Schnabel A, et al. – A meta–analysis of randomised controlled trials was conducted to evaluate the utility and safety of the addition of perineural buprenorphine to local anaesthetic compared with local anaesthetic alone, or combined with systemic administration of buprenorphine, or other perineural opioids for peripheral nerve blocks. This study concluded that the addition of buprenorphine to a local anaesthetic peripheral nerve block prolongs postoperative analgesia for about 8 h but significantly increases the risk for PONV. Moreover, perineural administration is more effective than systemic application but is associated with a similar risk of PONV. Nevertheless, these results were influenced by heterogeneity so that further trials are needed in the future.