atient-Position-During-Anesthesia：麻醉期间病人的位置课件

PatientPositionDuringAnesthesiaByDavidRoyGoddenCRNA,MSNLectureObjectivesGainanunderstandingofsafepositioningbasicsIdentifythepotentialnerveinjuriesfrommaskventilationStatethecorrecthandandarmpositioningforsupine,lateraldecubitusandpronepositions.Beabletorecitethepotentialnerveinjuriesofeachpatientposition.Identifythecomplicationsofthesittingposition.ObjectivesCon’tDefineandunderstandthehemodynamicsofeachpatientposition.Understandandbeabletoverbalize-thatmeansknowthoroughly-therespiratoryandautonomicresponsesofdifferingpatientpositionswhileawakeandundergeneralanesthesia.DiscussPostOperativeVisualLoss(POVL)CaseStudy:ComplicationsofPronepositionLookforKeyPointsPositioningisoftenacompromisebetweenwhatisrequiredforsurgicalexposureandpatientcomfort!Donotplacesedatedoranesthetizedpatientsinpositionsthattheyarenotcomfortablewithwhenawake.IfindoubtaboutpatientssafetyhavethepatientassumethepositionontheORtablebeforeinductiontoseehowtheytoleratetheposition.PatientpositioningisthejointresponsibilityofORNursing,AnesthesiaandSurgery.Allthreeindividualsandgroupsthatrepresentthemwillbeheldliableiferrorsinpositioningcausepatientharm.Document!DocumentationofPositioningTheonlythingthatrepresentswhatwasdoneintheoperatingroominacourtoflawisyourtestimonyandyourdocumentation.Howmuchdoyouthinkyoucanrememberfromonecasetothenextandhowmuchofyour“story”willthecourtofficers“believe”withoutyourcarefuldocumentationintheanesthesiarecord?Whattodocument?Pre-operativepatientlimitationsinmovementstrengthandnerveabnormalities.Doesthepatienthavenumbnesstinglingorlossofsensationtoanyextremitypre-operatively?Doesthepatienthavefootdrop?MaskInjuriesPotentialforcornealabrasionisalwayspresentwhenmaskventilatingpatients.Facestrapswhicharetightacrossthepatientsfacewithprolongedusemaycauseinjurytothefacialnerve.Whatarethefivebranchesofthefacialnerverememberingthemnemonic,“Twozebrasbitmycat”Thebucalbranchismostlikelyinjuredwithafacestrapcompression.TemporalZygomaticBucalMandibularcervicalDorsalDecubitusPositionsGravityeffectsbloodflowandmuchofpulmonarymechanics.Humans,giraffesanddinosaursshareonethingincommon.Whatisit?InthesupinepositiongravityequalizesbloodpressuregradientsbetweenheartandarteriesintheheadandlowerextremitiesCorrectAnatomicalPositionWhatistheventralsurface?WhatisthedorsalsurfaceNote:DorsaltodorsalandventraltoventralDorsalDecubitusPositionsHeadtilteitherupwardsordownwardswillchangethepressuregradients.Amovementof2.5cminverticalelevationwillchangethebloodpressure2mmHg.IntheparturientanIVbagundertherighthipwillshiftthegraviduterustotheleft.HaveyouheardofAorto-cavalsyndrome?HandpositioningLyingatattentionrequirescorrectarmandhandpositiontominimizethechancesofnerveinjuries.Armsaretobelessthan90degreeslateralizedfromthethoraxincorrectanatomicalpositionlookingattheshoulders.Thiswillminimizethechanceofbrachialplexusinjury.ArmsatsideofbodymustbeincorrectdorsaltodorsalalignmentwiththearmssupinatedORpalmstowardthebodyisOKaswell.Theulnarnervepassesclosetothesurfaceoftheskininthemedialcondyleoftheelbow.Theolectranonwillprotectthenerveifplaceddownwards.Radialnerveinjuryispossiblewithetherscreencompressiontothelateralarm.Radialnerveinjurymayresultinwristdrop.WhatisSupinationCorrectanatomicalpositionislyingatattentionorPalmsareventralsurfacesoventraltoventralDorsaltodorsalmeanbackofhandstoback.HeaddownthingsLoweringtheheadwillincreasethepressureinthecerebralveinswhichmayleadtovascularheadache,congestionofnasalmucosaandconjunctivainhealthyindividuals.Thismayleadtoedemainthelarynxaswell.Thescleraisthewindowtothevocalcords!Headloweringinpatientswithintra-craniallesionswillexacerbatetheconditionraisingCPPandICP(what'stheformulaforthis?)AutonomicfunctionAorticarchandcarotidsinushousebarorecetorsthatarepartofthebodieshomeostaticmechanismtomaintainbloodpressurewithinanarrowrange.Increasedfiringofthereceptorswhenstretchedfromanincreaseinbloodpressureispartofanegativefeedbackloop.Theincreasedfiringfromthebaroreceptorsenhancestheparasympatheticnervoussystemloweringbloodpressureandslowingtheheartrate.Rememberthis!Whatarethenervesresponsibleforthebaroreceptorreflexes?RespiratoryEffects

Respiratorymechanicswillsufferintheheaddownpositionhow?ReviewWest’szonesofthelung.Normalexcursionofthediaphragminheaddownpositionisimpededandincreasetheworkofbreathing.Intheparalyzedmechanicallyventilatedpatient,higherpeakpressureswillberequiredforadequateventilation.SupinepatientsdevelopVQmismatchduetovascularcongestioninthedorsalportionsofthelungandchangesincompliance.Thedorsallung(nowzone3)willhavereducedcompliance.Passiveventilationtendstodistributegaspreferentiallytothemoreeasilydistensiblesubsternalunitswherepulmonarybloodflowvolumeisless(Barish,2006).MoreRespiratorythingsTopreventdevelopmentofsignificantV-Qimbalanceduringuseofcontrolledventilation,tidalvolumesmustbeusedthataregreaterthantheaverageamountthatissufficientforthespontaneouslybreathingconsciouspt.Compareandcontrasttheawakespontaneouslybreathingptandtheparalyzedmechanicallyventilatedptinthelateralposition.HowwouldyouattempttodecreasePeakpressuresduringmechanicalventilationintheparalyzedanesthetizedpatient?Hint:deepenanesthetic,musclerelaxation,decreaseVtandincreaseRate,changeI:Eratiofrom1:2to1:1.5.ConsiderPressureControlventilationduetoitsdeceleratingwaveform.VariationsintheDorsalDecubitusPositionSupineotherwiseknownaslyingatattention.Placesstrainonlowersegmentsoflumbarspine.Lawnchairisamorephysiologicallytoleratedpositionduetodecreasedstretchonlowerback.Frogleg(healtohealwithlateralizationofknees)forperonealexaminationsmayplaceexcessivestretchonback,hipsandpelvicstructures.Padunderknees.Complicationsofexcessivestretchmayinclude1)postoperativehipandbackpain;2)dislocatedhiporfractureofanosteoporoticfemur;3)obturatornerveinjury.ComplicationsofDorsalDecubitusPressureAlopeciaduetoprolongedcompressionofhairfollicles.Mostalopeciaoccursbetweenthe3rdand28thpostoperativedaywhilere-growthusuallyoccurswithin3months(Barish,2006).Placementofgelpadordonutunderheadisworthwhile.Frequentrepositioningoftheheadiswarranted.ComplicationsofDorsalDecubitusPressurepointreactionsoccurwhenbonyprominencesareunsupportedforprolongedperiods.Hypothermiaandhypotensionenhancetheischemicprocess.Theheals,elbowsandsacrumshouldbegelpadded.NOTE:Therearenostudiesprovingdecreasedincidenceofperipheralneuropathiesduetogelpadding.Backpainduetolossoflordosis.Lawnchairpositionbest.LithotomyPositionLithotomypositiontraditionallyhasbeenusedduringgynecologicandurologicsurgery.Thehipsareflexed80to100degreesandthehipsareabducted30to45degreesfrommidline.Hipflexiongreaterthan90degreesmaycausestretchoftheinguinalligamentsandimpingethelateralfemoralcutaneousnerveswhichpassthroughtheinguinalligamentwhichleadstonumbnessinthelateralthigh.Thelegsshouldbemovedintoandoutofpositionsimultaneously.Thekneesarebroughttomidlineandthelegsslowlyunflexedtothesupinepositionattheendofthesurgicalprocedure.ComplicationsinLithotomyLegelevationcausesincreaseinvenousreturnandtransientriseinCOandICP.Alterationsinpre-Loadismostresponsibleforhemodynamicchangesduringanesthesia.AbdominalvisceraisdisplacedcephaladdecreasingVtandincreasingpeakpressures.Backpainfromlossoflordoticcurvatureofspineinlithotomyposition.LithotomyComplicationsDANGERtofingers.Watchcarefullywhenhandsaretuckedandraisingorloweringfootboard.Injurytothecommonperonealnerve.ThisistheMOSTCOMMOMnerveinjurytothelowerextremitiesaccountingfor78%ofalllowerextremitymotorneuropathiescausedbycompressionofthenervebetweenthelateralheadofthefibulaand“candycane”barstirrups.Durationofsurgerygreaterthan2hoursisapredictorofincreasedincidenceoflowerextremityneuropathy.MoreComplicationsofLithotomyPositioningCompartmentsyndromeisararecomplicationbutoccursinlithotomypositionduetoinadequateperfusiontotheraisedextremity.Ischemia,edemaandthepossibilityofrhabdomyolysisoccursfromtheincreasedpressureinthefascialcompartment.Foryounumberheads,compartmentsyndromeoccurredinabout1inamillionforpatientsinsupinepositionandabout1in9,000forptsinlithotomyposition.Whatdoyouthinkaboutlithotomy?Danger!LateralDecubituspositionLateraldecubituspositionisusedforsurgeriesonthorax,retroperitonealstructuresorhip.V-Qmismatchincreasesduetogravitationalforces.Perfusionisgreatestindependentstructuresordownlungwhileventilationisbetterinnondependentlung.Useof“ChestRoll”incidentallymisnamedaxillaryroll.Thepresenceofthechestrollistopreventcompressioninjurytothebrachialplexus.Monitorthepulseinthedependentarmplease.LateralDecubituspositionNondependentarmis“airplaned”orsupportedwithpillowsandnotallowedtobeabductedgreaterthan90degrees.Placepillowbetweenkneeswithdependentlegflexed.Pressurepointsincludeacromionprocess,iliaccrest,greatertrochanter,peronealnerveandlateralmaleolus.ComplicationsofLateralDecubitusEyeandearinjuries.Makesurethatdownsideearandeyeare“free”frompressure.Useadonutrollfortheear.UseoftheOpti-guardoreyeguardisconsideredusefulinlateralpositions.Neckflexionneedstobeavoided.Positionneckmidlinewithsupportingtowels.ComplicationsofLateralDecubitusSuprascapularnervestretchfromthecircumductionofthedependentshoulder.Thechestrollshouldpreventthis.Longthoracicnerveinjuryfromlateraldecubituspositionhasbeendocumented.Wingingofthescapulaisthetypicalclinicalsign.TheserratusanteriormuscleissolelysuppliedbythelongthoracicnervewhichbranchesfromC5C6andC7.KidneyPositionKidneypositionisaflexedlateraldecubituspositionwherethetableisflexedto“openup”thelateralstructuresforsurgicalexposure.Flexpointshouldbeunderiliaccrestnotribcage.Stabilizethepatienttopreventmovementandshiftscaudadonthetablesothatthekidneyrestmaynotrelocateditselfintothedownsideflank.VentilationissuesagainmayoccurduetodependentlungcompromiseandV-Qmismatching.PronePositioningPronepositionisprimarilyusedforsurgicalaccesstoposterioraspectofthespine,posteriorfossaofskull,buttocksandperirectalareasorposteriorportionsofthelowerextremities.Pronepositioningrequiresplanning.Inductionandintubationofthetracheaisaccomplishedwhilepatientissupineonstretcher.IVaccessisperformedaswellasarterialcatheterplacementpriortoturningproneonoperatingroomtable.WouldyouconsideruseofLMAorextubationintheproneposition?SupportingdevicesforProneTheheadissupportedusuallymidline.Mayfieldtongsareusedforcraniotomycasesintheproneposition.AtLACweusetheProneViewwithamirrortoseethefacialstructureswhilethepatientisprone.Turningtheheadtothesidemaybeusedbutlateralrotationoftheneckmaycompromisecarotidorvertebralarterialbloodflowandmayrestrictvenousdrainage.Eyeprotectionisrequired.SupportingdevicesforProneSupportofthethoraxwithfirmbolsterswhichareplacedunderthepatientssidesfromclavicaltoiliaccrest.Thisallowsthebellytohangfreeandincreasesventilationwhilepreventingaorto-cavalcompression.Breastsareplacedmedialandcephaladwhilegenitalsareinsuredtobenoncompressed.ArmplacementinProneptsPlacementofthearmsiseitheratthesidesofthepatientorforwardalongsidetheheadonpaddedarmboards.Paddingoftheelbowisrequired.Abductionofthearmsshouldbelimitedtolessthan90degreestopreventexcessivestretchofthebrachialplexus.Anklesmaybesupportedwithabendinthekneestoreducestretchtothelumbarspine.CalfcompressionstockingsareroutinelyusedtopreventvenousstasisorbloodpoolingwithreductioninDVT.ComplicationsofPronePositionPronepositionisoneofthemorechallengingpositionstotheanesthetist.Eyeandearinjuriesaremorecommoninthisposition.EyeprotectionwithOpti-guardiswarranted.Scleraledemaiscommoninpronepatients.Blindness.Permanentlossofvisioncanoccurafternonocularsurgicalproceduresespeciallyinpatientintheproneposition!Spinesurgerywithitsbloodloss,hypotensionandanemiamayallconspiretogethertoproduceopticnerveischemia.AdditionalProneProblemsNeckinjuriesduetomisalignment.Brachialplexusinjuriesduetoexcessivestretchormisalignmentofshoulders.Breastorgenitalinjuriescausingpainordysfunction.Notgood.Medialplacementofbreastsisrecommended.Abdominalcompressioninjuriesmaybealleviatedwiththeuseofbolsters.ProneProblemsKneeinjuriesareespeciallyprevalentintheobeseorinthosewithpathologicconditionsofthekneespreoperatively.Documentandpadthekneesheavily.Injurytothedorsumofthefeetisalsopossible.ThoracicOutletsyndrome.Howdoyoutestforit?DidyouforgetaboutPOVLintheProneposition?SittingPositionSeeattachedarticleinanesthesiapatientsafetynewsletter.Beachchairpositionmaycausedecreasedcerebralperfusion,CVA,andbraindeath-really.ApsfNewsletterarticleREADIT!Majorriskofsittingpositionishypotension.SittingpositionandtheriskofAIREMBOLIS.MoreSittingPosition

Sittingpositionisoftenusedforoutpatientshouldersurgeryandposteriorfossaapproaches–Why!Whenotherpositionsarelessdangerous!Hemodynamiceffectscanbedramatic.Poolingofbloodinthelowerpartofthebodyandthesubsequentdecreaseincerebralperfusion.Rememberthe2mmHgrule?TherewillbeaquestionaboutthisHintHint.Ofteninshouldersurgerywhileinthesittingpositionthesurgeon“requests”hypotension–reallyitstrue!ComplicationsofSittingPositionPotentialcomplicationsduetoflexionoftheneckwhichcanimpedebotharterialandvenousbloodflowthroughtheneck.Flexionoftheendotrachialtubemayleadtoexcessivepressureonthetongueleadingtomacroglossia.Neckflexionmaybemeasuredandkepttoacceptablelimitswithtwofingerbreadthsdistancebetweenchinandsternum.Venousairembolismisaseriouscomplicationofsittingpositionandthereasonforitsrareuse.VenousAirEmbolismThislifethreateningconditionmayoccuranytimeasurgicalsiteisabovetheleveloftheheart.Therearenovalvesinthecerebralvenouscirculationandtheriskofvenousairembolismisconstantinthesittingpositionwhentheoperativesiteevolvestheposteriorfossaormayoccurinspinalsurgerywhenprone!Rememberthis!Venousairembolismmaybemanifestedascardiacdysrhythmias,arterialoxygendesaturation,pulmonaryhypertensionorfrankcardiacarrest.Actionstotakeifyoususpectanairembolismistoaskthesurgeonstofloodthefieldwithsalineandtoapplybonewaxtoboneyedges.Forfurtherdiscussionrefertoyourneurolecture.OverviewofNerveinjuriesTheClosedClaimsProjectconductedbytheASAevaluatedadverseanestheticoutcomesin1990.UlnarneuropathyremainstheMOSTfrequent(28%)ofallnerveinjuriesfollowedbybrachialplexus(20%).Etiologyofperipheralnerveinjuriesremainslargelyunknown.Mostofthenerveinjuriestoulnarandbrachialplexusoccurredinpatientswithproperpositioningandadequatepadding.Ulnarneuropathyresultsinaninabilitytoabductoropposethefifthfinger,deminishedsensationinthefourthandfifthfingersandeventual“claw”hand.UlnarNeuropathyCurrentthinkingisthatulnarneuropathyismultifactorialandnotalwayspreventabledespiteroutineuseofarmboardsandpadding.Ulnarneuropathyismostcommoninoldermen,diabetesmellitus,vitamindeficiency,alcoholism,cigarettesmokingandcancer.Prevention?Avoidexcessivepressureonthepostcondylargrooveofthehumerus,limitabductionofthearmtolessthan90degrees,keepthehandandforearmeithersupinatedorinaneutralpositionwithpalmsfacingthigh.BrachialPlexusInjuryThebrachialplexusissubjecttoinjuryduetostretchingorcompressionasaresultofitslongsuperficialcourseintheaxilla.Armabductiongreaterthan90degrees,lateralrotationofthehead,asymmetricretractionofthesternumanddirecttraumaallmaycontributetobrachialplexusinjury.Cardiacsurgeryandsternotomyisassociatedwithahigherincidenceofbrachialplexusinjury.Shoulderbraceshavehistoricallybeenaculpritinbrachialplexusinjuryleadingtotheirrareuse.Thecompressionofproximalrootsorlateraldisplacementofthebracescanstretchtheplexuswhentheshouldersaredisplaced.Usenonslidingmattressinsteadofshoulderbraces.LowerExtremityNerveinjuryLithotomypositionisassocia