Prophylactic interventions to prevent rebound pain after peripheral nerve block in adults: a systematic review and network meta‐analysis of randomised controlled trials

INTRODUCTION: Rebound pain after peripheral nerve block is recognised increasingly as a postoperative complication that may diminish the benefits of regional anaesthesia. We undertook a systematic review and network meta-analysis to evaluate pharmacological strategies for its prevention. METHODS: We searched relevant databases for randomised controlled trials in adults undergoing surgery with peripheral nerve blocks. The primary outcome was the incidence of rebound pain. Secondary outcomes were: timing and severity of rebound pain; time to first rescue analgesia; patient satisfaction; sleep disturbance; and intervention-related adverse effects. RESULTS: Twenty-four randomised controlled trials (2130 patients, eight interventions) were included. Intravenous dexamethasone had the highest probability of reducing rebound pain incidence (surface under the cumulative ranking curve 0.91) and was judged 'definitely superior' to control. Perineural dexamethasone and perineural dexmedetomidine ranked highest for delaying rebound pain and prolonging time to first rescue analgesia. Pre-emptive opioids were probably inferior to control. Certainty of evidence ranged from very low to moderate. Data for pain severity, patient satisfaction and sleep disturbance were reported inconsistently and could not be pooled. DISCUSSION: Intravenous dexamethasone was the most effective intervention for preventing rebound pain following single-injection peripheral nerve blocks. Perineural dexamethasone and dexmedetomidine showed benefit in delaying onset and prolonging analgesia. These findings support intravenous dexamethasone as a first-line prophylactic drug, while highlighting the need for adequately powered trials of alternative strategies.