Patient-Position-During-Anesthesia：麻醉期間病人的位置課件

PatientPositionDuringAnesthesiaByDavidRoyGoddenCRNA,MSNPatientPositionDuringAnesth1LectureObjectivesGainanunderstandingofsafepositioningbasicsIdentifythepotentialnerveinjuriesfrommaskventilationStatethecorrecthandandarmpositioningforsupine,lateraldecubitusandpronepositions.Beabletorecitethepotentialnerveinjuriesofeachpatientposition.Identifythecomplicationsofthesittingposition.LectureObjectivesGainanunde2ObjectivesCon’tDefineandunderstandthehemodynamicsofeachpatientposition.Understandandbeabletoverbalize-thatmeansknowthoroughly-therespiratoryandautonomicresponsesofdifferingpatientpositionswhileawakeandundergeneralanesthesia.DiscussPostOperativeVisualLoss(POVL)CaseStudy:ComplicationsofPronepositionObjectivesCon’tDefineandund3Patient-Position-During-Anesthesia：麻醉期間病人的位置課件4Patient-Position-During-Anesthesia：麻醉期間病人的位置課件5Patient-Position-During-Anesthesia：麻醉期間病人的位置課件6MaskInjuriesPotentialforcornealabrasionisalwayspresentwhenmaskventilatingpatients.Facestrapswhicharetightacrossthepatientsfacewithprolongedusemaycauseinjurytothefacialnerve.Whatarethefivebranchesofthefacialnerverememberingthemnemonic,“Twozebrasbitmycat”Thebucalbranchismostlikelyinjuredwithafacestrapcompression.TemporalZygomaticBucalMandibularcervicalMaskInjuriesPotentialforcor7DorsalDecubitusPositionsGravityeffectsbloodflowandmuchofpulmonarymechanics.Humans,giraffesanddinosaursshareonethingincommon.Whatisit?InthesupinepositiongravityequalizesbloodpressuregradientsbetweenheartandarteriesintheheadandlowerextremitiesDorsalDecubitusPositionsGrav8CorrectAnatomicalPositionWhatistheventralsurface?WhatisthedorsalsurfaceNote:DorsaltodorsalandventraltoventralCorrectAnatomicalPositionWha9DorsalDecubitusPositionsHeadtilteitherupwardsordownwardswillchangethepressuregradients.Amovementof2.5cminverticalelevationwillchangethebloodpressure2mmHg.IntheparturientanIVbagundertherighthipwillshiftthegraviduterustotheleft.HaveyouheardofAorto-cavalsyndrome?DorsalDecubitusPositionsHead10HandpositioningLyingatattentionrequirescorrectarmandhandpositiontominimizethechancesofnerveinjuries.Armsaretobelessthan90degreeslateralizedfromthethoraxincorrectanatomicalpositionlookingattheshoulders.Thiswillminimizethechanceofbrachialplexusinjury.ArmsatsideofbodymustbeincorrectdorsaltodorsalalignmentwiththearmssupinatedORpalmstowardthebodyisOKaswell.Theulnarnervepassesclosetothesurfaceoftheskininthemedialcondyleoftheelbow.Theolectranonwillprotectthenerveifplaceddownwards.Radialnerveinjuryispossiblewithetherscreencompressiontothelateralarm.Radialnerveinjurymayresultinwristdrop.HandpositioningLyingatatten11WhatisSupinationCorrectanatomicalpositionislyingatattentionorPalmsareventralsurfacesoventraltoventralDorsaltodorsalmeanbackofhandstoback.WhatisSupinationCorrectanat12HeaddownthingsLoweringtheheadwillincreasethepressureinthecerebralveinswhichmayleadtovascularheadache,congestionofnasalmucosaandconjunctivainhealthyindividuals.Thismayleadtoedemainthelarynxaswell.Thescleraisthewindowtothevocalcords!Headloweringinpatientswithintra-craniallesionswillexacerbatetheconditionraisingCPPandICP(what'stheformulaforthis?)HeaddownthingsLoweringtheh13AutonomicfunctionAorticarchandcarotidsinushousebarorecetorsthatarepartofthebodieshomeostaticmechanismtomaintainbloodpressurewithinanarrowrange.Increasedfiringofthereceptorswhenstretchedfromanincreaseinbloodpressureispartofanegativefeedbackloop.Theincreasedfiringfromthebaroreceptorsenhancestheparasympatheticnervoussystemloweringbloodpressureandslowingtheheartrate.Rememberthis!Whatarethenervesresponsibleforthebaroreceptorreflexes?AutonomicfunctionAorticarch14RespiratoryEffects

Respiratorymechanicswillsufferintheheaddownpositionhow?ReviewWest’szonesofthelung.Normalexcursionofthediaphragminheaddownpositionisimpededandincreasetheworkofbreathing.Intheparalyzedmechanicallyventilatedpatient,higherpeakpressureswillberequiredforadequateventilation.SupinepatientsdevelopVQmismatchduetovascularcongestioninthedorsalportionsofthelungandchangesincompliance.Thedorsallung(nowzone3)willhavereducedcompliance.Passiveventilationtendstodistributegaspreferentiallytothemoreeasilydistensiblesubsternalunitswherepulmonarybloodflowvolumeisless(Barish,2006).RespiratoryEffectsRespirator15MoreRespiratorythingsTopreventdevelopmentofsignificantV-Qimbalanceduringuseofcontrolledventilation,tidalvolumesmustbeusedthataregreaterthantheaverageamountthatissufficientforthespontaneouslybreathingconsciouspt.Compareandcontrasttheawakespontaneouslybreathingptandtheparalyzedmechanicallyventilatedptinthelateralposition.HowwouldyouattempttodecreasePeakpressuresduringmechanicalventilationintheparalyzedanesthetizedpatient?Hint:deepenanesthetic,musclerelaxation,decreaseVtandincreaseRate,changeI:Eratiofrom1:2to1:1.5.ConsiderPressureControlventilationduetoitsdeceleratingwaveform.MoreRespiratorythingsToprev16VariationsintheDorsalDecubitusPositionSupineotherwiseknownaslyingatattention.Placesstrainonlowersegmentsoflumbarspine.Lawnchairisamorephysiologicallytoleratedpositionduetodecreasedstretchonlowerback.Frogleg(healtohealwithlateralizationofknees)forperonealexaminationsmayplaceexcessivestretchonback,hipsandpelvicstructures.Padunderknees.Complicationsofexcessivestretchmayinclude1)postoperativehipandbackpain;2)dislocatedhiporfractureofanosteoporoticfemur;3)obturatornerveinjury.VariationsintheDorsalDecub17ComplicationsofDorsalDecubitusPressureAlopeciaduetoprolongedcompressionofhairfollicles.Mostalopeciaoccursbetweenthe3rdand28thpostoperativedaywhilere-growthusuallyoccurswithin3months(Barish,2006).Placementofgelpadordonutunderheadisworthwhile.Frequentrepositioningoftheheadiswarranted.ComplicationsofDorsalDecubi18ComplicationsofDorsalDecubitusPressurepointreactionsoccurwhenbonyprominencesareunsupportedforprolongedperiods.Hypothermiaandhypotensionenhancetheischemicprocess.Theheals,elbowsandsacrumshouldbegelpadded.NOTE:Therearenostudiesprovingdecreasedincidenceofperipheralneuropathiesduetogelpadding.Backpainduetolossoflordosis.Lawnchairpositionbest.ComplicationsofDorsalDecubi19LithotomyPositionLithotomypositiontraditionallyhasbeenusedduringgynecologicandurologicsurgery.Thehipsareflexed80to100degreesandthehipsareabducted30to45degreesfrommidline.Hipflexiongreaterthan90degreesmaycausestretchoftheinguinalligamentsandimpingethelateralfemoralcutaneousnerveswhichpassthroughtheinguinalligamentwhichleadstonumbnessinthelateralthigh.Thelegsshouldbemovedintoandoutofpositionsimultaneously.Thekneesarebroughttomidlineandthelegsslowlyunflexedtothesupinepositionattheendofthesurgicalprocedure.LithotomyPositionLithotomypo20ComplicationsinLithotomyLegelevationcausesincreaseinvenousreturnandtransientriseinCOandICP.Alterationsinpre-Loadismostresponsibleforhemodynamicchangesduringanesthesia.AbdominalvisceraisdisplacedcephaladdecreasingVtandincreasingpeakpressures.Backpainfromlossoflordoticcurvatureofspineinlithotomyposition.ComplicationsinLithotomyLeg21LithotomyComplicationsDANGERtofingers.Watchcarefullywhenhandsaretuckedandraisingorloweringfootboard.Injurytothecommonperonealnerve.ThisistheMOSTCOMMOMnerveinjurytothelowerextremitiesaccountingfor78%ofalllowerextremitymotorneuropathiescausedbycompressionofthenervebetweenthelateralheadofthefibulaand“candycane”barstirrups.Durationofsurgerygreaterthan2hoursisapredictorofincreasedincidenceoflowerextremityneuropathy.LithotomyComplicationsDANGER22MoreComplicationsofLithotomyPositioningCompartmentsyndromeisararecomplicationbutoccursinlithotomypositionduetoinadequateperfusiontotheraisedextremity.Ischemia,edemaandthepossibilityofrhabdomyolysisoccursfromtheincreasedpressureinthefascialcompartment.Foryounumberheads,compartmentsyndromeoccurredinabout1inamillionforpatientsinsupinepositionandabout1in9,000forptsinlithotomyposition.Whatdoyouthinkaboutlithotomy?Danger!MoreComplicationsofLithotom23LateralDecubituspositionLateraldecubituspositionisusedforsurgeriesonthorax,retroperitonealstructuresorhip.V-Qmismatchincreasesduetogravitationalforces.Perfusionisgreatestindependentstructuresordownlungwhileventilationisbetterinnondependentlung.Useof“ChestRoll”incidentallymisnamedaxillaryroll.Thepresenceofthechestrollistopreventcompressioninjurytothebrachialplexus.Monitorthepulseinthedependentarmplease.LateralDecubituspositionLate24LateralDecubituspositionNondependentarmis“airplaned”orsupportedwithpillowsandnotallowedtobeabductedgreaterthan90degrees.Placepillowbetweenkneeswithdependentlegflexed.Pressurepointsincludeacromionprocess,iliaccrest,greatertrochanter,peronealnerveandlateralmaleolus.LateralDecubituspositionNon25ComplicationsofLateralDecubitusEyeandearinjuries.Makesurethatdownsideearandeyeare“free”frompressure.Useadonutrollfortheear.UseoftheOpti-guardoreyeguardisconsideredusefulinlateralpositions.Neckflexionneedstobeavoided.Positionneckmidlinewithsupportingtowels.ComplicationsofLateralDecub26ComplicationsofLateralDecubitusSuprascapularnervestretchfromthecircumductionofthedependentshoulder.Thechestrollshouldpreventthis.Longthoracicnerveinjuryfromlateraldecubituspositionhasbeendocumented.Wingingofthescapulaisthetypicalclinicalsign.TheserratusanteriormuscleissolelysuppliedbythelongthoracicnervewhichbranchesfromC5C6andC7.ComplicationsofLateralDecub27KidneyPositionKidneypositionisaflexedlateraldecubituspositionwherethetableisflexedto“openup”thelateralstructuresforsurgicalexposure.Flexpointshouldbeunderiliaccrestnotribcage.Stabilizethepatienttopreventmovementandshiftscaudadonthetablesothatthekidneyrestmaynotrelocateditselfintothedownsideflank.VentilationissuesagainmayoccurduetodependentlungcompromiseandV-Qmismatching.KidneyPositionKidneyposition28PronePositioningPronepositionisprimarilyusedforsurgicalaccesstoposterioraspectofthespine,posteriorfossaofskull,buttocksandperirectalareasorposteriorportionsofthelowerextremities.Pronepositioningrequiresplanning.Inductionandintubationofthetracheaisaccomplishedwhilepatientissupineonstretcher.IVaccessisperformedaswellasarterialcatheterplacementpriortoturningproneonoperatingroomtable.WouldyouconsideruseofLMAorextubationintheproneposition?PronePositioningPronepositio29SupportingdevicesforProneTheheadissupportedusuallymidline.Mayfieldtongsareusedforcraniotomycasesintheproneposition.AtLACweusetheProneViewwithamirrortoseethefacialstructureswhilethepatientisprone.Turningtheheadtothesidemaybeusedbutlateralrotationoftheneckmaycompromisecarotidorvertebralarterialbloodflowandmayrestrictvenousdrainage.Eyeprotectionisrequired.SupportingdevicesforProneTh30SupportingdevicesforProneSupportofthethoraxwithfirmbolsterswhichareplacedunderthepatientssidesfromclavicaltoiliaccrest.Thisallowsthebellytohangfreeandincreasesventilationwhilepreventingaorto-cavalcompression.Breastsareplacedmedialandcephaladwhilegenitalsareinsuredtobenoncompressed.SupportingdevicesforProneSu31ArmplacementinProneptsPlacementofthearmsiseitheratthesidesofthepatientorforwardalongsidetheheadonpaddedarmboards.Paddingoftheelbowisrequired.Abductionofthearmsshouldbelimitedtolessthan90degreestopreventexcessivestretchofthebrachialplexus.Anklesmaybesupportedwithabendinthekneestoreducestretchtothelumbarspine.CalfcompressionstockingsareroutinelyusedtopreventvenousstasisorbloodpoolingwithreductioninDVT.ArmplacementinProneptsPlac32ComplicationsofPronePositionPronepositionisoneofthemorechallengingpositionstotheanesthetist.Eyeandearinjuriesaremorecommoninthisposition.EyeprotectionwithOpti-guardiswarranted.Scleraledemaiscommoninpronepatients.Blindness.Permanentlossofvisioncanoccurafternonocularsurgicalproceduresespeciallyinpatientintheproneposition!Spinesurgerywithitsbloodloss,hypotensionandanemiamayallconspiretogethertoproduceopticnerveischemia.ComplicationsofPronePositio33AdditionalProneProblemsNeckinjuriesduetomisalignment.Brachialplexusinjuriesduetoexcessivestretchormisalignmentofshoulders.Breastorgenitalinjuriescausingpainordysfunction.Notgood.Medialplacementofbreastsisrecommended.Abdominalcompressioninjuriesmaybealleviatedwiththeuseofbolsters.AdditionalProneProblemsNeck34ProneProblemsKneeinjuriesareespeciallyprevalentintheobeseorinthosewithpathologicconditionsofthekneespreoperatively.Documentandpadthekneesheavily.Injurytothedorsumofthefeetisalsopossible.ThoracicOutletsyndrome.Howdoyoutestforit?DidyouforgetaboutPOVLintheProneposition?ProneProblemsKneeinjuriesar35SittingPositionSeeattachedarticleinanesthesiapatientsafetynewsletter.Beachchairpositionmaycausedecreasedcerebralperfusion,CVA,andbraindeath-really.ApsfNewsletterarticleREADIT!Majorriskofsittingpositionishypotension.SittingpositionandtheriskofAIREMBOLIS.SittingPositionSeeattacheda36MoreSittingPosition

Sittingpositionisoftenusedforoutpatientshouldersurgeryandposteriorfossaapproaches–Why!Whenotherpositionsarelessdangerous!Hemodynamiceffectscanbedramatic.Poolingofbloodinthelowerpartofthebodyandthesubsequentdecreaseincerebralperfusion.Rememberthe2mmHgrule?TherewillbeaquestionaboutthisHintHint.Ofteninshouldersurgerywhileinthesittingpositionthesurgeon“requests”hypotension–reallyitstrue!MoreSittingPositionSitting37ComplicationsofSittingPositionPotentialcomplicationsduetoflexionoftheneckwhichcanimpedebotharterialandvenousbloodflowthroughtheneck.Flexionoftheendotrachialtubemayleadtoexcessivepressureonthetongueleadingtomacroglossia.Neckflexionmaybemeasuredandkepttoacceptablelimitswithtwofingerbreadthsdistancebetweenchinandsternum.Venousairembolismisaseriouscomplicationofsittingpositionandthereasonforitsrareuse.ComplicationsofSittingPosit38VenousAirEmbolismThislifethreateningconditionmayoccuranytimeasurgicalsiteisabovetheleveloftheheart.Therearenovalvesinthecerebralvenouscirculationandtheriskofvenousairembolismisconstantinthesittingpositionwhentheoperativesiteevolvestheposteriorfossaormayoccurinspinalsurgerywhenprone!Rememberthis!Venousairembolismmaybemanifestedascardiacdysrhythmias,arterialoxygendesaturation,pulmonaryhypertensionorfrankcardiacarrest.Actionstotakeifyoususpectanairembolismistoaskthesurgeonstofloodthefieldwithsalineandtoapplybonewaxtoboneyedges.Forfurtherdiscussionrefertoyourneurolecture.VenousAirEmbolismThislifet39OverviewofNerveinjuriesTheClosedClaimsProjectconductedbytheASAevaluatedadverseanestheticoutcomesin1990.UlnarneuropathyremainstheMOSTfrequent(28%)ofallnerveinjuriesfollowedbybrachialplexus(20%).Etiologyofperipheralnerveinjuriesremainslargelyunknown.Mostofthenerveinjuriestoulnarandbrachialplexusoccurredinpatientswithproperpositioningandadequatepadding.Ulnarneuropathyresultsinaninabilitytoabductoropposethefifthfinger,deminishedsensationinthefourthandfifthfingersandeventual“claw”hand.OverviewofNerveinjuriesThe40UlnarNeuropathyCurrentthinkingisthatulnarneuropathyismultifactorialandnotalwayspreventabledespiteroutineuseofarmboardsandpadding.Ulnarneuropathyismostcommoninoldermen,diabetesmellitus,vitamindeficiency,alcoholism,cigarettesmokingandcancer.Prevention?Avoidexcessivepressureonthepostcondylargrooveofthehumerus,limitabductionofthearmtolessthan90degrees,keepthehandandforearmeithersupinatedorinaneutralpositionwithpalmsfacingthigh.UlnarNeuropathyCurrentthinki41BrachialPlexusInjuryThebrachialplexusissubjecttoinjuryduetostretchingorcompressionasaresultofitslongsuperficialcourseintheaxilla.Armabductiongreaterthan90degrees,lateralrotationofthehead,asymmetricretractionofthesternumanddirecttraumaallmaycontributetobrachialplexusinjury.Cardiacsurgeryandsternotomyisassociatedwithahigherincidenceofbrachialplexusinjury.Shoulderbraceshavehistoricallybeenaculpritinbrachialplexusinjuryleadingtotheirrareuse.Thecompressionofproximalrootsorlateraldisplacementofthebracescanstretchtheplexuswhentheshouldersaredisplaced.Usenonslidingmattressinsteadofshoulderbraces.BrachialPlexusInjuryThebrac42LowerExtremityNerveinjuryLithotomypositionisassociatedwithinjurytocommonperonealandsciaticnerves.Thesciaticnervemaybestretchedwithexternalrotationofthelegorwithhyperflexionofthehipsandextensionoftheknees.TheSaphenousnervemaybeinjuredifthemedialkneeiscompressedLowerExtremityNerveinjuryLi43LowerExtremityNerveInjuryThecommonperonealnervewhichisabranchofthesciaticmaybeinjuredwithcompressionbetweentheheadofthefibulaandthemetalframeof“candycane”stirrupswhenthepatientisinthelithotomyposition.ThisistheMostcommonnerveinjuryinlowerextremities!CommonperonealnerveinjuryresultsinFootDrop!LowerExtremityNerveInjuryTh44MorenerveinjurystuffMediannerveinjurymaybecausedby“searching”foranIVintheanticubitalfossaresultingintheinabilitytoopposethumbandthelittlefinger.ThepostoperativeneuropathythatmustbereferredtoaneurologistimmediatelyisanyMOTORdeficitfollowingsurgery.ThankyouforyourattentionandIamlookingforwardtoseeingyouintheOR.Sowhatisitlikeontheothersideofthatsteepmountain?MorenerveinjurystuffMedian45Patient-Position-During-Anesthesia：麻醉期間病人的位置課件46CaseStudy:POVLinPronePositionA58yearoldanesthesiologisthaschronicbackpainandisscheduledforlaminectomyataUniversityMedicalSchoolTeachinghospital.

Thecaseisscheduledfor6hoursbutrunsover-really?

Ofcourse-thisisapronepositioncasewithover500mlofbloodloss.CaseStudy:POVLinPronePosi47CaseStudyAfterthesuccessfulcompletionofthesurgerythepatienthasvisualcomplaintsincludingflashingcolors.

Fundoscopicexamwasnormal.

Overthenextweeksavisualfieldofvisionlossof70percentisreported.

CaseStudyAfterthesuccessful48CaseStudyDiscussion:

WhatarethedataconcerningPOVL.Whatrolldoesanesthesiaplayintheinformedconsentforpronecases?WhatistheliabilityoftheanesthesiaproviderforPOVL?

CaseStudyDiscussion:

Whatar49ReferencesapsfNewsletter,“BeachChairPositionDecreaseCerebralPerfusion”Vol22,No.2,25-40.apsfNewsletter,“Ifmyspinesurgerywentfine,whycan’tIsee?”Vol23,No.1,1-20.Bararshallofit!Miller’sAnesthesia6thed.Chapter28.ReferencesapsfNewsletter,“Be50PatientPositionDuringAnesthesiaByDavidRoyGoddenCRNA,MSNPatientPositionDuringAnesth51LectureObjectivesGainanunderstandingofsafepositioningbasicsIdentifythepotentialnerveinjuriesfrommaskventilationStatethecorrecthandandarmpositioningforsupine,lateraldecubitusandpronepositions.Beabletorecitethepotentialnerveinjuriesofeachpatientposition.Identifythecomplicationsofthesittingposition.LectureObjectivesGainanunde52ObjectivesCon’tDefineandunderstandthehemodynamicsofeachpatientposition.Understandandbeabletoverbalize-thatmeansknowthoroughly-therespiratoryandautonomicresponsesofdifferingpatientpositionswhileawakeandundergeneralanesthesia.DiscussPostOperativeVisualLoss(POVL)CaseStudy:ComplicationsofPronepositionObjectivesCon’tDefineandund53Patient-Position-During-Anesthesia：麻醉期間病人的位置課件54Patient-Position-During-Anesthesia：麻醉期間病人的位置課件55Patient-Position-During-Anesthesia：麻醉期間病人的位置課件56MaskInjuriesPotentialforcornealabrasionisalwayspresentwhenmaskventilatingpatients.Facestrapswhicharetightacrossthepatientsfacewithprolongedusemaycauseinjurytothefacialnerve.Whatarethefivebranchesofthefacialnerverememberingthemnemonic,“Twozebrasbitmycat”Thebucalbranchismostlikelyinjuredwithafacestrapcompression.TemporalZygomaticBucalMandibularcervicalMaskInjuriesPotentialforcor57DorsalDecubitusPositionsGravityeffectsbloodflowandmuchofpulmonarymechanics.Humans,giraffesanddinosaursshareonethingincommon.Whatisit?InthesupinepositiongravityequalizesbloodpressuregradientsbetweenheartandarteriesintheheadandlowerextremitiesDorsalDecubitusPositionsGrav58CorrectAnatomicalPositionWhatistheventralsurface?WhatisthedorsalsurfaceNote:DorsaltodorsalandventraltoventralCorrectAnatomicalPositionWha59DorsalDecubitusPositionsHeadtilteitherupwardsordownwardswillchangethepressuregradients.Amovementof2.5cminverticalelevationwillchangethebloodpressure2mmHg.IntheparturientanIVbagundertherighthipwillshiftthegraviduterustotheleft.HaveyouheardofAorto-cavalsyndrome?DorsalDecubitusPositionsHead60HandpositioningLyingatattentionrequirescorrectarmandhandpositiontominimizethechancesofnerveinjuries.Armsaretobelessthan90degreeslateralizedfromthethoraxincorrectanatomicalpositionlookingattheshoulders.Thiswillminimizethechanceofbrachialplexusinjury.ArmsatsideofbodymustbeincorrectdorsaltodorsalalignmentwiththearmssupinatedORpalmstowardthebodyisOKaswell.Theulnarnervepassesclosetothesurfaceoftheskininthemedialcondyleoftheelbow.Theolectranonwillprotectthenerveifplaceddownwards.Radialnerveinjuryispossiblewithetherscreencompressiontothelateralarm.Radialnerveinjurymayresultinwristdrop.HandpositioningLyingatatten61WhatisSupinationCorrectanatomicalpositionislyingatattentionorPalmsareventralsurfacesoventraltoventralDorsaltodorsalmeanbackofhandstoback.WhatisSupinationCorrectanat62HeaddownthingsLoweringtheheadwillincreasethepressureinthecerebralveinswhichmayleadtovascularheadache,congestionofnasalmucosaandconjunctivainhealthyindividuals.Thismayleadtoedemainthelarynxaswell.Thescleraisthewindowtothevocalcords!Headloweringinpatientswithintra-craniallesionswillexacerbatetheconditionraisingCPPandICP(what'stheformulaforthis?)HeaddownthingsLoweringtheh63AutonomicfunctionAorticarchandcarotidsinushousebarorecetorsthatarepartofthebodieshomeostaticmechanismtomaintainbloodpressurewithinanarrowrange.Increasedfiringofthereceptorswhenstretchedfromanincreaseinbloodpressureispartofanegativefeedbackloop.Theincreasedfiringfromthebaroreceptorsenhancestheparasympatheticnervoussystemloweringbloodpressureandslowingtheheartrate.Rememberthis!Whatarethenervesresponsibleforthebaroreceptorreflexes?AutonomicfunctionAorticarch64RespiratoryEffects

Respiratorymechanicswillsufferintheheaddownpositionhow?ReviewWest’szonesofthelung.Normalexcursionofthediaphragminheaddownpositionisimpededandincreasetheworkofbreathing.Intheparalyzedmechanicallyventilatedpatient,higherpeakpressureswillberequiredforadequateventilation.SupinepatientsdevelopVQmismatchduetovascularcongestioninthedorsalportionsofthelungandchangesincompliance.Thedorsallung(nowzone3)willhavereducedcompliance.Passiveventilationtendstodistributegaspreferentiallytothemoreeasilydistensiblesubsternalunitswherepulmonarybloodflowvolumeisless(Barish,2006).RespiratoryEffectsRespirator65MoreRespiratorythingsTopreventdevelopmentofsignificantV-Qimbalanceduringuseofcontrolledventilation,tidalvolumesmustbeusedthataregreaterthantheaverageamountthatissufficientforthespontaneouslybreathingconsciouspt.Compareandcontrasttheawakespontaneouslybreathingptandtheparalyzedmechanicallyventilatedptinthelateralposition.HowwouldyouattempttodecreasePeakpressuresduringmechanicalventilationintheparalyzedanesthetizedpatient?Hint:deepenanesthetic,musclerelaxation,decreaseVtandincreaseRate,changeI:Eratiofrom1:2to1:1.5.ConsiderPressureControlventilationduetoitsdeceleratingwaveform.MoreRespiratorythingsToprev66VariationsintheDorsalDecubitusPositionSupineotherwiseknownaslyingatattention.Placesstrainonlowersegmentsoflumbarspine.Lawnchairisamorephysiologicallytoleratedpositionduetodecreasedstretchonlowerback.Frogleg(healtohealwithlateralizationofknees)forperonealexaminationsmayplaceexcessivestretchonback,hipsandpelvicstructures.Padunderknees.Complicationsofexcessivestretchmayinclude1)postoperativehipandbackpain;2)dislocatedhiporfractureofan