急性肺损伤ALIppt课件

1、.,1,第二十二章急性肺损伤（ALI） 急性呼吸窘迫综合征（ARDS） ACUTE LUNG INJURY ACUTE RESPIRATORY DISTRESS SYNDROME,.,2,概述,DAD: diffuse alveolar damage（弥漫性肺泡损害） Etiology: shock, infection, trauma, aspiration, drugs, inhalation etc. ALI 1:17,.,4,ALI 138:720.,.,16,临床分期,ARDS分期： 第一期：原发病临床表现 第二期：轻度呼吸困难 第三期：呼吸窘迫 第四期：严重呼吸窘迫,.,17,4.

2、 Diagnosis Criteria,ALI: PaO2/FiO2300 (whatever PEEP) Bilateral infiltrates on chest radiograph PAWP18mmHg or no clinical findings suggestive of increased LAP ARDS: PaO2/FiO2200 (whatever PEEP) Bilateral infiltrates on chest radiograph PAWP18mmHg or no clinical findings suggestive of increased LAP,F

3、rom Bernard GR, Artigas A, Brigham KL, et al: The American-European consensus conference on ARDS definitions. Am J Respir Crit Care Med 1994;149:818,.,18,患者，女性，63，误吸。38mmHg, 100% 9h后： 56mmHg, 50% 13h后： 65mmHg, 50% 20h后： 79mmHg, 50% 34h后： 73mmHg, 50%,.,19,5. 治疗 therapy or treatment,积极治疗原发疾病7. 部分液体通气

4、控制感染8. 表面活性物质替代 机械通气支持9. 免疫疗法的应用 降低肺血管阻力 10. 营养代谢支持疗法 肾上腺糖皮质激素 12. 循环功能的支持 体外膜肺氧合,.,20,Fluid Therapy,Conventional Approach: Aims of resuscitation in ARDS: Attain normal vital signs while PAWPis kept as low as possible. Fluid restriction and diuretic administration. (1)Input and output records of lar

5、ge amount of fluids given befor the diagnosis of ARDS was given. (2)Clinical evidence of excessive fluid retention, such as peripheral edema. (3)Clinical radiologic evidence of pulmoary congestive and edema (4)Improvement in arterial blood gas values after diuretic therapy,.,21,Fluid Therapy,Critiqu

6、e of conventional approach: Pulmonary edema may be caused by so many diseases. In postoperative, posttrauma and sepsis patients, pulmonary edema is due to overexpansion of the interstitium, not to plasma volume overload. Peripheral and pulmonary edema reflect: interstitial fluid volumes increase, pl

7、asma oncotic pressure decrease, nutritional failure, endothelial permeability increase, lung hypoxia or anaphylactoid reactions(过敏反应) Hypovolumia is a major pathophysiologic factor of ARDS; pulmonary edema is an effect, not the cause of, ARDS.,.,22,Fluid Therapy,Fluid therapeutic goals values: CI4.5

8、 L/min.m2 DO2 600 ml/min.m2 VO2 170ml/min.m2 Blood volume 500 ml greater than normal 3.2 L/min.m2 (men) 2.7 L/min.m2 (women) All these values should be reached within 812h postoperatively or after trauma,From Shoemaker WC, Ayres SM, Ake Grenvik, Holbrook PR. Textbook of Critical Care, 4th Edition. H

9、arcourt Publishers Limited. 2000. 1397.,.,23,Fluid Therapy,For patients with severe lung injury, less is more. in a news release from the National Heart, Lung and Blood Institute with this headline. Fluid management is a complex issue, and, until now, it was not clear whether providing more or less

10、fluids was more beneficial. Current trends in usual care appear to more closely resemble the liberal fluid management arm of this study-the stdy arm with worse outcomes. Gordon Bemard, chair of NIH ARDS Network Steering Committee,.,24,Mechanical Ventilation,Lung-protective strategies(肺保护策略): Permiss

11、ive hypercapnia(允许性高碳酸血症) Low tidal volume + high PEEP Recruitment maneuver(肺复张法) Prone position(俯卧位) NO inhalation Extracorporeal gas exchange(体外气体交换) ECMO(体外膜肺氧合) ECCO2OR(体外CO2清除),.,25,Lung protective ventilation,Low tidal volume: 6 ml/kg vs 1012 ml/kg Peak airway pressure 30 cmH2O Driving pressur

12、e 20 cmH2O PaCO2 60 mmHg pH 7.20 High PEEP than conventional values,.,26,Lung protective ventilation-physiologic consequencies of hypercapnia,Cellular effects: intracellular acidosis In the absence of hypoxemia, intracellular acidosis appears to be well tolerated in critical ill patients. Cardiovasc

13、ular effects: high sympathetic activity Increase: HR, BP, PVR Decrease: SVR CNS effects: CBF and ICP increase Consciousness: severe agitation, seizure, coma.,.,27,Lung protective ventilation-recruitment maneuver,Open the lung and keep the lung open,.,28,Lung protective ventilation-stepwise recruitme

14、nt maneuver,PEEP titration depend on: Pdeflex 、PaCO2 、Compliance PEEP in crement: 23 cmH2O Maintain: 12 minutes PEEP target:16/1st RM; 20/2nd RM; 26-30/3rd RM PIPmax: 40 cmH2O Interval: twice a day,.,29,Prone position 俯卧位,Physiologic effects: Reexpand consolidated depedent lung region Improve V/Q matching Reduce