Traumatic Shock: Pathophysiology and Management

ShandsShands TraumaTrauma TracksTracks Goals/ObjectivesGoals/Objectives

¾¾ ReviewReview ShockShock andand TypesTypes ofof ShockShock ¾¾ ReviewReview Mechanisms/FeaturesMechanisms/Features ofof HypovolemicHypovolemic ShockShock andand PhysiologicPhysiologic ResponseResponse ¾¾ DiscussDiscuss Monitoring/ManagementMonitoring/Management ofof thethe PatientPatient inin HypovolemicHypovolemic ShockShock ShockShock

¾ Definition:Definition: ““AA clinicalclinical syndromesyndrome inin whichwhich thethe peripheralperipheral bloodblood flowflow isis inadequateinadequate toto returnreturn sufficientsufficient bloodblood toto thethe heartheart forfor normalnormal function,function, particularlyparticularly transporttransport ofof oxygenoxygen toto allall organsorgans andand tissues.tissues.””1

¾ Consequence:Consequence: InadequateInadequate tissuetissue oxygenationoxygenation toto meetmeet tissuetissue oxygenoxygen requirementsrequirements

1, From: Taber’s Cyclopedic Medical Dictionary, 17th Edition

FormsForms ofof ShockShock

¾¾ CardiogenicCardiogenic –– lossloss ofof contractilitycontractility ¾¾ DistributiveDistributive –– lossloss ofof vascularvascular tonetone

z NeurogenicNeurogenic,, septic,septic, anaphylacticanaphylactic ¾¾ ObstructiveObstructive –– relativerelative decreaseddecreased bloodblood volumevolume (preload)(preload)

z TensionTension pneumo,pneumo, cardiaccardiac tamponadetamponade ¾¾ HypovolemicHypovolemic –– lossloss ofof preloadpreload

z HemorrhagicHemorrhagic PhysiologicPhysiologic ConsiderationsConsiderations

¾¾ ShockShock representsrepresents aa failurefailure ofof OxygenOxygen DeliveryDelivery (DO2)(DO2) toto meetmeet OxygenOxygen ConsumptionConsumption ¾¾ InIn thethe carecare ofof thethe patientpatient inin shock,shock, wewe attemptattempt toto manipulatemanipulate DO2DO2 ¾¾ DO2DO2 == OxygenOxygen ContentContent XX CardiacCardiac OutputOutput ¾¾ CardiacCardiac OutputOutput == HRHR XX SVSV WhyWhy isis thisthis Important?Important? Metabolism!Metabolism! ¾¾ AerobicAerobic MetabolismMetabolism producesproduces 3636 ATPATP viavia thethe KrebsKrebs CycleCycle

z ATPATP isis thethe energyenergy sourcesource ofof thethe cellcell

¾¾ AnaerobicAnaerobic MetabolismMetabolism producesproduces 22 ATPATP andand producesproduces lactatelactate asas aa byproductbyproduct

z LactateLactate cancan decreasedecrease cardiaccardiac functionfunction

z MetabolicMetabolic acidosisacidosis AnaerobicAnaerobic MetabolismMetabolism

DecreasedDecreased ATPATP ⇓⇓ LossLoss ofof NaNa--KK PumpPump ⇓⇓ CellularCellular Swelling,Swelling, LossLoss ofof functionfunction ⇓⇓ LysosomesLysosomes rupture,rupture, AutoAuto--digestiondigestion ⇓⇓ CellCell deathdeath StagesStages ofof ShockShock

¾ CompensatoryCompensatory –– VSVS areare maintainedmaintained OnceOnce BPBP fallsfalls…………..

¾ ProgressiveProgressive –– compensatorycompensatory mechanismsmechanisms nono longerlonger supportsupport organorgan systems;systems; requiresrequires increasedincreased levelslevels ofof supportsupport ……………….... ¾ IrreversibleIrreversible

z Multiple Organ Dysfunction Syndrome

z Refractory State ResponseResponse CompensatoryCompensatory ChangesChanges

¾¾ SympatheticSympathetic NervousNervous SystemSystem –– fight/flightfight/flight

z Vasoconstriction,Vasoconstriction, ⇑⇑HR,HR, ⇑⇑ contractility,contractility, ⇓⇓ UOPUOP ¾¾ ReninRenin--AngiotensinAngiotensin--AldosteroneAldosterone

z ResponseResponse toto ⇓⇓ BP/BP/⇓⇓ bloodblood volumevolume withwith ⇑⇑ Na+Na+ ¾¾ TissueTissue InjuryInjury ÆÆ cytokinescytokines

z VasodilationVasodilation,, vasoconstriction,vasoconstriction, capillarycapillary permeabilitypermeability BloodBlood PressurePressure

¾¾ BodyBody SystemsSystems mobilizemobilize toto maintainmaintain homeostasishomeostasis –– BPBP isis oneone ofof thethe homeostatichomeostatic goalsgoals (other(other goalsgoals areare pH,pH, osmolalityosmolality,, ionicionic neutrality)neutrality) ¾¾ PerfusionPerfusion DOESDOES NOTNOT EQUALEQUAL BPBP ¾¾ PerfusionPerfusion (Cardiac(Cardiac Output)Output) willwill suffersuffer toto maintainmaintain BPBP –– i.e.i.e. vasoconstrictionvasoconstriction BodyBody MaintainsMaintains BloodBlood PressurePressure HemorrhagicHemorrhagic ShockShock

¾¾ HemorrhageHemorrhage isis thethe mostmost commoncommon causecause ofof shockshock inin thethe injuredinjured patientpatient ¾¾ ResuscitationResuscitation requires:requires:

z RapidRapid hemostasishemostasis

z AppropriateAppropriate fluidfluid replacementreplacement ¾¾ ResuscitationResuscitation isis completecomplete when:when:

z OxygenOxygen debtdebt isis repaidrepaid

z TissueTissue acidosisacidosis isis eliminatedeliminated

z NormalNormal aerobicaerobic metabolismmetabolism isis restoredrestored inin allall tissuetissue bedsbeds BloodBlood LossLoss

¾¾ InitialInitial signssigns -- ↑↑HR,HR, ↓↓PP,PP, ↓↓capilcapil refillrefill

z BetaBeta blockers,blockers, cardiaccardiac reserve,reserve, athletesathletes ¾¾ PulsePulse PressurePressure == sBPsBP –– dBPdBP ¾¾ DecreasedDecreased sBPsBP

z ↓↓ sBPsBP withwith contractility,contractility, fluidsfluids

z ↓↓ sBPsBP withwith ↓↓ StrokeStroke VolumeVolume ¾¾ IncreasedIncreased dBPdBP

z ↓↓ dBPdBP fromfrom vasoconstrictionvasoconstriction BloodBlood LossLoss withwith InjuryInjury TypeType

¾¾ LongLong bonebone fxfx –– assumeassume substantialsubstantial bloodblood lossloss ¾¾ ScalpScalp lacerationslacerations –– bleedbleed aa lotlot ¾¾ PelvicPelvic instabilityinstability oror distendeddistended abdomenabdomen –– assumeassume bleedingbleeding inin retroperitoneumretroperitoneum oror abdominalabdominal cavitycavity ¾¾ PenetratingPenetrating traumatrauma –– purepure bloodblood lossloss ¾¾ BluntBlunt traumatrauma –– mimicsmimics septicseptic shockshock moremore thanthan hypovolemichypovolemic ((↓↓ SVR)SVR) BloodBlood LossLoss ClassesClasses

Class I Class II Class III Class IV mL Loss < 750 750-1500 1500-2000 > 2000 % Loss < 15% 15-30% 30-40% > 40% HR < 100 >100 >120 >140 BP Normal Normal ↓↓ ↓↓ PP - or ↑↑ ↓↓ ↓↓ ↓↓ Fluids Xloid Xloid Xloid + B Xloid + B

BloodBlood LossLoss ClassesClasses

¾ VSVS areare NOTNOT thethe mostmost sensitivesensitive indicatorsindicators ofof fluidfluid lossloss ¾ EndEnd--OrganOrgan perfusionperfusion parametersparameters (UOP,(UOP, mentationmentation,, skinskin signs)signs) areare betterbetter indicatorsindicators ¾ Class/VolumeClass/Volume ofof BloodBlood LossLoss isis NOTNOT usedused toto determinedetermine resuscitationresuscitation ¾ However,However, failurefailure ofof parametersparameters toto returnreturn toto normalnormal shouldshould causecause suspicionsuspicion ofof ongoingongoing losseslosses ¾ ResponseResponse toto initialinitial fluidfluid resuscitationresuscitation isis usedused toto determinedetermine planplan ofof actionaction………… Rapid Transient No Response Response Response VS Return to Transient Remain Normal improvement; abnormal recurrence of ↓ BP and ↑ HR EBL Minimal Moderate and Severe ongoing Need for More Low High High Xloid Need for Blood Low Mod to High Immediate

Blood Prep Type & Cross Type-specific Emerg blood release

Need for OR Possibly Likely Highly likely InitialInitial ResuscitationResuscitation

¾¾ AdministerAdminister 2L2L ofof isotonicisotonic xloidxloid ASAPASAP

z NS,NS, LR,LR, PlasmalytePlasmalyte

z NSNS cancan causecause hyperchloremichyperchloremic acidosisacidosis

¾¾ RapidRapid RespondersResponders

z CompleteComplete resuscitationresuscitation

z NoNo evidenceevidence ofof ongoingongoing fluid/bloodfluid/blood lossloss

z NoNo perfusionperfusion deficitsdeficits LessLess FavorableFavorable ResponsesResponses

¾¾ DegreeDegree ofof instabilityinstability dependsdepends on:on:

z OngoingOngoing losseslosses

z AbilityAbility toto compensatecompensate ¾¾ Remember,Remember, BPBP cancan bebe misleadingmisleading…….. ¾¾ Remember,Remember, HR,HR, BP,BP, PP,PP, UOPUOP cancan underestimateunderestimate bloodblood lossloss ¾¾ KeepKeep lookinglooking atat THETHE WHOLEWHOLE PICTUREPICTURE TransientTransient RespondersResponders

¾¾ TheseThese patientspatients showshow anan initialinitial responseresponse andand thenthen showshow signssigns ofof ongoingongoing lossloss andand perfusionperfusion deficitsdeficits ¾¾ ClassClass IIII oror IIIIII hemorrhagehemorrhage OROR cancan bebe duedue toto aa bleedbleed withwith aa rebleedrebleed ¾¾ GiveGive fluidsfluids andand looklook forfor losseslosses ¾¾ ConsiderConsider earlyearly bloodblood transfusiontransfusion NonNon--RespondersResponders

¾¾ DueDue toto aa lifelife--threateningthreatening hemorrhagehemorrhage ¾¾ GoalGoal isis toto findfind thethe sitesite ofof fluidfluid losseslosses ¾¾ AllAll thesethese patientspatients requirerequire bloodblood transfusionstransfusions ¾¾ NeedNeed toto administeradminister uncrossmatcheduncrossmatched bloodblood ResuscitationResuscitation Strategies/MonitoringStrategies/Monitoring FluidFluid ResuscitationResuscitation

¾¾ StandardStandard ofof CareCare == CrystalloidCrystalloid

z CanCan findfind studiesstudies usingusing colloids,colloids, hypertonichypertonic

z NoneNone ofof thesethese ↑↑OO2 carryingcarrying capacitycapacity

z HemodilutionHemodilution –– cancan worsenworsen DODO2

z FluidFluid OverloadOverload -- ↓↓ cardiaccardiac performanceperformance ¾¾ BloodBlood TransfusionsTransfusions

z OnlyOnly fluidfluid thatthat ↑↑OO2 carryingcarrying capacitycapacity CrystalloidCrystalloid ((XloidXloid))

¾¾ 3:13:1 RuleRule

z RoughRough estimateestimate –– replacereplace 33 mLmL ofof crystalloidcrystalloid forfor eacheach mLmL ofof bloodblood lossloss ¾¾ NaNa+ levelslevels + ++ z LRLR == 130;130; alsoalso hashas KK ,, CaCa ,, lactatelactate

z NSNS == 154154 Hypertonic/Hypertonic/DextranDextran

¾¾ HypertonicHypertonic (3%,(3%, 7.5%7.5% saline)saline) causescauses fluidfluid shiftshift fromfrom ISIS andand ICIC toto IVIV

z IntracellularIntracellular dehydrationdehydration ¾¾ DextranDextran (large(large glucoseglucose molecule)molecule) –– maintainsmaintains IVIV volumevolume

z RiskRisk ofof rebleedingrebleeding,, shortshort--livedlived ¾¾ WatchWatch fluidfluid overloadoverload –– espesp elderlyelderly ¾¾ MoreMore effectiveeffective withwith TBITBI ColloidsColloids

¾¾ Albumin,Albumin, hespanhespan ¾¾ IncreasedIncreased osmoticosmotic pullpull intointo thethe IVIV spacespace

z ColloidColloid osmoticosmotic pressurepressure (COP)(COP) ¾¾ QuestioningQuestioning researchresearch resultsresults

z HespanHespan maymay reducereduce reperfusionreperfusion injuryinjury

z AlbuminAlbumin –– helpful,helpful, nono effect,effect, harmfulharmful DoDo wewe needneed fluids?fluids?

¾¾ ““PermissivePermissive HypotensionHypotension””

z StudiedStudied mostlymostly withwith penetratingpenetrating traumatrauma ¾¾ LargeLarge fluidfluid resuscitationsresuscitations

z CauseCause hemodilutionhemodilution

z PreventPrevent clotclot formationformation ¾¾ TBI:TBI: hypotensionhypotension doublesdoubles mortalitymortality ¾¾ Elderly:Elderly: lowlow cardiaccardiac reservereserve……...... ischemia..ischemia……deathdeath WhatWhat areare bestbest indicatorsindicators forfor bloodblood transfusion?transfusion? ¾¾ PersistentPersistent tissuetissue hypoxiahypoxia despitedespite fluidfluid resuscitationresuscitation ¾¾ SignificantSignificant metabolicmetabolic acidosis,acidosis, eveneven ifif BPBP isis stablestable

z EspeciallyEspecially ifif acidosisacidosis persistspersists afterafter fluidsfluids

¾¾ SVOSVO2 oror CVOCVO2 << 55%55% HctHct isis NOTNOT aa usefuluseful indicatorindicator

¾¾ HematocritHematocrit == %% ofof rbcrbc toto circulatingcirculating volumevolume ¾¾ AcuteAcute bleedsbleeds –– loselose cellscells andand volumevolume equallyequally

z MayMay maintainmaintain normalnormal HctHct ¾¾ BetterBetter toto useuse serialserial HctsHcts thanthan absoluteabsolute ¾¾ IfIf HctHct isis lowlow –– tellstells youyou somethingsomething ¾¾ IfIf HctHct isis normalnormal –– tellstells youyou veryvery littlelittle ¾¾ TimeTime delaydelay ofof lablab proceduresprocedures PlateletsPlatelets

¾¾ NonNon--Trauma:Trauma: pltplt ofof 20,00020,000 isis sufficientsufficient toto preventprevent spontaneousspontaneous bleedingbleeding ¾¾ Trauma:Trauma: considerconsider ifif pltplt << 100,000100,000 oror evidenceevidence ofof ongoingongoing bleedingbleeding ¾¾ LessLess predictablepredictable isis plateletplatelet FUNCTIONFUNCTION ¾¾ PatientPatient historyhistory –– ASA,ASA, NSAIDSNSAIDS ¾¾ CHI:CHI: increasedincreased riskrisk ofof bleedsbleeds duedue toto damageddamaged neuralneural tissuetissue FFPFFP

¾¾ FreshFresh FrozenFrozen PlasmaPlasma == coagulationcoagulation factorsfactors ¾¾ TransfusionsTransfusions depletedeplete coagulationcoagulation factorsfactors ¾¾ PatientsPatients withwith decreaseddecreased hepatichepatic functionfunction –– cancan’’tt mobilizemobilize additionaladditional coagulationcoagulation factorsfactors ¾¾ IfIf 1010 unitsunits ofof PRBCsPRBCs –– coagulationcoagulation becomesbecomes paramountparamount (not(not proven,proven, intuitive)intuitive) HypothermiaHypothermia

¾¾ OngoingOngoing ConcernConcern withwith TraumaTrauma

z InjuryInjury SiteSite –– airair temp,temp, ““wetwet”” areaarea

z NosocomialNosocomial –– roomroom temp,temp, coldcold fluidsfluids ¾¾ Prevention:Prevention:

z WarmingWarming lights,lights, HuggyHuggy Bear,Bear, ThermostatThermostat

z KeepKeep bodybody andand headhead coveredcovered

z FluidFluid warmerswarmers –– warmwarm toto 3939 degreesdegrees ¾¾ ActiveActive RewarmingRewarming –– PD,PD, CTsCTs,, ventsvents HypothermiaHypothermia

¾¾ DeadlyDeadly TriadTriad

z HypothermiaHypothermia

z AcidosisAcidosis

z CoagulopathyCoagulopathy ¾¾ DecreasedDecreased cellularcellular oxygenoxygen extractionextraction ¾¾ DecreasedDecreased cardiaccardiac contractilitycontractility ¾¾ DecreasedDecreased plateletplatelet functionfunction ¾¾ TBITBI ptspts benefitbenefit fromfrom hypothermiahypothermia EndpointsEndpoints ofof ResuscitationResuscitation

¾¾ Problem:Problem: ““adequateadequate resuscitationresuscitation”” stillstill leavesleaves occultoccult hypoperfusionhypoperfusion andand ongoingongoing tissuetissue acidosisacidosis (compensated(compensated shock)shock) ¾¾ TraditionalTraditional markersmarkers underestimateunderestimate resuscitation:resuscitation: HR,HR, BP,BP, PP,PP, UOPUOP ¾¾ LookLook atat acidosis,acidosis, oxygenoxygen extraction,extraction, endend organorgan functionfunction ResuscitationResuscitation EndEnd--PointsPoints

¾¾ GlobalGlobal

z CardiacCardiac volumesvolumes andand indexesindexes –– EDV,EDV, LVSWILVSWI

z ExtractionExtraction valuesvalues –– SVOSVO2 z BaseBase deficitdeficit

z LactateLactate ¾¾ RegionalRegional

z pHipHi

z SkeletalSkeletal BaseBase DeficitDeficit

¾¾ ABGABG statesstates eithereither ““deficitdeficit”” oror ““excessexcess”” ¾¾ ReflectsReflects TOTALTOTAL bufferingbuffering systemsystem ofof thethe bloodblood (HCO(HCO3 isis onlyonly ½½ thethe total)total) –– amountamount ofof bufferingbuffering neededneeded forfor systemicsystemic acidosisacidosis ¾¾ pHpH levellevel isis lessless specificspecific becausebecause itit includesincludes compensationcompensation effectseffects ¾¾ BicarbBicarb levelslevels correlatecorrelate withwith basebase deficitdeficit LactateLactate

¾¾ ProducedProduced fromfrom anaerobicanaerobic metabolismmetabolism ¾¾ TimeTime toto normalizenormalize lactatelactate levelslevels alsoalso showsshows prognosticprognostic valuevalue ¾¾ NormalNormal hepatichepatic functionfunction metabolizesmetabolizes lactatelactate inin LR;LR; LRLR doesdoes notnot causecause lacticlactic acidosisacidosis pHipHi

¾¾ IntramucosalIntramucosal pHpH (not(not gastricgastric pH)pH) ¾¾ MucusMucus--producingproducing cellscells inin gutgut areare veryvery oxygenoxygen dependentdependent

z DecreasedDecreased oxygenoxygen deliverydelivery causescauses increasedincreased acidosisacidosis

z CanaryCanary testtest –– firstfirst signsign ofof hypoperfusionhypoperfusion ¾¾ EAST:EAST: earlyearly indicatorindicator ofof complicationscomplications ¾¾ RequiresRequires specializedspecialized NGNG tubetube NewerNewer MeasurementsMeasurements

¾¾ TranscutaneousTranscutaneous OO2 andand COCO2 levelslevels z COCO2 usedused asas markermarker ofof cellularcellular metabolismmetabolism endend--productproduct ¾¾ IntramuscularIntramuscular measuresmeasures

¾¾ SublingualSublingual COCO2 ¾¾ NearNear infraredinfrared spectroscopyspectroscopy

z SimultaneousSimultaneous measurementmeasurement ofof pH,pH, pO2,pO2, pCOpCO2 z AlsoAlso showsshows mitochondrialmitochondrial functionfunction EASTEAST –– 20032003 RecomemdationsRecomemdations

¾ LevelLevel 11

z Standard hemodynamic parameters are not adequate

z Supranormal DO2 correlates with survival* ¾ LevelLevel 22

z Time to normalization of base deficit, pHi, lactate is predictive

z Persistently high base deficit or pHi may indicate complications

z Base deficit predictive value is altered with alcoholics, hyperchloremic metabolic acidosis ThankThank youyou

Questions?Questions?