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Background and Aims This prospective observational study aimed to explore the frequency and risk factors of rebound pain (RP) in patients treated with multimodal analgesia and intravenous dexamethasone following peripheral nerve block (PNB) for anesthesia and multimodal analgesia in orthopedic surgeries.

Methods This study included patients who received preoperative PNB from August 2022 to December 2023. All patients received a standard multimodal analgesia regimen and intravenous dexamethasone. Motor and sensory block durations, RP severity and frequency were measured for the first 24 h post-PNB using a semi-structured questionnaire. RP was identified as acute postoperative pain within the first 12-24 h after sensory blockade resolution. The severity of RP was determined through the rebound pain score. Contributing risk factors (patient, surgical, or anesthesia-related) to the development of RP were investigated.

Results Following PNB worn off, RP developed in 107 out of 386 patients (27.72%). The following were identified as independent risk factors for RP: patient age, with an adjusted odds ratio (AOR) of 2.323 and a 95% confidence interval (CI) of 1.379–3.915; the use of bupivacaine in combination with lidocaine or prilocaine (AOR: 2.128, 95%CI: 1.206–3.754); preoperative pain (AOR:2.751, 95%CI:1.345–5.623); bone surgery (AOR:1.761, 95% CI:1.025–3.023); and the duration of the surgery (AOR:2.785, 95%CI:1.510–5.137).

Conclusions With standard multimodal analgesia methods and intravenous dexamethasone, the incidence of RP can be lessened. By correctly identifying RP risk factors, we can establish preventative strategies that target changeable factors, leading to optimized use of PNB, decreased RP incidence, and improved results.