Joyce Philip I, Rizzi Daniela, Caló Girolamo, Rowbotham David J, Lambert David G
University Department of Anaesthesia and Pain Management, Leicester Royal Infirmary, Leicester LE1 5WW, UK.
Anesth Analg. 2002 Nov;95(5):1339-43, table of contents. doi: 10.1097/00000539-200211000-00045.
Complex regional pain syndrome is often treated with the sympatholytic guanethidine and a local anesthetic in a Bier's block. The efficacy of this treatment has been questioned. Because local anesthetics inhibit the norepinephrine uptake transporter, we hypothesized that this variable efficacy results from the local inhibiting the uptake of guanethidine. In this study, we tested this hypothesis by using a sympathetically innervated mouse vas deferens preparation. Organ bath-mounted mouse vasa deferentia were electrically stimulated in the absence and presence of guanethidine, prilocaine, procaine, and cocaine in various combinations. Prilocaine (1 mM) induced an immediate inhibition of twitch response (maximum 100% after 2 min) that fully reversed after washing. Guanethidine (3 microM) also inhibited twitching by 95% +/- 3% in 15 min, but this effect was only partially reversed after 1 h of washing (33% +/- 12% of control). When prilocaine and guanethidine were added in combination, a reversal of 80% +/- 13% (at 1 h) was observed. Procaine (300 micro M) produced a transient increase (152% +/- 14%) in response. When co-incubated with guanethidine (3 microM), the twitch was reduced to 24% +/- 4% of control and was reversed to 77% +/- 7% after 1 h. Cocaine (30 microM) inhibited the twitch response to 53% +/- 8%, which was fully reversed by 1 h of washing. When co-incubated with guanethidine, the response was reduced to 39% +/- 6% of control and was reversed to 86% +/- 10% after 1 h. In all cases, the reversal produced by the combination was significantly more intense (P < 0.05) than that produced by guanethidine alone. Local anesthetics reduce the sympatholytic actions of guanethidine, and this may explain the variable efficacy of guanethidine in the treatment of complex regional pain syndrome.
In this study, with a sympathetically innervated vas deferens preparation, local anesthetics reduced the efficacy of the sympatholytic guanethidine, questioning its co-administration in the pain clinic.
复杂性区域疼痛综合征通常采用交感神经阻滞药胍乙啶和局部麻醉药进行 Bier 阻滞治疗。这种治疗方法的疗效一直受到质疑。由于局部麻醉药会抑制去甲肾上腺素摄取转运体，我们推测这种疗效的差异是由于局部麻醉药抑制了胍乙啶的摄取。在本研究中，我们通过使用交感神经支配的小鼠输精管制备物来验证这一假设。将安装在器官浴中的小鼠输精管在有无胍乙啶、丙胺卡因、普鲁卡因和可卡因的各种组合下进行电刺激。丙胺卡因（1 mM）可立即抑制抽搐反应（2 分钟后最大抑制率为 100%），冲洗后完全逆转。胍乙啶（3 microM）在 15 分钟内也可使抽搐抑制 95%±3%，但冲洗 1 小时后这种作用仅部分逆转（为对照的 33%±12%）。当丙胺卡因和胍乙啶联合使用时，观察到 1 小时后的逆转率为 80%±13%。普鲁卡因（300 microM）可使反应短暂增加（152%±14%）。当与胍乙啶（3 microM）共同孵育时，抽搐降至对照的 24%±4%，1 小时后逆转至 77%±7%。可卡因（30 microM）可将抽搐反应抑制至 53%±8%，冲洗 1 小时后完全逆转。当与胍乙啶共同孵育时，反应降至对照的 39%±6%，1 小时后逆转至 86%±10%。在所有情况下，联合使用产生的逆转作用均明显强于单独使用胍乙啶（P < 0.05）。局部麻醉药会降低胍乙啶的交感神经阻滞作用，这可能解释了胍乙啶在治疗复杂性区域疼痛综合征时疗效的差异。
在本研究中，利用交感神经支配的输精管制备物，局部麻醉药降低了交感神经阻滞药胍乙啶的疗效，这对其在疼痛诊所的联合使用提出了质疑。
