(1352) Impact of Quetiapine Dose on Delirium-Free Days in Adults With Intensive Care Unit Delirium

Introduction: Intensive care unit (ICU) delirium is associated with increased risk of morbidity and mortality. Antipsychotic medications are not recommended for treatment of ICU delirium; however, they are often used with little guidance on appropriate dosage. This study evaluated the effect of daily quetiapine dose on delirium-free ICU days (DFD) in critically ill adults with ICU delirium.

Methods: This was a single-center, retrospective, cohort study at the University of Cincinnati Medical Center. Adult ICU patients admitted from 2017-2022 that received scheduled quetiapine for at least 48 hours following at least one positive delirium assessment were included. There were three cohorts based on the maximum daily quetiapine dose: below 200mg, 200-400mg, above 400mg. The primary outcome was percent DFD from quetiapine initiation and first day of maximum daily quetiapine dose. Secondary outcomes included unplanned quetiapine discontinuation or dose reduction and delirium-related outcomes. Concomitant analgosedation infusion dosage was evaluated as a covariate.

Results: 127 patients were included (low dose: 42; moderate: 45; high: 40). Most patients were male (64.6%) and white (69.3%) with a mean age of 58+/-18 years. 62.9% required mechanical ventilation. Percentage of DFD was higher in the low dose cohort from quetiapine initiation (43.0%. vs. 24.0% vs. 0%; p=0.004) and from quetiapine maximum dose (45.0%, vs. 33.0% vs 0%; p=0.030). Patients in higher quetiapine dose cohorts received higher intensities of analgosedative agents at quetiapine initiation and maximum dose. Exploratory multivariate logistic regression controlling for analgosedation dosage did not show quetiapine maximum dose to be associated with percent DFD (OR 0.99; 95% CI 0.99-1.001; p=0.156). There was no difference in quetiapine discontinuation or dose reduction between cohorts. Hospital length of stay (p=0.003), ICU length of stay (p < 0.001), and duration of mechanical ventilation (p < 0.001) increased as quetiapine dose increased.

Conclusions: Patients receiving higher daily quetiapine dose had lower percent DFD. However, differences in analgosedation dosage were notable between cohorts, questioning the association between quetiapine dose and DFD. The impact of quetiapine dose on DFD remains uncertain.