ABG 简明血气分析PPT课件.ppt

ABGINTERPRETATION血气分析解读 SIMCICULiu 1 Objectives What sanABG UnderstandingAcid BaseRelationshipGeneralapproachtoABGInterpretationClinicalcausesAbnormalABG sCasestudies 2 WhatisanABG ArterialBloodGas动脉血气Drawnfromartery radial brachial femoral由动脉取样 一般取桡动脉 肱动脉 股动脉Itisaninvasiveprocedure 这是侵入性检查Cautionmustbetakenwithpatientonanticoagulants 有凝血功能障碍的患者慎用Helpsdifferentiateoxygendeficienciesfromprimaryventilatorydeficienciesfromprimarymetabolicacid baseabnormalities协助区分缺氧 通气不足和酸碱代谢异常 3 WhatIsAnABG pH H PCO2PartialpressureCO2PO2PartialpressureO2HCO3BicarbonateBEBaseexcessSaO2OxygenSaturation 4 Acid BaseRelationship Thisrelationshipiscriticalforhomeostasis酸碱平衡对内环境是非常重要的SignificantdeviationsfromnormalpHrangesarepoorlytoleratedandmaybelifethreatening酸碱严重失衡后果严重 甚至可能致命AchievedbyRespiratoryandRenalsystems一般由呼吸系统和肾脏决定 5 CaseStudyNo 1 60y omalecomesERc oSOB Tachypneic tachycardic diaphoreticandCyanotic Dxacuteresp failureandABG sShowPaCO2wellbelownl pHabovenl PaO2isverylow ThebloodgasdocumentResp failureduetoprimaryO2problem 60岁男性进入急诊室 查体见呼吸过速 心动过速 大汗 发绀 诊断急性呼衰 动脉血气分析结果PaCO轻度降低 PH升高 PaO2非常低 结果显示其主要问题为缺氧 6 CaseStudyNo 2 60y omalecomesERc oSOB Tachypneic tachycardic diaphoreticandCyanotic Dxacuteresp failureandABG sShowPaCO2veryhigh lowpHandPaO2ismoderatelylow ThebloodgasdocumentResp failureduetoprimarilyventilatorinsufficiency 60岁男性进入急诊室 查体 呼吸过塑 心动过速 大汗 发绀 诊断急性呼衰 动脉血气分析结果显示PaCO2非常高 PH降低 PaO2中度降低 结果显示其主要问题为通气不足 7 Buffers TherearetwobuffersthatworkinpairsH2CO3NaHCO3CarbonicacidbasebicarbonateThesebuffersarelinkedtotherespiratoryandrenalcompensatorysystem两者和呼吸 肾脏代偿密切相关 8 RespiratoryComponent functionofthelungsCarbonicacidH2CO3Approximately98 normalmetabolitesareintheformofCO2CO2 H2O H2CO3excessCO2exhaledbythelungs 9 MetabolicComponent FunctionofthekidneysbasebicarbonateNaHCO3ProcessofkidneysexcretingH intotheurineandreabsorbingHCO3 intothebloodfromtherenaltubules肾脏将H 排泄至尿液 并从肾小管重吸收HCO3 1 activeexchangeNa forH betweenthetubularcellsandglomerularfiltrate在肾小管和肾小球主动用Na 交换H 2 carbonicanhydraseisanenzymethataccelerateshydration dehydrationCO2inrenalepithelialcells可以加速CO2在肾上皮细胞的水化和脱水反应 10 Acid BaseRelationship H2O CO2 H2CO3 HCO3 H 11 NormalABGvalues pH7 35 7 45PCO235 45mmHgPO280 100mmHgHCO322 26mmol LBE 2 2SaO2 95 12 Acidosis酸中毒Alkalosis碱中毒 pH45HCO3 22 pH 7 45PCO226 13 RespiratoryAcidosis ThinkofCO2asanacid把二氧化碳想象成酸failureofthelungstoexhaleadequateCO2肺无法排出足够的二氧化碳pH45CO2 H2CO3 pH 14 CausesofRespiratoryAcidosis Emphysema肺气肿drugoverdose药物过量narcosis麻醉respiratoryarrest呼吸暂停airwayobstruction气道阻塞 15 MetabolicAcidosis failureofkidneyfunction bloodHCO3whichresultsin availabilityofrenaltubularHCO3forH excretionpH 7 35HCO3 22 16 CausesofMetabolicAcidosis renalfailure肾衰竭diabeticketoacidosis酮症酸中毒lacticacidosis乳酸酸中毒excessivediarrhea严重腹泻cardiacarrest心跳骤停 17 RespiratoryAlkalosis toomuchCO2exhaled hyperventilation 过度通气 PCO2 H2CO3insufficiency pHpH 7 45PCO2 35 18 CausesofRespiratoryAlkalosis hyperventilation过度通气panicd opainpregnancyacuteanemia急性贫血salicylateoverdose水杨酸过量 19 MetabolicAlkalosis plasmabicarbonatepH 7 45HCO3 26 20 CausesofMetabolicAlkalosis lossacidfromstomachorkidney由胃或肾脏过量丢失酸性物质hypokalemia低血钾excessivealkaliintake过量碱性物质摄入 21 HowtoAnalyzeanABG PO2NL 80 100mmHgpHNL 7 35 7 45Acidotic7 45PCO2NL 35 45mmHgAcidotic 45Alkalotic26 22 Four stepABGInterpretation Step1 ExaminePaO2 SaO2DetermineoxygenstatusLowPaO2 80mmHg SaO2meanshypoxiaPaO2和SaO2降低提示缺氧NL elevatedoxygenmeansadequateoxygenation正常或更高的数值表明氧合充分 23 Four stepABGInterpretation Step2 pHacidosis7 45 24 Four stepABGInterpretation Step3 studyPaCO2 HCO3respiratoryirregularityifPaCO2abnl HCO3NL呼吸系统异常会显示PaCO2异常 HCO3正常metabolicirregularityifHCO3abnl PaCO2NL代谢系统异常会显示HCO3异常 PaCO2正常 25 Four stepABGInterpretation Step4 DetermineifthereisacompensatorymechanismworkingtotrytocorrectthepH 判断机体是否在进行代偿ie ifhaveprimaryrespiratoryacidosiswillhaveincreasedPaCO2anddecreasedpH CompensationoccurswhenthekidneysretainHCO3 例如 如果主要是呼吸性酸中毒的话会导致PaCO2升高 PH降低 当肾脏仍有足够的HCO3时会进行代偿 26 PaCO2 pHRelationship 807 20607 30407 40307 50207 60 27 ABGInterpretation Compensated Respiratory Acidosis CO2 MoreAbnormal Respiratory Acidosis CO2 Expected Mixed Respiratory Metabolic Acidosis CO2 LessAbnormal CO2Change c w Abnormality Metabolic MetabolicAcidosis CO2 Normal Compensated Metabolic Acidosis CO2Change opposes Abnormality Acidosis酸中毒 28 ABGInterpretation Compensated Respiratory Alkalosis CO2 MoreAbnormal Respiratory Alkalosis CO2 Expected Mixed Respiratory Metabolic Alkalosis CO2 LessAbnormal CO2Change c w Abnormality Metabolic Alkalosis CO2 Normal Compensated Metabolic Alkalosis CO2Change opposes Abnormality Alkalosis 29 RespiratoryAcidosis pH7 30PaCO260HCO326 30 RespiratoryAlkalosis pH7 50PaCO230HCO322 31 MetabolicAcidosis pH7 30PaCO240HCO315 32 MetabolicAlkalosis pH7 50PCO240HCO330 33 Whatarethecompensations Respiratoryacidosis metabolicalkalosisRespiratoryalkalosis metabolicacidosisInrespiratoryconditions therefore thekidneyswillattempttocompensateandvisaversa Inchronicrespiratoryacidosis COPD thekidneysincreasetheeliminationofH andabsorbmoreHCO3 TheABGwillShowNLpH CO2andHCO3 Bufferskickinwithinminutes Respiratorycompensationisrapidandstartswithinminutesandcompletewithin24hours Kidneycompensationtakeshoursandupto5days 34 MixedAcid BaseAbnormalities CaseStudyNo 3 56yoneurologicdzrequiredventilatorsupportforseveralweeks SheseemedmostcomfortablewhenhyperventilatedtoPaCO228 30mmHg Sherequireddailydosesoflasix 速尿 toassureadequateurineoutputandreceived40mmol LIVK eachday On10thdayofICUherABGon24 oxygen VS 35 ABGResults pH7 62BP115 80mmHgPCO230mmHgPulse88 minPO285mmHgRR10 minHCO330mmol LVT1000mlBE10mmol LMV10LK 2 5mmol L Interpretation Acutealveolarhyperventilation resp alkalosis andmetabolicalkalosiswithcorrectedhypoxemia 36 CasestudyNo 4 27yoretarded withinsulin dependentDMarrivedatERfromtheinstitutionwherehelived OnroomairABG VS pH7 15BP180 110mmHgPCO222mmHgPulse130 minPO292mmHgRR40 minHCO39mmol LVT800mlBE 30mmol LMV32L Interpretation Partlycompensatedmetabolicacidosis 37 CasestudyNo 5 74yo withhxchronicrenalfailureandchronicdiuretictherapywasadmittedtoICUcomatoseandseverelydehydrated On40 oxygenherABG VS pH7 52BP130 90mmHgPCO255mmHgPulse120 minPO292mmHgRR25 minHCO342mmol LVT150mlBE17mmol LMV3 75L Interpretation Partlycompensatedmetabolicalkalosiswithcorrectedhypoxemia 38 CasestudyNo 6 43yo arrivesinER20minutesafteraMVAinwhichheinjuredhisfaceonthedashboard Heisagitated hasmottled coldandclammyskinandhasobviouspartialairwayobstruction Anoxygenmaskat10Lisplacedonhisface ABG VS pH7 10BP150 110mmHgPCO260mmHgPulse150 minPO2125mmHgRR45 minHCO318mmol LVT mlBE 15mmol LMV L Interpretation Acuteventilatoryfailure resp acidosis andacutemetabolicacidosiswithcorrectedhypoxemia 39 CasestudyNo 7 17yo 48kg withknowninsulin dependentDMcametoERwithKussmaulbreathingandirregularpulse RoomairABG VS pH7 05BP140 90mmHgPCO212mmHgPulse118 minPO2108mmHgRR40 minHCO35mmol LVT1200mlBE 30mmol LMV48L Interpretation Severepartlycompensatedmetabolicacidosiswithouthypoxemia 40 CaseNo 7cont d Thispatientisindiabeticketoacidosis IVglucoseandinsulinwereimmediatelyadministered AjudgementwasmadethatsevereacidemiawasadverselyaffectingCVfunctionandbicarbwaselectedtorestorepHto 7 20 Bicarbadministrationcalculation BasedeficitXweight kg 430X48 360mmol LAdmin1 2over15min 4repeatABG 41 CaseNo 7cont d ABGresultafterbicarb pH7 27BP130 80mmHgPCO225mmHgPulse100 minPO292mmHgRR22 minHCO311mmol LVT600mlBE 14mmol LMV13 2L 42 CasestudyNo 8 47yo wasinPACUfor3hourss pcholecystectomy Shehadbeenon40 oxygenandABG VS pH7 44BP130 90mmHgPCO232mmHgPulse95 min regularPO2121mmHgRR20 minHCO322mmol LVT350mlBE 2mmol LMV7LSaO298 Hb13g dL 43 CaseNo 8cont d Oxygenwaschangedto2LN C 1 2hourpt readytobeD CtofloorandABG VS pH7 41BP130 90mmHgPCO210mmHgPulse95 min regularPO2148mmHgRR20 minHCO36mmol LVT350mlBE 17mmol LMV7LSaO299 Hb7g dL 44 CaseNo 8cont d Whatisgoingon 45 CaseNo 8cont d Ifthepicturedoesn tfit repeatABG pH7 45BP130 90mmHgPCO231mmHgPulse95 minPO287mmHgRR20 minHCO322mmol LVT350mlBE 2mmol LMV7LSaO296 Hb13g dL Technicalerrorwaspresumed 46 CasestudyNo 9 67yo whohadclosedreductionoflegfxwithoutincident FourdayslatersheexperiencedasuddenonsetofseverechestpainandSOB RoomairABG VS pH7 36BP130 90mmHgPCO233mmHgPulse100 minPO255mmHgRR25 minHCO318mmol LBE 5mmol LMV18LSaO288 Interpretation Compensatedmetabolicacidosiswithmoderatehypoxemia Dx PE 47 CasestudyNo 10 76yo withdocumentedchronichypercapniasecondarytosevereCOPDhasbeeninICUfor3dayswhilebeingtxforpneumonia Shehadbeenstableforpast24hoursandwastransferredtogeneralfloor Ptwason2Loxygen ABG VS pH7 44BP135 95mmHgPCO263mmHgPulse110 minPO252mmHgRR22 minHCO342mmol LBE 16mmol LMV10LSaO286 Interpretation Chronicventilatoryfailure resp acidosis withuncorrectedhypoxemia 48 CaseNo