Richardson J, Jones J, Atkinson R
Department of Anesthetics, Bradford Royal Infirmary, England.
Anesth Analg. 1998 Aug;87(2):373-6. doi: 10.1097/00000539-199808000-00025.
The paravertebral nerve blocks used in upper abdominal or thoracic surgery provide excellent pain relief and can inhibit some aspects of the neuroendocrine stress response to surgical trauma, which suggests that a very high-quality afferent block can be effected. To confirm this, we evaluated intercostal somatosensory evoked potentials (SSEPs) in 10 patients undergoing paravertebral nerve blocks as a treatment for chronic pain. SSEPs were recorded before and after ipsilateral thoracic paravertebral deposition of 1.5 mg/kg bupivacaine 0.5%. Sensory loss to temperature was demonstrated in all patients at the level of injection and had a mean superior spread of 1.4 (range 0-4) dermatomes and a mean inferior spread of 2.8 (range 0-7) dermatomes. SSEPs were abolished (the normal waveform was rendered unrecognizable with unmeasurable latencies and a mean amplitude of zero) in all patients at the level of injection. In addition, a two-dermatome SSEP abolition was found in four patients and a three-dermatome abolition was found in two patients. SSEPs were modified, but not significantly, at all other test points. We conclude that cortical responses to thoracic dermatomal stimulation can be abolished at the block level and adjacent dermatomes by thoracic paravertebral nerve blockade. Equivalent results have not been demonstrated with more central forms of afferent blockade, which suggests that thoracic paravertebral nerve blocks may be uniquely effective.
To improve outcomes after major surgery, as much nociceptive information as possible should be prevented from entering the central nervous and neuroendocrine systems. We have shown that local anesthetics alongside the vertebral column can abolish the usual brain recordings that follow intercostal nerve stimulation, which suggests that paravertebral nerve blocks may be uniquely effective.
上腹部或胸部手术中使用的椎旁神经阻滞可提供出色的疼痛缓解效果，并能抑制手术创伤引起的神经内分泌应激反应的某些方面，这表明可以实现非常高质量的传入阻滞。为了证实这一点，我们评估了10例接受椎旁神经阻滞治疗慢性疼痛患者的肋间体感诱发电位（SSEP）。在同侧胸部椎旁注入1.5mg/kg 0.5%布比卡因前后记录SSEP。所有患者在注射水平均出现温度感觉丧失，平均向上扩散1.4个（范围0 - 4）皮节，平均向下扩散2.8个（范围0 - 7）皮节。在注射水平，所有患者的SSEP均消失（正常波形无法辨认，潜伏期无法测量，平均波幅为零）。此外，4例患者出现两个皮节的SSEP消失，2例患者出现三个皮节的SSEP消失。在所有其他测试点，SSEP有改变，但不显著。我们得出结论，胸椎旁神经阻滞可在阻滞水平及相邻皮节消除对胸部皮节刺激的皮质反应。更中枢形式的传入阻滞尚未显示出等效结果，这表明胸椎旁神经阻滞可能具有独特的有效性。
为改善大手术后的结局，应尽可能防止更多伤害性信息进入中枢神经和神经内分泌系统。我们已表明，脊柱旁的局部麻醉药可消除肋间神经刺激后通常的脑电记录，这表明胸椎旁神经阻滞可能具有独特的有效性。
