Rebound pain after a single-injection peripheral nerve block is common, distressing and predictable, and practice on preventing it has been built largely on habit. This network meta-analysis pooled 24 randomised trials covering 2,130 patients and eight interventions to rank them.
Intravenous dexamethasone came first for reducing the incidence of rebound pain, with a SUCRA of 0.91 and a judgement of definitely superior to control. Perineural dexamethasone and perineural dexmedetomidine ranked highest on the different question of delaying rebound pain and prolonging time to first rescue analgesia. So the route matters, and it matters differently depending on whether the goal is preventing the event or postponing it.
The finding most likely to change what people do is negative. Pre-emptive opioids were probably inferior to control — that is, worse than doing nothing. Giving an opioid before the block wears off is a widespread instinct and this analysis does not support it.
Certainty ranged from very low to moderate, and pain severity, satisfaction and sleep disturbance were reported too inconsistently to pool at all. So the ranking is the useful output, not any effect size. For a unit that gives regular single-injection blocks, intravenous dexamethasone as routine prophylaxis is a defensible protocol change today, and it is cheap and familiar.
- Give intravenous dexamethasone as prophylaxis for single-injection peripheral nerve blocks unless contraindicated.
- Drop pre-emptive opioids for this indication: they ranked probably inferior to control.
- If the aim is prolonging the block rather than preventing rebound, the perineural adjuncts ranked higher.
- Do not quote an effect size to patients — only rankings could be pooled reliably.
- Check glycaemic protocols before making intravenous dexamethasone routine in diabetic surgical lists.
The statistics, in plain English
SUCRA is the probability that an intervention sits among the best in the network, so 0.91 means intravenous dexamethasone was near the top across almost every simulation. That is a ranking, not an effect size: it says which is likely best, not by how much. The phrase doing the real work is the authors' own judgement of definitely superior to control, which is a GRADE-style statement combining effect and certainty rather than a p value. Note what could not be analysed: pain severity, satisfaction and sleep were reported too inconsistently to pool, so this ranks interventions on whether rebound pain happened, not on how bad it was. Certainty from very low to moderate means several of these comparisons could move with better trials.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for anaesthesiology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free