Postoperative Delirium Following Elective Cardiac Surgery: Frequency and Associated Factors at a Tertiary Cardiac Center in Pakistan

Abstract

Objective: Postoperative delirium (POD) is a common neuropsychiatric complication following cardiac surgery and is associated with adverse clinical outcomes, prolonged hospitalization, increased healthcare costs, and long-term cognitive impairment. This study aimed to determine the frequency of postoperative delirium and identify factors associated with its occurrence among patients undergoing elective cardiac surgery at a tertiary cardiac center in Pakistan. Methodology: A prospective observational cohort study was conducted between 10 January 2026 and 10 April 2026. A total of 184 adult patients aged 30–80 years undergoing elective cardiac surgery were enrolled through consecutive sampling. Demographic, clinical, surgical, and perioperative data were collected using a structured study proforma. Postoperative delirium was assessed twice daily using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) during hospitalization. Results: Among the 184 patients included in the study, postoperative delirium developed in 40 patients, yielding a frequency of 21.7%. The median time to delirium onset was postoperative day 2 (IQR: 1–3 days). Factors significantly associated with POD included age >50 years (OR=2.65, 95% CI: 1.01–6.94; p=0.031), low educational status (OR=2.05, 95% CI: 1.05–4.04; p=0.041), hypertension (OR=2.28, 95% CI: 1.02–5.11; p=0.031), diabetes mellitus (OR=2.61, 95% CI: 1.17–5.80; p=0.011), previous stroke (OR=5.63, 95% CI: 1.96–16.20; p<0.001), heart failure (OR=3.66, 95% CI: 1.68–7.96; p=0.001), current smoking (OR=2.11, 95% CI: 1.00–4.44; p=0.041), reduced preoperative ejection fraction (p=0.002), prolonged cardiopulmonary bypass duration >120 minutes (OR=3.69, 95% CI: 1.76–7.72; p<0.001), prolonged cross-clamp time >90 minutes (OR=2.78, 95% CI: 1.22–6.31; p=0.011), ICU stay >5 days (OR=4.09, 95% CI: 1.95–8.57; p<0.001), and postoperative anticholinergic medication use (OR=4.57, 95% CI: 2.10–9.93; p<0.001). Conclusion: Postoperative delirium occurred in approximately one-fifth of patients undergoing elective cardiac surgery and was associated with several demographic, clinical, and perioperative factors. Recognition of these associated factors may facilitate early identification of high-risk patients and support the development of targeted preventive and monitoring strategies in cardiac surgical practice.