吸入麻醉(雙語)

第七章吸入麻醉

InhalationalAnesthesia

一、概述（introduction）

1.概念(concept)

2.特點(characteristic)可控性好

不留任何后遺癥二、吸入麻醉藥的吸收、分布與消除

Uptake,distributionandelimination

ofinhalationalanesthetics1、吸收與分布Uptakeanddistribution

作用部位:大腦

centralnervesystemPAPBPBr

動態(tài)平衡

dynamicequilibrium吸收與分布影響因素：

吸入濃度inspiredconcentration分鐘通氣量minutevolume血/氣分配系數(shù)blood/gaspartitioncoefficient每分鐘肺灌流量perfusionofpulmonary

2.消除Elimination

●大部分以原形經(jīng)肺排出

Eliminatedmostlyinanunchanged

formviathelungs

●少部分經(jīng)肝、腎排出

asmallproportionismetabolizedin

liverandeliminatedviakidney

三、吸入麻醉藥的臨床評價

Clinicalevaluationofinhalationalanesthetics1.可控性

controllable

●

與血/氣分配系數(shù)有關(guān)associatedwith

blood/gaspartitioncoefficient

2.麻醉強度anestheticpotency

●

與油/氣分配系數(shù)有關(guān)

associatedwith

oil/gaspartitioncoefficient

●

MAC(minimalalveolarconcentration)

MACisminimalalveolarconcentration

ofaninhalationalanestheticat1atmosphereabsolutethatpreventsmovementsof50%ofthepopulationtoastandardstimulus.

3.對心血管的影響

EffectsonCardiovascularsystem

●心肌抑制

depressionofmyocardialcontractility

●增加心肌對兒茶酚胺的敏感性：氟烷

IncreasedmyocardialexcitabilityArrhythmiasarecommonduringhalothaneIncreasedcirculatingcatecholamines4.對呼吸的影響Effectsonrespiratory

●呼吸抑制

Respiratorydepression

dose-dependentdepressionofventilation

●呼吸道刺激

irritanttorespiratorydepression

●支氣管平滑肌舒張

relaxationofbronchialsmoothmuscle

5.對運動終板的影響

Effectsonneuromuscularjunction

●肌松作用，增強肌松劑的肌松作用Skeletalmusclerelaxationandpotentiatesnon-depolarizingrelaxants.

●安氟醚肌松作用最強

Skeletalmusclerelaxationofenfluraneisthegreatestinallinhalationalanesthetic.

●氟烷對子宮平滑肌松弛作用最強,增加產(chǎn)后出血可能

Hatholanerelaxesuterinemuscleandmaycausepostpartumhemorrhage.

●增加顱內(nèi)壓，異氟醚影響最小

increaseICP,andthisactionofisofluraneisthelowestinallvolatiles.

●抑制EEG，安氟醚可引起痙攣性EEG改變

Dose-dependentdepressionofEEGactivity,atmoderatetohighconcentration(morethan3%),enfluraneproducesepileptiformparoxysmalspikeactivity.

6.對顱內(nèi)壓及EEG的影響

EffectsonICPandEEG7.理想吸入麻醉藥的特點

PropertiesoftheidealinhalationalanestheticPleasantodour,non-irritanttorespiratorydepressionlowblood/solubility—rapidinductionandrecoverfromanesthesiaNeitherflammablenorexplosiveProducingunconsciousnesswithanalgesiaandsomedegreeofmusclerelaxationNotbemetabolizedinthebody,non-toxic,notprovokeallergicreactionsMinimaldepressionofcardiovascularandrespiratorysystemandnotinteractwiththeotherdrugsusedcommonlyduringanesthesia,e.g.catecholamines.優(yōu)點：

●毒性小，對循環(huán)系統(tǒng)抑制輕low-toxicity,lightdepressionofcardiovascularsystem

●呼吸道無刺激

non-irritanttorespiratorydepression

●適用于危重病人

suitableforseriouslyillpatient

●

誘導(dǎo)和蘇醒快

rapidinductionandrecoverfromanesthesia

8.氣體麻醉藥-氧化亞氮

anestheticgas—nitrousoxide注意事項announcements

●長時間高濃度吸入時，對紅細胞生成有一定的影響,補充vitB12

AffectsvitamineB12synthesiswhenthedurationofnitrousoxideexceeds8hours.

●不能單獨吸入，最低吸氧濃度為30%，否則，易導(dǎo)致缺氧

Diffusionhypoxia:essentialtoadministeraminimumFiO2of30%

●麻醉作用弱，常與安氟醚、異氟醚氧氣同時吸入Goodanalgesia,pooranesthesia,isusedcombinationwithenfluraneorisoflurane

四、常用吸入麻醉裝置

Inhalationalanesthesiaoutfit氣源Gases流量計Flowmeters蒸發(fā)器Vaporizers呼吸囊Breathingbag呼吸螺紋管Anestheticbreathingsystem呼吸活瓣Breathingvalue二氧化碳吸收裝置

Canisterorcarbondioxideabsorber

五、常用吸入麻醉方法

MethodsofInhalationalanesthesia

㈠

開放式(opencircuits))：開放點滴法、充

氣法、無重復(fù)吸入法特點：

●無重復(fù)吸入，無CO2吸收裝置優(yōu)點：

●簡單，機械無效腔及呼吸阻力小

●通過無重復(fù)吸入裝置可輔助或控制呼吸缺點：

●氣道干燥，污染空氣

●呼呼吸不易管理：舌后墜、呼吸道梗阻，

通氣困難

●麻醉深度不易掌握㈡

半開放式(semi-opencircuits)

suitableforspontaneous

特點：

●呼出氣部分被重復(fù)吸入，無CO2吸收裝置

及無重復(fù)吸入活瓣，重復(fù)吸收CO2<1%

缺點：

●吸入氣流量大（分鐘通氣量的2-3倍),吸入氣流