Abstract
BACKGROUND: Postoperative rebound pain, refers to an acute exacerbation of pain severity following the resolution of a peripheral nerve block (PNB). This transient but intense pain typically manifests within 24 h after block administration. Despite its clinical significance, rebound pain remains poorly characterized in trauma surgery populations. OBJECTIVE: This retrospective cohort study aimed to investigate the incidence and associated risk factors of rebound pain in orthopedic trauma surgery patients receiving PNB anaesthesia. METHODS: Adult patients undergoing orthopedic trauma surgery with preoperative PNB between April 2023 and March 2025 were included. Rebound pain was operationally defined as a transition from well-controlled pain (numerical rating scale [NRS] ≤ 3) to severe pain (NRS ≥ 7) within 24 h post-block. Potential associations with rebound pain including patient characteristics, surgical and anesthetic factors were examined by using univariate and multivariable logistic regression analyses. RESULTS: Four hundred and thirty-five (41.9%) of 1037 included patients experienced postoperative rebound pain. Multivariable analysis showed that the factors independently associated with rebound pain were younger age (OR 0.797; 95% CI [0.655-0.971]), diabetes (OR 1.439; 95% CI [1.249-2.832]), preoperative moderate-to-severe pain (OR 2.353; 95% CI [2.234-2.543]), preoperative Neutrophil-lymphocyte ratio (NLR) elevation (OR 2.034; 95% CI [1.759-2.454]), and surgery involving bone (OR 2.786; 95% CI [2.553-3.147]), but a lower risk of rebound pain was perioperative i.v. dexamethasone (OR 0.462; 95% CI [0.304-0.632]) or i.v. dexmedetomidine (OR 0.363; 95% CI [0.238-0.545]). Despite a high incidence of rebound pain, there were high rates of patient satisfaction (80.5%), and there was no statistical difference in sleep quality. CONCLUSIONS: Postoperative rebound pain showed associations with younger age, diabetes, preoperative moderate-to-severe pain, preoperative NLR elevation, bone surgery, and absence of intraoperative use of i.v. dexamethasone or dexmedetomidine. The current data suggest that preventive measures remain clinically warranted, especially for at higher risk patients, though future studies are needed to refine optimal protocols.