PACU Delirium in Older Surgical Patients: Incidence, Nursing-Sensitive Correlates, and Outcomes in a Multicenter...

Post-anesthesia care unit (PACU) delirium in older surgical patients is poorly characterized in Chinese multicenter settings, and whether nursing-sensitive PACU variables add explanatory value beyond conventional clinical risk factors has not been formally tested.

In this prospective cohort study across five Chinese tertiary hospitals, 2200 patients aged 65 years or older undergoing elective major noncardiac surgery (after excluding 60 with persistent deep sedation) were assessed for PACU delirium using a Richmond Agitation-Sedation Scale (RASS)-gated, repeated Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) protocol at three timepoints (10-20 and 40-60 minutes after admission, and before discharge). Two prespecified nested logistic models were compared in an explanatory framework: Model A (conventional clinical predictors) and Model B (Model A plus eight nursing-sensitive PACU variables). Complete-case analysis included 2,048 patients; models were compared using the likelihood ratio (LR) test, C-statistic, and integrated discrimination improvement (IDI).

PACU delirium occurred in 422 of 2,200 patients (19.2%; 95% CI: 17.6%-20.9%) and was predominantly hypoactive (64.2%). In descending order of effect size, independent conventional correlates were known cognitive impairment, chronic kidney disease, ASA ≥ III, stroke/TIA, older age, anxiety, lower MoCA, and lower albumin. Adding the nursing-sensitive block modestly improved overall fit (LR test p = 0.037), but the discrimination gain was small (C-statistic 0.675 to 0.686; ∆AUC = +0.011) and the IDI was non-significant (IDI = +0.008, p = 0.384); urinary catheterization was the only independent nursing-sensitive correlate (OR 1.49; 95% CI: 1.18-1.89; p = 0.0009). PACU delirium was associated with all secondary outcomes, including ward delirium (OR 3.26), falls (OR 4.63), non-home discharge (OR 4.75), and prolonged hospitalization (geometric mean ratio 1.46), all p < 0.001.

PACU delirium affected approximately one in five older patients and was predominantly hypoactive. The nursing-sensitive block added statistically detectable but clinically limited discriminative value, with the signal concentrated in urinary catheterization. Structured, repeated PACU delirium screening-particularly for hypoactive presentations-and targeted catheter minimization are practical nursing priorities; external validation is required before any bedside risk prediction.