Transcript 椎管内麻醉

椎管内麻醉
Intrathecal Anesthesia
临床麻醉教研室
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Concepts:
Subarachnoid space(csf) →subarachnoid block
(spinal anesthesia)
Local anesthetic
Epidural space →epidural and caudal anesthesia
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第一节 蛛 网 膜 下 隙 阻 滞
Section one Subarachnoid block (spinal anesthesia)
一、概述(outline)
Block classifications:
1.According
to the differences of gravity between the local
anesthetic and csf:
◆Hyperbaric solution: It is heavier than csf,and it can be made by
(重比重)
the addition of glucose.
◆Hypobaric solution: It is lighter than csf ,and it can be made by
(轻比重)
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 1.003～1.009)
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2.According to the level of neural blockade:
high position: The sensory blockade ＞T4
Spinal anesthesia mid position: The sensory blockade≤T5—9
low position: The sensory blockade＜T10.
“saddle block”:
means that the level of neural blockade is
(鞍麻）
limited to perineum(会阴) or hip (臀部).
“Unilateral block”:means that the level of neural blockade
(单侧阻滞)
is limited to unilateral lower extremity.
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二、蛛网膜下隙阻滞的机制及其对生理的影响
(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
(有髓鞘的本体感觉纤维)
▲ The differential level of block:
Sympathetic block may be 2-4 segments higher than
sensory block, which in turn is 1-4 segments higher
than motor block.
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2. 间接作用(全身影响):
Indirect actions(systemic effects):
★ Cardiovascular manifestations:
vasodilation of venous capacitance vessels
↓
capacity of venous return to heart↓
Sympathetic nf block
arterial vasodilation
↓
systemic vascular resistance↓
BP↓
sympathetic cardiac accelarator fibers block
↓
HR↓
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★ Pulmonary manifestations:
Clinically significant alteration in pulmonary physiology are
usually minimal with spinal block. even with high thoracic levels,
tidal volume(潮气量) is unchanged;there is but a small decrease in
vital capacity(肺活量).
patients with severe chronic lung disease may rely on
accessory muscles of respiration(intercostal and abdominal
muscles) to actively inspire or exhale.These muscles will be
impared below the level of the block,for these reasons,spinal block
should be used with caution in patients with limited
respiratory reserve.
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★Gastrointestinal manifestations:
Spinal block
induces
sympathectomy allows vagal tone
（交感神经阻滞）
dominance
（迷走张力占优势）
results in a contracted gut with active peristasis.
（内脏收缩，蠕动↑）
★Urinary tract manifestations:
Renal blood flow is maintained through autoregulation, and
there is little clinical effect on renal function from spinal block.
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三、蛛网膜下隙阻滞的临床应用
(The clinical applications of subarachnoid block)
(一)适应证(indications)：
▼Lower abdominal, inguinal（腹股沟的） surgery.
▼Urogenital(泌尿生殖器的),rectal(直肠的)surgery.
▼Lower extremity surgery.
▼Lumbar spinal surgery.
▼Neonatal(新生儿的)surgery.
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( 二) 禁忌证(contraindications)：
◆Absolute:
▼ Preexisting neurologic deficits or demyelinating
lesion or increased intracranial pressure(ICP↑).
▼ Infection at the site of injection or sepsis.
▼ Severe hypovolemia.
▼ Coagulopathy or other bleeding diathesis.
▼ Severe aortic stenosis or severe mitral stenosis.
▼ Patient refusal.
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◆Relative:
▼Spinal deformity.
▼Hypertention accompanied by coronary artery disease.
▼Increased intra-abdominal pressure(pregnancy:term
parturient;ascites;large abdominal tumors).
▼Uncooperative patient(dementia;psychosis;emotional
instability;young children)
◆Controversial:
▼Prior back surgery at the site of injection.
▼Maneuvers that compromise respiration.
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(三)常用局麻药：
(Commonly used spinal anesthetic agents)
▲Procaine：procaine 150mg+csf2.7ml or
+ 5%G.S 2.7ml+0.1%Adr0.3ml.
▲Dicaine: 最常用重比重液（1-1-1溶液）:
1%Dicaine 1ml+3-5% Ephedrine 1ml+10%G.S 1ml：
即: 0.33%Dicaine（10-15mg，最高≯20mg)
▲Bupivacaine：常用重比重液：
0.75% Bupivacaine 2ml+10%GS 1ml
常用8-12mg，最多≯20mg.
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(四)蛛网膜下隙穿刺术:
( Performing a lumbar puncture)
●体位 (Patient position):
★Sitting position:
★Lateral decubitus:
★Prone position:
●定位(Identification of lumbar interspaces):
A line drawn between both iliac crests usually crosses
either the body of L4 or the L3-4 interspace.
●穿刺间隙(Lumbar interspace of penetration): L3-4.
Performing a lumbar puncture below L1 in adults
or L3 in children avoids needle trauma to the cord. 14
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●方法(approachs):
★直入法(midline approach)：
The needle is advanced from skin through
subcutaneous tissues to supraspinous ligment
to interspinous ligment to ligamentum flavum
to dura-arachnoid membrances as signaled by
free flowing csf.
★旁入法(paramedian approach):
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(五)阻滞平面的调节
(regulating the level of blockade)
阻滞平面指皮肤感觉消失的界限。
The level of sensory blockade can be assessed
With pinprick. The motor blockade is two segments
lower than the sensory blockade.
麻醉药注入蛛网膜下隙后，要在短时间内主动调节
和控制麻醉平面，达手术所需范围，但应避免平面
过高.
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影响腰麻阻滞平面调节的因素：
(factors affecting the level of spinal anesthesia)
●Most important factors:
▲interspace of penetration:
▲position of the patients , gravity and dosage of
anesthetic solution:
▲the speed of drug injection:
▲the direction of the needle bevel or injection port:
● Other factors:
▲Curvature of the spine: ▲Patient height: ▲Age:
▲ pregnancy: intra-abdominal pressure:
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(六)麻醉中的管理
(intra-anesthesia management)：
●BP↓and HR↓: 多发生于腰麻阻滞平面＞T4者.
▼ 表现:BP↓:多发生于注药后15-30min, 伴HR↓.
严重者 躁动 不安、面色苍白.
小A扩张→外阻↓.
▼ BP↓原因:交感N阻滞
小V扩张→血液淤积于周围
血管系→回心血量↓→C.O.↓.
▼HR↓原因: sympathectomy →vagal tone dominance
▼ 处理: 补充血容量：加快输液200-300ml.
Ephedrine 5-10mg iv or 30mg im.
HR↓→Atropine.
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●呼吸抑制(inhibition of respiration):
▼原因：麻醉平面过高→肋间肌麻痹.
复合药的影响（杜氟等).
▼表现：胸式呼吸微弱、腹式呼吸增强.潮气量↓
咳嗽无力、不能发声、紫绀.
▼处理：有效吸O2、扶助呼吸.
（“全脊麻”→呼吸停止、BP↓、心停→CPR）
●恶心、呕吐(nausea and vomit):
▼诱因：BP↓↓→脑供血↓↓→兴奋呕吐中枢.
迷走N功能亢进→胃肠蠕动↑.
手术牵拉内脏.
▼处理：对症治疗：
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四、蛛网膜下隙阻滞的并发症
(complications of subarachnoid block)
头痛(headache)：
post-dural puncture headache:PDPH
发病机制:穿刺后csf外漏（低压性头痛).
PDPH is believed to result from decreased intracranial
pressure as CSF leaks from the dural defect.
预防：细针穿刺.
术后免枕平卧or头低位仰卧.
液体正平衡(intravenous or oral fluid administration).
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处理:
▼卧床(recumbent position).
▼ 对症:镇静or小剂量镇痛药(analgesics).
▼ 硬膜外注入GS或右旋糖酐10+ml.
▼ 15-20ml 自体血10秒内注入硬膜外腔→“补丁(patch)”.
(Epidural blood patch involves injecting 15-20ml of
autologous blood into the epidural space)
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尿潴留(urinary retention)：
原因:骶2-4阻滞→膀胱张力丧失.
(Local anesthetic block of S2-S4 root fibers decreases
urinary bladder tone and inhibits the voiding reflex.)
处理：暗示或导尿.
Persistent bladder dysfunction can also be a manifestation of
serious neural injury(cauda equina syndrome:马尾综合症).
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神经并发症(neural complications)：
脊麻致N损害原因：局麻药的组织毒性.
意外带入的有害物质.
穿刺损伤.
●脑N受累:累及第6对脑N最多见.
原因:csf外漏→csf量↓→降低了csf对脑组织的“衬垫作用”.
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●马尾神经综合征：
(cauda equina syndrome)
症状: 脊麻后下肢感觉及运动功能长时间不恢复，直肠功
能失调（大便失禁），会阴部感觉丧失，尿道括约
肌 麻痹（尿潴留）,下肢异感，足下垂.
原因:局麻药直接注入马尾N or 局麻药N毒性过剧.
●其他:脑脊膜炎(meningitis)
蛛网膜炎(arachnoiditis)
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第二节 硬脊膜外阻滞
Section two Epidural anesthesia
一、概述(Outline):
分类: 单次法:（少用）
延长麻醉作用时间.
连续法
显著提高硬膜外阻滞
的控制性和安全性.
高位：穿刺部位：C5-T6
中位：穿刺部位：T6-12
低位：穿刺部位：﹤T12
骶麻：穿刺部位：骶管
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二、硬膜外阻滞的作用机制及其生理影响
(The mechanism of action and physiologic responses)
◆局麻药作用的部位(the site of action)：
可能作用机制:
▲椎旁阻滞.
▲经根蛛网膜绒毛阻滞脊N根.
▲局麻药弥散过硬膜→蛛网膜下隙
→“延 迟”的脊麻.
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◆局麻药在硬膜外间隙的扩散(pervasion)：
●局麻药的容积和浓度 (volume and concentration):
容量→决定硬麻“量”的重要因素.
浓度→决定硬麻“质”的重要因素.
●注射速度(the speed of drug injection) :
注药过快→眩晕.
●体位、身高、年龄、妊娠 (position,height,age,pregnancy)
●其他：动脉硬化(arteriosclerosis)
脱水(dehydration)
→需药量↓.
休克(shock)
◆硬膜外间隙压力(pressure)：
硬膜外间隙为负压(negative pressure):以颈部、胸部最高.
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◆硬膜外阻滞的影响(systemic effects):
●CNS
manifestations:
▼注药后一过性csf pressure↑（过速→一过性
头晕）.
▼局麻药逾量或注入V丛→大量局麻药进入循
环 →惊厥(convulsion).
▼连续法→较长时间内累积性吸收→精神症状
(psychological symptom)、幻觉(illusion).
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● Cardiovascular manifestations:
▲N性因素：
阻力血管(resistance vessels)
★ 节段性交感N阻滞
扩张
容量血管(capacitance vessels)
★ 平面＞T4→心交感N(cardiac sympathetic nerve)麻痹→HR↓
▲药理性因素: ★局麻药吸收→平滑肌抑制
→抑制 β-R→C.O.↓
★局麻药中Adr吸收→兴奋β-R→C.O.↑
▲局部因素: 注速快→csf pressure↑→短暂C.O.反射性↑
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●Respiratory
manifestations：
▲阻滞平面的影响(effects of level of blockade)：
The level of sensory blockade＜T8→呼吸功能无明显影响.
The level of sensory blockade ≥T2-4→膈N（diaphragm nerve)抑
制→肺活量(vital capacity)↓.
▲局麻药种类、浓度的影响:
▲年老、体弱、久病者→平面过高→通气储备不足:
▲其他因素:
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●Visceral manifestations:
●Effects on muscular tension:
运动N阻滞不全,但仍有肌松作用.
▲反射性松弛：传入Nf被阻滞.
▲局麻药吸收后→选择性阻滞运动N末梢.
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三、硬膜外阻滞的临床应用
(The clinical applications of epidural block)
硬麻优、缺点(advantages and disadvantages):
优点(advantages):
●可产生从颌下至足部任何脊N的阻滞.
●可根据手术部位选择不同穿制点.
●对循环扰乱轻，发生过程较慢，机体有时间代
偿→可考虑用于一般情况差、某些心脏病人甚
至老年人.
●肌松好—适用于腹部手术.
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●局麻药浓度恰当时,可施高位硬麻→不致于呼吸肌麻
痹→ 适用于胸部、上肢或颈部手术.
●可任意延长麻醉时间,可进行术后镇痛.
●术中病人神志清醒,对代谢及肝肾功能影响小，术
后并发症少,易护理.
●所需器械简单.
缺点(disadvantages):
操作技术上难度大，要求高，一旦误将药物注入
蛛网膜下腔→短时间内出现全脊麻→呼吸停止，神志
消失，BP↓↓→抢救不及时，因缺O2死亡.
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(一)适应证与禁忌证：
(Indications and contraindications)
适应证(indications):可用于除头及胸腔外的任何手术.
禁忌证(contraindications)：
★穿刺部位感染(infection).
★脊柱严重畸形(deformity).
★全身肝素化(heparinize)—出血(bleeding).
★CNS疾患(neurologic deficits) .
★休克(shock)—血容量基本纠正后可行小剂量分次给药.
★严重贫血(anemia)、心功代偿不全慎用.
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(二)局麻药选择：
◆药物要求：
◆ 药物种类: 酯类: Dicaine0.25-0.33%(一次最大用量60mg).
酰胺类:Lidocaine (成人一次最大剂量400mg).
Bupivacaine：用于硬麻有争议.
(三)应用局麻药注意事项:
◆局麻药中加用肾上腺素：
减缓局麻药吸收速度、延长作用时间，局部轻度血管收缩，
无明显全身反应. 常用1:20万(高血压病人禁用).
◆局麻药浓度选择:
决定硬膜外阻滞范围的最主要因素——麻醉药容量.
决定硬膜外阻滞深度和作用持续时间——麻醉药浓度.
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◆局麻药的混合使用：
起效快+起效慢
潜伏期短
混合→
长效+短效
维持时间长
常用:1%Lidocaine+0.15%-0.2%Dicaine+1:20万 Adr
◆注药方式:
●注射试验量(test dose):3-5ml.
目的:排除误入蛛网膜下隙的可能.
●注入增加量(incremental dose):注入试验量5-10min，
如无腰麻征象 →可每隔5min注入3-5ml，直至阻滞
范围满足手术要求.
●追加维持量(maintain dose):首次总量的1/2—1/3.
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(四)硬膜外间隙穿刺术：
穿刺点选择：
取支配手术范围中央的脊N相应棘突间隙.
体表定位标志: ★颈部最大突起的棘突为C7.
★两侧肩胛角连线为T7.
★两髂嵴最高点连线为L4 or L4-5.
硬膜外间隙的确定:
◆阻力突然消失(sudden loss of resistance)：突破黄韧
带时阻力顿时消失的 “落空感(pop)”,注入空气、
盐
水无阻力 .
◆负压(negative pressure)现象:悬滴法、玻管法. 40
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(五)连硬外阻滞置管方法:
▲插管注意事项:
▲拔针过程中不要随意改变针尖斜口方向.
(六)硬膜外阻滞平面的调节:
▲穿刺部位(最重要)
▲导管位置和方向.
▲局麻药容量和注射速度 ▲体位.
▲病人情况：婴幼儿、老年人、妊娠后期.
(七)硬膜外阻滞失败：
▲阻滞范围达不到手术要求.
▲阻滞不全.
▲完全无效.
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(八)硬膜外阻滞术中病人的管理:
BP↓and HR↓：多见于胸段硬膜外阻滞：
● 内脏大小N麻痹→腹内血管扩张 →回心血量↓→BP↓.
● 迷走N功能相对亢进→HR↓.
Inhibition of respiration：
颈部、上胸段硬麻→肋间肌、膈肌不同程度麻痹→呼吸抑制
（严重者呼吸停止).(高位硬麻宜采用小剂量、低浓度) .
Nausea and vomit：
硬麻不能消除内脏牵拉痛，必要时行腹腔N丛阻滞.
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四、硬膜外阻滞的并发症
全脊麻:Total spinal anesthesia
◆概念(Concept)：
硬麻时→穿刺针或硬膜外导管误入蛛网膜下隙未能及时发现
→超过腰麻数倍的局麻药误入蛛网膜下隙→全部脊N甚至颅
N被阻滞→称全脊麻 .
anesthesia ascending into the cervical levels causes severe
hypotention, bradycardia, and respiratory insufficiency,
unconsciousness, apnea, and is referred to as a “total spinal
anesthesia”.It can occur following attempted epidural/caudal
anesthesia if there is inadvertent intrathecal injection.
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◆表现(manifestation):
★全部脊N支配区域无痛觉(no sense of pain).
★严重低血压休克(severe hypotention).
★意识丧失(unconsciousness).
★呼吸停止(respiratory arrest) → 心跳停止(cardiac
arrest)（处理不及时).
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◆处理原则(principle of treatment)：
维持循环、呼吸功能:
(Treatment consists of supporting the airway, maintaining an
adequate ventilation, and supporting the circulation).
●人工通气:
When respiratory insufficiency becomes evident, supplemental
oxygen is mandatory . Assisted ventilation, intubation, and
mechanical ventilation may be necessary.
●加速输液 :
Hypotention can be treated with rapid administration of
intravenous fluid.
●升压药等对症处理:
Aggressive use of vasopressors. Bradycardia should be treated
with atropine.
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全脊麻阻滞平面消退后可恢复(无后遗症)
全脊麻→延误→缺O2→呼吸心跳停止→死亡.
◆预防措施(measure of prevention):
★防止穿破硬膜(avoid puncturing the dura mater).
★强调注入全量局麻药前先注入试验剂量(test dose).
★妥善管理导管(management of the catheter).
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异常广泛阻滞:
It has a similar clinical presentation to the total spinal,with
The exception that the onset may be delayed for 15-30minutes.
The effects generally last from one to several hours.
●注入常规剂量局麻药后→异常广泛的脊N阻滞现象.
（并非 全脊麻）
●范围虽广，仍为节段性，骶N支配区域、甚至腰部
N 功能仍正常.
●广泛阻滞缓慢发生→注入药量后20-30min.
●胸闷、呼吸困难、说话无力、烦躁不安→通气严重
不 足 →呼吸停止、BP↓↓.
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穿破硬膜:
◆原因: ★操作因素:
★病人因素:
◆预防: 严格操作规程.
◆穿破后处理:
穿刺置管损伤血管或导管进入并留滞于血管:
导管误入血管→注麻药后立即出现全身中毒反应而麻醉
作用缺如.
处理：退管1-2cm or换间隙重穿置管.
空气栓塞：注气试验时→空气进入循环→量多时致死.
穿破胸膜：气胸、纵隔气肿.
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硬膜外血肿(Epidural hematoma)：
◆ Needle or catheter trauma to epidural veins often Causes
minor bleeding , although this is usually benign and selflimiting.A clinical significant epidural hematoma can occur
following epidural anesthesia, especially in the presence of
abnormal coagulation or bleeding disorder.
发生率0.01‰,虽罕见，但在麻醉并发截瘫原因中占首位.
◆ The need for rapid diagnosis and intervention is paramount
if permanent neurologic sequelae is to be avoided.
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◆ Symptoms include sharp back and leg pain with a
progression to numbness and motor weakness and/or
sphincter dysfunction.
◆ When hematoma is suspected, neurologic image(MRI,CT)
must be obtained immediately.Most cases of good neurologic
recovery have occurred in patients who have undergone
surgical decompression within 8-12 hours.
预防：
●导管质地柔软，穿刺置管要轻巧.
● 对 有 凝 血 障 碍 (coagulopathy) 或 血 小 板 功 能 障 碍 （ platelet
dysfunction)正在抗凝(anticoagulation)的病人避免做硬麻.
●凡疑硬膜外血肿→立即造影→24h内手术减压.
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脊神经根或脊髓损伤:
◆神经根损伤(neural root trauma):
脊N根损伤主要是后根→根痛（受伤N根的分布区疼痛).咳嗽、
喷嚏、用力憋气时疼痛or 麻木加重(脑脊液冲击征),损伤后3天
内最剧,遗留片状麻木区数月以上.
◆脊髓损伤(spinal cord trauma) ：
导管插入脊髓or局麻药注入脊髓→横贯性损害(立即感剧痛,一
过性意识障碍→完全性松驰性截瘫)→终生残废.
脊髓穿刺伤→继发性水肿(截瘫).
治疗：脱水、激素(及早使用).
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神经根损伤
脊髓损伤
●触电或痛感
剧痛，一过性意识障碍
●感觉障碍为主,典型根痛
感觉、运动障碍
很少运动障碍
●感觉缺乏仅限于1～2根脊N支
配区,与穿刺点棘突平面一致
感觉障碍与穿刺点不在
同一平面，比穿刺点低
感染(infection)：
◆硬膜外间隙感染：★污染的麻醉用具or局麻药.
★穿刺针经过感染组织.
★其他部位感染.
◆蛛网膜下隙感染： 脑脊膜炎(meningitis)症状.
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腰麻与硬麻全面比较
蛛网膜下隙阻滞
硬膜外隙阻滞
穿刺注药部位
蛛网膜下隙
硬膜外隙
局麻药作用
部位
蛛网膜下隙脊N、脊髓表面
硬膜外隙脊N
穿刺点选择
L3-4棘间隙以下
从颈段到骶裂孔
适应症
下腹、盆腔、下肢等手术
除头部外的许多手术
显效时间
快，2-3min
慢：8-10min
麻醉剂量及
容积
小
大
平面调节
穿刺间隙、病人体位、
注药速度
穿刺间隙、注药容积
对循环干扰
重、发展快
轻、发展慢
操作难度
小
大
主要并发症
头痛、尿潴留
全脊麻、异常广泛阻滞
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五、小儿硬膜外阻滞：
出生时脊髓终止于L3水平，1岁时达L1-2水平。
药物剂量： 新生儿：0.75% Lidocaine 2～3ml
早产新生儿、一般情况不佳→适当降
低浓度、剂量.
婴儿：1%
小儿：1.5%
儿童：2%
剂量于0.7-1.0ml/kg（7-10mg/kg）
(Lidocaine)
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六、骶管阻滞(Caudal anesthesia)
概念：
经骶骨孔→局麻药→阻滞骶N→骶管阻滞.
骶管穿刺术: 骶骨孔与左、右髂棘的等边三角关系(定位参 考).
穿刺针端不超过两髂棘联线—不致于穿破硬膜.
骶管容积： 25ml±（成人），麻药必须将骶管充满才能使所有
骶N阻滞.
▼腰骶部硬外间隙解剖结构特殊→麻药不易由骶侧向腰侧
扩散→麻醉范围主要集中于肛门、会阴、臀部→对生理
功能影响轻微.
▼骶骨孔解剖变异多→成功率相对低（75—80%).
▼ 骶管内血管窦粗大→易出血、局麻药中毒.
（现已用L3-4↓代替骶麻）
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第三节 蛛网膜下隙与硬脊膜外
联合阻滞麻醉(CSEA)
Section three Combination of spinal and epidural anesthesia
CSEA已广泛用于腹盆腔手术.
既有脊麻优点：起效快,镇痛、肌松完善.
又有硬麻优点：手术时间不受限制.
一点穿刺法：L3-4 orL2-3穿刺→蛛网膜下隙注药→硬膜外置管.
两点穿刺法：T12-L1 穿刺→硬膜外置管.
L3-4穿刺→蛛网膜下隙注药→硬膜外置管.
脊麻穿刺针较细、术后头痛发生率低，国内广泛应用.
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谢谢！
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