Development and validation of a nomogram for determining patients requiring prolonged postanesthesia care unit length of stay after laparoscopic cholecystectomy

BACKGROUND Laparoscopic cholecystectomy (LC) is a common surgical procedure for managing gallbladder disease. Prolonged length of stay (LOS) in the postanesthesia care unit (PACU) may lead to overcrowding and a decline in medical resource utilization. In this work, we aimed to develop and validate a predictive nomogram for identifying patients who require prolonged PACU LOS. METHODS Data from 913 patients undergoing LC at a single institution in China between 2018 and 2019 were collected, and grouped into a training set (456, cases during 2018) and a test set (457, cases during 2019). The definition of PACU LOS is the duration between admission to discharge from PACU, which we can derive from the electronic medical record system. Using the least absolute shrinkage and selection operator regression model, the optimal feature was selected, and multivariable logistic regression analysis was used to build the prolonged PACU LOS risk model. The C-index, calibration plot, and decision curve analysis (DCA) were used in assessing the model calibration, discrimination, and clinical application value, respectively. For external validation, the test set data was evaluated. RESULTS The predictive nomogram had 8 predictor variables for prolonged PACU LOS, including age, American Society of Anesthesiologists (ASA) grade, active smoker, gastrointestinal disease, liver disease, and cardiovascular disease. This model displayed efficient calibration and moderate discrimination with a C-index of 0.662 (95% confidence interval, 0.603 to 0.721) for the training set, and 0.609 (95% confidence interval, 0.549 to 0.669) for the test set. DCA demonstrated that the prolonged PACU LOS nomogram was reliable for clinical application when an intervention was decided at the possible threshold of 7%. CONCLUSIONS We developed and validated a predictive nomogram with efficient calibration and moderate discrimination, and can be applied to identify patients most likely to be subjected to prolonged PACU LOS. This novel tool may shun overcrowding in PACU and optimize medical resource utilization.