Relationship between in-hospital angiotensin converting enzyme inhibitors and Angiotensin receptor blockers administration and delirium in the cardiac ICU.

Objectives: Delirium may be associated with neuroinflammation and reduced blood-brain barrier (BBB) stability. ACE Inhibitors (ACEIs) and Angiotensin Receptor Blockers (ARBs) reduce neuroinflammation and stabilize the BBB, thus slowing the progression of memory loss in patients with dementia. This study evaluated the effect of these medications on delirium prevalence.

Methods: This was a retrospective study of data from all patients admitted to a Cardiac ICU between 1 January 2020-31 December 2020. The presence of delirium was determined based on the International Classification of Diseases (ICD) 10 codes and nurse delirium screening.

Results: Of the 1684 unique patients, almost half developed delirium. Delirious patients who did not receive either ACEI or ARB had higher odds (odds ratio [OR] 5.88, 95% CI 3.7-9.09,  < .001) of in-hospital death and experienced significantly shorter ICU lengths of stay (LOS) ( = .01). There was no significant effect of medication exposure on the time to delirium onset.

Conclusions: While ACEIs and ARBs have been shown to slow the progression of memory loss for patients with Alzheimer's disease, we did not observe a difference in time to delirium onset.