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[A Perspective View on Peripheral Nerve Block of the Future: Preface and Comments].

Ultrasound-guided nerve blocks (UGNBs) have been gaining popularity since 2000 in Japan. This is not only because ultrasound technology has developed recently but also because remifentanil has become available in 2006 with the risk of opioids for recurrence of cancer after surgery shown in 2006. Thus, UGNBs have been employed widely in the anesthesiology field, and anes- thesiologist have tried to reduce consumption of opioid during perioperative periods by using UGNBs, non- steroidal anti-inflammatory drugs, acetoaminophen and so on; that is, multi-modal analgesic technique. In a special issue of this month, experts discuss the efficacy and use of UGNBs for the upper extremities, thorax, abdomen, and lower extremities. In these articles, they will highlight the data on clinical outcome for UGNBs and discuss specific limitations of UGNB. The articles will help readers to know much more about the future direction of UGNBs.