Factors associated with postoperative shivering after total knee arthroplasty and development and validation of a predictive model.

Postoperative shivering is a common complication following anesthesia, which can increase oxygen consumption, prolong recovery, and affect patient comfort and safety. Understanding its risk factors is important for improving postoperative outcomes and guiding preventive strategies. To investigate the associated risk factors for postoperative shivering after total knee arthroplasty (TKA) and to develop and validate a predictive model. A retrospective review of medical records of patients who underwent TKA at our hospital from January 2023 to December 2024 was conducted. Single-factor and multi-factor logistic regression analysis was used to identify independent risk factors for postoperative shivering, and a nomogram was created to visualize the model. The discriminatory ability of the model was evaluated using receiver operating characteristic curves and the area under the curve, while the goodness-of-fit was assessed using the Hosmer-Lemeshow test. To enhance the robustness of the validation results, internal assessment was conducted using the Bootstrap method combined with 10-fold cross-validation, and calibration plots and decision curves were used to analyze the clinical application value of the model. A total of 685 patients who underwent TKA were included in the study, and 143 patients developed postoperative shivering, with an incidence rate of 20.88%. Through logistic regression analysis, 5 independent risk factors for postoperative shivering were identified: age over 65 years (OR: 1.784, 95% CI: 1.234-2.654), operating room temperature not exceeding 21°C (OR: 3.024, 95% CI: 2.083-6.174), intraoperative fluid administration exceeding 1500 mL (OR: 1.970, 95% CI: 1.288-3.194), use of a pain pump (OR: 1.573, 95% CI: 1.116-2.309). Anesthesia duration exceeding 150 minutes (OR: 2.549, 95% CI: 1.607-4.621). Based on the results of receiver operating characteristic curves and the Hosmer-Lemeshow test, combined with bootstrap and cross-validation, the model demonstrates good discriminative ability and adaptability, strong stability, and high clinical reference value. Postoperative shivering after TKA are influenced by multiple factors, and the nomogram model established in this study has good predictive performance, providing a scientific basis for clinical identification of high-risk patients and early intervention.