Department of Anesthesiology, Cleveland Clinic, Cleveland, Ohio, USA.
Department of Anesthesiology and Reanimation, Ataturk University, Medical School, Erzurum, Turkey.
Reg Anesth Pain Med. 2020 Jul;45(7):552-556. doi: 10.1136/rapm-2019-101154. Epub 2020 Apr 21.
Cervical erector spinae plane (ESP) block has been described to anesthetize the brachial plexus (BP), however, the mechanism of its clinical effect remains unknown. As the prevertebral fascia encloses the phrenic nerves, BP and erector spinae muscles to form a prevertebral compartment, a local anesthetic injected in the cervical ESP could potentially spread throughout the prevertebral compartment. This study utilizes cadaveric models to evaluate the spread of ESP injections at the C6 and C7 levels to determine whether the injection can reach the BP and its surrounding structures.
For each of the five cadavers, an ESP injection posterior to the transverse process of C6 was performed on one side, and an ESP injection posterior to the transverse process of C7 was performed on the contralateral side. Injections were performed under ultrasound guidance and consisted of a 20 mL mixture of 18 mL water and 2 mL India ink. After cadaver dissection, craniocaudal and medial-lateral extent of the dye spread in relation to musculoskeletal anatomy as well as direct staining relevant nerves was recorded. The degree of dye staining was categorized as "deep," "faint," or "no."
The phrenic nerve was deeply stained in 1 injection and faintly stained in 2 injections. Caudally, variable staining of C8 (100%) and T1 (50%) roots were seen. Faintly staining at C4 root was only seen in one sample (10%). There was variable staining of the anterior scalene muscles (40%) anterior to the BP and the rhomboid intercostal plane caudally (30%).
Ultrasound-guided cervical (C6 and C7) ESP injections consistently stain the roots of the BP and dorsal rami. This study supports the notion that the cervical ESP block has the potential to provide analgesia for patients undergoing shoulder and cervical spine surgeries.
颈椎竖脊肌平面（ESP）阻滞已被描述为用于麻醉臂丛（BP），但其临床效果的机制尚不清楚。由于椎前筋膜将膈神经、BP 和竖脊肌包围在一个椎前间隙内，因此在颈椎 ESP 内注射局部麻醉剂可能会扩散到整个椎前间隙。本研究利用尸体模型评估 C6 和 C7 水平 ESP 注射的扩散情况，以确定注射是否能到达 BP 及其周围结构。
对于每个 5 个尸体，在一侧进行 C6 横突后 ESP 注射，在对侧进行 C7 横突后 ESP 注射。注射在超声引导下进行，由 18ml 水和 2ml 印度墨水组成的 20ml 混合物组成。尸体解剖后，记录染料在肌肉骨骼解剖结构中的头尾和内外延伸程度以及对相关神经的直接染色情况。染料染色程度分为“深”、“浅”或“无”。
膈神经在 1 次注射中被深染，在 2 次注射中被浅染。在尾部，C8（100%）和 T1（50%）根有不同程度的染色。仅在一个样本（10%）中可见 C4 根的浅染色。BP 前的前斜角肌（40%）和尾部的菱形肋间平面（30%）有不同程度的染色。
超声引导的颈椎（C6 和 C7）ESP 注射可始终对 BP 和背侧皮支染色。本研究支持颈椎 ESP 阻滞有可能为接受肩部和颈椎手术的患者提供镇痛的观点。
