A predictive nomogram based on sub-anesthetic esketamine and clinical variables for estimating the risk of postoperative depression following laparoendoscopic single-site hysterectomy

Objective To construct a nomogram combining sub-anesthetic esketamine administration with perioperative clinical characteristics for predicting postoperative depression in patients undergoing laparoendoscopic single-site (LESS) hysterectomy. Methods Clinical records from 326 patients who underwent LESS hysterectomy were retrospectively reviewed. Participants were randomly assigned to training ( n =228) and internal validation ( n = 98) cohorts at a 7:3 ratio. Using the 17-item Hamilton Depression Rating Scale (HAMD-17) on postoperative day 7, patients in the training cohort were classified into depression (HAMD-17 ≥ 7) and non-depression (HAMD-17 < 7) groups. A nomogram was established, and its discrimination, calibration, and clinical utility were evaluated using receiver operating characteristic (ROC) analysis, calibration curves, and decision curve analysis (DCA). Results Postoperative depression occurred in 23.62% (77/326) of patients: 22.81% (52/228) and 25.51% (25/98) in the training and internal validation cohorts, respectively. Multivariable logistic regression identified the 12-hour postoperative visual analogue scale (VAS) score (OR = 3.165, 95% CI: 1.223–8.192), increasing age (OR = 1.126, 95% CI: 1.053–1.205), and prolonged operative duration (OR = 1.046, 95% CI: 1.014–1.078) as independent risk factors (all P < 0.05), whereas higher preoperative serum albumin (OR = 0.785, 95% CI: 0.684–0.900), single-dose esketamine (OR = 0.290, 95% CI: 0.118–0.714), and continuous-dose esketamine (OR = 0.306, 95% CI: 0.116–0.803) were protective (all P < 0.05). The nomogram achieved areas under the ROC curve of 0.884 (95% CI: 0.829–0.942) and 0.772 (95% CI: 0.637–0.906) in the training and validation cohorts. Calibration was good in the training cohort (slope = 1.000, intercept = 0.000) but was poor in the internal validation cohort (slope = 0.467, 95% CI: 0.215–0.719; intercept = −0.925, 95% CI: −1.386 to −0.464; Brier score = 0.167), indicating systematic overestimation of predicted risk and overfitting. DCA indicated favorable clinical utility. SHapley Additive exPlanations ranked predictors as operative time, age, preoperative albumin, esketamine administration, and 12-hour VAS score. Conclusion The nomogram demonstrated acceptable discrimination but poor calibration in internal validation, systematically overestimating postoperative depression risk; it should be regarded as an exploratory tool for postoperative risk stratification and requires external validation and recalibration before any clinical application. Chinese Clinical Trial Registry Number ChiCTR2500103453