【原】【罂粟摘要】含有和不含有选择性佐剂的局麻药混合物的结晶：半定量光学显微镜分析

含有和不含有选择性佐剂的局麻药混合物的结晶：半定量光学显微镜分析

贵州医科大学  麻醉与心脏电生理课题组

翻译：周菁  编辑：王婷婷  审校：曹莹  

引言：在区域麻醉，尤其是产科麻醉中，注射含有或不含有佐剂的局麻药混合物是一种常见的做法，以减少剖宫产的阻滞开始时间和/或增强硬膜外镇痛。虽然这种做法的疗效证据尚不明确，但就局部麻醉剂的药理学兼容性而言，对其安全性知之甚少。

方法：我们使用半定量光学显微镜（范围从0到5）评估了七种局部麻醉剂（布比卡因、罗哌卡因、利多卡因、普鲁卡因、氯普鲁卡因、甲哌卡因、丙胺卡因）与四种佐剂（碳酸氢钠、地塞米松、可乐定、芬太尼）的单独混合物中的结晶等级，重复长达60分钟，并进行结晶等级和初始溶液pH之间的相关性分析。

结果：在测试的 50 种混合物中，26 种在混合时显示出结晶等级≥4，41 种在 60 分钟后显示出结晶等级≥4。向局部麻醉混合物中添加佐剂并没有显着改变结晶的等级。与罗哌卡因相比，布比卡因的沉淀倾向稍低。发现佐剂混合物的初始 pH 值与 15 分钟后结晶程度之间存在中等关系（R=0.33，p=0.04），但在其他时间点则不然。

讨论：局部麻醉剂（±佐剂）混合物的制备会导致高程度的结晶，结晶程度会在 60 分钟内增加，并且与溶液 pH 值无关。应严格评估在区域麻醉中混合具有未知物理或化学相容性的药物的风险，并在未来的转化研究中阐明其临床意义。

原始文献来源：Hoerner E, Stundner O, Seisl A, Fiegl H, Gasteiger L. Crystallization of mixtures of local anesthetics with and without select adjuvants: a semiquantitative light microscopy analysis. Reg Anesth Pain Med. 2024;rapm-2023-105229.

Crystallization of mixtures of local anesthetics with and without select adjuvants: a semiquantitative light microscopy analysis

Introduction：Injecting mixtures of local anesthetics with or without adjuvants is a common practise in regional and particularly obstetric anesthesia to decrease block onset time and/or augment epidural analgesia for cesarean section. While evidence on the efficacy of this practise is equivocal, little is known about its safety in terms of the pharmacologic compatibility of local anesthetics.

Method:We assessed the grade of crystallization in individual mixtures of seven local anesthetics (bupivacaine, ropivacaine, lidocaine, procaine, chloroprocaine, mepivacaine, prilocaine) with or without four adjuvants (sodium bicarbonate, dexamethasone, clonidine, fentanyl) using a semiquantitative light microscopy scale (ranging from 0 to 5), repeatedly for up to 60 min and performed correlation analysis between grade of crystallization and initial solution pH.

Results:Of the 50 mixtures tested, 26 showed grades of crystallization ≥4 at admixture and 41 showed grades of crystallization ≥4 after 60 min. The addition of adjuvants to local anesthetic mixtures did not substantially change the grades of crystallization. Bupivacaine has a slightly lower precipitation tendency, compared with ropivacaine. A moderate relationship was found between initial pH and grade of crystallization after 15 min for the adjuvant mixtures (R=0.33, p=0.04), but not at other time points.

Discussion： The preparation of local anesthetic (±adjuvant) mixtures leads to high grades of crystallization, which increase over 60 min and appear independent of solution pH. The risk of mixing medications with unknown physical or chemical compatibility profiles in regional anesthesia should be critically appraised and its clinical significance elucidated in future translational research.