血?dú)夥治?英文版

APracticalApproachtoAcid-BaseDisordersBinDU,MDMedicalIntensiveCareUnitPekingUnionMedicalCollegeHospitalPrimaryAcid-BaseDisordersVariablePrimaryDisorderNormalRange,ArterialGasPrimaryDisorderpHAcidemia7.35–7.45AlkalemiaPCO2,mmHgRespiratoryalkalosis35–45RespiratoryacidosisHCO3,mmol/LMetabolicacidosis22–26MetabolicalkalosisRulesofThumbforRecognizingPrimaryAcid-BaseDisordersWithoutUsingaNomogramRule1LookatthepH.Whicheversideof7.40thepHison,theprocessthatcausedittoshifttothatsideistheprimaryabnormality.Principle:Thebodydoesnotfullycompensateforprimaryacid-basedisordersSimpleAcid-BaseDisordersAcuteRespiratoryAlkalosisArterialGasValueInterpretationpHPCO2*HCO37.5029mmHg22mmol/LAlkalemiaRespiratoryalkalosisNormalHCO3CausesAnxietyHypoxiaLungdiseasewithorwithouthypoxiaCentralnervoussystemdiseaseDruguse–salicylates,catecholamins,progesteronePregnancySepsisHepaticencephalopathyMechanicalventilation*ThisistheprimaryabnormalityAcuteRespiratoryAcidosisArterialGasValueInterpretationpHPCO2*HCO37.2560mmHg26mmol/LAcidemiaRespiratoryacidosisNormalHCO3CausesCentralnervoussystem(CNS)depression–drugs,CNSeventNeuromusculardisorders–myopathies,neuropathiesAcuteairwayobstruction–upperairway,laryngospasm,bronchospasmSeverepneumoniaorpulmonaryedemaImpairedlungmotion–hemothorax,pneumothoraxThoraciccageinjury–flailchestVentilatordysfunction*ThisistheprimaryabnormalityChronicRespiratoryAcidosisWithMetabolicCompensationArterialGasValueInterpretationpHPCO2*HCO37.3460mmHg31mmol/LRespiratoryacidosisMetaboliccompensationCausesChroniclungdisease–obstructiveorrestrictiveChronicneuromusculardisordersChronicrespiratorycenterdepression–centralhypoventilation*ThisistheprimaryabnormalityTheImportanceofDifferentiatingAcuteFromChronicRespiratoryAcidosisAcuterespiratoryacidosisMedicalemergencyrequiringemergentintubationandmechanicalventilationChronicrespiratoryacidosisOftenaclinicallystableconditionMetabolicAcidosisWithRespiratoryCompensationArterialGasValueInterpretationpHPCO2HCO3*7.5048mmHg36mmol/LAlkalemiaRespiratorycompensationMetabolicalkalosisCausesUrinaryChlorideLevelLowUrinaryChlorideLevelNormalorHighVomiting,nasogastricsuctionDiureticuseinpastPosthypercapniaExcessmineralocorticoidactivity–Cushing’ssyndrome,Conn’ssyndrome,exogenoussteroids,licoriceingestion,increasedreninstates,Bartter’ssyndromeCurrentorrecentdiureticuseExcessalkaliadministrationRefeedingalkalosis*ThisistheprimaryabnormalityImportanceofUrinaryChlorideLevelinMetabolicAlkalosisLowurinarychloridelevelDecreasedECFOrposthypercapnicstateNormalorhighurinarychloridelevelNormalorincreasedECFOrrecentdiureticuseUrinarychloridelevel=preferredmethodforassessingtherenalresponsetocirculatingvolumeinpatientswithmetabolicalkalosisUrinarysodiumlevel=lessreliableasaguideMetabolicAcidosisWithRespiratoryCompensationArterialGasValueInterpretationpHPCO2HCO3*7.2021mmHg8mmol/LAcidemiaRespiratorycompensationMetabolicacidosisAniongap=sodium–chloride－bicarbonateNormal=122(SD)mmol/LCausesNonanionGapAnionGapGIbicarbonateloss–Diarrhea–UreteraldiversionsHydrochloricadministrationPosthypocapniaGI=gastrointestinalRenalbicarbonateloss–Renaltubularacidosis–Earlyrenalfailure–Carbonicanhydraseinhibitors–AldosteroneinhibitorsKetoacidosis–Diabetic–AlcoholicRenalfailureLacticacidosisRhabdomyolysisToxins–Methanol–Ethyleneglycol–Paraldehyde–Salicylates*ThisistheprimaryabnormalityMixedAcid-BaseDisordersABGInterpretationABGpH7.49,PCO247mmHg,HCO335mmol/L,Na139mmol/L,K3mmol/L,Cl89mmol/LInterpretationSimplemetabolicalkalosiswithcompensatoryrespiratoryacidosis? orMixedmetabolicalkalosisandrespiratoryacidosis?SummaryofExpectedCompensationforSimpleAcid-BaseDisordersPrimarydisorderInitialchemicalchangeCompensatoryresponseExpectedrangeofcompensationMetabolicacidosisHCO3decreasePCO2decreasePCO2=1.5(HCO3)+8

2PCO2=lasttwodigitsofpH

PCO2=1–1.3(

HCO3)MetabolicalkalosisHCO3increasePCO2increasePCO2:variableincreasePCO2=0.9(HCO3)+9

PCO2=0.6(

HCO3)SummaryofExpectedCompensationforSimpleAcid-BaseDisordersPrimarydisorderInitialchemicalchangeCompensatoryresponseExpectedrangeofcompensationRespiratoryacidosisPCO2increaseHCO3increaseAcute(H+)=0.8(PCO2)

HCO3=PCO2/10Chronic(H+)=0.3(PCO2)

HCO3=3.5xPCO2/10RespiratoryalkalosisPCO2decreaseHCO3decreaseAcute(H+)=0.8(PCO2)

HCO3=2xPCO2/10Chronic(H+)=0.17(PCO2)

HCO3=5xPCO2/10ABGInterpretationABGpH7.40,PCO240mmHg,HCO324mmol/L,Na139mmol/L,K4mmol/L,Cl105mmol/LCalculationAG=139–105–24=10InterpretationnormalABGInterpretationABGpH7.49,PCO247mmHg,HCO335mmol/L,Na139mmol/L,K3mmol/L,Cl89mmol/LCalculationAG=139–89–35=15

PCO2=0.6(

HCO3)=0.6x11=6.6mmHgInterpretationSimplemetabolicalkalosisABGInterpretationABGpH7.45,PCO225mmHg,HCO317mmol/L,Na139mmol/L,K3.5mmol/L,Cl107mmol/LCalculationAG=139–107–17=15

HCO3=2(

PCO2/10)=2x15/10=3mmHgInterpretationSimplerespiratoryalkalosis?ABGInterpretationABGpH7.65,PCO230mmHg,HCO332mmol/L,Na139mmol/L,K2.8mmol/L,Cl92mmol/LCalculationAG=139–92–32=15

HCO3=2(

PCO2/10)=2x10/10=2mmHgInterpretationMixedmetabolicandrespiratoryalkalosisABGInterpretationABGpH7.67,PCO230mmHg,HCO334mmol/L,Na140mmol/L,K3mmol/L,Cl94mmol/LCalculationAG=140–94–34=12

HCO3=2(

PCO2/10)=2x10/10=2mmHgInterpretationMixedmetabolicandrespiratoryalkalosisABGInterpretationABGpH7.61,PCO230mmHg,HCO329mmol/L,Na140mmol/L,K3mmol/L,Cl94mmol/LCalculationAG=140–94–29=17

HCO3=2(

PCO2/10)=2x10/10=2mmHgInterpretationMixedmetabolicandrespiratoryalkalosisandlacticacidosisABGInterpretationABGpH7.33,PCO270mmHg,HCO336mmol/L,Na140mmol/L,K4.0mmol/L,Cl94mmol/LCalculationAG=140–94–36=10

HCO3=3.5(

PCO2/10)=3.5x30/10=10.5mmHgInterpretationSimplechronicrespiratoryacidosisABGInterpretationABGpH7.40,PCO267mmHg,HCO340mmol/L,Na140mmol/L,K3.5mmol/L,Cl90mmol/LCalculationAG=140–90–40=10

HCO3=3.5(

PCO2/10)=3.5x27/10=9.5mmHgInterpretationMixedrespiratoryacidosisandmetabolicalkalosisABGInterpretationABGpH7.11,PCO216mmHg,HCO35mmol/L,Na140mmol/L,K4.5mmol/L,Cl125mmol/LCalculationAG=140–125–5=10

PCO2=11mmHgInterpretationSimplehyperchloremicmetabolicacidosisABGInterpretationABGpH7.11,PCO216mmHg,HCO35mmol/L,Na140mmol/L,K4.0mmol/L,Cl105mmol/LCalculationAG=140–105–5=30

PCO2=11mmHgInterpretationSimplehighAGmetabolicacidosisABGInterpretationABGpH7.11,PCO216mmHg,HCO35mmol/L,Na140mmol/L,K4.0mmol/L,Cl115mmol/LCalculationAG=140–115–5=20

PCO2=11mmHgInterpretationMixedhyperchloremicandhighAGmetabolicacidosisIsThereASimpleWay?MixedAcid-BaseDisordersABGpH7.32,PCO228mmHg,HCO314mmol/L,BUN100mmol/LInterpretationAcidemicwithlowPCO2andlowbicarbonateconcentrationLowbicarbonateasaprimarydisorder–metabolicacidosis(secondarytorenalfailure)PaCO2<30inthepresenceoflowHCO3–primaryrespiratoryalkalosisPaCO2<30inthepresenceoflowHCO3–primaryrespiratoryalkalosisMixedAcid-BaseDisorders?ABGpH7.12,PCO288mmHg,HCO328mmol/LInterpretationAcidemicwithhighPCO2andhighbicarbonateconcentrationHighPCO2asaprimarydisorder–respiratoryacidosis(secondarytocorpulmonale)HCO3>30inthepresenceofacutelyelevatedPCO2–primarymetabolicalkalosisHCO3>45inthepresenceofchronicallyelevatedPCO2–primarymetabolicalkalosisHCO3>30inthepresenceofacutelyelevatedPCO2orHCO3>45inthepresenceofchronicallyelevatedPCO2–primarymetabolicalkalosisMixedAcid-BaseDisorders?ABGpH7.50,PCO238mmHg,HCO331mmol/L,K3.5mmol/LInterpretationAlkalemicwithlowPCO2andhighbicarbonateconcentrationHighHCO3asaprimarydisorder–metabolicalkalosisPCO2>55inthepresenceofelevatedHCO3–primaryrespiratoryalkalosisPCO2>55inthepresenceofelevatedHCO3–primaryrespiratoryacidosisMixedAcid-BaseDisorders?ABGpH7.48,PCO229mmHg,HCO323mmol/LInterpretationAlkalemicwithlowPCO2andnormalbicarbonateconcentrationLowPCO2asaprimarydisorder–respiratoryalkalosis(secondarytoasthma)HCO3<20inthepresenceofacutelydecreasedPCO2–primarymetabolicacidosisHCO3<15inthepresenceofchronicallydecreasedPCO2–primarymetabolicacidosisHCO3<20inthepresenceofacutelydecreasedPCO2orHCO3<15inthepresenceofchronicallydecreasedPCO2–primarymetabolicacidosisIsThereAnotherSolution?RulesofThumbforRecognizingPrimaryAcid-BaseDisordersWithoutUsingaNomogramRule1LookatthepH.Whicheversideof7.40thepHison,theprocessthatcausedittoshifttothatsideistheprimaryabnormality.Principle:Thebodydoesnotfullycompensateforprimaryacid-basedisordersRule2Calculatetheaniongap.Iftheaniongapis20mmol/L,thereisaprimarymetabolicacidosisregardlessofpHorserumbicarbonatecon