Delirium is associated with failure to rescue after cardiac surgery

Postoperative delirium after cardiac surgery is associated with long-term cognitive decline and mortality. We investigated whether increased ICU Confusion Assessment Method scores were associated with greater 30-day mortality and failure to rescue after cardiac surgery.

We studied 4030 patients who underwent a Society of Thoracic Surgeons index operation at the University of Virginia Health System from 2011 to 2021. We obtained all ICU Confusion Assessment Method scores recorded during patients' admission and summarized scores for the first 7 postoperative days. Univariate and multivariable logistic regression analyzed the association between ICU Confusion Assessment Method score/delirium presence and postoperative complications, operative mortality, and failure to rescue.

Any episode of ICU Confusion Assessment Method screen-positive delirium and nearly all components of the score were associated with increased 30-day mortality on univariate analysis. We found that a single episode of delirium was associated with increased mortality. Feature 2 (inattention) had the strongest association with poorer outcomes, including failure to rescue in our analysis, as were patients with higher peak Richmond Agitation Sedation Scale scores. Patients with higher mean Richmond Agitation Sedation Scale scores had an association with decreased failure to rescue.

A single episode of delirium, as measured using ICU Confusion Assessment Method scores, is associated with increased mortality. Inattention and higher peak Richmond Agitation Sedation Scale scores were associated with failure to rescue. Screening may clarify diagnosing delirium and assessing its implications on mortality and failure to rescue. Our findings suggest the importance of identifying and managing risk factors for delirium to improve patient outcomes and reduce mortality and failure to rescue rates.