动物医学麻醉学07wasva吸入麻醉wsava2inhal agentswag49ch final

1、DeliveringInhalation Anaesthesia 输送吸入麻醉Dr Colin DunlopDip. American College Vet. Anesthesiologists美国兽医麻醉师学会会员Advanced Anaesthesia SpecialistsSydney, Australia澳大利亚, 悉尼, 高级麻醉师 Volatile Inhalation Anaesthetics挥发性的吸入麻醉剂- liquids at room temperature 室温下是液体- is a vapour layer above the liquid 在液面有一层气体 - c

2、oncentration of the vapour is up to 30 x above the anaesthetic level 挥发出的 药物气体浓度可以是麻醉剂量的30倍- this concentration is lethal 这个浓度是致死的Physical Properties of Volatile Anaesthetics 挥发性麻醉剂的 物理特性 “liquids at room temperature” 室温下是液体Agent 药物Vapour Pressure mmHg 蒸汽压Blood:Gas Solubility 气:血溶解度MAC vol % 最小肺泡浓度I

3、soflurane 异氟烷240 (240/760=30%)1.271.30Halothane 氟烷2432.460.90Sevoflurane七氟烷 1600.622.10Desflurane地氟烷6640.427.20N2O 笑气7600.47200%Methoxyflurane甲氧氟烷23150.24Anaesthetic Vaporisers麻醉蒸发罐Mix O2 with volatile vapour above the liquid 让氧气和液面上的挥发性气体混合Predictable amount delivered可以预测麻醉量- vapour picked up by O2

4、 氧气带上了蒸发气体- constant level delivered to breathing circuit 以稳定的浓度进入麻醉回路内Vaporiser Output Effect of Vapour Pressure, Temp. & Gas Flow蒸发罐的输出量 受蒸汽压，温度，和气流的影响Anaesthetic Vaporisers麻醉蒸发罐In-Circuit: gas flow over liquid by animals ventilation(dont ventilate animals!)在回路内：动物呼吸时气体经过麻醉药液面（不要轻易让动物增加换气）Out-of-C

5、ircuit: gas flow through vaporiser from pressurized O2 via the O2 flowmeter在回路外：高压氧气通过气体流速计进入蒸发罐In-Circuit Vaporisers 7 kg回路内设置蒸发罐 适用于大于 7公斤的动物- Variable output for variations in Temperature & Ventilation “glass jar” 麻醉药输出量与环境温度和 动物的呼吸情况有关“ 玻璃罐” - Dial setting = IS NOT concentration 蒸发罐上的控制盘不等于麻醉药浓度

6、- Inefficient: most of the breath volume passes through the vaporiser 没有效率：大部分的呼吸气量经过蒸发罐- Not suitable for Non-Rebreathing circuits 不适用于非重吸入回路麻醉装置 - Same vaporiser can work for a number of anaesthetic agents 同一蒸发罐可以用于好几种麻醉剂- can use lower O2 flows: 10 ml/kg/min 可以使用底流速供氧Out-of-Circuit Vaporisers回路外装

7、置蒸发罐- Constant output for variations in Temperature & Flow heavy brass 在温度和流速改变时还可以有稳定底麻醉输出重金属黄铜 - Dial setting = actual % concentration 控制盘上底底 刻度真实的麻醉药浓度- Efficient: only a small portion of gas passes through the vaporiser & mixes with by-pass gas to produce an accurate mixture 效率高：只有少量的 气体经过蒸发罐，并和

8、绕行的气体混合，产生精确的药物混合- Vaporisers are specific for each anaesthetic agent & work for all circuits/all sizes of animal 蒸发罐只能使用特定的麻醉剂，但适用于各种回路和各种大小动物- Need higher O2 flows: 30 ml/kg/min start 开始时需要高流速的氧气Physical Properties of Volatile Anaesthetics 挥发性麻醉剂的 物理特性 “liquids at room temperature” 室温下是液体Agent 药物V

9、apour Pressure mmHg 蒸汽压Blood:Gas Solubility 气:血溶解度MAC vol % 最小肺泡浓度Isoflurane 异氟烷240 (240/760=30%)1.271.30Halothane 氟烷2432.460.90Sevoflurane七氟烷 1600.622.10Desflurane地氟烷6640.427.20N2O 笑气7600.47200%Methoxyflurane甲氧氟烷23150.24Blood Gas Solubility (BGS) 血液气体溶解度 BGS is a measure of the solubility of a gas

10、in blood 测量气体在血液中的溶解度Inhaled anesthetics must be carried from the lungs to the brain by the blood 吸入的麻醉剂必须通过血液来达到大脑If a gas has a low BGS, the blood quickly es saturated and can release the anesthetic into the brain. 如果气体的 血液溶解度低，会很快变成饱和，就可以很快把药物释放到大脑Low BGS = Fast Acting Anaesthetic 低血液气体溶解度快速麻醉剂Br

11、ain大脑Blood血液Blood血液Lungs肺脏Inspired/ Expired Gas呼吸的气体Effect of Blood:Gas Solubility on Uptake and Elimination of Inhalation Anaesthetics 血气溶解度对吸入麻醉药的吸收和排泄的影响Benefits Of A Low BGS 血液气体溶解度的好处 Faster induction & transition from short acting IV anaesthetics to inhalation agents 诱导麻醉更快，也使静脉给药麻醉过渡到吸入麻醉很快 F

12、aster changes to anaesthetic depth for varying surgical stimulus during surgery 在手术过程中，因手术刺激程度不同而快速改变麻醉深度 Faster recovery from anaesthesia 麻醉后苏醒过程也很快Physical Properties of Volatile Anaesthetics 挥发性麻醉剂的物理特性 “liquids at room temperature” 室温下是液体Agent 药物Vapour Pressure mmHg 蒸汽压Blood:Gas Solubility 气:血溶解

13、度MAC vol % 最小肺泡浓度Isoflurane 异氟烷240 (240/760=30%)1.271.30Halothane 氟烷2432.460.90Sevoflurane七氟烷 1600.622.10Desflurane地氟烷6640.427.20N2O 笑气7600.47200%Methoxyflurane甲氧氟烷23150.24MAC values differ for each anaesthetic agent 每种麻醉剂的最小肺泡浓度不一样MAC: “the minimum concentration of an anesthetic that produces immob

14、ility in 50% of animals exposed to a painful stimulus” 最低肺泡有效浓度：“一个麻醉剂的最小浓度使得在受到疼痛刺激时50的动物没有反应。”Surgical anaesthesia: around 1.5 x MAC as sole anaesthetic 外科麻醉：单一麻醉药时，一般是MAC的1.5 倍Surgical anaesthesia: 1.25 MAC with premed. & IV induction 外科麻醉：如果有麻醉前给药，或静脉给药诱导，可以是MAC的1.25倍0.9%Halo氟烷7.20%2.10%1.30%Des

15、地氟烷Sevo七氟烷Iso 异氟烷Anaesthetics depress ventilation as dose increases剂量大时麻醉药抑制呼吸Respiratory Depression with Inhalational Drugs吸入麻醉药的呼吸系统抑制Apneic Concentration (AC) is “the % concentration of anesthetic at which an animal will stop breathing spontaneously” 窒息浓度（AC）：能引起动物呼吸自动停止的麻醉药浓度Apnoeic Index (AI) =

16、 AC MAC窒息指数 （AI）= 窒息浓度最低肺泡有效浓度The AI provides a measure of how many multiples of MAC are required to cause apnea. 窒息指数表明几倍MAC的麻醉药浓度可以引起窒息The higher the AI, the greater the safety margin for respiratory depression.窒息指数越高麻醉剂的呼吸抑制安全范围更大Comparison of Volatile Anaesthetics挥发性麻醉剂的比较 “liquids at room tempe

17、rature” 室温下是液体Agent 麻醉药ml vapour/ml liquid毫升蒸汽/毫升液体Apnoeic Indexx MAC 窒息指数Metabolism %代谢百分率Isoflurane 异氟烷1952.60Halothane 氟烷2272.920Sevoflurane 七氟烷1853.53Desflurane 地氟烷210Not Done0N2O 笑气GASNot Done?Methoxyflurane 甲氧氟烷2073.450Anaesthetics depress cardiac function as dose increases剂量增加时对心脏功能的抑制 - Card

18、iac Output & Blood Pressure decrease with dose 剂量增加会引起心脏输出量和 血压降低 - Heart rate changes are variable: ? increase with depth but may decrease with pain! 心率的变化不一：？麻醉加深时，疼痛减少了 - anaesthetics increase ventricular arrhythmias 麻醉加深引起心室心率不齐Inhalation Anaesthetics Increase Ventricular Arrhythmias吸入麻醉剂加剧心室心律失

19、常Ventricular Arrhythmias Effect of Pre-anaesthesia Oxygen心室心律失常麻醉前供氧的影响O2 by face mask 100 ml/kg/min面罩给氧，每分钟每公斤体重100毫升Geriatric Anaesthesia老年动物的麻醉Change in Renal Function with Age年老和肾功能改变Loose +/- 60% renal function before BUN and creatinine rise!在BUN和肌酐升高之前，约有60的肾功能丢失Geriatric Anaesthesia老年动物的麻醉Cha

20、nge in Renal Function with Age年老和肾功能改变Elevated liver enzymes in healthy dogs ? normal; Liver disease (jaundice) care健康动物的肝功酶升高？正常；肝脏疾病（黄疸） 小心Comparison of Volatile Anaesthetics挥发性麻醉剂的比较 “liquids at room temperature” 室温下是液体Agent 麻醉药ml vapour/ml liquid毫升蒸汽/毫升液体Apnoeic Indexx MAC 窒息指数Metabolism %代谢百分率I

21、soflurane 异氟烷1952.60Halothane 氟烷2272.920Sevoflurane 七氟烷1853.53Desflurane 地氟烷210Not Done0N2O 笑气GASNot Done?Methoxyflurane 甲氧氟烷2073.450Comparison of Volatile Anaesthetics挥发性麻醉剂的比较 “liquids at room temperature” 室温下是液体Agent 麻醉药ml vapour/ml liquid毫升蒸汽/毫升液体Apnoeic Indexx MAC 窒息指数Metabolism %代谢百分率Isofluran

22、e 异氟烷1952.60Halothane 氟烷2272.920Sevoflurane 七氟烷1853.53Desflurane 地氟烷210Not Done0N2O 笑气GASNot Done?Methoxyflurane 甲氧氟烷2073.450Anaesthetic Delivery & Cost 麻醉剂的供给和成本 Isoflurane: 195 ml vapor/ml 异氟烷：195毫升气/毫升液Vap 2% & O2 flow 1000 ml/min= 20 ml vapor/min 蒸发麻醉剂的浓度2和氧气流速20毫升蒸发气/分钟20 x 60 min = 1200 ml vap

23、/hr 1200ml 蒸发气/小时1200/195 = 6 ml liquid/hr = 6 ml 液体/小时In Australia: 6 x 30c = AU$1.80/hr 1.8 澳元 /小时Client Communication 与顾客的沟通How do you discuss anesthesia and with your clients Risk vs Quality 如何与顾客讨论麻醉衡量麻醉危险性与动物生活质量Should you market anaesthesia in your practice?是否可以在医院内推销麻醉？ Does this influence p

24、ricing? 这是否影响到标价？What are the vet. or client concerns for considering a particular approach to anaesthesia? 当面对一个特定的麻醉操作，兽医或主人在关心什么？Can marketing & pricing anaesthesia appropriately influence profitability? 推销麻醉和合理麻醉标价是否影响效益？Oral Translation Done by INTERVET PPT Translation Done by Hills China今天本讲座的

25、翻译:英特威公司宠物事业部技术总监梁燕明主任兽医电子邮件： 幻灯片翻译为：美国希尔思宠物营养中国部戴庶 兽医师 （兽医事务经理）张莹 兽医师 （技术服务经理）电子邮件： 电子邮件： 如果发现有错误请向他们反馈。谢谢！OH&S & Waste AnaestheticGas Management麻醉废气的管理Dr Colin DunlopDip. American College Vet. Anesthesiologists美国兽医麻醉师学会会员Advanced Anaesthesia SpecialistsSydney, Australia澳大利亚, 悉尼, 高级麻醉师 Excess Or Wa

26、ste Anaesthetic Gas (WAG) 过量麻醉气体或麻醉废气 the anaesthetic supplied to a breathing circuit is absorbed by the animal (15 ml O2/kg/min 6 ml O2/kg/min = 9 ml/kg/min)呼吸回路中1/2的麻醉剂被动物吸收Excess gas (WAG) is pushed out of the “pop-off” valve & then through the ducting to the exterior vent point by the continual

27、O2 flow from the pressurised cylinder把多余的气体从气压安全阀排出，然后通过从高压气罐持续来的氧气把它们从管道流到外部排气处排出Volatile anaesthetics in the vapour phase are similar to all gases so diffuse rapidly into the room air, so scavenge the WAG气体状态下的挥发性麻醉剂与所有的气体都相似，可以迅速扩散到室内空气内，所以要排除麻醉废气Comparison of Volatile Anaesthetics挥发性麻醉剂的比较 “liqu

28、ids at room temperature” 室温下是液体Agent 麻醉药ml vapour/ml liquid毫升蒸汽/毫升液体Apnoeic Indexx MAC 窒息指数Metabolism %代谢百分率Isoflurane 异氟烷1952.60Halothane 氟烷2272.920Sevoflurane 七氟烷1853.53Desflurane 地氟烷210Not Done0N2O 笑气GASNot Done?Methoxyflurane 甲氧氟烷2073.450Occupational Safety: Fluoride ion production职业安全：氟离子的生成Occ

29、upational Safety 职业安全Evidence for health problems from WAG is only suggestive 麻醉废气对健康的 影响只是一种推测Pregnant women have increased risk of abortion (? other factors)怀孕妇女增加流产的危险（？其他因素）minimise WAG pollution of work areas: 50 ppm = smell threshold减小麻醉废气对工作环境的污染 50 ppm = 嗅觉阈值Scavenge WAG from anaesthetic cha

30、mbers & face masks麻醉箱 & 面罩中麻醉废气的清除Pregnant women should avoid WAG exposure when chambers are opened 当麻醉箱敞开时，怀孕妇女应避免与麻醉废气接触Waste Anaesthetic Gas (WAG) Management 麻醉废气的处理WAG absorbed by charcoal (- N2O)用活性炭吸附麻醉废气WAG ducted to the atmosphere麻醉废气导管连接到大气中Anaesthetic molecule life up to 30 yrs麻醉剂分子可存在30年之

31、久Use lower O2 flows: less WAG/cost使用低氧气流量：减少麻醉废气/花费Recovery rooms: large & ventilated恢复室：宽敞 & 通风Passive “Through-the-Wall” WAG systems被动的“穿墙”麻醉废气装置Vent to the atmosphere与大气相连Fit with an insect screen装上窗纱网布 NO resistance无阻力Distance less than 6 m. 20 mm ID pipe)距离小于6 m. 内径20 mm的管Longer distances use l

32、arger pipe 使用较长的距离则需要更大的管Active Waste Anaesthetic Gas (WAG) systems主动麻醉废气装置WAG passive from “pop-off” valve麻醉废气从气压安全阀中被动排出blow or suck WAG to the building vent or to activated charcoal将麻醉废(吹或吸)气排到建筑通风管道中或排到活性炭中used with long distances to vent用远距离的抽风机Need +ve/-ve pressure relief device 需要缓减正负压力的装置Act

33、ivated charcoal WAG canisters活性炭麻醉废气过滤罐Absorb anaesthetic vapour (not N2O)吸收麻醉蒸汽（而不是N2O）Increase charcoals weight by 20%使活性炭重量增加20%500g charcoal absorbs 125ml anaesthetic liquid500克的活性炭吸收125毫升麻醉剂液体discard charcoal when opening a new 250 ml bottle (125 ml is in the animal/s)开启新的250毫升瓶子时，就该扔掉活性炭了Human

34、 facemasks have activated charcoal人用面罩含有活性炭Work Habits That Reduce WAG Pollution降低麻醉废气污染的工作习惯Only turn the vaporizer on when the breathing circuit is connected to the patient and the ET tube cuff is inflated当呼吸回路与动物连接以及气管插管套囊充气后才开启蒸发罐End anaesthesia: before disconnection turn off the vap. & O2 flow, then empty the breathing bag into the WAG system结束麻醉：在断开连接之前关闭蒸发罐&氧气流动，然后将呼吸气囊中气体排到麻醉废气系统中Flush the circuit 1 x with O2 , then disconnect the animal用氧气“冲洗”整个回路，然后与动物断开连接Fill vaporizers at the end of the day - turn OFF before opening每天最后要补充满蒸发罐 在打开盖之前先关闭开关Dont