the DR. DRE mnemonic:

Disease Remediation: dealing with the underlying conditions (eg, sepsis, COVID clotting, congestive heart failure, chronic obstructive pulmonary disease)

Drug Removal: removing the drugs that are not good for the patients and using lighter sedation (eg, using Spontaneous Awakening Trials [SATs] and Spontaneous Breathing Trials [SBTs], avoiding benzodiazepines)

Environmental factors: trying to get the patient’s environment like it is at home (eg, mobilizing them, getting them to sleep at the right time, getting them hearing aids and glasses, reducing noise, allowing for virtual or in-person family visitation)

The CIBDS Center launched the COVID-D International Cohort Study of Acute Brain Dysfunction, which is an international, multicenter, retrospective cohort study of more than 2000 adults treated for COVID-19 in the ICU. The data were collected from 69 sites in 14 countries. The findings are currently under peer review.

The median age of the patient population was 64 years, and 88% were on invasive mechanical ventilation, 81% had coma at some point lasting for a median of 10 days, and 55% experienced delirium for a median of 3 days, Pun explained.

“These numbers are quite a bit different from what we’re normally used to in patients,” she said simply.

The study followed patients for 21 days and found that in the first week, half of the patients were in a coma, which is very unusual in the ICU pre­–COVID-19, Pun explained. The study also found that the rate of delirium increases early on and stays steady over the full course of care in the ICU and that the number of patients who neither have delirium nor are in a coma dropped low within the first 3 days and stayed low throughout the 21 days.

They were able to identify some risk factors and the prevalence of these risk factors. Of the 2088 patients studied, 64% were on benzodiazepines for a median of 7 days, 71% on propofol for median of 7 days, and 44% on dexmedetomidine for median of 4 days, Pun said. Less than one-fourth of the patients received SATs/SBTs when they were qualified for them, she added.

The last factor the study looked at was family visitation. Patients had family engagement for only 17% of the days in the study. Only 8% were in person, and 9% were virtual.

“So, these risk factors are quite a bit different than what we see in our pre-COVID or non-COVID patients,” Pun said.

Of the significant risk factors for delirium, 2 were largely modifiable: sedative infusions and family/friends visitation. Patients treated with benzodiazepines had higher odds of delirium compared with patients who were not treated with benzodiazepines, and patients who were visited by friends/family, either in person or virtually, had lower odds of developing delirium.

“Delirium and coma were really epidemic within this pandemic and prolonged more than what we see in our non-COVID patients,” Pun said.

The study found double the duration of acute brain dysfunction compared with what is typically seen, from 1 week to 2 weeks. This longer duration of acute brain dysfunction puts patients at greater risk and portends greater long-term cognitive outcomes, she said.

These findings are particularly important right now since many parts of the country are seeing spikes in COVID-19 cases again, Pun said.

“Let’s not go backward to this deep and prolonged sedation, but let’s go forward and learn from this,” she said.