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; 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