【正文】 椎管內(nèi)麻醉 Neuraxial Anesthesia 夏 瑞 Introduction——Correlated Anatomy ? 三條韌帶 (由外到內(nèi) ) – 棘上韌帶 supraspinous ligament – 棘間韌帶 interspinous ligament – 黃韌帶 ligamentum flavum (yellow ligament) Correlated Anatomy ? 脊髓由脊膜所包裹 ? 脊膜 (由內(nèi)至外 )分為： – 軟膜 pia mater – 蛛網(wǎng)膜 arachnoid mater – 硬脊膜 dura mater ? 兩層：內(nèi)膜、外膜 ? 硬膜外腔 epidural space 硬脊膜內(nèi)、外層之間的區(qū)域 ? 蛛網(wǎng)膜下腔 subarachnoid space 軟膜和蛛網(wǎng)膜之間的區(qū)域 Correlated Anatomy Classification of Neuraxial Anesthesia ?蛛網(wǎng)膜下腔阻滯麻醉 Spinal Anesthesia ?硬膜外腔阻滯麻醉 Epidural Anesthesia ?蛛網(wǎng)膜下腔與硬膜外腔聯(lián)合阻滯麻醉 Combined spinalepidural Anesthesia ,CSEA ?骶管阻滯麻醉 Caudal Anesthesia 第一節(jié) 蛛 網(wǎng) 膜 下 腔 阻 滯（脊麻 ) Section one Subarachnoid block (spinal anesthesia) ? 定義 （ definition） The agent is injected into the CSF(cerebrospinal fluid) in the subarachnoid space of the meninges (the threelayered covering of the spinal cord) using a lumbar interspace in the vertebral column. 局麻藥 腦脊液 脊神經(jīng)、背根神經(jīng)節(jié)及脊髓表面 一、概述 (outline) 第一節(jié) 蛛 網(wǎng) 膜 下 腔 阻 滯 Section one Subarachnoid block (spinal anesthesia) ?比重： According to the differences of gravity between the local anesthetic and CSF Hyperbaric solution: It is heavier than CSF,and it can be made (重比重 ) by the addition of glucose. Hypobaric solution: It is lighter than CSF,and it can be made (輕比重 ) by the addition of sterile water. Isobaric solution: It is nearly equal to gravity of CSF, and it is (等比重 ) mixed with CSF(at least 1:1). (The gravity of CSF is ～ ) 概述 (outline) 平面： According to the level of neural blockade Spinal anesthesia high position: The sensory blockade ＞ T4 mid position: The sensory blockade≤T5—9 low position: The sensory blockade＜ T10. ―saddle block‖ (鞍麻） means that the level of neural blockade is limited to perineum(會(huì)陰 ) or hip (臀部 ). “Unilateral block‖ means that the level of neural blockade is limited to unilateral lower extremity (單側(cè)阻滯 ) 一、概述 (outline) 二、蛛網(wǎng)膜下隙阻滯的機(jī)制及其對(duì)生理的影響 (The mechanism of action and physiologic responses) 1. 直接作用 (Direct actions) : ▲ The site of action: The principal site of action is the nerve root. ▲ The sequence of block: Autonomic Nf* sensory Nf motor Nf myelinated Ar Nf * (有髓鞘的本體感覺纖維 ) ▲ The differential level of block: Sympathetic block may be 24 segments higher than sensory block, which in turn is 14 segments higher than motor block. Nf: nerve fiber 2. 間接作用 (全身影響 ): Indirect actions(systemic effects) ★ Cardiovascular manifestations——心血管系統(tǒng)影響 Sympathetic Nf block vasodilation of venous capacitance vessels capacity of venous return to heart arterial vasodilation systemic vascular resistance sympathetic cardiac accelarator fibers block HR BP Indirect actions(systemic effects) ★ Pulmonary manifestations（ 呼吸系統(tǒng)影響） ? Tidal volume remains unchanged during high spinal anesthesia, and vital capacity decreases a small amount from to L 潮氣量改變不明顯 ,肺活量少量下降 ? The rare respiratory arrest associated with spinal anesthesia is also unrelated to phrenic or inspiratory dysfunctio