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1、Chapter 5 Hypoxia病理生理学教研室于小玲 ventilationgas exchangeInternal RespirationExternal RespirationairalveoliAlveolar capillary transportTissue cellsSystem CircuitHypoxiaHypoxia can be defined as a deficiency in either the delivery or the utilization of oxygen at the tissue level,which can lead to changes

2、in function,metabolism and even structure of the body.Parameters of Blood Oxygen(血氧指标血氧指标)1.1.Partial Pressure of Oxygen（PO2 2）PaO2 100mmHg PvO2 40mmHg决定因素决定因素:吸入气氧分压和肺的呼吸功吸入气氧分压和肺的呼吸功能能2.2.Oxygen Binding Capacity of hemoglobin(CO2max /氧容量氧容量)正常参考值正常参考值:20ml/dl决定因素：决定因素：HbHb 的的 质质 和和 量量100100mlml血液中

3、的血液中的HbHb被氧充分饱和时的最大被氧充分饱和时的最大带氧量带氧量3.3.Oxygen Content（CO2/氧含量氧含量）正常参考值正常参考值:CaO2 19ml/dl CvO2 14ml/dl 决定因素：决定因素：氧分压，氧容量氧分压，氧容量100100mlml血液的血液的HbHb实际带氧量实际带氧量正常参考值正常参考值:SaO295%;SvO270%4.4.Oxygen Saturation（SO2/氧饱和度氧饱和度）血氧含量溶解的氧量血氧含量溶解的氧量氧容量氧容量SO2 100%决定因素：决定因素：氧分压氧分压氧分压与氧饱和度的关系氧分压与氧饱和度的关系氧离曲线氧离曲线20406

4、080100204060801002,3-DPG,H,CO2温度温度 2,3-DPG,H,CO2 温度温度 P50Classification,Etiology and Pathogenesis of HypoxiaHbO2O2O21234低张性缺氧低张性缺氧血液性缺氧血液性缺氧循环性缺氧循环性缺氧组织性缺氧组织性缺氧1.Hypotonic Hypoxia:Characterized by the decrease Characterized by the decrease of PaO2of PaO2 -hypoxic hypoxiahypoxic hypoxia(1)Etiology an

5、d mechanisms1)1)POPO2 2 of inspired air of inspired air -Atmosphere Hypoxia-Atmosphere Hypoxia（大气性缺氧（大气性缺氧)2)External respiratory dysfunction2)External respiratory dysfunction -Respiratory Hypoxia-Respiratory Hypoxia（呼吸性缺氧（呼吸性缺氧）3)Venous-to-arterial shunts3)Venous-to-arterial shunts CO2maxPaO2CaO2 S

6、aO2Ca-vO2(2)Characteristics of blood O2NNNNHbO2HHb2.6g/dlNormalHHb 5g/dlhypoxiaCyanosisCyanosis (发绀发绀)HbO2Cyanosis 2.Hemic Hypoxia（血液性缺氧（血液性缺氧）Hemic hypoxia refers to the altered affinity of Hb for oxygen or decrease in amount of Hb in the blood.(1)Etiology and mechanisms1 1)Anemia)Anemia (贫血贫血)Hb，携

7、带氧的数量减少携带氧的数量减少成年男性成年男性Hb12.0g/dl成年女性成年女性Hb11.0/dl 2 2)CarboxyhemoglobinemiaCarboxyhemoglobinemia (一氧化碳中毒一氧化碳中毒)CO+HbHbCOCannot take up O2 Inhibit O2 releasing from HbO2吉林延边一氧化碳中毒一氧化碳中毒已有291人住院,16人死亡2 2月月1313日日,延吉等六个县市，部分居住在平房里自己延吉等六个县市，部分居住在平房里自己烧煤取暖的居民发生了散发性一氧化碳中毒。烧煤取暖的居民发生了散发性一氧化碳中毒。2 2月月1414日安徽省

8、合肥市也发生多起一氧化碳中毒病日安徽省合肥市也发生多起一氧化碳中毒病例，例，8080多人因一氧化碳中毒入院，多人因一氧化碳中毒入院，3 3人死亡。这类人死亡。这类散发性一氧化碳中毒事件的发生，引起了有关部散发性一氧化碳中毒事件的发生，引起了有关部门的关注。门的关注。3 3)MethemoglobinemiaMethemoglobinemia (高铁血红蛋白血症高铁血红蛋白血症)Cant to carry O2 Increase the affinity of HbO2 n豆腐中毒:厂家过量使用亚硝酸钠造成的一起急性中毒事件,豆制品中亚硝酸盐含量过高.n咸菜中毒：2003年12月17日,龙海市溪

9、尾村发生进食自家腌制咸菜，3人亚硝酸盐急性中毒事件.n扒鸡中毒：2002年9月8日,武城县武城镇候王庄村,发生一起食用扒鸡引起的亚硝酸盐中毒中毒症状：n潜伏期13小时n紫绀:口唇、舌尖、指尖青紫，重者眼结膜、面部及全身皮肤青紫n嗜睡或烦躁、呼吸困难、恶心、呕吐、腹痛、腹泻，严重者昏迷、惊厥、大小便失禁，可因呼吸衰竭而死亡。肠源性紫绀肠源性紫绀(EnterogenousEnterogenous Cyanosis)Cyanosis)CO2maxPaO2CaO2 SaO2Ca-vO2(2)Characteristics of blood O2NNNN3.Circulatory Hypoxia（循环性

10、缺氧（循环性缺氧）Circulatory hypoxia refers to inadequate blood flow leads to inadequate oxygenation of the tissues.(1)Etiology and mechanismsTissue ischemia：Tissue congestion:PaO2 CO2max CaO2 SaO2 Ca-vO2Characteristic of blood oxygenNNNNNNNN4.Histogenous Hypoxia（组织性缺氧（组织性缺氧）Histogenous hypoxia refers to th

11、e tissue cell cannot make use of the O2 supplied to them.(1)Etiology and mechanisms 1 1)Inhibition of mitochondrial)Inhibition of mitochondrial oxidative oxidative phosphorylationphosphorylation(组织中毒组织中毒:氰化物、砷化物中毒）氰化物、砷化物中毒）2 2)Mitochondria injury)Mitochondria injury3 3)PaO2 CO2max CaO2 SaO2 Ca-vO2(

12、2)Characteristics of blood O2：NNNNNNNN皮肤粘膜：皮肤粘膜：血管中血管中鲜红色或玫瑰红色鲜红色或玫瑰红色Alterations of Metabolism and Function1.Respiratory SystemChemoreceptorHyperpneaP PA AO O2 2(1)Compensatory response -Hyperventilation1)High altitude pulmonary edema(2)Injury manifestationHypoxiaPulmonary vasoconstrictionPulmonary

13、 hypertensionEdemaCapillary permeability2)Central respiratory failurePaO2 30mmHg Depresses the respiratory center2.Circulatory System(1)Increase of cardiac outputHypoxiaSN+HRMyocardial contractilityVenous returnRespiratory movementCO O2 delivery(2)Pulmonary vasoconstrictionV /Q 0.8 Hypoxia Ca2+enter

14、ing Humoral factor：SN+/catecholamine AGII,TXA2,ET,LTs PGI2,HA,EDRF(3)Redistribution of blood Skin/renal/visceral vasoconstrictionCoronary vasodilationCerebral unconstrictionEnsure for vital organs supply of O2(4)Capillary hyperplasiaDensity of capillaries Facilitate O2 diffusion to tissue cellsChron

15、ic hypoxia VEGF gene expression Capillary hyperplasianPulmonary hypertensionn Diastolic and systolic myocardial functionnArrhythmian Venous return to the heart(5)Injury manifestation(1)(1)Amount of RBC and HbChronic hypoxia kidney EPO3.Hematologic systemCaO2 O2 supply to tissue cellPlasma viscosity/

16、resistance of blood flow/after-load of heart20406080100204060801002,3-DPG,H,CO2温度温度 2,3-DPG,H,CO2 温度温度 P50(2)Improved erthrocyte oxygen release capability4.Central nervous systemWithout O2 supply:1020s-unconsciosness 45min-brain deathWeight of brain:2%O2 consumption:23%Cerebral edema and neuron inju

17、ry HypoxiaCerebral vessel dilated and tissue fluid Metabolic acidosisCapillary permeabilityEdemaIntracranial hypertension Na+-k+pump ATP 4.Central nervous systemn急性缺氧：急性缺氧：头痛，烦躁，记忆力下降，运头痛，烦躁，记忆力下降，运动不协调动不协调n慢性缺氧：慢性缺氧：疲劳，嗜睡，注意力不集中，抑郁疲劳，嗜睡，注意力不集中，抑郁n严重缺氧：严重缺氧：不安，惊厥，昏迷，死亡不安，惊厥，昏迷，死亡(1)Compensation response5.Tissues and cells1)Enhanced cells capability for use of O22)Ehanced anaerobic glycolysis3)Ehanced myoglobin 4)Low metabolic states(2)Injury manifestationOxygen Therapyn消除病因n吸氧：缺氧病因/分类不同，吸氧疗效 不同问题：哪种类型吸氧疗效最好？