Disclosure(s): No relevant financial relationship(s) to disclose.
First Author: Joon Kim, MD Co-Author: Young Ae Kang, RN – Clinical Nurse Specialist, Asan Medical Center Co-Author: Pil-Je Kang, MD – Professor of cardiothoracic surgery, Asan Medical Center
Introduction: Delirium is a common postoperative complication associated with increased morbidity and mortality in critically ill patients. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a validated tool for detecting delirium; however, limited studies have examined its association with prolonged mechanical ventilation (PMV) following major cardiac surgery. This study aimed to investigate whether a positive CAM-ICU assessment is associated with PMV and other postoperative outcomes in this population.
Methods: We conducted a retrospective cohort study of 1,437 adult patients who underwent cardiac surgery between January and December 2022. Delirium was assessed daily using the CAM-ICU during the early postoperative period. PMV was defined as ventilation lasting more than 24 hours after surgery. Clinical outcomes were analyzed using logistic regression and time-dependent Cox regression after adjustment with inverse probability of treatment weighting (IPTW).
Results: Among 1,437 patients, 281 (19.6%) were assessed as CAM-ICU positive in the early postoperative period. The incidence of PMV was significantly higher in CAM-ICU positive patients than in negatives (37.4% vs. 5.4%; p < 0.001). After IPTW adjustment, CAM-ICU positivity was significantly associated with increased risk of PMV (OR 3.60; 95% CI, 2.53–5.10; p < 0.001), reintubation (OR 3.37; 95% CI, 1.52–7.31; p = 0.002), ICU readmission (OR 2.53; 95% CI, 1.22–5.03; p = 0.010), and prolonged ICU stay after extubation (OR 2.95; 95% CI, 2.19–3.96; p < 0.001). No significant association was found with early mortality (OR 1.13; 95% CI, 0.37–2.86; p = 0.805). At 24 months, all-cause mortality showed a non-significant trend toward increased risk in CAM-ICU positive patients (HR 1.77; 95% CI, 0.79–3.95; p = 0.164). Marginal effect analysis showed the predicted probability of PMV increased with age and remained consistently higher in CAM-ICU positive patients across all ages.
Conclusions: A positive CAM-ICU assessment was strongly associated with prolonged mechanical ventilation, reintubation, ICU readmission, and extended ICU stay following major cardiac surgery. Routine CAM-ICU screening may help identify high-risk patients and facilitate timely intervention to improve postoperative recovery.
