动脉血气分析与高乳酸血症课件.ppt
动脉血气分析及高乳酸血症病例摘要n男性，45岁，病历号1612296n入院日期2010/02/21n入ICU日期2010/02/24n既往史n24年前因感冒后颈部淋巴结肿大行左颈部淋巴结活检术，自述病理阴性n8年前阑尾切除术n1年前行鼻中隔弯曲矫正术病例摘要n2009/12/30n大量饮酒后头昏、恶心，右胁肋部及后背部胀痛n胃镜：糜烂性胃炎伴胆汁返流n2010/01/18n生化检查：ALT、AST、LDH、HBDH、尿淀粉酶进行性升高n腹部超声检查提示胆囊炎病例摘要n2010/01/24n静滴脂肪乳过程中出现气促、胸闷n抗过敏、改善循环、补液及对症处理后缓解n2010/01/28n胸闷、气促，深大呼吸伴酸碱平衡紊乱n无创通气病例摘要nWCC 2.46 6.26 x 109/LnPlt30 115 x109/LnALT 137 U/LnAST 97 U/LnUA 680 mol/LnaPTT/PT明显延长n纠正后PT 13.6 sec,aPTT 48.0 sec,Fib 1.41 g/Ln血淀粉酶237 588 U/Ln尿淀粉酶839 3330 U/Ln肿瘤指标未见异常nCA199,CEA,NSE,CA242,AFP,PSA,CA125病例摘要nABG7.435/6.2/116/4.1/-19.2nAG20 27n血乳酸14.8 16.0 mmol/Ln血丙酮酸6.62 mg/dL(0.3-0.9)n0.83 mmol/LnL/P17.8 19.3病例摘要n胸部CTn左下肺多发肺大疱n腹部增强CTn肝左外叶及右后叶多发海绵状血管瘤,肝右后叶囊肿,脾稍大n胃十二指肠镜n胆汁返流性胃炎伴糜烂,重度胆汁返流,返流性食管炎1级n病理结果n胃窦两块粘膜组织,中度慢性炎症,另见小片炎性渗出物n胃底两块粘膜组织,重度慢性炎症,活动+,另见小片炎性渗出物病例摘要n诊断：重症胰腺炎?n治疗n按胰腺炎治疗，恶心、呕吐症状缓解n输血浆及冷沉淀纠正DICn亚甲蓝中和乳酸病例摘要n呼吸困难（深大呼吸）合并代谢性酸中毒n2010/02/12n血液透析n乳酸可短暂下降至7 mmol/L病例摘要n2010/02/21n转入北京协和医院内分泌科nABG:7.496/8.7/142/6.6/-15.3nNa 137,Cl 95,K 3.7n血乳酸 19.6 mmol/Ln血淀粉酶241 U/L，脂肪酶2430 U/LnALT 126 U/L,TBil 23.3 mol/L,Cr 157 mol/L,BUN 8.82 mmol/L血气结果分析Step 1pH=7.496 7.45原发性酸碱失衡应包括碱中毒ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L血气结果分析Step 2判定碱中毒为呼吸性抑或代谢性ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L血气结果分析Step 3AG=Na Cl HCO3=137 95 6.6=35 20 高AG代酸ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L血气结果分析Step 4AG=35 12=23HCO3+AG=6.6+23=29.6 26代谢性碱中毒ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L血气结果分析Step 5pCO2=1.5 x HCO3+8 2=1.5 x 6.6+8 2=9.9+8 2=15.9 to 19.9呼吸性碱中毒ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L血气结果分析诊断高AG代谢性酸中毒代谢性碱中毒呼吸性碱中毒ABGpH7.496pCO28.7pO2142HCO36.6BE-15.3LytesNa137Cl95K3.7血乳酸19.6 mmol/L高AG代酸的常见原因n甲醇(methanol)中毒n尿毒症n酮症酸中毒n糖尿病*n酒精性n饥饿性n三聚乙醛(paraldehyde)中毒n异烟肼n乳酸酸中毒*n乙醇(ethanol)中毒*n乙二醇(ethylene glycol)中毒*n水杨酸(salicylic acid)中毒*高AG代酸最常见的原因*常伴渗透压间隙升高病例诊断n高AG代酸 高乳酸血症n高乳酸血症的病因?病例摘要n2010/03/01nABG 7.525/26.9/121/22.1/-0.5nLac 9.6n血渗透压312nNa 146,Cl 101,BUN 3.32,Glu 7.4nAG=22.9nOsmcalc=146 x 2+3.32+7.4=302.7nOsmolarity gap=9.3传统观点认为n缺氧可以导致无氧代谢n无氧代谢产生乳酸n无氧代谢是有害的n缺氧是有害的现阶段临床思维认为，高乳酸血症是缺氧的后果治疗上采取提高心输出量和氧输送的方法因此，这是否意味着?n高乳酸是有害的?n高乳酸提示存在缺氧?n高乳酸提示存在无氧代谢 n高乳酸=预后不佳 乳酸是如何生成的?GlucoseGlycogenGlucose 6-PFructose 6-PFructose-1,6-BisphosphateTriose PhosphatesPhosphoenolpyruvatePyruvateLactateOxidation InCitric Acid CyclePhosphofructonasePyruvate kinasePDHLactate dehydrogenaseAnaerobic Metabolism乳酸基础生成率肌肉脑RBCWBC血小板肾脏髓质胃肠道粘膜皮肤0.13 mmol/kg/hr0.14 mmol/kg/hr0.18 mmol/kg/hr0.11 mmol/kg/hr0.11 mmol/kg/hrTotal=1290 mmol/24 hours for 70 kg乳酸的代谢Excretion renal threshold=5-6 mmol/L高乳酸血症(2 mmol/L)生成利用/排出因此n一旦丙酮酸氧化过程受到影响,任何能够增加糖酵解的因素都能够导致高乳酸血症不仅仅是无氧代谢不仅仅是无氧代谢!感染性休克时的高乳酸血症Curtis SE,Cain SM.Regional and systemic oxygen delivery/uptake relations and lactate flux in hyperdynamic,endotoxin-treated dogs.Am Rev Respir Dis 1992;145:348-35402468Serum Lactate(mEq/L)04080120160Time(min)输输注内毒素注内毒素FiO2=12%dichloroacetate二氯乙酸(dichloroacetate)仅在有氧情况下激活PDH乳酸/丙酮酸比值Lactate/Pyruvate=K x(NADH/NAD)x H+缺氧能够阻断氧化磷酸化过程组织NADH氧化为NAD增加NADH/NAD比值增加乳酸/丙酮酸比值正常值约为10:1心源性休克L/P比值=40:1符合组织缺氧表现经过复苏的感染性休克L/P比值=14:1不符合组织缺氧表现何时乳酸=组织灌注不足n心源性休克n出血性休克n以下情况的感染性休克n儿茶酚胺抵抗+心输出量降低n未经过复苏(参见Rivers)何时乳酸 组织灌注不足n有氧糖酵解加速n碳水化合物代谢 线粒体氧化能力n儿茶酚胺/细胞因子刺激ne.g.血液/肺的白细胞乳酸(ARDS)n丙酮酸蓄积n全身性感染时PDH功能障碍何时乳酸 组织灌注不足n乳酸清除减少n结果相互矛盾：测定方法与初始乳酸水平的影响n可能导致轻度高乳酸血症n当乳酸生成率接近正常时通常并不重要n丙酮酸脱氢酶功能障碍nPDH使丙酮酸进入Kreb循环,而不产生乳酸n全身性感染时肌肉中PDH水平低于正常n应用二氯乙酸可恢复功能,从而导致乳酸水平下降n蛋白质分解代谢n氨基酸转化为丙酮酸,随后产生乳酸n线粒体呼吸抑制n全身性感染,药物如二甲双胍(罕见),氰化物,抗逆转录病毒药物乳酸酸中毒的分类Type A Lactic AcidosisAssociated with malperfusion/dysoxiaType B Lactic AcidosisIn the absence of malperfusion/dysoxiaB1 Disease states e.g.DKA,leukaemia,lymphoma,thiamine deficiencyB2 Drugs e.g.metformin,cyanide,beta-agonists,HARRTB3 inborn errors of metabolismClassification of Lactic AcidosisTissue hypoperfusionAbnormal vascular tone or permeability,left ventricular failure,decreased cardiac outputReduced arterial oxygen contentAsphyxia,hypoxemia(PaO2 35),carbon monoxide poisoning,life-threatening anemiaB1(common disorders)SepsisHepatic failureRenal failureDiabetes mellitusCancerMalariaCholeraB2(drug or toxins)Vitamin deficiencyAcetaminophenEthanol,MethanolCocaineSalicylatesIsoniazidCatecholaminesEthylene glycolPapaverineCyanideParenteral nutritionNitroprussideLactuloseTheophyllineB3(other conditions)Strenuous muscle exerciseGrand mal seizuresD-lactic acidosisType ADue to tissue hypoxiaType BNot due to tissue hypoxia预后价值n来源并不重要n高乳酸仍然为严重生理应激和死亡危险的标志n高乳酸常与低氧无关,但仍提示严重应激下存在代谢改变因此,我们应当?n寻找组织灌注不足的证据n如果存在组织灌注不足,应提高CO和氧输送n但是,不应仅仅针对乳酸水平进行上述治疗n治疗组织灌注不足而非高乳酸n考虑导致高乳酸的其他原因nLactate is the messengerdont shoot it!病例诊断n全身血流动力学稳定n组织灌注无明显异常n意识清楚n皮肤无花斑n毛细血管再充盈时间正常n尿量正常n药物因素n患病前未使用任何药物n中毒n毒物监测未发现异常n先天性因素Classification of Lactic AcidosisTissue hypoperfusionAbnormal vascular tone or permeability,left ventricular failure,decreased cardiac outputReduced arterial oxygen contentAsphyxia,hypoxemia(PaO2 35),carbon monoxide poisoning,life-threatening anemiaB1(common disorders)SepsisHepatic failureRenal failureDiabetes mellitusCancerMalariaCholeraB2(drug or toxins)Vitamin deficiencyAcetaminophenEthanol,MethanolCocaineSalicylatesIsoniazidCatecholaminesEthylene glycolPapaverineCyanideParenteral nutritionNitroprussideLactuloseTheophyllineB3(other conditions)Strenuous muscle exerciseGrand mal seizuresD-lactic acidosisType ADue to tissue hypoxiaType BNot due to tissue hypoxia病例诊断n骨髓活检n淋巴瘤骨髓侵犯n诊断n非霍杰金氏淋巴瘤病例摘要02/2102/2202/2302/2416:5014:0010:0017:0019:3022:3007:30pH7.4967.4737.4247.3037.3627.5187.341PCO28.714.78.96.87.514.98.1PO2142122143148142140134HCO36.610.65.73.34.212.04.3SBE-17.1-12.6-19.0-23.5-21.6-10.6-21.7Lac20.014.614.016.014.311.120.0病例摘要总结n动脉血气结果分析-基本技能n高乳酸血症的鉴别诊断
