病理生理学-呼吸系统.ppt

1、a,1,病理生理学系 Department of Pathophysiology 高远生,呼吸衰竭 Respiratory Failure,a,2,a,3,a,4,Symbols,a,5,呼吸衰竭(Respiratory Failure),呼吸功能不全(Respiratory Insufficiency),a,6,呼衰的类型 Classification of Respiratory failure,1. 按PaCO2 是否升高： 低氧血症型（I型） 低氧血症伴高碳酸血症（II型） 2. 按主要发病机制：通气障碍型 换气障碍型 3. 按病变部位：中枢性和外周性,a,7,一、呼衰的原因和发病机制

2、 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,a,8,（一）肺通气功能障碍: Disorders in Pulmonary Ventilation,a,9,a,10,气道阻力(正常人平静呼吸)： 80%: 直径 2mm 气管 20%: 直径 0.8 0.8,1. 部分肺泡通气不足(Alveolar Ventilation Insufficiency)

3、功能性分流 (functional shunt) 静脉血掺杂（venous admixture),a,23,血液氧和二氧化碳解离曲线 Oxygen and Carbon Dioxide Dissociation Curves,a,24,氧和二氧化碳血液中的运输 Transport of O2 and CO2 in the Blood,a,25,2. 解剖分流增加(Increase in Anatomic Shunt),a,26,3. 部分肺泡血流不足(Alveolar Perfusion Insufficiency) 死腔样通气(dead space like ventilation）,a,2

4、7,血液氧和二氧化碳解离曲线 Oxygen and Carbon Dioxide Dissociation Curves,a,28,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?,a,29,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)

5、 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.,a,30,a,31,a,32,A previously healthy 23

6、-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 orthopedi

7、c 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.,Clinica

8、l Case,a,33,24 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

9、-ray now showed diffuse infiltrates in a white out pattern.,Clinical Case,a,34,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 80 mmHg

10、CO2麻醉(头痛,头昏,嗜睡，精神错乱, 扑翼样震颤, 抽搐, 及昏迷等中枢神经系统症状） 肺性脑病(pulmonary encephalopathy): 呼衰引起的脑功能障碍,（四）中枢神经系统变化 Changes in Central Nervous System,a,41,肺性脑病发生机制 Pathogenesis of pulmonary encephalopathy,a,42,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？,a,43,（一）一般原则 (General Principals) 1. 防治原发病 2. 防止或去除诱因 3. 改善肺通

11、气 4. 纠正水、电解质及酸碱平衡紊乱,保 护重要器官功能,五、呼衰的防治原则 Principals of the Prevention and Treatment of Respiratory Failure,a,44,1 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50 2. 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),a,45,问题： II型呼吸衰竭吸氧的原则？,a,46,respiratory failure ( respiratory insuffi

12、ciency ( ) 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 ( ),a,47,respiratory failure (呼吸衰竭) respiratory insufficiency (呼吸功能不全) restrictive hypoventilation (限制性通气不足) obstructive hypoventilation (阻塞性通气不足) diffusion impairment (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