TheAdultPatientWithMorbidObesityand/orObstructiveSleepApneaForAmbulatorySurgeryGirishP.Joshi,MBBS,MD,FFARCSI協和規培：石磊病態肥胖及阻塞性睡眠呼吸暫停病人的門診手術麻醉（一）Introduction

Morbidlyobese（病態肥胖）

haveanincreasedriskofCo-morbidities(并存病，Table1),andthereforeposeconsiderablechallengestotheanesthesiologist(Table2).

Oneof

themajorco-morbiditiesassociatedwithobesityincludesobstructivesleepapnea(阻塞性睡眠呼吸暫停，OSA),reportedin60-70%of

morbidlyobese.簡介IntroductionTable1:Co-morbidities（并存?。?/p>

AssociatedWithObesity（肥胖）Respiratory（呼吸系統）:Restrictivepulmonarydisease（限制性肺疾?。?obstructivesleepapnea（阻塞性睡眠呼吸暫停）,asthma（哮喘）,Pulmonary

hypertension（肺動脈高壓）Cardiac（心血管）:Systemichypertension（系統性高血壓）,coronary

arterydisease（冠狀動脈心臟?。?dysrhythmias（心律失常）,Cardiomyopathy（心肌?。?CHF（慢性心衰）Neurologic（神經系統）:Stroke（中風）Renal（泌尿系統）:Renaldysfunction（腎功能不全）Metabolic（內分泌）:Metabolicsyndrome（代謝癥候群）,type2

diabetesmellitus（2型糖尿?。?hypothyroidism（甲低）IntroductionImmediate

postoperative（術后即刻）:Delayedextubation（拔管延遲）Obstructionand/ordesaturationafterextubation（拔管后梗阻）Post-obstructivepulmonaryedema（梗阻后肺水腫）Needfortrachealreintubation（再插管）Exacerbationofcardiaccomorbidities（心血管并存病加重）Cerebrovasculardisorders(e.g.,stroke)（腦血管疾?。㏄ostoperativedelirium（術后譫妄）ProlongedPACUstay（恢復室逗留時間延長）Delayeddischargehome（住院時間延長）IntroductionPost-discharge（出院后）:Readmissionafterdischarge

（出院后再入院）Hypoxicbraindeathanddeath（缺氧性腦死亡和死亡）SelectionofAdultPatientsMorbidlyObesityand/orOSAForAmbulatorySurgery(病態肥胖及阻塞性睡眠呼吸暫停病人的選擇)

A

recentsystematicreviewrevealedthatBMIalonemightnotinfluenceperioperativecomplications

orunplanned

admissions（BMI指數并不單獨影響圍術期并發癥).

Therefore,BMIshouldnotbeconsideredthesolepatientselectioncriterionforambulatorysurgery(BMI不應作為獨立的選擇標準).

Overall,thepatientselectionforambulatorysurgeryshoulddependupontheseverityofco-morbidities,the

surgicalprocedure,andthe

anesthetictechnique（取決于并存病嚴重程度、手術過程、麻醉技術）.SelectionofAdultPatientsMorbidlyObesityand/orOSAForAmbulatorySurgery

Overall,patientswithinadequatelytreatedco-morbidconditions（未經充分治療的并存病狀況）arenotsuitableforambulatorysurgery（不適合門診手術）.

Also,itisimperativethatallsurgicalpatients

areevaluatedforpresenceofOSA,preoperatively（術前對OSA評估）.

Patientswithknowndiagnosisofmoderate-to-severeOSA（確診中重度的OSA）

and

optimizedcomorbidconditions（并存病處在最佳狀況）canbeconsideredfor

ambulatorysurgery,iftheyareabletousetheCPAP

devicein

the

postoperativeperiod（術后使用持續正壓通氣）.PreoperativeConsiderations

Morbidlyobesepatients(BMI≥40kg/m2)sufferfromnumerouschronicmedicalconditions(許多慢性醫療癥狀，Table1).

BecauseOSAisundiagnosedinanestimated60-70%ofpatients（大約60-70%未確診）,screeningforOSAshouldbepartofroutinepreoperativeevaluation（篩查OSA應作為常規術前評估）.

TheSTOP-BANGscreening

toolisauser-friendlyquestionnaire（STOP-BANG是一個病人易掌握的調查問卷）

thatcouldbeincludedinroutinepreoperativeevaluationtoidentify

unrecognizedOSA(Table3).

Tworecentstudieshavevalidated（證實）

theSTOP-BANG

questionnaireandfoundthat

ahigherSTOP-BANGscoreidentifiedpatientswithhighprobabilityofmoderate/severeOSA（高分提示中重度OSA的可能）術前注意事項PreoperativeTesting

TheAmericancollegeofCardiology(ACC)andAmericanHeartAssociation(AHA)recommendedthat

ECGbeobtainedinpatientswithatleastoneriskfactorforCHDand/orpoorexercisetolerance（有至少一個冠心病危險因素或運動耐量差的病人）.

ECGsignsofright

ventricularhypertrophyincludingright-axisdeviationandrightbundle-branchblockwouldsuggestpulmonary

Hypertension（右心室肥大提示肺動脈高壓）,whilealeftbundle-branchblockmaysuggestoccultCHD（左束支阻滯提示隱匿冠心病）.

Inaddition,chestX-rayshould

beobtained

onallmorbidlyobesepatientsasitmaysuggestundiagnosedheartfailure,cardiacchamberenlargement,or

abnormalpulmonaryvascularitysuggestiveofpulmonaryhypertension（提示未診斷的心衰、心室增大或異常的肺血管分布）,whichwarrantsfurthercardiovascular

Investigation（作為其他心血管檢查的依據）.術前檢查PreoperativeMedications

Obesepatientsmaybeonmultiplemedicationsincludingprescriptionandnon-prescription(i.e.,over-thecounterorherbaldietdrugs)（非處方藥或者中草藥）thatmighthavedetrimentalcardiopulmonaryeffectsaswellasadverselyinteractwith

anestheticdrugs（對心肺有害或影響麻醉藥作用）.

Patientsshouldbeaskedtocontinuetheirpreoperativemedicationsuntilthedayofsurgery（囑咐病人用藥直至手術當天）,Becausemorbidobesityisoneofthemajorrisk

factorsforthedevelopmentofpulmonaryembolism（病態肥胖是肺栓塞發展的主要危險因素之一）,prophylaxisfordeepveinthrombosis（預防深靜脈血栓）,lowdoseheparinin術前用藥PreoperativeMedications

combinationwithintermittentpneumaticcompression,arerecommend（建議小劑量肝素，同時間歇氣壓療法）Preoperativeprophylaxisagainstacidaspiration(e.g.,H2-receptorantagonistsandprotonpumpinhibitors)（返流誤吸措施包括H2受體阻滯劑和質子泵抑制劑）

is

commonlyused.

However,theirroutineuseisquestioned,astheriskofregurgitationof、gastriccontentsforthe

morbidlyobeseandthenon-obeseappearstobesimilar（是否常規使用值得商榷，因為病態肥胖病人返流的風險與常人無異）.IntraoperativeConsiderations

Althoughthesurgicalprocedureandtheneedforpostoperativeopioids,ratherthanthechoiceofanesthetic

techniqueappeartobemoreimportantdeterminantsofperioperativecomplicationsinthemorbidlyobeseparticularlythosewithOSA（病態肥胖，特別是合并OSA的病人中，相對麻醉選擇的技術，手術過程和術后阿片類的需要似乎更應該是圍術期并發癥的決定因素）,localorregionalanesthesiashouldbepreferred（即使如此，也應該選擇局部區域阻滯麻醉應）.

Local/regionalanesthesiaobviatesthe

needforairwaymanipulationaswellasavoidshypnotic-sedatives,opioids,andmusclerelaxants（局部區域阻滯避免了氣道管理、鎮靜催眠和阿片類、肌松藥的使用）.

Inaddition,these

techniquesprovidepostoperativeanalgesiaandreducepostoperativeopioidrequirements（同時也提供了術后鎮痛、減少阿片類的使用量）.術中注意事項SedationandAnalgesiaintheObeseandOSAPatients

PatientswithOSAaremoresensitivetosedative-hypnoticsandopioids（病人對鎮靜催眠和阿片類更敏感）,whichcausedose-dependentupperairwaycollapse,respirationdepression,andreducedrespiratoryresponsestohypoxiaandhypercapnia（導致劑量依量性呼吸道塌陷，呼吸抑制、減少呼吸系統對缺氧和二氧化碳潴留的反應）.

Ofnote,

duringsedationOSAmaydevelopinpreviouslyunrecognizedpatients（鎮靜狀態下，之前未發現的病人可能出現新發展的OSA）.

Therefore,monitoringshouldinclude

continuouscapnographyasitallowsdetectionofupperairwayobstructionmuchpriortooxygendesaturation（必須持續監測二氧化碳因為相對氧飽和度，它能更早提示上呼吸道梗阻）.SedationandAnalgesiaintheObeseandOSAPatients

Midazolamandpropofolhaveasimilarpropensityforupperairwayobstructionatsimilarlevelsofsedation（咪達唑侖和丙泊酚有類似的引起上呼吸道梗阻的傾向）.

Dexmedetomidine,a

highlyselectivealpha-2adrenergicagonistwithsedative,amnestic,analgesic,andsympatholyticpropertieswithnorespiratorydepression（右美托咪定，同時具有鎮靜、遺忘、鎮痛和抗交感，但無呼吸抑制）,canbeusedtoprovidesedation/analgesia.

Inaddition,itreducessalivarysecretionsthrough

sympatholyticandvagomimeticeffects（除此之外，通過抗交感和類迷走作用能減少腺體分泌）.GeneralAnesthesia

Theoptimalgeneralanesthetictechniquewouldallowrapidandclear-headedrecoveryincludingearlyreturnof

thepatient’sprotectiveairwayreflexes（最佳的全麻技術可以讓病人快速恢復清醒，包括呼吸道的保護反射）,whichwouldallowmaintenanceofapatentairway（維持通暢呼吸道）.

Inaddition,early

recoveryshouldreducepostoperativecardiaccomplicationsduetoresidualanestheticeffects（及早恢復清醒可減少殘余麻醉效果導致的術后心血管并發癥）.AirwayManagement

BecauseBMIaloneisnotapredictorofdifficultintubation（由于BMI并不能單獨作為困難插管的指標）,‘awake’trachealintubationmaynotalwaysbenecessary（清醒插管不總是必須的）.

Nevertheless,OSAhasbeenreportedtobeapredictorofdifficultairway（OSA是作為困難氣道的指標之一）

Predictorsofdifficult

trachealintubationincludehighMallampatiscore(IIIorIV),neckcircumference（頸圍）≥40cm,limitedmandibularprotrusion（短下頜）,andsevereOSA\(AHI≥40).InductionofGeneralAnesthesia

Recentstudies,inmorbidlyobesepatients,haveshownthatthebarrierpressure(loweresophagealpressure–gastric

pressure)remainspositivethroughoutinductionofanesthesia屏障壓力（食道下段壓力-胃內壓）在麻醉誘導的過程中仍然維持作用）.

Thissuggeststhattheriskofgastricregurgitationin

themorbidlyobeseissimilartothatinthenon-obesepatients（提示病態肥胖病人的返流風險并沒有比其他病人更高）.

Most

anesthesiadrugsincludingintravenousanestheticdrugsandopioidsshouldbedosedaccordingtoleanbodyweight

(notactualbodyweight)（包括靜脈麻醉藥和阿片類在內的大多數麻醉藥應該依據去脂體重計算）,

exceptforneuromuscularblockingdrugs,whichshouldbedosedaccordingidealbodyweight（除了依據理想體重計算的肌松藥）.全麻誘導MaintenanceofGeneralAnesthesiaSeveralstudieshavereportedthatinthemorbidlyobese,Comparedwithsevoflurane,desfluraneallowsearlierabilitytoswallowwaterwithoutcoughingordrooling（和七氟醚相比，地氟醚允許病人出現更早的吞咽動作）,suggestinganearlierreturnofprotectiveairwayreflexes（提示病人更早恢復氣道保護反射）.

Arecentstudyusedanesthesia

informationmanagementsystemaswellasmetaanalysisof29randomizedcontrolledtrialscomparingdesfluraneandsevofluranetodeterminethetimefromendofsurgerytotrachealextubation（對比了手術結束到拔管的時間）.

Theyfoundthatcompared

withsevoflurane,desfluranereducedthemeanextubationtimeby25%（地氟醚的平均拔管時間少了25%）全麻維持MechanicalVentilation

Itisimportanttoavoidhyperventilationandhypocapnia（避免通氣過度和低碳酸血癥）,asthismayresultinmetabolic

alkalosis（代謝性堿中毒）andleadtopostoperativehypoventilation（術后通氣不足）.

Mildhypercapnia（輕微的高碳酸血癥）

(i.e.,ETCO2of40mmHg)canimprovetissue

oxygenationthroughimprovedtissueperfusionresultingfromincreasedcardiacoutputandvasodilatationaswellas

increasedoxygenoff-loadingfromtheshiftoftheoxyhemoglobindissociationcurvetotheright（可以提高心排出量和舒張血管，同時使氧合血紅蛋白曲線右移，來提高組織氧供）.NauseaandVomitingProphylaxis

PatientsundergoingambulatorysurgeryareatahigherriskofPONVandshouldreceiveprophylactic

multimodalantiemetictherapy（預防性多方式止吐治療）

(e.g.,combinationsof5-HT3-receptorantagonists,droperidol,anddexamethasone，5-HT3受體抑制劑、氟哌利多、地塞米松).

Althoughitisrecommendedthatthenumberofantiemeticsbebasedonthepatient’slevelofriskasdeterminedby

riskfactorassessment,doubleortripleantiemeticprophylaxisisoptimalforthispatientpopulation（雖然建議止吐藥的種類由病人的風險因素水平決定，但二聯或三聯止吐預防通常最佳）.預防惡心嘔吐IntraoperativeFluidManagement

Adequatepreoperativehydration

(i.e.,encouragepatientstoconsumewateruntil2hpreoperatively，術前足夠補液，鼓勵患者術前喝水直到術前2小時)andhigher

intraoperativefluidadministration(20-40ml/kg)havebeenreportedtoreduceposturalhypotension,postoperative

dizziness,drowsiness,nausea,andfatigue（較好的術中液體管理可以減少體位性低血壓、術后眩暈、嘔吐和疲勞）.

Inaddition,becausethemorbidlyobeseareatahighriskofRhabdomyolysis（肥胖病人是橫紋肌溶解高危病人）,administrationofhigherfluidvolumesmayreducethepotentialformyoglobinuricacuterenalfailureassociatedwithrhabdomyolysis（高液體容量可以減輕潛在的肌紅蛋白引起的急性腎衰）.術中液體管理EmergenceFromAnesthesia

Extubationshouldbeperformedinasemi-upright(25-30ohead-up)position,whenpossible（可能的話，拔管應該在半臥位下）.Also,useofanasalairway,placedbeforetrachealextubation,mayavoidpostextubationairwayobstruction（拔管前使用鼻咽通氣道，可以預防拔管后氣道梗阻）.

Arecentstudysuggeststhatanasalairwayismoreeffectivethanacombinationoforalandnasalairway（鼻咽通氣道比同時使用鼻咽和口咽通氣道有效）.ArecentstudyreportedthatCPAPinstitutedimmediatelyaftertracheal

extubationissuperiorinmaintaininglungfunctionat24hafterlaparoscopicbariatricsurgerythanCPAPinitiated

laterintherecoveryroom（一個研究顯示腹腔鏡治療肥胖癥的病人中，拔管后立即使用CPAP在維持肺功能方面，優于晚到恢復室再使用CPAP）.PostoperativeConsiderations

Potentialpostoperativecomplicationsincludeairwayobstruction,respiratoryfailure,needforreintubation,life

threateninghypoxiaaswellassystemichypertension,ischemia,andcardiacarrhythmia（潛在的術后并發癥包括氣道梗阻、呼吸衰竭、再插管的需求、低氧血癥、高血壓、組織缺血即心律失常）.

OnceinthePACU,patients

shouldbemaintainedinasemi-upright(25-30ohead-up)position,ifpossible（如果可能，病人進入恢復室應立即給予半頭高位）.術后注意事項PostoperativeCPAP/BiPAP

Althoughsupplementaloxygenis

beneficialformostpatients,itshouldbeadministeredwithcautionasitmayreducehypoxicrespiratorydriveandincreasetheincidenceanddurationofapneicepisodes（雖然補充氧氣對大部分病人有益，但也可能降低呼吸系統的低氧驅動功能和對呼吸暫停的耐受）.

BecauseobesepatientsmighthaveunrecognizedOSA,recurrenthypoxemiamaybebettertreatedwithCPAPorbi-levelpositiveairwaypressure(BiPAP)alongwith

oxygenratherthanoxygenalone（如果反復出現低氧血癥，病人最好使用CPAP或BiPAP，而不是單獨吸氧）.Post-PACUDischargeCare

PriortodischargefromthePACUtheoxygensaturationonroomairshouldreturntobaseline（出恢復室前氧飽和度回到基本水平）andthePatient

shouldnotbecomehypoxicordevelopairwayobstructionwhenleftundisturbedintherecoveryarea（未打擾情況下不應該有低氧血癥或氣道梗阻）.

Ithasbeen

suggestedthatmostsignificantpostoperativecomplicationsinOSApatientsusuallyoccurwithin2hoursafter

Surgery（大多數的OSA病人并發癥發生在術后2小時內）.

Therefore,itmaybeworthwhiletoobservethesepatientsintherecoveryroomforatleast2h（因此建議這類病人在恢復室至少停留2小時）.Post-PACUDischargeCare

TheASA-OSAPractice

GuidelinessuggestthatOSApatientsbemonitoredforamedianof3hourslongerthantheirnon-OSAcounterparts

beforedischargefromthefacility（建議OSA病人較非OSA病人增加平均3小時的監護時間）.

Inaddition,themonitoringshouldcontinueforamedianof7hoursafterthe

lastepisodeofairwayobstructionorhypoxemiawhilebreathingroomairinanunstimulatedenvironm