Risk factors associated with prolonged stay in the post-anesthesia care unit: a case-control study

Prolonged length of stay in Post-Anesthesia Care Unit (PLOS in PACU) reduces PACU bed turnover rates, increases healthcare costs, and lowers patient and surgeon satisfaction. This study aims to identify additional factors associated with prolonged PACU stay and to develop a nomogram for individualized risk assessment.

This retrospective study included 69,123 adult patients who were transferred to PACU after general anesthesia from January 2022 to January 2024. PLOS was defined as PACU stay > 2 hours; non-PLOS controls were matched 3:1 by operative date (±1 month), age (±1 year), and gender. A predictive model was developed using LASSO regression for variable selection and multivariable conditional logistic regression, then presented as a nomogram.

Among 68,178 eligible patients, 210 subjects were identified as PLOS in PACU. Multivariable conditional logistic regression showed that the potential risk factors were emergency surgery (OR 7.678, 95% CI 2.606-22.618, P < 0.001), increased intraoperative blood loss (OR 1.002, 95% CI 1.001-1.004, P = 0.005), longer operative time (OR 1.004, 95% CI 1.001-1.008, P = 0.011), cerebrovascular diseases (OR 2.248, 95% CI 1.162-4.346, P = 0.016) and major surgery (OR 4.954, 95% CI 1.801-13.624, P = 0.002). The optimism-corrected AUC of 0.825 (95% CL 0.801-0.849). A higher preoperative prealbumin level (OR 0.990, 95% CI 0.986-0.994, P < 0.001) was inversely associated with the risk of PLOS in PACU.

This study found that a higher preoperative prealbumin level was associated with a lower risk of prolonged PACU stay, possibly reflecting patients' preoperative nutritional status, systemic inflammation, chronic illness, or frailty. A nomogram was constructed, though its single-center and exploratory nature requires external validation.