《肌松药.ppt》由会员分享,可在线阅读,更多相关《肌松药.ppt(72页珍藏版)》请在三一文库上搜索。
1、CHAPTER NINE CLINICAL USE OF MUSCLE RELAXANTS 第九章 肌松药的临床应用,Part 1 The Rational Use of Muscle Relaxants 第一节 肌松药的合理应用,Muscle relaxants can lead to skeletal muscle relaxation. Their principal pharmacologic effect is to interrupt transmission of synaptic signaling at the neuromuscular junction (NMJ) by
2、antagonism of the nicotinic acetylcholine receptor (AChR) .,Main Goals of Use 一.应用肌松药的目的,1.As the very important adjuncts for general anesthesia,muscle relaxants can provide adequate paralysis needed tracheal intubation, or relaxation for surgery. 肌松药是全麻的重要辅助用药,用于全麻诱导时气管插管或维持全麻时肌松,避免深麻醉带来的危害。,2. To
3、be used in the critical patients who are receiving mechanical ventilation care. 危重病人机械通气时用肌松药来消除自主呼吸对呼吸机的拮抗。,3.To be used in the treatment of spasmodic diseases. 用于治疗痉挛性疾病。,4. To be used in the electric shock treatment.在电休克治疗时用其控制肌张力和减少肌强烈收缩引起的并发症。,Fundamental Principles of Use 二. 应用肌松药的基本原则,1. Musc
4、le relaxants should be viewed as adjuncts,not as substitutes for anesthesia. Perfect general anesthesia should include:analgesia, amnesia and relaxation. 肌松药不能代替麻醉药,应有完善的镇痛。,2. Strict control of airway. 应有严密的呼吸管理。 Muscle relaxants can influence the respiration ability of patients to maintain adequat
5、e ventilation, so strict control measures of airway must be given.,3. Proper muscle relaxants and appropriate doses (minimal doses). 选择合适的肌松药和最小有效剂量。,4. To avoid inappropriate combined administration. 避免不恰当的联合用药。,5. To utilize the synergistic action between muscle relaxants and anesthetics properly.
6、 合理利用麻醉药与肌松药的协同作用。,6. Proper monitoring of neuromuscular function. 最好能够对肌松药的作用进行监测。,Part 2 Use of Muscle Relaxants During Anesthesia 第二节 肌松药在麻醉期间的应用,There are two important safety issues in practice with muscle relaxants: cardiovascular side effects and adequacy of recovery to normal neuromuscular f
7、unction. Of the two, the latter is by far the more important. To avoid prolonged residual paralysis or inadequate antagonism of residual blockade or both, the main goal should be to use the lowest possible dose that will provide adequate relaxation for surgery.,For Tracheal Intubation 一用于气管插管 To pro
8、vide the very deep paralysis needed for tracheal intubation, the initial dose in the range two to three times the ED95 is usually given to facilitate the maneuver within one to three minutes, depending on the choice and dose of muscle relaxant. Succinylcholine is still preferred for this critical ma
9、neuver. Now, however, there are suitable alternatives among the nondepolarizing relaxants but as yet no replacement,For Maintenance of relaxation 二. 肌松维持 Maintenance of relaxation by continuous infusion of intermediate and short-acting drugs can be performed and is useful to keep relaxation smooth a
10、nd to rapidly adjust the depth of relaxation to surgical needs.,Dosage for Priming 三. 预给量 A small subparalysis dose of nondepolarizer be given 2 to 4 minutes before giving a second large dose for tracheal intubation. This procedure, termed priming, has been shown to accelerate the onset of block of
11、most nondepolarizing relaxants by about 30 to 60 seconds, with the result that intubation can be performed within about 90 seconds following the second dose.,Interaction of Succinylcholine with Nondepolarizing muscle relaxants 四. 琥珀胆碱与非去极化肌松药的相互作用 This Interaction is very complex, depending on wheth
12、er Succinylcholine is administered before or after the nondepolarizer.,1.Succinylcholine is commonly given to facilitate intubation, and then a nondepolarizing relaxant is administered. Succinylcholine given first enhance the depth of block induced by a subsequent dose of nondepolarizing relaxant. 用
13、 Succinylcholine 诱导,用非去极化肌松药维持,后者肌松作用被增强。,2. A small dose of nondepolarizing relaxant is commonly given before administration of Succinylcholine to prevent some of the adverse effects of the later. The depth of block induced by Succinylcholine can be reduced. 为减少Succinylcholine的副作用,用Succinylcholine诱
14、导前静注小剂量非去极化肌松药,此时琥珀胆碱作用被削弱,必须增加剂量。,3. A nondepolarizing relaxant can be injected for prolonged relaxation, and then the short-acting Succinylcholine can be given to facilitate closure of the peritoneum. It maybe lead to severe residual paralysis. 术中长时间用非去极化肌松药维持,手术后期如为了关闭腹膜再加用短效的Succinylcholine,此时琥珀
15、胆碱即拮抗非去极化肌松药又产生去极化阻滞,还有相阻滞,常可导致异常的肌松延长。,Interaction among nondepolarizing relaxants 非去极化肌松药的相互作用,The changeover from one drug to another, when the duration are dissimilar, is a matter of simple kinetics.Three half-lives will be required for a clinical changeover and for the block duration to begin t
16、o take on the characteristics of the second drug.,Part 3 Side Effects of Muscle Relaxants 第三节 肌松药的不良反应,Autonomic Nerve System Effects 一. 植物神经系统作用: 肌松药对植物神经系统的兴奋或抑制,常可以引起心血管副反应。,Histamine Release 二. 组胺释放 快速静注相当量的肌松药均可以引起组织浆细胞和嗜碱性细胞释放组胺,使血浆组胺浓度升高可引起血压下降和心动过速。 组胺释放还可能引起支气管痉挛。,TABLE 1. Clinical Autonomi
17、c Effects of Neuromuscular Blocking Drugs,Part 4 PHARMACOLOGY OF MUSCLE RELAXANTS 第四节 影响肌松药的因素,Pharmacokinetics 一. 影响肌松药的药代动力学 Renal failure influences the pharmacology of nondepolarizing muscle relaxants by producing either decreased elimination of the drug, or its metabolites via the kidney, or de
18、creased activity of enzymes that metabolize the drug. Consequently, the duration of action of muscle relaxants may be prolonged in patients with renal failure. Patients with hepatobiliary disease may exhibit prolonged block with many muscle relaxants .,表2 肌松药经肾清除,Pharmacodynamics 二.影响肌松药的药效动力学,1.Aci
19、d-base state and electrolyte 水、电解质和酸碱平衡 Both metabolic and respiratory acidosis may augment a nondepolarizing neuromuscular blockade. Hypopotassaemia, hypernatremia, hypocalcemia, and hypermagnesemia do enhance the blockade from nondepolarizing muscle relaxants and diminish the ability of neostigmin
20、e to antagonize the blockade.,2. Temperature 低温 Hypothermia significantly prolongs the duration of most kinds of muscle relaxants,3. Age 年龄 Neonates and infants are more sensitive than adults to the neuromuscular blocking effects of dTC.However,the infants have a large volume of distribution and slo
21、wer clearance, so it leads to a longer elimination half-life,which means that in infants dTC may require less frequent dosing than in older children.,The pharmacodynamics of muscle relaxants are altered in elderly patients.Because of decreases in total body water,increases in total body fat,decrease
22、s in hepatic and renal blood flow and decreases in cardiac reserve, it can prolong the duration of action of most kinds of muscle relaxants.,4. Myasthenia Gravis and Myasthenic Syndrome 重症肌无力和肌无力综合征,Myasthenia patients are often extremely sensitive to nondepolarizing relaxants and are usually somewh
23、at resistant to succinylcholine. 重症肌无力:对非去极化肌松药异常敏感,对去极化肌松药轻度拮抗,且呈现出相阻滞和肌张力恢复延迟。,The patients who suffer Myasthenic Syndrome are usually sensitive to both nondepolarizing and depolarizing relaxants. 肌无力综合征:对非去极化和去极化肌松药均十分敏感。 麻醉时尽量不用肌松药,若需用时,应在肌松监测下用少量中时效肌松药,术后维持通气。,5.Pseudocholinesterase 假性胆碱酯酶活性异常
24、Pseudocholinesterase has an enormous capacity to hydrolyze succinylcholine at a very rapid rate ,Neuromuscular block induced by succinylcholine can be prolonged by a decreased concentration of normal enzyme or by the presence of an atypical form of the enzyme.,6. Inhaled Anesthetics Inhaled anesthet
25、ics augment the neuromuscular blockade from nondepolarizing muscle relaxants in a dose-dependent fashion, which may also depend on the duration of anesthetics. 吸入全麻药达到一定深度即可产生肌松,与非去极化肌松药合用时,后者用量减少,时效延长,存在量效关系,7. Local Anesthetics and Antiarrhythmics Local Anesthetics can enhance the neuromuscular bl
26、ock from both nondepolarizing and depolarizing relaxants. 局麻药能增强肌松作用。 抗心律失常药如奎尼丁对肌松药有协同作用,8. Antibiotics 抗生素 氨基甙类抗生素:新霉素和链霉素最强,9.Antiepileptic 抗惊厥药,Part 5 Antagonism of Residual Neuromuscular Blockade 第五节 肌松药的拮抗,Evaluation of recovery of relaxation 一. 肌张力恢复的评定 The ability of a patient to maintain su
27、stained adequate ventilation and to protect the airway, particularly during stresses such as airway obstruction or vomiting, is a main concern when looking at adequacy of recovery of neuromuscular function.,1. Procedure of recovery 肌松作用的消退过程 With the elimination of the muscle relaxants, the plasma c
28、oncentrations of drugs decrease, the concentrations of drugs decrease and the concentrations of ACh increase in neuromuscular junction, and consequently neuromuscular function begins to recover. 肌张力充分恢复,抬头5秒钟,伸舌、举臂4-5秒和抬腿。T4/T10.7,BS2/BS1为0.5-0.6,2.Residual neuromuscular blockade 残余肌松作用 乙酰胆碱结合的受体量增加
29、低于25-30%时出现,表现为清醒病人面无表情、上睑下垂、咬肌张力弱、不能伸舌、发音不清、头不能抬和握拳无力。,Antagonism of nondepolarizing muscle relaxants 二.非去极化肌松药的拮抗,1. Antagonist拮抗药 The drugs used to antagonize residual neuromuscular blockade, neostigmine, edrophonium, and pyridostigmine are anticholinesterases. They antagonize a nondepolarizing n
30、euromuscular blockade primarily by increasing the concentration of acetylcholine at the muscle end plate mainly be inhibition of acetylcholinesterase.,In addition, they may also increase release of acetylcholine from the motor nerve terminals, block neural potassium channels, and have a direct agoni
31、st effect.,1. 拮抗药的选择 对于非去极化肌松药应用拮抗药时,一般要待肌颤搐恢复到25%或四个成串刺激已出现2个以上肌颤搐反应 胆碱酯酶抑制药:新斯的明(Neostigmine),吡啶斯的明(Pyridostigmine)和依酚氯胺(腾喜龙Edrophonium)。,2.Factors that may interfere with antagonism Dose of antagonist Larger doses of anticholinesterases should antagonize neuromuscular blockade more rapidly and mo
32、re completely than smaller doses. However, further amounts of anticholinesterases will not produce any greater antagonism.,2. 影响抗胆碱酯酶药的因素,拮抗残余肌松的用量取决于肌松深度。新斯的明,吡啶斯的明和依酚氯胺的最大用量一般不超过0.07mg/kg,0.28mg/kg,1mg/kg。 It is not advisable to administer further antagonist if maximal doses fail to antagonize res
33、idual block. The most likely cause of the inadequate antagonism should be sought.,Rate of recovery of the relaxation Following administration of an anticholinesterase, two processes contribute to recovery of neuromuscular function. The first is antagonism induced by the effect of the anticholinester
34、ase at the neuromuscular junction,the second is the natural process of decrease in plasma concentration of the relaxant consequent on its elimination.,拮抗时肌张力恢复的时间由残余肌松的深度和肌松药自然恢复快慢两者决定。,Acid-base state and electrolyte imbalance 酸碱和电解质失衡 Acid-base state and electrolyte imbalance can prevent adequate
35、antagonism. The probability of achieving adequate antagonism in the presence of significant respiratory acidosis (PaCO2 greater than 50 mm Hg) is low. metabolic alkalosis, Hypopotassaemia, and hypermagnesemia do diminish the antagonism of the residual blockade.,Hypothermia 低温,Warning of use of antag
36、onist 3.拮抗药使用注意事项,合用抗胆碱药如阿托品和格隆溴铵 新斯的明,吡啶斯的明主张合用格隆溴铵 依酚氯胺与阿托品合用较好 老年人慎用抗胆碱酯酶药 使用拮抗药时应进行心电图监测,CASE 病 例,患者,男性,48岁,因梗阻性黄疸入院,行肝内外胆管切开取石手术,于1PM入PACU。入室后接呼吸机行SIMV。患者明显呈现呼吸恢复延迟,不能脱机,6PM查血气分析,PH:7.06,PCO2:48,HCO3:19.8, 患者呈现呼吸恢复延迟的原因? 如何处理? 用拮抗剂有效吗?,Recovery of succinylcholine 4. 琥珀胆碱的肌松消退,其引起的去极化阻滞,不需用拮抗药,待
37、其自行消退。 相阻滞,拮抗药有效, T4/T1比值愈小则效果愈肯定。 肌张力恢复延迟时应用人工通气维持让其自然恢复。,Part 6 Neuromuscular Monitoring 第六节 肌松药作用的监测,Introduction 一. 概述,Goal of monitoring 1. 监测目的 用药剂量个体化,合理使用肌松药,减少不良反应。 根据手术需要控制肌松深度。 鉴别术后呼吸抑制的原因。 鉴别残留的神经肌肉兴奋传导阻滞的性质。 指导拮抗药的应用和评定拮抗药的效果。,Way to monitoring 2.监测方法 Nerve stimulators 神经刺激器 Observation
38、 directly 直接测定随意肌的肌力及测定呼吸运动,Patterns of nerve stimulation 二. 不同神经刺激的临床意义,Single twitch stimulation 1.单次肌颤搐刺激 恢复指数:肌颤搐高度由25%恢复到75%的时间,反映肌颤搐恢复速率。,Tetanic stimulation 2. 强直刺激 临床上强直刺激引起的衰减和其后的易化可鉴别肌松阻滞性质和判断阻滞程度;,Train-of-four stimulation TOF 3.四个成串刺激:可直接从T4/T1来评定阻滞程度,可根据有无衰减来确阻滞性质: 部分去极化阻滞时,四个肌颤搐幅度均降低,T
39、4/T10.9或接近1.0。 非去极化阻滞加深时,T4/T1比值逐渐降低;而T1到T4全部恢复相当于单刺激恢复25%。 T4/T10.75,提示临床上肌张力己充分恢复。,Post tetanic count PTC 4.强直刺激后单次刺激的肌颤搐计数 Double-burst stimulation DBS 5. 双短强直刺激,Choice of stimulation 三. 刺激种类的选择,(一) 确定阻滞性质 1. 非去极化阻滞的特点 在阻滞起效前无肌纤维成束收缩。 对强直刺激肌张力不能维持,出现衰减。 强直刺激后出现易化。 为去极化肌松药拮抗。 TOF出现衰减。 为抗胆碱酯酶药所拮抗和逆转。,2. 去极化阻滞的特点 在阻滞起效前有肌纤维成束收缩。 强直刺激肌张力无衰减。 强直刺激后无易化。 为非去极化肌松药拮抗。 不能为抗胆碱酯酶药所拮抗和逆转。,3. 双相阻滞的特点 强直刺激和TOF均出现衰减。 为抗胆碱酯酶药部分或完全拮抗。,(二) 不同刺激种类在围术期的应用,表3 围术期各类刺激的应用,
链接地址:https://www.31doc.com/p-2259068.html