The Association of Selective Serotonin Reuptake Inhibitors With Delirium in Critically Ill Adults: A Secondary Analysis of the Bringing to Light the Risk Factors and Incidence of Neuropsychologic Dysfunction in ICU Survivors ICU Study

OBJECTIVES: To assess the association between selective serotonin reuptake inhibitors (SSRI) and delirium in the subsequent 24 hours after drug administration in critically ill adults. DESIGN: Retrospective cohort study utilizing the Bringing to Light the Risk Factors and Incidence of Neuropsychologic Dysfunction in ICU Survivors dataset. SETTING: Two large U.S. ICUs. PATIENTS: Critically ill adults admitted to a medical or surgery ICU between March 2007 and May 2010 with respiratory failure or shock. INTERVENTIONS: Our primary outcome was the occurrence rate of delirium or coma during each day in the ICU. Our exposure variable was SSRI administration on the prior day in the ICU. As a secondary question, we assessed the association of SSRI administration and delirium the same day of SSRI administration in the ICU. MEASUREMENTS AND MAIN RESULTS: We analyzed 821 patients. The median age was 61.2 years old (interquartile range, 50.9–70.7), and 401 (48.8%) were female. A total of 233 patients (28.4%) received prescribed SSRIs at least once during their ICU admission. Delirium was present in 606 (74%) of the patients at some point during hospitalization in the ICU. Coma was present in 532 (64.8%) of the patients at some point during hospitalization in the ICU. After adjusting for multiple potential confounding factors, we found that SSRI administration in the ICU was associated with lower odds of delirium/coma (odds ratio [OR], 0.75; 95% CI, 0.57–1.00) the next day. An SSRI administered on the same day reduced the odds of delirium/coma as well (OR, 0.66; 95% CI, 0.50–0.87). CONCLUSIONS: SSRI administration is associated with decreased risk of delirium/coma in 24 hours and on the same day of administration in critically ill patients in a medical or surgical ICU.