Tsutsui Yukako, Sunada Katsuhisa
Department of Dental Anesthesiology, The Nippon Dental University School of Life Dentistry at Tokyo, Japan.
Anesth Prog. 2017 Winter;64(4):230-234. doi: 10.2344/anpr-65-01-08.
Recent reports have stated that dexmedetomidine (DEX), an α-adrenoreceptor agonist, enhances the local anesthetic effects of ropivacaine and prolongs its effective duration. However, little is known about the effect of a combination of DEX and lidocaine on anesthetic duration. Therefore, we investigated whether DEX can prolong the local anesthetic effect of lidocaine, using the thermal paw withdrawal test in Wistar rats in order to measure local anesthetic duration. We subcutaneously injected 50 μL of either normal saline, 2% lidocaine, a combination of 0.5 μg/kg DEX and 2% lidocaine, or a combination of 2% lidocaine with 1:80,000 epinephrine into the plantar surface of the left hind paw of the rats. The plantar region was stimulated using heat. We measured the perceived acute pain according to paw movement in response to stimulation. We found DEX significantly prolonged the paw withdrawal latency of lidocaine. Moreover, we found that DEX can prolong the local anesthetic duration of lidocaine as much as 1:80,000 epinephrine, up to 35 minutes after injection. In conclusion, this study concluded that a combination of DEX and lidocaine may be useful as a local anesthetic, similar to a combination of epinephrine and lidocaine, for short procedures.
近期报道称，α-肾上腺素能受体激动剂右美托咪定（DEX）可增强罗哌卡因的局部麻醉效果并延长其有效持续时间。然而，关于DEX与利多卡因联合使用对麻醉持续时间的影响却知之甚少。因此，我们通过在Wistar大鼠中进行热足退缩试验以测量局部麻醉持续时间，来研究DEX是否能延长利多卡因的局部麻醉作用。我们将50μL生理盐水、2%利多卡因、0.5μg/kg DEX与2%利多卡因的组合，或2%利多卡因与1:80,000肾上腺素的组合皮下注射到大鼠左后爪的足底表面。使用热刺激足底区域。我们根据爪子对刺激的运动反应来测量感知到的急性疼痛。我们发现DEX显著延长了利多卡因的足退缩潜伏期。此外，我们发现DEX可将利多卡因的局部麻醉持续时间延长至与1:80,000肾上腺素相同的程度，注射后长达35分钟。总之，本研究得出结论，对于短时间手术，DEX与利多卡因的组合可能作为局部麻醉剂有用，类似于肾上腺素与利多卡因的组合。
