Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea.
Department of Anesthesiology and Pain Medicine, Wonkwang University School of Medicine, 460 Iksan-daero, Iksan 54538, Republic of Korea.
Medicina (Kaunas). 2022 Dec 19;58(12):1871. doi: 10.3390/medicina58121871.
: Although epidural steroid injections are used as an effective treatment, this technique is associated with rare but serious ischemic complications, especially when particulate steroids are used. However, recent studies have reported that even if non-particulate steroids are used, particulates are formed by the interaction with some local anesthetics (LA), causing ischemic complications. This observational study evaluated commonly used combinations of non-particulate steroids and LA with contrast media via microscopic analysis and analyzed the chemical properties of each mixture to identify the correlation of particulate formation. : Commonly used clinical non-particulate and particulate steroids, contrast media, and LA agent combinations were evaluated macroscopically and microscopically. The pH values were also measured at both room temperature (26 °C) and body temperature (36 °C). Where particulates were observed, the particulate size was measured. : Macroscopically, the mixture of non-particulate steroid and ropivacaine had a slightly cloudy appearance at all concentrations, but there was no visible particulate. However, when observed under a microscope, the pH-dependent particulate formation was observed at all concentration combinations tested. (0.1% ropivacaine: from 19 μm to 70 μm, and 0.2% ropivacaine: from 37 μm to 108 μm at room temperature (26 °C)). When contrast media was mixed or the temperature was raised to body temperature (36 °C), the number and size of the particulates decreased or dissolved. : The combination of ropivacaine and dexamethasone, a non-particulate steroid, mainly used in epidural injections, forms particulates. However, when mixed with contrast media, particulates are dissolved because of changes in pH and factors affecting particulate formation. In fluoroscopy-guided injections, the use of contrast media could resolve particulate formation.
虽然硬膜外类固醇注射被用作一种有效的治疗方法，但这种技术与罕见但严重的缺血性并发症有关，尤其是当使用颗粒状类固醇时。然而，最近的研究报告称，即使使用非颗粒状类固醇，与一些局部麻醉剂（LA）相互作用也会形成颗粒，从而导致缺血性并发症。这项观察性研究通过显微镜分析评估了常用的非颗粒状类固醇和 LA 与对比剂的组合，并分析了每种混合物的化学性质，以确定颗粒形成的相关性。
研究人员评估了常用的临床非颗粒状和颗粒状类固醇、对比剂和 LA 制剂组合的宏观和微观特征。还测量了室温（26°C）和体温（36°C）下的 pH 值。在观察到颗粒的地方，测量了颗粒的大小。
宏观上，所有浓度的非颗粒状类固醇和罗哌卡因混合物都呈现出轻微混浊的外观，但没有可见的颗粒。然而，在显微镜下观察时，在所有测试的浓度组合中都观察到了 pH 依赖性的颗粒形成。（0.1%罗哌卡因：从 19μm 到 70μm，0.2%罗哌卡因：从 37μm 到 108μm，室温（26°C））。当混合对比剂或温度升高到体温（36°C）时，颗粒的数量和大小减少或溶解。
罗哌卡因和地塞米松的组合，一种常用于硬膜外注射的非颗粒状类固醇，主要形成颗粒。然而，当与对比剂混合时，由于 pH 值的变化和影响颗粒形成的因素，颗粒会溶解。在荧光镜引导下注射时，使用对比剂可以解决颗粒形成的问题。
