1

HemodynamicMonitoringandCirculatoryAssistDevices

(RelatestoChapter66,“NursingManagement:CriticalCare,”

inthetextbook)

HemodynamicMonitoring

•  Measurementofpressure,flow,andoxygenationwithinthecardiovascularsystem

•  Includesinvasiveandnoninvasivemeasurements

– Systemicandpulmonaryarterialpressures

HemodynamicMonitoring

•  Invasiveandnoninvasivemeasurements(cont’d)– Centralvenouspressure(CVP)– Pulmonaryarterywedgepressure(PAWP)– Cardiacoutput(CO)/cardiacindex(CI)

HemodynamicMonitoring

•  Invasiveandnoninvasivemeasurements(cont’d)– Strokevolume(SV)/strokevolumeindex(SVI)– O2saturationofarterialblood(SaO2)– O2saturationofmixedvenousblood(SvO2)

HemodynamicMonitoringGeneralPrinciples

•  Preload:Volumeofbloodwithinventricleatendofdiastole

•  Afterload:Forcesopposingventricularejection– Systemicarterialpressure

– Resistanceofferedbyaorticvalve– Massanddensityofbloodtobemoved

HemodynamicMonitoringGeneralPrinciples

•  Contractility:Strengthofventricularcontraction

•  PAWP:Measurementofpulmonarycapillarypressure;reflectsleftventricularend‐diastolicpressureundernormalconditions

2

HemodynamicMonitoringGeneralPrinciples

•  CVP:Rightventricularpreloadorrightventricularend‐diastolicpressureundernormalconditions,measuredinrightatriumorinvenacavaclosetoheart

PrinciplesofInvasivePressureMonitoring

•  Equipmentmustbereferencedandzerobalancetoenvironmentanddynamicresponsecharacteristicsoptimized

•  Referencing:Positioningtransducersozeroreferencepointisatlevelofatriaofheartorphlebostaticaxis

IdentificationofPhlebostaticAxis

Fig. 66-4

PrinciplesofInvasivePressureMonitoring

•  Zeroing:Confirmsthatwhenpressurewithinsystemiszero,monitorreadszero– Duringinitialsetupofarterialline–  Immediatelyafterinsertionofarterialline

PrinciplesofInvasivePressureMonitoring

•  Zeroing(cont’d)– Whentransducerhasbeendisconnectedfrompressurecableorpressurecablehasbeendisconnectedfrommonitor

– Whenaccuracyofvaluesisquestioned

TypesofInvasivePressureMonitoring

•  Continuousarterialpressuremonitoring– Acutehypertension/hypotension– Respiratoryfailure– Shock– Neurologicshock

3

TypesofInvasivePressureMonitoring

•  Continuousarterialpressuremonitoring(cont’d)– Coronaryinterventionalprocedures– Continuousinfusionofvasoactivedrugs– FrequentABGsampling

ComponentsofanArterialPressureMonitoringSystem

Fig. 66-3

ArterialPressureMonitoring

•  High‐andlow‐pressurealarmsbasedonpatient’sstatus

•  Measureatendofexpiration

•  Risks– Hemorrhage,infection,thrombusformation,neurovascularimpairment,lossoflimb

ArterialPressureTracing

Fig. 66-6

ArterialPressureMonitoring

•  Continuousflushirrigationsystem– Delivers3to6mlofheparinizedsalineperhour

•  Maintainslinepatency•  Limitsthrombusformation

– Assessneurovascularstatusdistaltoarterialinsertionsitehourly

PulmonaryArteryPressureMonitoring

•  Guidesmanagementofpatientswithcomplicatedcardiac,pulmonary,andintravascularvolumeproblems– PAdiastolic(PAD)pressureandPAWP:Indicatorsofcardiacfunctionandfluidvolumestatus

– MonitoringPApressuresallowsfortherapeuticmanipulationofpreload

4

PulmonaryArteryCatheter

Fig. 66-7

InsertionofPulmonaryArteryCatheter

Fig. 66-8

PulmonaryArteryPressureMonitoring

•  Whenmeasurementsareobtained– PA:Atendexpiration– PAWP:ByinflatingballoonwithairuntilPAwaveformchangestoaPAWPwaveform•  Balloonshouldbeinflatedslowlyandfornomorethanfourrespiratorycyclesor8to15seconds

PAWaveformsduringInsertion

Fig. 66-9

CentralVenousPressureMonitoring

•  Measurementofrightventricularpreload– Obtainedfrom

•  PAcatheterusingoneoftheproximallumens•  Centralvenouscatheterplacedininternaljugularorsubclavianvein

MeasuringCardiacOutput

•  Intermittentbolusthermodilutionmethod•  Continuouscardiacoutputmethod

5

MeasuringCardiacOutput

Fig. 66-12

ComplicationswithPACatheters

•  Infectionandsepsis– Asepsisforinsertionandmaintenanceofcatheterandtubingmandatory

– Changeflushbag,pressuretubing,transducer,andstopcockevery96hours

•  Airembolus(e.g.,disconnection)

ComplicationswithPACatheters

•  Ventriculardysrhythmias– DuringPAcatheterinsertionorremoval

–  IftipmigratesbackfromPAtorightventricle

•  PAcathetercannotbewedged– Mayneedrepositioning

PulmonaryArteryWaveforms

Fig. 66-10

PreventingPARuptureandPulmonaryInfarction

•  Neverinflateballoonbeyondballoon’scapacity– Usually1to1.5mlofair

•  CheckPApressurewaveformsoftenforsignsofcatheterocclusion,dislocation,orspontaneouswedging

NursingManagementHemodynamicMonitoring

•  Baselinedataobtained– Generalappearance– Levelofconsciousness– Skincolor/temperature– Vitalsigns– Peripheralpulses– Urineoutput

6

NursingManagementHemodynamicMonitoring

•  Baselinedatacorrelatedwithdataobtainedfrombiotechnology(e.g.,ECG;arterial,CVP,PA,andPAWPpressures;SvO2/ScvO2)

•  Singlehemodynamicvaluesarerarelysignificant

NursingManagementHemodynamicMonitoring

•  Monitortrendsandevaluatewholeclinicalpicture

•  Goals– Recognizeearlyclues–  Intervenebeforeproblemsdeveloporescalate

CirculatoryAssistDevices(CADs)

•  Decreasecardiacworkandimproveorganperfusionwhendrugtherapyfails

•  Provideinterimsupportwhen– Left,right,orbothventriclesrequiresupportwhilerecoveringfrominjury(MI)

– Heartrequiressurgicalrepairandpatientmustbestabilized(e.g.,rupturedseptum)

– Hearthasfailedandpatientneedscardiactransplantation

IntraaorticBalloonPump(IABP)

•  Providestemporarycirculatoryassistance

– ↓Afterload

– Augmentsaorticdiastolicpressure

•  Outcomes

–  Improvedcoronarybloodflow–  Improvedperfusionofvitalorgans

IABPMachine

Fig. 66-13

IABP

Fig. 66-14

7

VentricularAssistDevices(VADs)

•  Provideslonger‐termsupportforfailingheart•  AllowsmoremobilitythanIABP

•  Insertedintopathofflowingbloodtoaugmentorreplaceactionofventricle

SchematicDiagramofLeftVAD

Fig. 66-16

VentricularAssistDevices(VADs)

•  IndicationsforVADtherapy– Extensionofcardiopulmonarybypass

•  Failuretowean•  Postcardiotomycardiogenicshock

– Bridgetorecoveryorcardiactransplantation

NursingManagementCirculatoryAssistDevices

– Observepatientfor:Bleeding,cardiactamponade,ventricularfailure,infection,dysrhythmias,renalfailure,hemolysis,andthromboembolism

– Patientmaybemobileandwillrequireanactivityplan

SIRSandMODS

(RelatestoChapter67,“NursingManagement:Shock,

SystemicInflammatoryResponseSyndrome,andMultipleOrganDysfunctionSyndrome,”

inthetextbook)

SIRS

•  Systemicinflammatoryresponsesyndrome(SIRS)isasystemicinflammatoryresponsetoavarietyofinsults

•  Generalizedinflammationinorgansremotefromtheinitialinsult

8

SIRS

•  Triggers– Mechanicaltissuetrauma:burns,crushinjuries,surgicalprocedures

– Abscessformation:intra‐abdominal,extremities–  Ischemicornecrotictissue:pancreatitis,vasculardisease,myocardialinfarction

SIRS

•  Triggers– Microbialinvasion:Bacteria,viruses,fungi– Endotoxinrelease:Gram‐negativebacteria– Globalperfusiondeficits:Post–cardiacresuscitation,shockstates

– Regionalperfusiondeficits:Distalperfusiondeficits

MODS

•  Multipleorgandysfunctionsyndrome(MODS)isthefailureoftwoormoreorgansystems– Homeostasiscannotbemaintainedwithoutintervention

– ResultsfromSIRS

MODS

– SIRSandMODSrepresenttheendsofacontinuum

– TransitionfromSIRStoMODSdoesnotoccurinaclear‐cutmanner

RelationshipofShock,SIRS,andMODS

Fig. 67-1

SIRSandMODS

•  Consequencesofinflammatoryresponse– Releaseofmediators

– Directdamagetotheendothelium– Hypermetabolism– VasodilationleadingtodecreasedSVR–  Increaseinvascularpermeability– Activationofcoagulationcascade

9

SIRSandMODSPathophysiology

•  Organandmetabolicdysfunction

– Hypotension– Decreasedperfusion– Formationofmicroemboli

– Redistributionorshuntingofblood

SIRSandMODSPathophysiology

•  Respiratorysystem– Alveolaredema

– Decreaseinsurfactant–  Increaseinshunt– V/Qmismatch

– Endresult:ARDS

SIRSandMODSPathophysiology

•  Cardiovascularsystem– Myocardialdepressionandmassivevasodilation

SIRSandMODSPathophysiology

•  Neurologicsystem– Mentalstatuschangesduetohypoxemia,inflammatorymediators,orimpairedperfusion

– OftenearlysignofMODS

SIRSandMODSPathophysiology

•  Renalsystem

– Acuterenalfailure•  Hypoperfusion•  Releaseofmediators

•  Activationofrenin–angiotensin–aldosteronesystem

•  Nephrotoxicdrugs,especiallyantibiotics

SIRSandMODSPathophysiology

•  GIsystem– Motilitydecreased:Abdominaldistentionandparalyticileus

– Decreasedperfusion:RiskforulcerationandGIbleeding

– Potentialforbacterialtranslocation

10

SIRSandMODSPathophysiology

•  Hypermetabolicstate– Hyperglycemia–hypoglycemia

–  Insulinresistance– Catabolicstate– Liverdysfunction– Lacticacidosis

SIRSandMODSPathophysiology

•  Hematologicsystem

– DIC•  Electrolyteimbalances

•  Metabolicacidosis

SIRSandMODSCollaborativeCare

•  PrognosisforMODSispoor•  Goal:PreventtheprogressionofSIRStoMODS

•  Vigilantassessmentandongoingmonitoringtodetectearlysignsofdeteriorationororgandysfunctioniscritical

SIRSandMODSCollaborativeCare

•  Preventionandtreatmentofinfection– Aggressiveinfectioncontrolstrategiestodecreaseriskfornosocomialinfections

– Onceaninfectionissuspected,instituteinterventionstocontrolthesource

SIRSandMODSCollaborativeCare

•  Maintenanceoftissueoxygenation– DecreaseO2demand

• Sedation• Mechanicalventilation

• Paralysis• Analgesia

SIRSandMODSCollaborativeCare

•  Maintenanceoftissueoxygenation– OptimizeO2delivery

•  Maintainnormalhemoglobinlevel•  MaintainnormalPaO2

– IndividualizetidalvolumeswithPEEP

11

SIRSandMODSCollaborativeCare

•  Maintenanceoftissueoxygenation

– EnhanceCO– Increasepreloadormyocardialcontractility

– Reduceafterload

SIRSandMODSCollaborativeCare

•  Nutritionalandmetabolicneeds– Goalofnutritionalsupport:Preserveorganfunction

– Totalenergyexpenditureisoftenincreased1.5to2.0times

SIRSandMODSCollaborativeCare

•  Nutritionalandmetabolicneeds– Useoftheenteralrouteispreferredtoparenteralnutrition

– Monitorplasmatransferrinandprealbuminlevelstoassesshepaticproteinsynthesis

SIRSandMODSCollaborativeCare

•  Supportoffailingorgans– ARDS:AggressiveO2therapyandmechanicalventilation

– DIC:Appropriatebloodproducts– Renalfailure:Continuousrenalreplacementtherapyordialysis