Predictive model for postoperative hyperalgesia in patients with lower limb fractures undergoing nerve block surgery.

OBJECTIVE

To establish and validate a predictive model for postoperative hyperalgesia in patients with lower limb fractures undergoing nerve block surgery.

METHODOLOGY: This retrospective study analyzed 168 patients receiving postoperative nerve block analgesia at Huzhou Nanxun Hospital of Traditional Chinese Medicine (January 2022-October 2024). Patients were stratified into hyperalgesia and non-hyperalgesia groups. Logistic regression identified independent risk factors, followed by the development and validation of a nomogram model using R.

RESULTS

Hyperalgesia incidence was 14.88% (25/168). Significant differences existed in smoking history, diabetes history, operation time, distal compression at the injection site at injection site, and ropivacaine dosage (P<0.05). Multivariate analysis confirmed diabetes history (OR=4.12), operation time (OR=3.85), distal compression at the injection site (OR=0.24), and ropivacaine dosage (OR=3.21) as independent predictors (P<0.05). The nomogram achieved an AUC of 0.819 (95%CI: 0.732-0.906), with a calibration curve slope of 1 and an intercept <0.001. Decision curve analysis showed optimal net benefit at threshold probabilities between 0.05 and 0.55.

CONCLUSION

Postoperative hyperalgesia is primarily associated with a history of diabetes, prolonged operation time, absence of distal compression at the injection site, and higher ropivacaine dosage. The validated nomogram provides accurate individualized risk prediction.