首医大临床麻醉学课件：Anesthesia for Obstetrics

AnesthesiaforObstetrics

PHYSIOLOGICCHANGESOFPREGNANCY1CardiovascularSystem:cardiacoutput,heartrateHematologicSystem:bloodvolumeincreasesbyupto45%,redcellvolumeincreasesbyonly30%--physiologicanemiaRespiratorySystem:increaseintherespiratoryminutevolumeandworkofbreathingGastrointestinalSystem:endotrachealintubationRenalSystem:GFRrises50%;glycosuriaCentralNervousSystem:↑

sensitivitytoanesthetics.PHYSIOLOGICCHANGESOFPREGNANCY2PLACENTALTRANSFEROFANESTHETICDRUGS

SimplediffusionActivetransportPinocytosisReadilycross:

lowmolecularweights,

highlipidsolubility,non-ionized

Approximately50%bypassestheliver.MorphinePlacentaltransferisrapidMother:uterusreactiveness↓orthostatichypotensionnauseavomitingdelayedgastricemptyingFetus:respiratorydepressionPethidine

Mostcommonlyused

duringlabor

intramusculardose:50-100mg

TimeofIM:beforeexpulsion1hor4huterinecontraction,frequencyandintension↑Fentanyl

Alfentanil

Sufentanil

Placentaltransferisrapid

Lowdose:10-25µgfentanylor5-10µg sufentanilinsubarachnoidspacePCEA:lowdoseoffentanyland0.1%- 0.3%ropivacaineTramadol

PlacentaltransferNoinhibitinguterinecontractionNoRespiratorydepressionDiazepam

Readilycrosstheplacenta

Half-lives:48hoursProblems:sedation,hypotonia,cyanosis,impairedmetabolicresponsestostress.

Midazolam

Plasmaproteinbinding:94%Respiratorydepression:dependedon dose0.075mg/kg–noproblem0.15mg/kg–differentdegreeChlorderazin

PreeclampsiaandeclampsiaIM：12.5–25mgOverdose:centralinhibitionPromethazine

PreventemesisAppearsinfetalbloodwithin1to2 minutesafterintravenousinjectionin themotherReachesequilibriumwithin15minutesDroperidol

Pregnantwoman:慎用Apgarscore↓Thiopentalsodium

Neonatussleep:littlePrematureandintrauterineembarrass: carefullyusingKetamine

Highdoses(greaterthan2mg/kg)maycause lowApgarscoresandabnormalitiesin neonatalmuscletoneLaborpains

ofuterinecontractionUterinemusculartensionandcontraction forceContraindication:psychosis,gestational hypertensionsyndromeorpreeclampsia,

metrorrhexisPropofol

Recommendation:

induction:<2.5mg/kgmaintenance:2.5-5.0mg/kgDiscontinuegravidityonlyN2O

PlacentaltransferisrapidMother’srespiration,circulationand Uterinemuscularcontractionforce↑20-30sbeforeoffirststageoflabor: 50%O2and50%N2OEnfluraneandIsoflurane

Lightanesthesia:noinhibitionDeepanesthesia:mother:inhibitionofuterinecontraction,uterinebleedingfetus:disadvantageSevoflurane

Placentaltransferismorerapidthan halothane

Inhibitionofuterinecontraction: >halothaneSuccinylcholine

CholinesteraseDose>300mgorsingledoseisjustomajor:stillhaveplacentaltransferNondepolarizingMuscleRelaxants

Onsetisquick,maintanenceisshort andplacentaltransferisleastAtracuriumLocalanestheticsFactors:Proteinbinding:MolecularweightLiposolubility

CatabolismintheplacentLocalanesthetics

Procaine

Lidocaine

Bupivacaine

RopivacaineANESTHESIAFORCESAREANSECTIONChoicedependson:

theindicationsforthesurgerythedegreeofurgencymaternalstatusdesiresofthepatientSpinalAnesthesia

Hyperbaricbupivacaine

Advantages:rapidonset,denseneural block,littleriskoflocalanesthetic toxicity,minimaltransfertothefetus, infrequentfailure.Disadvantages:finitedurationhypotensionEpiduralAnesthesia

L2～3orL1～2

1.5%～2%Lidocaineor0.5%RopivacaineemergencycesareansectionCombinedSpinal-EpiduralTechnique

Increaseddramaticallyinpopularity

Advantages:rapidonsetsupplementedatanytimeanestheticdose↓

sacralnervesblockissufficientGeneralAnesthesia

rapidinduction:obviatepositivepressureventilationoppressthecricoidcartilage

mainterance:lightansthesiavomiting,backstreamingandaspiration:atropine,0.5mg,IMorglycopyrolate,0.2mg,IMSupinehypotensivesyndrome

Incidence:2%～30%Time:after28weeks,specially32～36 weeksSymptoms:

◆hypotension,◆dizziness,

◆nausea,◆chestdistress,

◆coldsweat,◆toyawn,

◆pulserate↑,◆

pallescenceMechanismPreventHighriskpregnancy

Emergencyoperation:latetrimesterofpregnancygestationalhypertensionsyndromand eclampsia

Selectiveoperation:hypertensioncardiacdiseasediabetes

multifetation

PlacentaPreviaandPlacentalAbruption

Preanesthticpreparation:

bloodcoagulationfunctionDICsiftingtestacuterenalfailurePrinciple:

generalanesthesia:activebleeding, hypovolemicshock,definitebloodcoagulation disfunctionorDIC

intraspinalanesthesia:conditionofmother andfetusisokay

Managementdegreesofabruptio

placentae.A,Concealedhemorrhage.B,Externalhemorrhage.C,Completeplacentalseparation.

Typesofplacentaprevia.

Managementofanesthesia

Announcementsoftheinduction:difficultairway

cricoidcartilage

backstreamingandaspirationPreparetosalvagethebloodcoagulation disfunctionandthehemorrhoea.Preventtheacuterenalfunctionfailure:urinevolumeureanitrogenandcreatininePreventionandcureofDICPregnancy-inducedhypertensionsyndrome

Incidence:10.3%Causeofdeath:

cerebrovascularaccident,

pneumonedema,livernecrosis

Pathophysiology:systemicarteriolasystole,<200

µm,calciumion,

pachemia,hypovolemia→wholebloodandplasma viscosity↑and

hyperlipemia→microcirculation

perfusion↓→intravascularcoagulationPregnancy-inducedhypertensionsyndromecomplicatingcardiacfailure

Digitalization,diuresis,morphine,↓BP.Anesthesia:

epiduralanesthesia

generalanesthesiaManagement:

毛花苷C--maintenancedose:0.2-0.4mg

furosemide(呋塞米）--20-40mgoxygenmaintainstabilizationoftherespiratoryand circulatorysystemSeverePregnancy-inducedhypertensionsyndrome

Preanesthesiaprepare:

★informationofmedication

★magnesiumsulfate

★

hypotensivedrug

★liquidintakeandoutputvolumeAnesthesia:terminationofpregnancy

epiduralanesthesia:nobloodcoagulation disfunction,noDIC,noshockandno cataphora

generalanesthesia:safeofmother>fetus

Management:HELLPsyndrome

cardiacfailurecerebralhemorrhageplacentalabruptionbloodcoagulationdisfunction

haematolysishepaticenzyme↑thrombocytopeniaacuterenalfailureManagement1

tryingstableanesthesia:↓stressreaction:fentanylavoidtouseketamineSBP:140150mmHg,DBP:about90mmHg

ganglioplegicornitroglycerinmaintainheart,kindeyandlungfunction:treatmentofcomplication:Management2

basicmonitoring:

◆ECG◆SpO2

◆NIBP◆CVP

◆urinevolume◆bloodgasanalysispreparetosalvagetheneonatalasphyxiaICU

postoperationanalgesiaMultipleBirths

pathophysiology:

◆abdominalaortaandinferiorvenacava compression;

◆fetallungmaturity;

◆incidenceofpostpartumhemorrhage.anesthesia:epiduralanesthesiamanagement:

◆additionofvolume:colloid

◆oxygen,

preventionandcureofSupinehypotensive syndrome

◆preparationofresuscitationofnewbornNeonatalasphyxiaandemergencytreatmentASSESSMENTOFTHEFETUSATBIRTH

Apgarscore

isasimple,usefulguide

-

TheApgarscoringsystem

Score

*

Sign

0

1

2

Heartrate

Absent

Lessthan100/min

Morethan100/min

Respiratoryeffort

Absent

Slow,irregular

Good,crying

Color

Blue,pale

Bodypink,extre

mitiesblue(acrocyanosis)

Completelypink

Reflex

irritability(responsetoinsertionofanasalcatheter)

Absent

Grimace

Cough,sneeze

Muscletone

Limp

Someflexionofextremities

Activemotion

Apgarscore

1-minutescore---degreeofasphyxia5-minutescore---prognosisevaluatedat1and5minutes.shouldnotwaituntil1minutehaspassed beforeinitiatingresuscitation.normal:7-10mildasphyxia:4-6

severeasphyxia:0-3

Resuscitationofnewborn

A(Airway)B(Breathing)C(Circulation)D(Drug)E(Evaluation)Initialresuscitation

Incubation:27～31℃Position:

Suctioning:mouthandnoseStimulate:Completeitwithin20sEvaluationandfurthertreatment

Evaluation:accordingtobreath,heartrate andskincolourNormal:stopresuscitationNospontaneouslybrathing,HR<100/min: bagrespiratorHR<80/min:closedcardiacmassage;trachealintubation,medicationBagrespirator

ManiphalanxpressurizeTidalvolume:20～40mlI:E=1.5:1RP:30～40/minfirsttwice:pressure–30～40cmH2Osubsequently:pressure–10～20cmH2ORESUSCITATIONEQUIPMENTClosedcardiacmassageHR:120/minDepth:1～2cmRESUSCITATIONDRUGS

30saftertheclosedcardiacmassage, stilldon’trecovery:drugEpinephrine:0.1～0.2mg/kg, intratrachealdropinHypovolemia

causes

umbilicalcordwasclampedandcut earlierintrauterineasphyxiaplacentalabruptionhemo