Risk factors for delayed recovery in postanesthesia care unit after surgery: a large and retrospective cohort study

Delayed recovery in the postanesthesia care unit (PACU) after surgery, as a severe occurrence, influences enhanced recovery after surgery. The data from the observational clinical study is a paucity.

This large, retrospective, and observational cohort study initially included 44 767 patients. The primary outcome was risk factors for delayed recovery in PACU. A generalized linear model and nomogram were employed to identify risk factors. Discrimination and calibration were used to evaluate the performance of the nomogram via internal and external validation.

Of 38 796 patients, 21 302 (54.91%) were women. The delayed recovery aggregate rate was 1.38% [95% CI, (1.27, 1.50%)]. In a generalized linear model, risk factors for delayed recovery were old age [RR, 1.04, 95% CI, (1.03,1.05), P <0.001], neurosurgery [RR, 2.75, 95% CI, (1.60, 4.72), P <0.001], using antibiotics during surgery [RR, 1.30, 95% CI, (1.02, 1.66), P =0.036], long anesthesia duration [RR, 1.0025, 95% CI, (1.0013, 1.0038), P <0.001], ASA grade of III [RR, 1.98, 95% CI, (1.38, 2.83), P <0.001], and postoperative analgesia [RR, 1.41, 95% CI, (1.10, 1.80), P =0.006]. In the nomogram, old age and neurosurgery had high scores in the model and contributed significantly to the increased probability of delayed recovery. The area under the curve value of the nomogram was 0.77. The discrimination and calibration of the nomogram estimated by internal and external validation were generally satisfactory.

This study demonstrates that delayed recovery in PACU after surgery was associated with old age, neurosurgery, long anesthesia duration, an ASA grade of III, using antibiotics during surgery, and postoperative analgesia. These findings provide predictors of delayed recovery in PACU, especially neurosurgeries and old age.