Opioid and benzodiazepine use in the emergency department and the recognition of delirium within the first 24 hours of hospitalization

Objective: Delirium is a common and serious brain dysfunction. The objective of our study was to test the hypothesis that opioids and benzodiazepines exposure in the emergency department (ED) is associated with delirium. Methods: This was a retrospective cohort study, including patients aged 65 years and older who were hospitalized from ED at an academic medical center from 2014 to 2017. Medication administration records were used to identify opioids and benzodiazepines given during the ED stay. Nurses used the Delirium Observation Screening Scale (DOSS) twice daily to assess delirium during hospitalization. The outcome was a positive DOSS within 1 day of ED encounter. We used logistic regression to predict the outcome of positive delirium screening by opioids and benzodiazepines. Results: A total of 7927 ED encounters that resulted in hospitalization were included in the analysis. We identified 2008 visits (25.3%) with a positive delirium screen. A total of 3304 (41.7%) received opioids, and 1801 (22.7%) received benzodiazepines. In this cohort, opioids were not associated with an increased odds of delirium (OR 1.00, 95% CI 0.87-1.15). Benzodiazepines were associated with increased odds of delirium (OR 1.37, 95% CI 1.13-1.65), as were benzodiazepines combined with opioids (OR 1.61, 95% CI 1.33-1.97). Conclusion: In this study, the use of benzodiazepines was associated with a risk of delirium. The use of opioids did not increase the risk of delirium. Our findings imply that judicious pain management with opioids in the ED might not increase the risk of delirium.