Efficacy of different routes of dexamethasone administration for preventing rebound pain following peripheral nerve blocks in adult surgical patients: a systematic review and network meta-analysis

Introduction: Rebound pain, characterised by intense pain or discomfort as the effects of a peripheral nerve block diminish, remains a clinical problem. Peri-operative dexamethasone administration may reduce the incidence of rebound pain. This systematic and network meta-analysis aimed to determine the optimal route of dexamethasone administration for the prevention of rebound pain. Methods: We searched databases for randomised controlled trials according to pre-determined criteria. We compared intravenous and perineural dexamethasone as an adjunct to peripheral nerve blocks, with the control group as a common comparator. The primary outcome was the incidence of rebound pain. The likelihood of an intervention ranking highest was calculated using the surface area under the cumulative ranking curve. Results: In total, 14 studies with 1058 patients were included. When compared with the comparator group, we found that intravenous dexamethasone ranked the highest, with an anticipated effect of 298 fewer cases of rebound pain per 1000 people (odds ratio (OR) (95% credible interval (CrI) 0.12 (0.03–0.44)); moderate certainty evidence). This was followed by perineural dexamethasone with an anticipated effect of 190 fewer cases per 1000 people (OR (95%CrI) 0.34 (0.07–1.32); low certainty evidence). There was no evidence of an effect between the route of administration and time to onset of rebound pain. Discussion: Intravenous dexamethasone was associated with a high probability of decreasing the incidence of rebound pain following peripheral nerve block. This is based on moderate certainty of evidence. Future studies on identifying the optimal dose are now warranted.