血气分析(英文版).pptx

ABGINTERPRETATIONDebbieSanderPAS-II

0102ObjectivesWhat’sanABG?

UnderstandingAcid/BaseRelationship

GeneralapproachtoABGInterpretation

ClinicalcausesAbnormalABG’s

Casestudies

Takehome

WhatisanABGArterialBloodGasDrawnfromartery-radial,brachial,femoralItisaninvasiveprocedure.Cautionmustbetakenwithpatientonanticoagulants.Helpsdifferentiateoxygendeficienciesfromprimaryventilatorydeficienciesfromprimarymetabolicacid-baseabnormalities

pH [H+]01PCO2PartialpressureCO202PO2PartialpressureO203HCO3Bicarbonate04BE Baseexcess05SaO2 OxygenSaturation06WhatIsAnABG?

Acid/BaseRelationshipThisrelationshipiscriticalforhomeostasis

SignificantdeviationsfromnormalpHrangesare

poorlytoleratedandmaybelifethreatening

AchievedbyRespiratoryandRenalsystems

Tachypneic,tachycardic,diaphoreticandCyanotic.Dxacuteresp.failureandABG’sShowPaCO2wellbelownl,pHabovenl,PaO2isverylow.ThebloodgasdocumentResp.failureduetoprimaryO2problem.32145y/omalecomesERc/oSOB.CaseStudyNo.1

y/omalecomesERc/oSOB.Tachypneic,tachycardic,diaphoreticandCyanotic.Dxacuteresp.failureandABG’sShowPaCO2veryhigh,lowpHandPaO2ismoderatelylow.ThebloodgasdocumentResp.failureduetoprimarilyventilatoryinsufficiency.CaseStudyNo.2

TherearetwobuffersthatworkinpairsH2CO3 NaHCO3

Carbonicacid basebicarbonateThesebuffersarelinkedtotherespiratoryand

renalcompensatorysystemBuffers

RespiratoryComponentCarbonicacidH2CO3ofCO2CO2+H2O?H2CO3functionofthelungsApproximately98%normalmetabolitesareintheformexcessCO2exhaledbythelungs123456

MetabolicComponentFunctionofthekidneysbasebicarbonateNaHCO3ProcessofkidneysexcretingH+intotheurineandreabsorbing

HCO3-intothebloodfromtherenaltubules

1)activeexchangeNa+forH+betweenthetubular

cellsandglomerularfiltrate

2)