This article is part of Pulmonology Advisor’s coverage of the CHEST Virtual 2020 meeting.
Patients with acute respiratory distress syndrome (ARDS) and a preexisting psychiatric illness, particularly generalized anxiety disorder (GAD), were more likely to develop intensive care unit (ICU) delirium, according to study results presented at the CHEST Annual Meeting, held virtually October 18 to 21.
Patients in the study were admitted to the ICU between January 2016 and December 2018 with ARDS according to the Berlin definition. Patients were all older than 18 years and had been on mechanical ventilation for more than 48 hours. Data collected included patient demographics; preexisting psychiatric illnesses; comorbidities; and therapies given in ICU such as sedatives, neuromuscular blocking agents, and antipsychotics. Psychiatric illnesses defined prior to admission were the presence of a major depressive disorder, GAD, bipolar disorder, schizophrenia, or posttraumatic stress disorder.
Researchers identified 150 patients with ARDS, 58 (38.7%) of whom were diagnosed with ICU delirium. In ARDS patients with preexisting psychiatric illnesses, 48.3% were found to have ICU delirium compared to 32.6% without any preexisting psychiatric illness (odds ratio [OR], 1.93; 95% CI, 0.98-3.79; P =.055).
In a subgroup analysis of individual psychiatric illnesses, GAD was associated with the development of ICU delirium (OR, 3.00; 95% CI, 1.32-6.83; P =.007). Of the patients with ARDS and ICU delirium, 22.1% of patients were on anxiolytics prior to admission, compared to 7.6% of patients without delirium (OR, 3.59; 95% CI, 1.34-9.64; P =.008).
The researchers noted that a possible explanation for the higher rate of delirium in this group could be the need to use higher doses of benzodiazepines to achieve adequate sedation, thereby putting them at a higher risk of withdrawal symptoms when the doses are decreased or eliminated. Furthermore, ventilated patients taking home psychotropic medications do not usually receive these medications when hospitalized as they are often prescribed other sedatives that can potentially predispose them to withdrawal symptoms, which often appears as delirium.
Further studies are necessary to assess ways to mitigate risk factors for this particular patient population.
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Jaber J, Reddy R, Hyde R, et al. Preexisting psychiatric illness is associated with higher incidence of delirium in ARDS. Presented at: the CHEST Virtual Annual Meeting 2020; October 18-21, 2020. Abstract 578.