病理生理学呼吸系统.pptx
呼吸全过程呼吸全过程RespirationRespiration肺通气肺通气pulmonarypulmonaryventilationventilation肺换气肺换气gasgasexchangeexchangein thein thelungslungs组织换气组织换气gasgasexchangeexchangein the in the tissuestissues细胞氧化代谢细胞氧化代谢cellularcellularrespirationrespiration气体血液气体血液运输运输gas transportgas transportin the bloodin the blood 外呼吸外呼吸 external external respirationrespiration 内呼吸内呼吸 internal internal respirationrespiration第1页/共47页第2页/共47页SymbolsP P PressurePressurePartial pressurePartial pressureA AAlveolarAlveolara aarterialarterialv vvenousvenousV VVolume of gas/unit timeVolume of gas/unit timeQ QVolume of blood/unit timeVolume of blood/unit time.第3页/共47页呼吸衰竭(Respiratory Failure)外呼吸功能严重障碍外呼吸功能严重障碍 PaOPaO2 ,2 ,伴伴有或不伴有有或不伴有PaCOPaCO2 2 的病理过程。的病理过程。判断标准：判断标准：PaOPaO2 2 60mmHg 50mmHg 50mmHg (正常：正常：40 mmHg)40 mmHg)呼吸功能不全(Respiratory Insufficiency)第4页/共47页呼衰的类型呼衰的类型Classification of Classification of Respiratory failureRespiratory failure1.1.按按PaCOPaCO2 2 是否升高：是否升高：低氧血症型（低氧血症型（I I型）型）低氧血症伴高碳酸血症（低氧血症伴高碳酸血症（IIII型）型）2.2.按主要发病机制：按主要发病机制：通气障碍型通气障碍型 换气障碍型换气障碍型3.3.按病变部位：按病变部位：中枢性和外周性中枢性和外周性第5页/共47页一、呼衰的原因和发病机制 Respiratory Failure:The Causes and the Mechanisms.肺通气功能障碍 Disorders in Pulmonary Ventilation.肺换气功能障碍 Disorders in Gas Exchange of the Lungs 第6页/共47页（一）肺通气功能障碍:Disorders in Pulmonary Ventilation?限制性通气不足:肺泡扩张受限?2.阻塞性通气不足:呼吸道阻塞或狭窄 气道阻力增加。第7页/共47页1.限制性通气不足（RestrictiveHypoventilation）：肺泡扩张受限中枢神经受损,周围神经受损,呼吸肌本身 收缩功能障碍。肺充血和严重肺纤维化,肺泡表面活性物 质减少。胸廓和胸膜本身病变。呼吸肌活动障碍呼吸肌活动障碍肺顺应性降低肺顺应性降低胸廓顺应降低胸廓顺应降低胸腔积液和气胸胸腔积液和气胸第8页/共47页气道阻力(正常人平静呼吸)：80%:直径 2mm 气管 20%:直径 0.8 0.8 0.83.部分肺泡血流不足(Alveolar Perfusion Insufficiency)死腔样通气(dead space like ventilation）第25页/共47页血液氧和二氧化碳解离曲线Oxygen and Carbon DioxideDissociation Curves第26页/共47页问题：弥散障碍的发生机制?功能性分流,静脉血掺杂?解剖分流,真性分流?死腔样通气?第27页/共47页肺泡-毛细血管膜(alveolar capillary membrane)损伤引起的急性呼吸衰竭。病因：感染（肺炎，败血症等），休克，严重创伤，吸入毒物或胃酸等。（四）急性呼吸窘迫综合征Acute Respiratory Distress Syndrome(ARDS)Severe acute respiratory syndrome(SARS)is a good example of a probable infectious pneumonia that pathologically and clinically is ARDS.Experts have speculated that the cause is from a corona virus that may be transmitted via respiratory secretions and develops after 2-11 days of a febrile illness.第28页/共47页第29页/共47页ARDS发生机制(Pathogenesis)肺泡膜内皮细胞损伤致病因子释放中性粒细胞趋化因子中性粒细胞聚集，释放氧自由基、蛋白酶、炎症介质肺水肿死腔样通气肺泡型上皮细胞损伤表面活性物质合成支气管痉挛血管收缩微血栓肺泡膜通透性肺不张功能性分流PaO2PaCO2第30页/共47页 A previously healthy 23-year-old male sustained numerous traumatic crush,burn,and smoke inhalation injuries during a landing accident in an airplane.His initial B.P.was 80/50 mmHg,and he was immediately infused with saline at the maximal rate.In the ER he was intubated and had no signs of pneumothorax.His orthopedic injuries and burns were treated.The ventilator was placed on the assist-control mode with the initial settings of inspired O2 concentration at 40%,respiration rate at 12/min,and tidal volume at 900 ml.Arterial blood gas measurements were:pH=7.47,PCO2 of 33 mmHg,and PO2 of 62 mmHg.Clinical Case 第31页/共47页 24 hrs.after admission,the patient becomes agitated and his respiration rate increased to 30/min.His minute ventilation also increased from 8.5 l/min to 20 l/min.Airway pressure increased from 18 to 65 cm H2O.Repeat arterial blood gas measurement of PO2 indicated 35 mmHg and chest x-ray now showed diffuse infiltrates in a white out pattern.Clinical Case 第32页/共47页 The diagnosis of ARDS is contingent upon 5 factors:1.Hypoxemia,2.Diffuse pulmonary infiltrates on radiography,3.Absence of congestive heart failure,4.Decreased lung compliance(effective static compliance 25-35 ml/cm H2O),and 5.Appropriate antecedent history.Currently,there are no specific laboratory tests for ARDS.A definitive diagnosis is made when these signs and symptoms are linked with diffuse alveolar damage.Clinical Case 第33页/共47页急性呼吸窘迫综合征(ARDS)的概念及发生机制?问题：第34页/共47页二、呼衰时机体功能和代谢变化 Functional and Metabolic Change in Respiratory Failure（一）酸碱平衡紊乱(acid-base balance disturbance)和电解质变化呼酸:型呼衰 CO2潴留 血 K+,血 Cl-呼碱：I型呼衰 肺过度通气 血 K+,血 Cl-代酸：严重缺氧 无氧代谢 乳酸第35页/共47页（二）呼吸系统的变化（二）呼吸系统的变化(Changes in(Changes in Respiratory System)Respiratory System)?呼吸调节(Regulation of Respiration)?的变化外周化学感受器中枢化学感受器呼吸加深加快抑制呼吸中枢PaO250 mmHgPaO280 mmHg第36页/共47页（三）循环系统变化(Changes in Circulation System)轻度PaO2 和 PaCO2 可兴奋心血管运动中枢 严重PaO2 和 PaCO2 抑制心血管运动中枢 第37页/共47页缺氧 肺小动脉收缩 肺动脉压 右心后负荷长期缺氧 肺血管平滑肌增殖 管壁增厚长期缺氧 红细胞增多 血液粘度 心负荷缺氧、酸中毒 心肌舒缩功能呼吸衰竭 右心衰竭 肺源性心脏病 (cor pulmonale)第38页/共47页PaOPaO2 2:60 mmHg 60 mmHg 智力，视力轻度减退智力，视力轻度减退40-50 mmHg 40-50 mmHg 神经精神症状神经精神症状20 mmHg 20 mmHg 神经细胞不可逆损坏神经细胞不可逆损坏(慢性呼衰慢性呼衰PaOPaO2 2 20 mmHg20 mmHg神志仍可清醒）神志仍可清醒）PaCOPaCO2 2 80 mmHg80 mmHg CO CO2 2麻醉麻醉(头痛头痛,头昏头昏,嗜睡，嗜睡，精神错乱精神错乱,扑翼样震颤扑翼样震颤,抽搐抽搐,及昏迷等及昏迷等中中枢神经系统症状）枢神经系统症状）肺性脑病肺性脑病(pulmonary encephalopathy):(pulmonary encephalopathy):呼衰呼衰引起的脑功能障碍引起的脑功能障碍（四）中枢神经系统变化Changes in Central Nervous System第39页/共47页肺性脑病发生机制Pathogenesis of pulmonary encephalopathy-氨基丁酸脑脊液 pH溶酶体酶释放中枢抑制磷脂酶活性神经损伤颅内压PO2PaCO2血管内皮损伤血管通透性脑水肿脑血管扩张脑充血第40页/共47页问题：呼吸衰竭时呼吸调节的变化？肺源性心脏病发生机制?肺性脑病的定义及发生机制？第41页/共47页（一）一般原则（一）一般原则 (General Principals)(General Principals)1.1.防治原发病防治原发病 2.2.防止或去除诱因防止或去除诱因 3.3.改善肺通气改善肺通气 4.4.纠正水、电解质及酸碱平衡紊乱纠正水、电解质及酸碱平衡紊乱,保保 护重要器官功能护重要器官功能五、呼衰的防治原则五、呼衰的防治原则 Principals of the Prevention andPrincipals of the Prevention and Treatment of Respiratory Failure Treatment of Respiratory Failure第42页/共47页1 I 型呼衰只有缺O2而无CO2潴留，可吸入较高浓度O2，一般不超过502.II型呼衰有CO2潴留,应持续低浓度低流量吸氧，如30，12L/min，使PaO2上升到 60 mmHg（二）吸氧(Oxygen Inhalation)第43页/共47页问题：II型呼吸衰竭吸氧的原则？第44页/共47页respiratory failure(respiratory insufficiency()restrictive hypoventilation()obstructive hypoventilation()diffusion impairment()functional shunt()venous admixture()anatomic shunt();true shunt()dead space like ventilation()ventilation-perfusion ratio ()acute respiratory distress syndrome(ARDS)()cor pulmonale()pulmonary encephalopathy()第45页/共47页respiratory failure(呼吸衰竭)respiratory insufficiency(呼吸功能不全)restrictive hypoventilation(限制性通气不足限制性通气不足)obstructive hypoventilation(阻塞性通气不足阻塞性通气不足)diffusion impairment(弥散障碍弥散障碍)functional shunt(功能性分流)venous admixture(静脉血掺杂)anatomic shunt(解剖分流);true shunt(真性分流)dead space like ventilation(死腔样通气)ventilation-perfusion ratio (肺泡通气与血流比例肺泡通气与血流比例)acute respiratory distress syndrome(ARDS)(急性呼吸窘迫综合征)cor pulmonale(肺源性心脏病)pulmonary encephalopathy(肺性脑病)Vocabulary.(VA/Q)第46页/共47页感谢您的观看！第47页/共47页
