Yamada Tomotsugu, Hasegawa-Moriyama Maiko, Kurimoto Tae, Saito Takayuki, Kuwaki Tomoyuki, Kanmura Yuichi
From the *Department of Anesthesiology and Critical Care Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; †Department of Anesthesiology and Pain Medicine, Juntendo University School of Medicine, Tokyo, Japan; and ‡Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
Reg Anesth Pain Med. 2016 Sep-Oct;41(5):593-600. doi: 10.1097/AAP.0000000000000458.
Anesthesia with peripheral nerve block (PNB) improves the early recovery profile of patients undergoing surgery, including the control of postoperative pain, opioid consumption, and the length of hospital stay. However, the influence of PNB on wound inflammation and the repair process has not been fully investigated. Therefore, we evaluated the effects of PNB on local inflammation of incised tissue in the acute phase of postoperative pain development.
Sciatic nerve block with 0.5% ropivacaine was performed before plantar incision in mice. Pain behavior, neutrophil infiltration, phagocytosis of apoptotic cells, and gene induction of inflammatory mediators were assessed for 7 days postoperatively.
Sciatic nerve block with 0.5% ropivacaine treatment transiently increased the withdrawal threshold to mechanical stimuli and thermal latency for 2 hours after surgical incision, whereas no changes were observed from 3 hours after incision throughout the postoperative period. However, Gr-1 neutrophil infiltration and the number of CD68 macrophages engulfing TdT-mediated dUTP nick-end labeling apoptotic cells were significantly increased after incision. Tumor necrosis factor α and prostaglandin E2 were up-regulated at the incised sites. In addition, the expressions of lipoxygenase-15 and heme oxygenase-1, which resolve inflammation and promote wound healing after the acute inflammatory phase, were increased.
Single PNB before incision promoted acute phase inflammation mediated by neutrophils and macrophages at the sites of incision, whereas postoperative pain was not altered. Peripheral nerve block might locally accelerate innate immune responses after surgical incision without altering the nociceptive profile.
外周神经阻滞（PNB）麻醉可改善手术患者的早期恢复情况，包括术后疼痛控制、阿片类药物用量及住院时间。然而，PNB对伤口炎症及修复过程的影响尚未得到充分研究。因此，我们评估了PNB对术后疼痛急性期切开组织局部炎症的影响。
在小鼠足底切开前用0.5%罗哌卡因进行坐骨神经阻滞。术后7天评估疼痛行为、中性粒细胞浸润、凋亡细胞吞噬作用及炎症介质的基因诱导情况。
0.5%罗哌卡因治疗的坐骨神经阻滞在手术切口后2小时内短暂提高了对机械刺激的撤足阈值和热潜伏期，但在切口后3小时至整个术后期间未观察到变化。然而，切口后Gr-1中性粒细胞浸润及吞噬TdT介导的dUTP缺口末端标记凋亡细胞的CD68巨噬细胞数量显著增加。肿瘤坏死因子α和前列腺素E2在切开部位上调。此外，在急性炎症期后可减轻炎症并促进伤口愈合的脂氧合酶-15和血红素加氧酶-1的表达增加。
切开前单次PNB促进了切口部位由中性粒细胞和巨噬细胞介导的急性期炎症，而术后疼痛未改变。外周神经阻滞可能在不改变伤害感受的情况下局部加速手术切口后的固有免疫反应。
