Pre-hospital Anticholinergic Burden and Delirium in Critically Ill Patients

This work investigates the relationship between pre-hospital cumulative anticholinergic medication use and delirium outcomes in critically ill patients. Delirium is a frequent and serious complication in ICU settings and is associated with poor clinical outcomes, yet the role of chronic anticholinergic exposure remains unclear. The research includes three components: (1) a systematic review of studies examining community-based anticholinergic use and delirium outcomes, (2) a secondary analysis evaluating the association between 5-year cumulative anticholinergic burden and prevalent delirium at ICU admission, and (3) a secondary analysis exploring the relationship between pre-hospital anticholinergic burden, delirium severity, and short-term mortality. Anticholinergic burden was quantified using Total Standardized Daily Doses (TSDD), a dose- and duration-sensitive metric. The systematic review found consistent associations between high anticholinergic burden and delirium, though studies in critically ill patients assessing delirium severity and duration were limited. In the second study, higher cumulative burden was significantly associated with increased delirium prevalence, particularly among patients aged 50 and older. However, pre-hospital anticholinergic burden was not associated with delirium severity or 30- and 90-day mortality. These findings underscore anticholinergic medications as a potentially modifiable predisposing risk factor for delirium and highlight the need for better exposure measurement and deprescribing strategies in vulnerable populations.