Role of adjuvants in regional anesthesia: A systematic review

The combination of drugs and routes of administration produces a synergistic effect, and one of the most important components of multimodal analgesic strategies are, therefore, nerve blocks for pain management. The effect of a local anaesthetic can be prolonged by administering an adjuvant. In this systematic review, we included studies on adjuvants associated with local anaesthetics in peripheral nerve blocks published in the last 5 years in order to evaluate their effectiveness. The results were reported according to the PRISMA guidelines. The 79 studies selected using our criteria showed a clear prevalence of dexamethasone (n=24) and dexmedetomidine (n=33) over other adjuvants. Different meta-analyses comparing adjuvants suggest that dexamethasone administered perineurally achieves superior blockade with fewer side effects than dexmedetomidine. Based on the studies reviewed, we found moderate evidence to recommend the use of dexamethasone as an adjuvant to peripheral regional anaesthesia in surgeries that can cause moderate to severe pain.

[Peroneal nerve injury: anesthesia is not always to blame]

We introduce a case report of a woman that was operated of foot surgery under locoregional anesthesia with an echo-guided peripheral sciatic-popliteal nerve block. As post operatory complication a peroneal nerve injury was noticed. We revised differential diagnosis of peripheral nerve block and therapeutic strategy we should take. In our case the finding was a high degree axonotmesis secondary to extrinsic compressure due to pneumatic tourniquet placed in the ankle used during surgery. There was no relationship with the anesthetic technique.