Schwartz Ruben H, Hernandez Stephanie, Noor Nazir, Topfer Jacob, Farrell Kyle, Singh Naina, Sharma Ayushi, Varrassi Giustino, Kaye Alan D
Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL.
Florida International University, Herbert Wertheim College of Medicine, Miami, FL.
Pain Physician. 2022 Mar;25(2):E193-E201.
Spinal Anesthesia was the first regional anesthetic technique to be performed. It was performed by Dr. August Bier, known for the Bier block, and his colleagues on August 16, 1898. Dr. Bier opted for, what he referred to at the time as "cocainization of the spinal cord" by introducing 15 mg of cocaine intrathecally prior to the operation. The surgery was largely uneventful and painless. The patient only experienced some vomiting and a headache postoperatively. Dr. Bier's use of neuraxial anesthesia aimed to directly inject local anesthetics in and around the central nervous system (CNS) for more direct control of pain and anesthesia. Local anesthetics were an important discovery in anesthesiology. However, since the advent of local anesthetics and spinal anesthesia as an alternative technique to general anesthesia, much has been learned about both the benefits and adverse effects of local anesthetics. It was quickly learned that use of local anesthetics would be limited by their potential for life-threatening toxic effects. For this reason, there was a push towards development of novel local anesthetics that had a larger therapeutic window with less likelihood of serious side effects. In addition to developing newer local anesthetics, the idea of adding adjuvants provided an opportunity to potentially limit the life-threatening events. These adjuvants would include medications such as epinephrine and alpha-2 agonists, such as clonidine and dexmedetomidine. Other adjuvants include opioids, glucocorticoids, and mineralocorticoids.
In this review, we will delve further into the indications, contraindications, uses, mechanisms, and future of spinal anesthesia and its adjuvants.
A literature review of recent publications in the field of alpha 2 agonists used in spinal anesthetics was carried out from 2015 to present day. Consensus opinions were formulated in various areas.
This literature review was carried out at various medical universities throughout the nation and Europe.
As research has only just begun in this field data is limited at this time.
The use of spinal anesthesia provides a reliable dermatome blockade to facilitate many different surgical procedures. The combination of local anesthetics with opioid medications within the subarachnoid space has been the standard of care. Adjuvant medications like alpha 2 agonists may play a significant role in prolonging spinal blockade as well as limiting cardiovascular complications such as hypotension and bradycardia. The use of alpha 2 agonists instead of opioid medications intrathecally decreases pruritus and delayed respiratory depression. Animal models have demonstrated the synergistic effects of utilizing alpha 2 agonists with opioids in the subarachnoid space. The addition of clonidine to fentanyl and local anesthetic demonstrated a shorter time to neural blockade, but no significant change in duration of the spinal. Interestingly alpha 2 agonists with local anesthetics showed increase block duration compared to opioid with local anesthetics. Further human trials need to be undertaken to analyze the effectiveness of alpha 2 agonists in the intrathecal space, but preliminary data does indicate it is an exemplary alternative to opioids.
脊髓麻醉是最早实施的区域麻醉技术。1898年8月16日，以比尔阻滞闻名的奥古斯特·比尔博士及其同事进行了该操作。比尔博士选择在手术前鞘内注射15毫克可卡因，他当时将此称为“脊髓可卡因化”。手术基本顺利且无痛。患者术后仅出现了一些呕吐和头痛症状。比尔博士使用神经轴麻醉旨在将局部麻醉药直接注射到中枢神经系统（CNS）及其周围，以更直接地控制疼痛和麻醉。局部麻醉药是麻醉学中的一项重要发现。然而，自局部麻醉药和脊髓麻醉作为全身麻醉的替代技术出现以来，人们对局部麻醉药的益处和不良反应有了更多了解。很快人们就认识到，局部麻醉药的使用会受到其潜在的危及生命的毒性作用的限制。因此，人们推动开发具有更大治疗窗且严重副作用可能性较小的新型局部麻醉药。除了开发更新的局部麻醉药外，添加佐剂的想法为潜在地限制危及生命的事件提供了机会。这些佐剂包括肾上腺素和α-2激动剂等药物，如可乐定和右美托咪定。其他佐剂包括阿片类药物、糖皮质激素和盐皮质激素。
在本综述中，我们将进一步深入探讨脊髓麻醉及其佐剂的适应证、禁忌证、用途、作用机制和未来发展。
对2015年至今该领域中用于脊髓麻醉的α2激动剂的近期出版物进行了文献综述。在各个领域形成了共识意见。
本文献综述在全国和欧洲的多所医科大学进行。
由于该领域的研究才刚刚开始，目前数据有限。
脊髓麻醉的使用为促进许多不同的外科手术提供了可靠的皮节阻滞。蛛网膜下腔内局部麻醉药与阿片类药物的联合使用一直是标准治疗方法。像α2激动剂这样的佐剂药物在延长脊髓阻滞以及限制低血压和心动过缓等心血管并发症方面可能发挥重要作用。鞘内使用α2激动剂而非阿片类药物可减少瘙痒和延迟性呼吸抑制。动物模型已证明在蛛网膜下腔内将α2激动剂与阿片类药物联合使用具有协同作用。在芬太尼和局部麻醉药中添加可乐定显示神经阻滞时间缩短，但脊髓麻醉持续时间无显著变化。有趣的是，与局部麻醉药联合使用阿片类药物相比，α2激动剂与局部麻醉药联合使用显示阻滞持续时间增加。需要进行进一步的人体试验来分析α2激动剂在鞘内空间的有效性，但初步数据确实表明它是阿片类药物的一种典范替代品。
