危重兒液體管理

FluidandElectrolyteEmergenciesinCriticallyIllChildren

RichardT.Blaszak,M.D.StephenM.Schexnayder,M.D.Objectives Attheendofthispresentationlearnerswillbeableto:1)Recognizecommonfluidandelectrolytedisordersincriticallyillchildren2)Listadiagnosticstrategyforthesedisorders3)ApplyappropriatemanagementprinciplesCaseStudy#1HPI:

A3month-oldisinthePICUforshockfollowingatwodayhistoryoffeverandirritability.BloodandCSFculturesarepositiveforStreptococcuspneumoniae.Hospitalcourse:

Decreasingurineoutput(<0.5ml/kg/hr)overthelast24hours.CaseStudy#1

Whatisyourdifferentialdiagnosis?

Whatdiagnosticstudieswouldyouorder?CaseStudy#1

DifferentialdiagnosisOliguria1)Pre-Renal(decreasedeffectiverenalbloodflow)Diminishedintravascularvolume,cardiacdysfunction,vasodilitation2)Post-RenalOutletobstruction(intrinsicvs.extrinsic),foleycatheterocclusion3)RenalAcutetubularnecrosis,acuterenalfailure,SIADH,...CaseStudy#1

LaboratorystudiesSerumstudiesSodium126mEq/L BUN4mg/dLChloride98mEq/L Creatinine0.4mg/dLPotassium3.7mEq/L Glucose129mg/dLBicarbonate25mEq/L Osmolality260mosmol/kgUrinestudiesSpecificgravity1.025 Sodium58mEq/LOsmolality645mosmol/kg FeNa2.4%Whataretheprimaryabnormalities?CaseStudy#1

LaboratorystudiesMajorabnormalities

1)Hyponatremia 2)Oliguria(inappropriatelyconcentratedurine)

Whatisthemostlikelyexplanationforthesefindings?CaseStudy#1

SyndromeofInappropriateAntidiureticHormone(SIADH)VariableetiologyTraumaInfectionPsychosisMalignancyMedicationsDiabeticketoacidosisCNSdisordersPositivepressureventilation“Stress”CaseStudy#1

SIADHManifestationsBydefinition,“inappropriate”implieshavingexcludednormalphysiologicreasonsforreleaseofADH:1)Inresponsetohypertonicity.2)Inresponsetolifethreateninghypotension.HyponatremiaOliguriaConcentratedurineelevatedurinespecificgravity“inappropriately”highurineosmolalityinfaceofhyponatremiaNormaltohighurinesodiumexcretionCaseStudy#1

SIADHDiagnosisCriticallevelofsuspicion.Demonstrationofinappropriatelyconcentratedurineinfaceofhyponatremiaurineosmolality,SG,urinesodiumexcretion(FeNa)BecertaintoexcludenormalphysiologicreleaseofADH

FrequentlysecondarytodecreasedperfusionSerumsodium,urineosmolality,urinesodiumexcretion(lowFeNa)consistentwithdehydrationordiminishedrenalbloodflow.Lookatpatientmoreclosely!!CaseStudy#1

SIADHTreatmentFluidrestriction.50-75%ofmaintenancerequirements,becertaintoincludeoralintake.Dailyweights.CaseStudy#1

Thesagacontinues….Hospitalcourse:

Fourhoursafterbeginningfluidrestriction,youarecalledbecausethepatientishavingageneralizedseizure.ThereisnoresponsetotwodosesofIVlorazepam(Ativan?)andaloadingdoseoffosphenytoin(Cerebyx?)Whatisthemostlikelyexplanation?CaseStudy#1

ThesagacontinuesSeizure

1)Worseninghyponatremia 2)Intracranialevent 3)Meningitis 4)Otherelectrolytedisturbance 5)Medication 6)Hypertension Whatdiagnosticstudieswouldyouorder?

CaseStudy#1

ThesagacontinuesStatlabs: Sodium117mEq/L Whatwouldyoudonow?

CaseStudy#1

HyponatremicseizureTreatmentHypertonicsaline(3%NaCl)infusionTocorrectsodiumto125mEq/L,thedeficitisequalto(0.6)(weight[kg])(125-measuredsodium)(0.6)(8)(125-117) =38.4mEqBecausepatientissymptomaticwithseizures,immediatelyincreaseserumsodiumby5mEq/LmEqsodium=(0.6)(8kg)(5)=24mEq3%NaCl=0.5mEq/L,therefore24mEqbolus=48mls,followedbyslowinfusionofremaining14.4mEq(29mls)overnextseveralhoursCaseStudy#2HPI:

A5month-oldgirlpresentswithaonedayhistoryofirritabilityandfever.Motherreportsthreedaysof“bad”vomitinganddiarrhea.Homemeds:AcetaminophenandibuprofenforfeverPE:

BP70/40,HR200,R60,T38.3C.Irritable,sunkeneyesandfontanelle,skinfeelslikePillsburyDoughBoyCaseStudy#2

NoonecanobtainIVaccessafter15minutes,whatwouldyoudonow?

CaseStudy#2PlaceintraosseouslineBolus40ml/kgofisotonicsaline Reassessment(HR170,RR40,BP75/40)Serumstudies Sodium164mEq/L BUN75mg/dL Chloride139mEq/L Creatinine3.1mg/dL Potassium5.5mEq/L Glucose101mg/dL Bicarbonate12mEq/L pH7.07 pCO211 pO2121 HCO38 CaseStudy#2

Whatisthemostlikelyexplanationofthispatientsacidosis?CaseStudy#2

MetabolicacidosisandtheaniongapAnionGap

Sodium-(chloride+bicarbonate) Normal12+/-2meq/L Elevatedaniongapconsistentwithexcessacid Normalaniongapconsistentwithexcesslossofbase

164-(139+12)=131.Normalgap2.IncreasedgapRenal“HCO3” losses2.GI“HCO3”lossesProximalRTADistalRTA

Diarrhea1.Acidprod2.AcideliminationLactateDKAKetosisToxins

AlcoholsSalicylatesIronRenaldiseaseCaseStudy#2

MetabolicacidosisandtheaniongapCaseStudy#3HPI:Afiveyearold(18kg)boywasinvolvedinaamotorvehicleaccidenttwodaysago.Hesustainedanisolatedheadinjurywithintraventricularhemorrhageandmultiplelargecerebralcontusions.Threehoursago,hehadanepisodeofsevereintracranialhypertension(ICP90mmHg,MAP50mmHg,requiringvolumeplusepinephrineinfusionforhypotension.Overthelasttwohours,hisurineoutputhasincreasedto130-150ml/hour(~8ml/kg/hr).Whatisyourdifferentialdiagnosis?Whattestwouldyouorder?CaseStudy#3

DifferentialdiagnosisPolyuria1)Centraldiabetesinsipidus

DeficientADHsecretion(idiopathic,trauma,pituitarysurgery,hypoxic ischemicencephalopathy)2)Nephrogenicdiabetesinsipidus

RenalresistancetoADH(X-linkedhereditary,chroniclithium,hypercalcemia,...)3)Primarypolydipsia(psychogenic)

Primaryincreaseinwaterintake(psychiatric),occasionally hypothalamiclesionaffectingthirstcenter4)Solutediuresis

Diuretics(lasix,mannitol,..),glucosuria,highproteindiets,post-obstructive uropathy,resolvingATN,….CaseStudy#3

LaboratorystudiesSerumstudiesSodium155mEq/L BUN13mg/dLChloride114mEq/L Creatinine0.6mg/dLPotassium4.2mEq/L Glucose86mg/dLBicarbonate22mEq/L Serumosmolality:320mosmol/kgOtherUrinespecificgravity1.005,noglucose.Urineosmolality:160mosmol/kgWhatarethemainabnormalities?CaseStudy#3

LaboratorystudiesMajorabnormalities 1)Hypernatremia 2)Polyuria(inappropriatelydiluteurine)Whatisthemostlikelyexplanation?CaseStudy#3

DiabetesInsipidusDiagnosis CentralDiabetesinsipidus

1)Polyuria 2)Inappropriatelydiluteurine(urineosmolality<serum osmolality)

Maybeseewithmidlinedefects Frequentlyoccursinbraindeadpatients

Whatshouldyoudototreatthischild?CaseStudy#3

DiabetesInsipidusTreatment

Acute:Vasopressininfusion-beginwith0.5milliunits/kg/hour,doubleevery15-30minutesuntilurineflowcontrolledChronic:DDAVP(desmopressin)WarningCloselymonitorfordevelopmentofhyponatremiaCaseStudy#4HPI:

Asixyearold,25kg,boywithsevereasthma(S/PECMOforapreviousexacerbation)presentswithatwodayhistoryofseverevomitinganddiarrheatotheEmergencyDepartment.Homemeds:AlbuterolMDItwopuffsQID,SalmeterolMDItwopuffsBID,Prednisone10mgdaily,Fluticasone220mcgtwopuffsBIDPE:

BP70/40,HR168,R40,T39.0C.Heisverylethargic(GCS11).Poorperfusionwithcoolextremities,mottling,anddelayedcapillaryrefill,otherwisenospecificsystemabnormalities.CaseStudy#4

Whatisyourdifferentialdiagnosis?

Whatdiagnosticstudieswouldyouorder?CaseStudy#4

DifferentialdiagnosisShock1)Cardiogenic Myocarditis

Pericardialeffusion2)Hypovolemic Hemorrhage,excessiveGIlosses,“3rdspacing”(burns,sepsis)3)Distributive Sepsis,anaphylaxisCaseStudy#4

LaboratorystudiesSerumstudiesSodium130mEq/L BUN43mg/dLChloride99mEq/L Creatinine0.6mg/dLPotassium5.7mEq/L Glucose48mg/dLBicarbonate12mEq/LOtherWBC:13k(60%P,30%L),HCT35%,PLT223kChestradiograph:noabnormalitiesWhataretheelectrolyteabnormalities?CaseStudy#4

DiagnosisMajorabnormalities

1)Hyponatremicdehydration 2)Hypoglycemia 3)Hyperkalemia,mild 4)Acidosis 5)AzotemiaWhatisthemostlikelyexplanationforthesefindings?CaseStudy#4

AdrenalInsufficiency1oadrenalinsufficiency

(Addison’sdisease)Adrenalglanddestruction/dysfunction(ie.autoimmune,hemorrhagic)mostcommonininfants5-15daysold2ndadrenalinsufficiency

ACTHdeficiency(ie.panhypopituitarismorisolatedACTH)“Tertiary”or“iatrogenic”

Suppressionofhypothalamic-pituitary-adrenalaxis(ie.chronicsteroiduse)CaseStudy#4

AdrenalInsufficiencyManifestationsMajorhormonalfactorprecipitatingcrisisismineralcorticoiddeficiency,notglucocorticoid.Dehydration,hypotension,shockoutofproportiontoseverityofillnessNausea,vomiting,abdominalpain,weakness,tiredness,fatigue,anorexiaUnexplainedfeverHypoglycemia(morecommoninchildrenandtertiary)Hyponatremia,hyperkalemia,azotemiaCaseStudy#4

AdrenalInsufficiencyDiagnosisCriticallevelofsuspicioninallpatientswithshock1)DemonstrationofinappropriatelylowcortisolsecretionBasalmorninglevelvs.random“stress”level2)DeterminewhethercortisoldeficiencydependentorindependentofACTHsecretion.ACTH,

cortisol

1oadrenalinsufficiencyACTH,cortisol

2ndortertiaryinsufficiency3)SeekatreatablecauseCaseStudy#4

AdrenalInsufficiencyWhatshouldyoudototreatthischild?CaseStudy#4

AdrenalInsufficiencyTreatmentDonotwaitforconfirmatorylabsFluidresuscitation-isotoniccrystalloidTreathypoglycemiaGlucocorticoidreplacement-hydrocortisoneinstressdoses-25-50mg/m2(1-2mg/kg)IVConsider

mineralocorticoid(Florinef?)CaseStudy#5 HPI:Aneightmontholdinfantwithautosomalrecessivepolycystickidneydiseasepresentswithirritability.Sheisonnightlyperitonealdialysisathome.Thelabcallsapanicpotassiumvalueof7.1meq/L.Thetechsaysitisnothemolyzed.Whatdoyoudonow?CaseStudy#5

HyperkalemiaTreatmentImmediatelyrepeatserumpotassium.DonotwaitforconfirmatorylabsespeciallyifEKGchangespresent.AnticipatoryStoppotassiumadministrationincludingfeedsCardiacMonitorWhatisthisrhythm?Whatisyourimmediatetreatment?CaseStudy#5

HyperkalemiaTreatment(cont)ControleffectsAntagonismofmembraneactionsofpotassiumCalciumchloride10-20mg/kgover5minutes;mayrepeatx2ShiftpotassiumintracellularlyGlucose1gm/kgplus0.1unit/kgregularinsulinAlkalinize(increaseventilatorrate;Sodiumbicarbonate1mEq/kgIV)Inhaled2adrenergicagonist(albuterol)RemovalofpotassiumfromthebodyLoop/thiazidediureticsCationexchangeresin:sodiumpolstyrenesulfonate(Kayexelate?)1gm/kgPOorPR(orboth)DialysisCaseStudy#6 HPI:Athreeyear