病理生理學(xué)-呼吸系統(tǒng).ppt

1、a,1,病理生理學(xué)系 Department of Pathophysiology 高遠(yuǎn)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,呼衰的類型 Classification of Respiratory failure,1. 按PaCO2 是否升高： 低氧血癥型（I型） 低氧血癥伴高碳酸血癥（II型） 2. 按主要發(fā)病機制：通氣障礙型 換氣障礙型 3. 按病變部位：中樞性和外周性,a,7,一、呼衰的原因和發(fā)病機制

2、 Respiratory Failure: The Causes and the Mechanisms,. 肺通氣功能障礙 Disorders in Pulmonary Ventilation . 肺換氣功能障礙 Disorders in Gas Exchange of the Lungs,a,8,（一）肺通氣功能障礙: Disorders in Pulmonary Ventilation,a,9,a,10,氣道阻力(正常人平靜呼吸)： 80%: 直徑 2mm 氣管 20%: 直徑 0.8 0.8,1. 部分肺泡通氣不足(Alveolar Ventilation Insufficiency)

3、功能性分流 (functional shunt) 靜脈血摻雜（venous admixture),a,23,血液氧和二氧化碳解離曲線 Oxygen and Carbon Dioxide Dissociation Curves,a,24,氧和二氧化碳血液中的運輸 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) 死腔樣通氣(dead space like ventilation）,a,2

4、7,血液氧和二氧化碳解離曲線 Oxygen and Carbon Dioxide Dissociation Curves,a,28,問題 ： 彌散障礙的發(fā)生機制? 功能性分流,靜脈血摻雜? 解剖分流, 真性分流? 死腔樣通氣?,a,29,肺泡-毛細(xì)血管膜 (alveolar capillary membrane) 損傷引起的急性呼吸衰竭。 病因：感染（肺炎，敗血癥等），休克，嚴(yán)重創(chuàng)傷，吸入毒物或胃酸等。,（四）急性呼吸窘迫綜合征 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(頭痛,頭昏,嗜睡，精神錯亂, 撲翼樣震顫, 抽搐, 及昏迷等中樞神經(jīng)系統(tǒng)癥狀） 肺性腦病(pulmonary encephalopathy): 呼衰引起的腦功能障礙,（四）中樞神經(jīng)系統(tǒng)變化 Changes in Central Nervous System,a,41,肺性腦病發(fā)生機制 Pathogenesis of pulmonary encephalopathy,a,42,問題： 呼吸衰竭時呼吸調(diào)節(jié)的變化？ 肺源性心臟病發(fā)生機制? 肺性腦病的定義及發(fā)生機制？,a,43,（一）一般原則 (General Principals) 1. 防治原發(fā)病 2. 防止或去除誘因 3. 改善肺通

11、氣 4. 糾正水、電解質(zhì)及酸堿平衡紊亂,保 護(hù)重要器官功能,五、呼衰的防治原則 Principals of the Prevention and Treatment of Respiratory Failure,a,44,1 I 型呼衰只有缺O(jiān)2而無CO2潴留，可吸入較高濃度O2，一般不超過50 2. II型呼衰有CO2潴留, 應(yīng)持續(xù)低濃度低流量吸氧，如30，12L/min，使PaO2上升到 60 mmHg,（二）吸氧(Oxygen Inhalation),a,45,問題： II型呼吸衰竭吸氧的原則？,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 (限制性通氣不足) obstructive hypoventilation (阻塞性通氣不足) diffusion impairment (彌散障礙) functional shunt (功能性分流) venous admixture (靜脈血摻雜) anatomic shunt (解剖分流); true shunt