Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan.
Anesthesiology. 2010 Jun;112(6):1473-81. doi: 10.1097/ALN.0b013e3181d4f66f.
Postoperative pain management is important for preventing perioperative complications. The authors examined the effectiveness of controlled-release lidocaine for sciatic nerve block in a rat model of postoperative pain.
The authors created a novel slow-release lidocaine sheet (SRLS) with polylactic-coglycolic acid. In male Sprague-Dawley rats (postoperative pain model), the authors applied the SRLS, lidocaine alone, or polylactic-coglycolic acid (control) near the ipsilateral sciatic nerve just before making the paw incision. Mechanical hypersensitivity was assessed using von Frey filaments, and c-fos expression was examined in the spinal cord dorsal horn at segments L4-L5. Neurotoxicity and muscle toxicity were also evaluated via histopathology.
The SRLS (30%, w/w) continuously released lidocaine for 1 week in vitro. The withdrawal threshold in the SRLS-treated group was higher than that in the control group at all time points measured (2 h to 7 days). The withdrawal threshold in the lidocaine-treated group was higher than that in the control group only at 2 h after paw incision. The mean number of c-fos immunoreactive neurons in the SRLS-treated group was lower than in the control group at 2, 5, and 48 h after paw incision and lower than in the lidocaine-treated group at 5 and 48 h after paw incision. On histopathology, signs of inflammation were only slightly present in the muscle and nerve tissues of the SRLS-treated group.
Single treatment with the SRLS inhibited hyperalgesia and c-fos expression in the spinal cord dorsal horn for 1 week. Slow-release local anesthetics are promising for the management of postoperative pain.
术后疼痛管理对于预防围手术期并发症很重要。作者研究了控释型利多卡因用于坐骨神经阻滞在大鼠术后疼痛模型中的效果。
作者使用聚乳酸-乙醇酸制作了一种新型的控释利多卡因贴剂（SRLS）。在雄性 Sprague-Dawley 大鼠（术后疼痛模型）中，作者在制作爪切口前将 SRLS、单独的利多卡因或聚乳酸-乙醇酸（对照）应用于同侧坐骨神经附近。使用 von Frey 纤维评估机械性超敏反应，并用脊髓背角 L4-L5 节段评估 c-fos 表达。还通过组织病理学评估神经毒性和肌肉毒性。
SRLS（30%，w/w）在体外持续释放利多卡因 1 周。在所有测量时间点（2 小时至 7 天），SRLS 治疗组的退缩阈值均高于对照组。在爪切口后 2 小时，利多卡因治疗组的退缩阈值高于对照组。在爪切口后 2、5 和 48 小时，SRLS 治疗组的 c-fos 免疫反应性神经元数量低于对照组，在爪切口后 5 和 48 小时，SRLS 治疗组的 c-fos 免疫反应性神经元数量低于利多卡因治疗组。在组织病理学上，SRLS 治疗组的肌肉和神经组织中仅存在轻微的炎症迹象。
单次 SRLS 治疗可抑制脊髓背角痛觉过敏和 c-fos 表达 1 周。缓慢释放的局部麻醉剂有望用于管理术后疼痛。
