剖腹產(chǎn)的麻醉進(jìn)展

剖腹產(chǎn)的麻醉進(jìn)展Introduction

Associatedwithhighmaternalmortality（二十世紀(jì)前，剖腹產(chǎn)由于產(chǎn)婦高死亡率，開(kāi)展得并不多）untiltheturnofthe20thcentury,cesareandeliverynowaccounts

forapproximatelyonethirdofallbirthsin

developedcountries（發(fā)達(dá)國(guó)家三分之一分娩通過(guò)剖腹產(chǎn)）

Thisincreasehasresultedfromimprovementsin

surgicalandanesthetictechniques,diminisheduseofforcepsforextractions,fewerbreechandmultiplegestation

vaginaldeliveries,andgreateruseofrepeatcesareandeliveries（得益于外科及麻醉技術(shù)的發(fā)展、產(chǎn)鉗使用的減少、臀位和復(fù)雜分娩的減少、以及二次剖腹產(chǎn)的發(fā)展）.Introduction

TheupdatedPracticeGuidelinesforObstetricalAnesthesiafromtheASATaskForceonObstetricalAnesthesia

observethatneuraxialtechniques(spinal,epidural,CSE)areassociatedwithimprovedmaternalandfetaloutcomes

whencomparedtogeneralanesthesia(GA)（觀察到椎管內(nèi)麻醉與全麻相比，對(duì)于產(chǎn)婦和胎兒有更好的預(yù)后）,particularlyinthepresenceofhighbodymassindexandairwayissues（特別是高體重指數(shù)和氣道問(wèn)題的病人）.

However,specificanestheticmanagementshouldbechosenonacase-by-caseassessmentofpatient,medical（具體麻醉方式必須建立在對(duì)病人完全評(píng)估之上）,anesthetic,andobstetricissues.IntroductionAnestheticparticipationcanalsoreducetheincidence、ofcesareandeliveries[e.g.improvingforcep/vacuumanalgesia,increasingthesuccessofmultiplegestationvaginalbirths,reducingfetalheadentrapmentwithintravenousnitroglycerin,andimprovingexternalcephalicversion(ECV)success].(麻醉在自然分娩中的參與同樣可以減少剖腹產(chǎn)率，比如為使用產(chǎn)鉗時(shí)提供鎮(zhèn)痛，提高復(fù)雜分娩的成功率以及改善胎位不正回轉(zhuǎn)術(shù)的成功率)IntroductionNeuraxialtechniquesimproveECVsuccessbyrelaxingtheabdominalwallmuscles,improvingpatientcomfort,andallowingamoreconcertedattempt.（神經(jīng)阻滯可以松弛腹壁肌肉，提高病人舒適度，從而提高回轉(zhuǎn)術(shù)成功率）anesthesia(lidocaine45mgwithfentanyl10μg)combinedwithuterinetocolysis(nitroglycerin50μgiv,wait50sec)hasbeenassociatedwithahighsuccessrate(83%)forexternalcephalicversion(ECV).（使用45mg利多卡因+10ug芬太尼，同時(shí)用50ug硝酸甘油抑制子宮收縮，可以使回轉(zhuǎn)術(shù)成功率提高到83%）IsthereaPreferredAnestheticTechnique（什么是剖腹產(chǎn)首選麻醉方式）?

Complicationsrelatedtoanesthesiastillrepresentthesixthleadingcauseofperipartummaternalmortalityinthe

UnitedStates（麻醉相關(guān)并發(fā)癥是產(chǎn)婦圍生期第六大死亡原因）.

Notsurprisingly,thesedeathsmostcommonlyresultfromfailuresinoxygenationandventilation（通常由氧合或通氣失敗導(dǎo)致）,however,theseepisodesarecurrentlybeingwitnessedmorefrequentlyduringextubationandpostoperative

recovery,ratherthanwithintubation（通常在拔管及恢復(fù)期發(fā)現(xiàn)，而不是插管時(shí)）.IsthereaPreferredAnestheticTechnique?

Theestimatedcase-fatalityriskratioforGAversusneuraxialanesthesiahasundergoneasignificantreduction（全麻與椎管內(nèi)麻醉的死亡率比例經(jīng)歷了極大的下降）.

Thischangemostlikelyrepresentstwo

Trends（代表了兩種趨勢(shì)）:

1)areductioninGAuse,coupledwith

moresuccessfulmanipulation(e.g.Alternate

airwaydevices)ofthematernalairway（全麻的減少，和更多氣道替代設(shè)備的熟練操作）.

2)agrowingacceptanceofneuraxialtechniqueuseinparturientswith

significantcomorbidities(e.g.obesity,severepreeclampsia,hematologicandcardiacdisease)（對(duì)合并有包括肥胖，嚴(yán)重子癇前期，凝血功能障礙及心臟病產(chǎn)婦使用椎管內(nèi)麻醉的接受程度）IsthereaPreferredAnestheticTechnique?

Thecombinedspinalepidural(CSE)techniquemayofferthemostflexibility（腰硬聯(lián)合提供更多的靈活度）

intermsofreducingtheinitialdrug

dose(通過(guò)減少初始劑量），allowingforpotentiallylesshypotensionandfasterrecovery（更少的低血壓發(fā)生率和更快的恢復(fù)）,aswellasprolongingtheblockadeshould

operativecomplications（減少手術(shù)并發(fā)癥）

orpostoperativepainmanagement（術(shù)后鎮(zhèn)痛管理）

issuesoccur.ShouldNewerLocalAnestheticsbeused（新型局麻藥的使用）?

Potentiallyreducedrecoverytimesandtoxicityprofileshavefosteredaninterestinthenewerlocalanesthetics為了減少恢復(fù)時(shí)間和毒性反應(yīng)，促使了新型局麻藥的發(fā)展）,

ropivacaineandlevobupivacaine（羅哌卡因和左布比卡因）.

Althoughestablishedtobesafeandacceptableforelectivecesareandeliveries（雖然被證實(shí)剖腹產(chǎn)時(shí)更安全）,thesetwolocalanestheticsmaynotbesignificantlylesscardiotoxicthanbupivacaine（并沒(méi)有比布比卡因明顯減少心臟毒性）

Moreover,becausethetoxicityofbupivacainedoesnotappeartobeenhancedinpregnancy（因?yàn)椴急瓤ㄒ虻亩拘栽趹言衅诓](méi)有增加）,cardiactoxicityshouldonlyoccurwithunintentionallargeintravasculardoses（心臟毒性只在血管內(nèi)意外大量注射后發(fā)生）.ShouldNewerLocalAnestheticsbeused?

Withthecommonandmore

forgivinguseofchloroprocaine3%andlidocaine2%forconversionofepidurallaboranalgesiatocesarean

Anesthesia（隨著普魯卡因和利多卡因作為剖腹產(chǎn)硬膜外麻醉的藥物,coupledwithproperdrugadministrationpractices(e.g.attentiontoincrementaldosingpractices,total

doseguidelines,andtoxicitysymptoms，如果掌握正確的給藥方式（例如注意追加劑量、總劑量的給藥方法、掌握判斷毒性反應(yīng)的方法),toxicintravascularlevelsshouldbearare（血管內(nèi)毒性水平可以降到很低）.ShouldLowerDosesofBupivacainebeused（低劑量布比卡因的使用）?

Thedoseoflocalanestheticshasbeenreduced

asamethodtopotentiallyobtainlesshypotension,fastermotor

recoveryanddischargetimes,andimprovedmaternalsatisfaction（減少局麻藥用量可以作為預(yù)防低血壓，改善恢復(fù)時(shí)間和產(chǎn)婦滿意度的方法）

Suchdosereductionsmaybeachievedbyusingspinalversusepiduralanesthesia（通過(guò)使用腰麻）,aswellaslesstotallocalanesthetic（減少局麻藥總用量）;withthesechanges,reductionsintime,costs,andcomplicationshavebeenrealized.

Whenspinalbupivacaineinintermediatetolowdoses(3-9mg)areused（當(dāng)腰麻布比卡因使用中到低劑量即3-9mg）,theneedforsupplementalmedicationscanbesignificant(可能需要更多追加劑量),andthusacatheterbasedtechnique(以至于需要導(dǎo)管技術(shù)比如CSE)shouldbeused.CanHypotensionbeprevented?

（避免低血壓）

Neuraxial-inducedhypotension,whensevereandsustainedcanimpairuterineandintervillousbloodflowandresult

infetalhypoxia,acidosis,andneonataldepression（椎管內(nèi)麻醉后嚴(yán)重并且持續(xù)的低血壓會(huì)影響子宮及絨毛血供，導(dǎo)致胎兒缺血，甚至胎兒窘迫）.

Leftuterinedisplacementandtreatmentorprophylaxiswith

vasopressorshavereducedtheincidenceofhypotensionwithvariablesuccess（子宮左旋或血管加壓藥可以預(yù)防）.

Preloadingwithcrystalloidhas

limitedeffectsonmitigatinghypotension,evenwithlargedoses(即使給予大劑量晶體預(yù)充血容量，效果仍然有限);moreeffectiveispreloadingwith

colloids,orsimultaneouslygivingrapidcrystalloidorcolloidscoincident(co-loading)withthespinaltechnique（最好預(yù)充膠體液或晶膠同時(shí)預(yù)充）.CanHypotensionbeprevented？

Hypotension

mayalsobereducedwiththeuseofsmallerspinallocalanestheticdoses（低血壓同樣可以通過(guò)較少的腰麻藥用量避免）.

Prophylaxisandtreatmentofmaternal

hypotensionwithphenylephrine（去氧腎上腺素）,versusincombinationwithephedrineorephedrinealone（合用或單用麻黃素）,ismore

effectiveinimprovingmaternalhemodynamics（更好改善母體血流動(dòng)力學(xué)）

andfetalacid-basevalues（胎兒酸堿水平）;WhatAdjuvantMedicationsshouldbeused?輔助用藥的使用

Adjuvantmedicationsexpressanumberofbenefits,including

theabilitytoreducethedoseandsideeffectsoflocal

anesthetics（輔助藥可以減少局麻藥用量和副作用）.

Neostigmineandclonidine（新斯的明和可樂(lè)定）

aretwonovelagentsundergoingclinicalinvestigation.

Inwomen

undergoingelectivecesareandelivery,neostigmineinspinaldosesupto100μgsignificantlyreducedpost-operative

pain（顯著減少術(shù)后疼痛）

withnoeffectonfetalheartrateorApgarscores（對(duì)胎兒心率\和Apgar評(píng)分無(wú)影響）.WhatAdjuvantMedicationsshouldbeused?

However,inspinaldosesaslittleas6.25μg,ahighincidenceofsideeffects

includingprolongedmotorblockade,nausea,andvomitinghavebeenobserved（觀察到比如延長(zhǎng)的運(yùn)動(dòng)阻滯、惡心嘔吐等副作用發(fā)生率較高）.

Asa

consequence,thespinalroutewillmostlikelybeabandoned（因此最好放棄在腰麻中使用）;however,somepromise

hasbeennotedwiththe

epiduralroute（可以嘗試使用硬膜外路徑）WhatAdjuvantMedicationsshouldbeused?

Clonidine（可樂(lè)定）,inspinalandepiduraldosesvaryingfrom15-50μgand50-120μg,respectively,canprolonganalgesia

anddecreaseshivering（無(wú)論腰麻或硬膜外，都可以延長(zhǎng)鎮(zhèn)痛，較少寒戰(zhàn)）;However,mildhypotensionandsedationarenotinfrequentsideeffects（可能出現(xiàn)不常見(jiàn)的輕微低血壓和催眠）.

Currently

clonidinehasonlyonespecificneuraxialindication(intractablecancerpain，只有一種適應(yīng)證即頑固性癌痛),FDAwarningthat

“epiduralclonidine（硬膜外可樂(lè)定）

isnotrecommendedforobstetrical,postpartum,andperioperativepainmanagement”（不建議使用于分娩、產(chǎn)后及圍手術(shù)期鎮(zhèn)痛）.

WhatAdjuvantMedicationsshouldbeused?

Preservativefreemorphinesulfate（鹽酸嗎啡）

can

provide17-27hofpost-cesareananalgesia（17-27小時(shí)的產(chǎn)后鎮(zhèn)痛）.Intrathecally（蛛網(wǎng)膜下腔給藥）,acomparisonof0.025,0.05,0.1,0.2,0.3,0.4,and0.5mgdosesobservedthat0.1mgproducedanalgesiacomparabletodosesashighas0.5mg（0.1mg與高達(dá)0.5mg的效果無(wú)異）.

Theincidenceofpruritus,butnotnauseaandvomiting,appeareddoserelated（瘙癢癥與劑量相關(guān)，但惡心嘔吐與劑量不相關(guān)）.

Intheepiduralspace（硬膜外）,a

comparisonof1.25,2.5,3.75,and5mgdosesobservedthatthequalityofpost-cesareananalgesiadidnotimprove

beyond3.75mg（鎮(zhèn)痛效果在達(dá)到3.75mg后就不再變化）.Pruritus,nauseaandvomitingdidnotappeardoserelated.WhatAdjuvantMedicationsshouldbeused?

Extended-releaseepiduralmorphine(緩釋嗎啡，商品名Depodur)canprovideanalgesiafor48hrswith10and15mgdoses;However,cautionshouldbeappliedtodosing

theepiduralcatheter

withlocalanestheticimmediatelyaftertheDepodur（硬膜外導(dǎo)管給予緩釋嗎啡后立刻給予局麻藥時(shí)應(yīng)該小心）,andevenupto1hourbefore,asthe

maximumplasmaconcentrationsofmorphinewillbehigher（即使是1小時(shí)前給予的嗎啡，局麻藥會(huì)升高嗎啡的血漿峰值濃度）.DoesaPerfectCocktailExist（最佳藥物組合）?

Themostrecentevidencewouldsuggestthefollowingcombinationsareoptimal:MedicationSpinalEpiduralLocalAnestheticBupivacaine

9-12mg2%Lidocaine+Bicarb8.4%(10mL/1mLratio)Fentanyl15-35μg50-100μgMorphine0.1mg3.75mgASSOCIATEDANESTHETICCONCERNSDURINGCESAREANDELIVERY（剖宮產(chǎn)麻醉相關(guān)問(wèn)題）AntibioticUseandTiming

（抗生素使用）

Postpartuminfectionis5to20-foldgreaterinthosepatientsdeliveringbycesareanversusvaginalroutes（剖宮產(chǎn)的產(chǎn)后感染比自然分娩高5-20倍）

and

remainswithinthetopfivecausesofpregnancy-relatedmortality（產(chǎn)后五大死亡原因之一）.

Thetraditionalpracticeofadministering

antibioticsafterinfantdeliveryandumbilicalcordclampingoriginatedtopreventfetalexposuretoantibiotics（傳統(tǒng)的使用方法是胎兒娩出、臍帶夾閉之后，為了避免胎兒接觸到抗生素）.

However,recentstudiesofantibioticusepriortocesareanskinincision（切皮前）

haveobservedsignificantlyfewermaternalinfections（觀察到產(chǎn)婦感染的顯著減少）

withnodifferencesinthefrequencyofneonatalsepsiswork-upsorprovensepsiscases（胎兒膿毒血癥檢驗(yàn)結(jié)果無(wú)差異）

OxytocinandUterotonicAgentUse（縮宮素使用）

Thecurrentguidelinesfortheadministrationof

oxytocinduringcesareandeliveryarediverse,

empiric,andvague,withnonevidence-baseddosesof20-40IUbeingadvocated（目前的縮宮素使用并沒(méi)有循證支持）.

However,adequateuterinecontractions（足夠的子宮收縮）

duringelectivecesareandeliveriesinnon-laboringwomen(未進(jìn)入產(chǎn)程的孕婦）

requireonlysmallloadingdosesofoxytocin（只需要少量的縮宮素負(fù)荷量）(ED90=0.35IU);asimilarlylowloadingdose(ED90=2.99IU)isrequiredinlaboringwomen（產(chǎn)程中的孕婦）.OxytocinandUterotonicAgentUse

Consequently,aloweroxytocin,

hasbeenadvocated:OxytocinProtocolforCesareanDelivery:“RuleofThrees”3IUOxytocinIVLoadingDose(administeredbyrapidinfusion,ratherthanabolus,nofasterthan15seconds)3MinuteAssessmentIntervals（3分鐘評(píng)估間隔）.Ifinadequateuterinetone,give3IUOxytocinIVrescuedose.3TotalDosesofOxytocin(InitialLoad+2RescueDoses)3IUOxytocinIVMaintenanceDose(3IU/Lat100mL/h)upto8hrs.3PharmacologicOptions(e.g.Ergonovine麥角新堿,carboprost卡前列素

andmisoprostol米索前列醇)ifinadequateuterinetonepersistsIntra-andPost-partumHemorrhage（產(chǎn)時(shí)產(chǎn)后出血）

Hemorrhageoccurringduringorfollowingcesareandeliveryisanincreasingcomplication（出血是日益增長(zhǎng)的產(chǎn)時(shí)產(chǎn)后并發(fā)癥）

thatisassociatedwith

significantmaternalmorbidityandmortality.

Theidentificationofriskfactorsassociatedwithuterineatony（發(fā)現(xiàn)子宮收縮乏力高危因素證據(jù)后需輸血）requiringbloodt