hemodynamic monitoring · 2019-08-09 · intra-arterial blood pressure indications • beat-to-beat...
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HemodynamicMonitoring
Albert R. Robinson III, M.D.Associate Professor
Department of AnesthesiologyThe University of Florida
College of Medicine
Josh Sappenfield, M.D.Assistant Professor
Department of AnesthesiologyThe University of Florida
College of Medicine
Objectives
• Understandtheimportanceofmonitoring• Reviewtheindications,contraindications,andcomplications forthemostwidelyusedAnestheticmonitors
• Learntheimportanceofinvasivemonitors:arterialcatheter,centralvenouscatheter,andpulmonarycatheter
Monitors
“Nomonitoristherapeuticinitselfbutrequirestheskillandvigilanceofatrainedobservertointerprettheinformationinthecontextofthe
ever-changingclinicalpicture.”
Euliano T,Gravenatein JS.etal.EssentialAnesthesia:FromSciencetoPractice.Chapter7:Monitoring.CambridgeUniversityPress,NewYork,2011.
MonitoringImportance
• Monitoringprovidesanearlywarningofadversechangesortrendsbeforeirreversibledamageoccurs
• Monitoring– reflectsphysiologichomeostasis– allowspromptrecognitionofresponsestotherapeuticinterventions
– allowspromptrecognitionofadversechanges.• Whatisthemostimportantmonitor?– Vigilance!
Stoelting RK,MillerRD.BasicsofAnesthesia.4th Ed.Chapter16.Monitoring.ChurchillLivingstone,Philadelphia,2000.
Monitors• VigilantPhysicians(Subjectivedata)– Monitors– (Visual,Tactile,Auditory,Olfactory)
• StandardMonitoringEquipment(ObjectiveData)• PulseOximetry• Capnography• BodyTemperature• ECG• SystemicBloodPressure
BuildingBlocksofMonitoring
“Allmonitoringbuildsonold-fashionedinspection,auscultation,andpalpation.”
Euliano T,Gravenatein JS.etal.EssentialAnesthesia:FromSciencetoPractice.Chapter7:Monitoring.CambridgeUniversityPress,NewYork,2011.
MonitoringthatRequiresNoInstrumentation
• Inspection– Skin– NailBeds–Mucousmembranes– Surgicalfield
– BodilyMovement
– Eyes
MonitoringthatRequiresNoInstrumentation
• Inspection– Skin (Istherenormalcapillaryrefill?Delayed
returnsuggestsabnormalityinregionalorsystemiccirculation)
• Palpation– Skin (Isthepatientwarmorcoldandclammy)– Pulse (Presence/Absenceofpulse)– Skeletalmuscle (Aremusclesfasciculating)
• Percussion– Gastric (Isthereabdominaldistension)
• Auscultation– Chest (Listenforbreathsoundsoverbothlung
field,isthereparadoxicalbreathing)– Heart (Aresoundsmuffled,ormurmurspresent)
MinimalMonitoringStandards
• TheAmericanSocietyofAnesthesiologist(ASA)callsforstandardmonitorsforallpatientsundergoinggeneralanesthesia– Oxygenation(inspiredgasandsaturationofarterialblood(SpO2))
– Ventilation(capnography andclinicalassessment)– Circulation(ECG,arterialbloodpressure)– Temperature
Electrocardiogram(ECG)
• Providesinformationon– cardiacarrhythmias– myocardialischemia/infarction– electrolytechanges,particularlypotassium
• ECGisnot ameasureofheartfunction• ECGreflectsonlytheelectricalactivitiesoccurringintheheart
Stoelting RK,MillerRD.BasicsofAnesthesia.4th Ed.Chapter16.Monitoring.ChurchillLivingstone,Philadelphia,2000.
ECG5-LeadPlacement
• “SnowontheGrass”→WhiteECGelectrodetorightshouldovergreenECGelectrode
• “Smokeoverfire”→BlackECGelectrodetoleftshouldoverredECGelectrode
• BrownECGelectrodeattheV5position(Leftanterioraxillarylinebetweenfourthandfifthintercostalspace)
Euliano T,Gravenatein JS.etal.EssentialAnesthesia:FromSciencetoPractice.Chapter7:Monitoring.CambridgeUniversityPress,NewYork,2011.
ECG
• LeadV5isthemostsensitiveleadfordetectingischemia
• LeadIIisthemostsensitiveleadfordetectingarrhythmias
• PwavesarebestseenonLeadII– bestenablesonetoobservethecardiacrhythm.
PulseOximetry• Assesstheoxygenationofblood• Reduced(ordeoxygenated)hemoglobin(Bluish)• Oxygenatedhemoglobin(Red)• Howitworks?– Aprobesendlightimpulsesintoafingerandcollectsthelightthatpassthroughit.
– Theunitsestimatestheproportionofoxyhemoglobin toreducedhemoglobin
• SpO2– thesaturationbasedonpulseoximetry• SaO2– thesaturationobtainedfromdirectarterialbloodsample
Pulseoximetry (cont)
CorrelationofSpO2 toarterialpartialpressureofoxygen(PaO2)
SpO2 PaO2
100% 100mmHgorhigher
90% 60mmHg
80% 50mmHg
60% 30mmHg
BloodPressure(BP)Monitoring• Thelateralpressureexertedbythecontainedbloodonthewallsofthevesselsisarterialpressure.
• FactorscontrollingbloodpressureincludeØ Hormonalmechanisms(i.e.catecholamines,renin-angiotensin,antidiuretichormone,atrialnatriureticpeptide
ØCentral&autonomicnervousfunctionØPeripheralvascularresistanceØCardiacoutput
• BPmonitoringiscommonlyperformedØ Indirectly – noninvasivecuffaroundextremityØDirectly – insertingcatheterintoartery
Barash PG,CullenBF,Stoelting RK.ClinicalAnesthesia(5th ed).Ch.24:MonitoringtheAnesthetizedPatient.LippincottWilliams&Wilkins.Philadelphia.2006.
BP- NoninvasiveMonitoring
• MechanicaldeformationfromthebloodpressurecuffofanarteryleadstothecreationofKorotkoff soundsresultfromturbulentflow
• TheappearanceofthefirstKorotkoff soundisthesystolicbloodpressure
• ThedisappearanceoftheKorotkoff soundsignalsthediastolicbloodpressure.
BloodPressure
• SystolicBloodPressure(SBP)– Pressurewhichejectedbloodwillovercometoperfusevesselsdistally
• DiastolicBloodPressure(DBP)– Pressureunderwhichthebloodflowwillbelaminar
• PulsePressure=SBP- DBP• MeanArterialBloodPressure(MAP)– Timeweightedaverageofarterialpressuresduringapulsecycle
– MAP=[SBP+(2xDBP)]/3
NIBPBladderCuff• AmericanHeartAssociationrecommends
– Bladderwidth– approximately40%ofthecircumferenceoftheextremity
– BladderLength– sufficienttocircleatleast60%oftheextremity
• Falselylowestimatesoccur:– afterquickdeflation– whentheextremityisabovetheheart– whencuffsaretoolarge
• Falselyhighestimatesoccurwhen:– cuffsareappliedtooloosely– whentheextremityisbelowheartlevel– whencuffsaretoosmall
Barash PG,CullenBF,Stoelting RK.ClinicalAnesthesia(5th ed).Ch.24:MonitoringtheAnesthetizedPatient.LippincottWilliams&Wilkins.Philadelphia.2006.
NoninvasiveBloodPressureMonitoringProblems
• Hematomasresultsduetoincreasevenouspressureafterfailuretodeflatethecuff
• Delayedcuffdeflationcanresultsfromshiveringandtremors
• Ulnarneuropathycanoccurduetocompressionoftheulnarnerve
InvasiveMonitors
• Intra-arterialbloodpressure• Centralvenouspressure• Pulmonaryarterycatheters(Swan-Ganz)• Transesophagealechocardiography(TEE)
Intra-arterialBloodPressureIndications
• Beat-to-beatmonitoring• Expectedrapidchangesinhemodynamicstability
• Inducedhypotension,acutehypotension• Reliableaccessforanalysisofarterialbloodgases,pH,and/orelectrolytes
• Inabilitytoachievenoninvasivemonitoring• Vasoactivedrugs• Sepsis
SystemicBloodPressureMonitoringSites
• ArterialCannulation Sites– Aorta– Axillaryartery– Brachialartery– Radialartery - mostpopularsiteduetopresenceofacollateralbloodsupplyandaccessibility
– Ulnarartery– Femoralartery– Dorsalis pedis artery
ArterialBloodPressureMeasurement
• Wavereflectiondistortsthearterialpressurewaveform,leadingtoanexaggerationofsystolicandpulsepressure,asapulsemovesperipherallythroughthearterialtree
• Forexample,dorsalpedis arterypressuresareusuallyhigherthanaorticsystolicpressurebecauseoftheformer’smoredistallocation(seeFigure)
Changesinarterialbloodpressurewaveformconfigurationasawaveformmovesperipherally
ShahN,BedfordRF:Invasiveandnoninvasivebloodpressuringmonitoring.In:clinicalMonitoring:PracticalApplicationsinAnesthesiaandCriticalCareMedicine.LakeCL,HinesRL,Blitt CD[editors].WBSanders,Philadelphia,2001,p.182.
ArterialPressureWaveform
• Rateofupstrokeindicatescontractility
• Rateofthedownstrokeindicatesperipheralvascularresistance
• Dicrotic notchreflectstheclosureoftheaorticvalve
• ThefartheroutthedicroticnotchthelowertheSVRorperipheralvascularresistance
ComplicationsofIntra-arterialBPCatheterization
• Hematoma• Bleeding• Vasospasm• ArterialThrombosis• DistalEmboli• InfectionandNecrosis• Airembolism• Lossofdigits• Unintentionalintraarterial druginjection• Pseudoaneurysm• Damagetoadjacentnerves
CentralVenousAccessIndications
• Monitoringcentralvenouspressure(CVP)• Rapidadministrationoffluidtotreathypovolemiaandshock(i.e.acutehemorrhaging)
• Infusionsofdrugs• Long-termIVFeeding(i.e.Hyperalimentation)• Aspirationofairemboli• InsertionofTranscutaneouspacingleads• VenousAccessinpatientswithpoorperipheralveins
InternalJugular(IJ)CentralVenousMonitoring
• RightIJveinisthepreferredsiteforcannulation– Highsuccessrateinbothadultsandchildren– Predictableanatomy– Accessiblefromtheheadoftheoperatingtable
• LeftsideIJislessdesirablebecauseofpotentialdamagetothe– Thoracicduct– Challengeofplacingcatheterthroughthejugular-subclavianjunction.
Barash PG,CullenBF,Stoelting RK.ClinicalAnesthesia(5th ed).Ch.24:MonitoringtheAnesthetizedPatient.LippincottWilliams&Wilkins.Philadelphia.2006.
CVCPlacementSitesAdvantages Disadvantages
R Internal jugular vein Good landmarksPredictable anatomyAccessible from head of OR table
Carotid artery punctureTrama to brachial plexus
L Internal jugular vein Same as above Same as aboveThoracic duct damage
Subclavian vein Good landmarksRemains patent despite hypovolemiaPatient comfort when awake
Pneumothorax
External jugular vein Superficial location Often difficult to thread catheter into the central circulation
Femoral vein Good landmarksAccessible in low flow state
Risk of local hematoma
Antecubital vein Safety Often difficult to thread into the central vein
CVCContraindications
• Anticoagulants• Ipsilateral carotidendarterectomy• Fungating tricuspidvalvevegatations• Renalcelltumorextensionintotherightatrium
• ContralateralPneumothorax
CVPWaveform• Centralvenouspressureparallelsrightatrialpressure,whichisamajordeterminantofvenousblood.
• Normalpressuresmightrangefrom-2to12mmHginaspontaneouslybreathingpatient.
• Pressuresof6to15mmHg(ormorewithhighpeakinspiratorypressures)canbeexpectedifthepatient’slungarebeingmechanicallyventilated.
• Theshapeofthecentralvenouswaveformcorrespondstotheeventsofthecardiaccontractions.
Euliano T,Gravenatein JS.etal.EssentialAnesthesia:FromSciencetoPractice.Chapter7:Monitoring.CambridgeUniversityPress,NewYork,2011.
CVPWaveform• Thenormalwaveformconsistsofthreepeaksandtwodescents.
• Thea- waveisatrialcontraction(theseareabsentinatrialfibrillation).
• Thecwavesareduetotricuspidvalveelevationduringearlyventricularcontraction
• Thev-wavereflectvenousreturnagainstaclosedtricuspidvalve.
• Thetwodescents(xandy)areduetothedownwarddisplacementofthetricuspidvalveduringsystoleandtricuspidvalveopeningduringdiastole.
CVPWaveform• Threepeak(a,c,andv
waves)andtwodescents(x,y)canbeseeninanormalCVPwaveform.
• Ifawavesareabsent,thepwaveisabsentonECGtracing
• Largeawavesarepresentswhenresistancetoemptyingoftherightatriumispresent(i.e.tricuspidstenosisorpulmonaryhypertension)
• Alargevwavemaysuggesttricuspidregurgitation
MorganGE.MikhailMS.MurrayMJ.ClinicalAnesthesiology(4th ed.).Ch.6.PatientMonitors.,NewYork,2006
ElevatedCVP• TricupsidStenosis• TricupsidRegurgitation• PulmonaryHypertension• MitralStenosis• MitralRegurgitation• LVFailure• VolumeOverload• CardiacTamponade• Arrhythmias• IncreasedPVR(Anxiety,Pain)
ComplicationsofCVCPlacement
• Arterialpuncture• Pneumothorax• Chylothorax• TrachealInjury• CardiacTamponade• Arrhythmias• Airembolus• Thrombosis• Infection
PulmonaryArteryCatheterization(PAC)
• Flow-directed,balloon-tippedcatheter
• Allowsforcatheterizationofrightheartformeasurementofpressures
• Pulmonaryarteryocclusion(wedge)reflectsleftatrialpressure
• Samplingmixedvenousblood
• Thermistorattipofcathetermeasurestemperatureofbloodflowingpast
PulmonaryArteryCatheterization• Theeffectivenessofpulmonaryarterycatheter(PAC)monitoring
remainslargelyunproveninmanygroupsofsurgicalpatient.• TheAmericanSocietyofAnesthesiology(ASA)concludesthatthe
appropriatenessofPACdependsonthecombinationofrisksassociatedwiththepatient.
• MonitoringPAPandcardiacoutputincriticallyillpatientshasbeenshowntoprovidecardiovascularinformationthatismoreaccuratethanthatobtainedbyclinicalassessment.
• Thesemeasurementsproveparticularlyimportantinpatientsathighriskforhemodynamicinstability(e.g.recentM.I.orTAAA).
• WhenPAOPoccurs,thereisnobloodflow,thepressurescanequilibratebetweenthedistalendofthepulmonaryarterycatheterandtheleftatrium.
MorganGE.MikhailMS.MurrayMJ.ClinicalAnesthesiology(4th ed.).Ch.6.PatientMonitors.,NewYork,2006
PACIndications
• Poorleftventricularfuction (EF<40%)• Assessmentofintravascularfluidvolume• Valvular heartdiseases• ResponsetoIVfluidinfusionoradministrationofdrugs(vasopressors,vasodilators,intropes)
• Recentmyocardialinfarction• Massivetrauma(shock,hemorrhage)• Majorvascularsurgery(cross-clampingoftheaorta,largefluidshifts)
TypesofSwans
• Paceport – capableofprovidingcardiacpacing
• ContinuousCardiacOutput– producesathermodilution curvetodeterminecardiacoutput
• MixedvenousO2- candeterminevenousoxygensaturationwhenthereisadecreaseintissuebloodfloworO2 delivery
• Heparin vs Un-heparincoated
ContraindicationstoPAC• Relative
– Surgicalfield– Leftbundlebranchblock– Traumatizedtissue– Coagulopathy– Mitraloraorticvalvular stenosis
• Absolute– Pulmonaryvalvestenosis– ArtificialorProstheticRightSidedValves– PatientRefusal– Infectionatthelocalsite
PACWaveform
Euliano T,Gravenatein JS.etal.EssentialAnesthesia:FromSciencetoPractice.Chapter7:Monitoring.CambridgeUniversityPress,NewYork,2011.
ComplicationsforPACPlacement
• Dysrhythmias• Rightventriculardamage• Pulmonaryarteryrupture• Pulmonaryinfarction• Thrombosis• Infection• Intracardiac knotformation
ElevatedPAP
• PulmonaryHypertension• IncreasePVR(i.e.drugs,COPD)• LeftHeartFailure• MitralStenosis• MitralRegurgitation• CardiacTamponade• Arrhythmias
PACUsedtoEvaluateHemodynamicDisorders
CVP PAOP PAEDP
Hypovolemia Decreased Decreased PAEDP=PAOP
Left ventricular failure
Increased Increased PAEDP=PAOP
Right ventricular failure
Increased No change PAEDP=PAOP
Pulmonary embolism
Increased No change PAEDP>PAOP
Cardiac Tamponade
Increased Increased PAEDP=PAOP
Transesophageal Echocardiography(TEE)
• GreatadvantageoverPAC• Usedtocharacterizecardiacvalvemorphologyandfunction
• Determineregionalwallmotionabnormalities(myocardialischemia)
• Assesscardiacoutput• Adequacyofintravascularfluidvolume• LessinvasivethanPAC
HemodynamicVariables
• CalculatingSystemicVascularResistance
Recall,V=I*R
SVR=(MAP– CVP)*80______________
C.O.
Normally, SVR = 1200-1500 dynes*s*cm-5
MoreHemodynamicVariables
• CalculatePulmonaryVascularResistance(PVR)
PVR=(MPAP– PAOP)*80_________________
C.O.
Normally, PVR = 100-300 dynes*s*cm-5
PreloadandCardiacPerformance
• Greenline– Venodilatortherapydecreasespreloadandinotropictherapyincreasescardiacindex(theheartmovesupwardandtotheleftonthecurve)
• Yellowline– Theventricularfunction(Starling)curveofthenormalleftventricularisaffectedmuchmorebychangesinpreloadthanitisbyanincreaseinafterload
• Redline– thefailingheartmovestoacurvedownwardandtotherightofthenormalheart
Barash PG,CullenBF,Stoelting RK.ClinicalAnesthesia(5th ed).Ch.24:MonitoringtheAnesthetizedPatient.LippincottWilliams&Wilkins.Philadelphia.2006.
FickPrincipleTheamountofoxygenconsumedbyanindividualequalsthedifferencebetweenarterialandvenousoxygencontentmultiplebycardiacoutput.
C.O.=O2 consumptiona-vO2 contentdifference
C.O.=VO2_________________CaO2 – CvO2
TheEnd
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