2022年医学专题—呼吸功能的评价指标(1).ppt

第十四章肺功能(gngnng)不全 Chapter 14Respiratory Failure,1,第一页，共六十四页。,概 述 General description,肺的正常功能及其评价指标；呼吸衰竭的概念(ginin)；呼吸衰竭的分类。,2,第二页，共六十四页。,一、肺的正常(zhngchng)功能及其评价指标；Respiratory function(External respiration)Non-respiratory functions,概 述 General description,3,第三页，共六十四页。,呼吸功能的评价(pngji)指标,肺容量；肺通气功能的评价(pngji)指标,4,第四页，共六十四页。,呼吸功能的评价(pngji)指标,肺弥散量(diffusing capacity)：指气体 在分压差作用下，每分钟经肺泡膜弥散的容量。正常值为：188ml/minkPa。反映肺换气效率(xio l)。肺泡气-动脉血氧分压差(PA-aO2)：指肺泡 气氧分压与动脉血氧分压之差。PA-aO2=PAO2-PaO2 反映肺泡膜氧交换状态。,换气(hun q)功能的评价指标,5,第五页，共六十四页。,肺通气、换气功能指标 呼衰指数(respiratory failure index，RFI)：指动脉血氧分压与吸入气氧浓度之比值。反映外呼吸(hx)效率。,呼吸功能的评价(pngji)指标,6,第六页，共六十四页。,呼吸动力功能：呼吸的动力功能包括：气道阻力(zl)（Raw）肺顺应性（CL）呼吸肌力（Fm）等。最常用的测定指标是气道阻力（Raw）。,呼吸(hx)功能的评价指标,7,第七页，共六十四页。,Non-respiratory functions,FiltrationDefense and immune function Clearance of the foreign body in the airway Immune functionMetabolism,8,第八页，共六十四页。,Generally diagnosed by PaO2 60mmHg（at sea level）;When FiO2 20%,then RFI 300 can be used as the index of diagnosis.,二、概念(ginin)Concept,External respiratory dysfunction PaO2 60mmHg（at sea level）With or without PaCO2 50mmHg,呼吸衰竭（Respiratory failure）,9,第九页，共六十四页。,呼吸功能不全（Respiratory insufficiency）外呼吸功能障碍而不能维持血气稳态但未达上述水平；或在静息状态时,血气值正常，仅在运动负荷(fh)时PaO2才明显下降或伴PaCO2增高者，称为呼吸功能不全。,二、概念(ginin)Concept,10,第十页，共六十四页。,1.According to whether PaCO2 is normal Type PaO2(50mmHg),三、呼吸衰竭的分类(fn li)Classifications,11,第十一页，共六十四页。,2.According to PathogenesisVentilation RF;Exchanging RF.3.According to Primary SiteCentral RF;Peripheral RF.4.According to DurationAcute RF;Chronic RF.,三、呼吸衰竭的分类(fn li)Classifications,12,第十二页，共六十四页。,1 病因(bngyn)和发病机制 Etiology and Pathogenesis,Pulmonary ventilation disorder,Pulmonary gas exchange dysfunction,13,第十三页，共六十四页。,一、肺通气(tng q)功能障碍 Pulmonary ventilation disorder-hypoventilation,限制性通气(tng q)不足 Restrictive hypoventilation 阻塞性通气不足 Obstructive hypoventilation,14,第十四页，共六十四页。,（一）限制性通气(tng q)不足Restrictive hypoventilation,指呼吸动力减弱或胸廓和肺的扩张性能降低(jingd)（弹性阻力增大）使肺泡扩张受限引起的通气功能障碍。During inspiration,the dilation or inflation of alveoli are restricted.It is caused by the diseases that affect the distensibility of the alveolar.,15,第十五页，共六十四页。,Paralysis of respiratory muscles,Decreased compliance of chest wall,Causes of restrictive hypoventilation,Decreased compliance of lung,Hydrothorax or pneumothorax,16,第十六页，共六十四页。,由于(yuy)气道阻塞或狭窄,使气道阻力增加引起的通气障碍。Obstructive hypoventilation is produced by airway constriction or obstruction.,（二）阻塞性通气(tng q)不足Obstructive hypoventilation,Central airway obstruction,Peripheral airway obstruction,trachea crotch,影响气道阻力的最主要因素(yn s)是气道内径,17,第十七页，共六十四页。,中央(zhngyng)气道阻塞:Central airway obstruction,Extrathoracic airwayobstruction,Intrathoracic airway obstruction,Expiration,Expiration,*吸气(x q)性呼吸困难Inspiratory dyspnea,*呼气(h q)性呼吸困难Exspiratory dyspnea,Inspiration,Intra-airway pressure Atmospheric pressure,Intra-airway pressure Atmospheric pressure,Inspiration,Intra-airway pressure Intra-thoracic pressure,Intra-airway pressure Intra-thoracic pressure,18,第十八页，共六十四页。,2.外周气道阻塞(zs)Peripheral airway obstruction,It refers to the airway obstruction at the bronchiole whose diameter is 2mm.Causes：慢性支气管炎 chronic bronchitis支气管哮喘 bronchial asthma慢性阻塞性肺气肿等 chronic obstructive emphysema,etc.（主要(zhyo)损害小气道）,19,第十九页，共六十四页。,*呼气(h q)性呼吸困难,呼气时肺泡缩小，对小气道的牵拉作用减弱，胸内负压减小，气道内径变小，阻力增大，小气道狭窄(xizhi)更加明显；吸气时反之，小气道狭窄减轻。,20,第二十页，共六十四页。,肺气肿病人(bngrn)肺弹性回缩力降低，等压点也向肺泡端移动(上移)，易致小气道受压而闭合.,21,第二十一页，共六十四页。,（三）全肺通气不足时的血气(xuq)变化Blood gas changes in hypoventilation,22,第二十二页，共六十四页。,二、肺换气(hun q)功能障碍 Pulmonary gas exchange dysfunction,弥散障碍(Diffusion disorder)肺泡通气与血流比例失调(Ventilation/perfusion imbalance)解剖分流(fn li)增加(Increase of anatomic shunt),23,第二十三页，共六十四页。,(一)弥散(msn)障碍Diffusion disorder,1.概念 Concept弥散障碍是指由肺泡膜面积(min j)减小或肺泡膜异常增厚和弥散时间缩短引起的气体交换障碍。,24,第二十四页，共六十四页。,2.弥散(msn)障碍的常见原因Common causes of diffusion disorder,Area of alveolar-capillary membrane,Normal adult R-M:80 m2At rest,used R-M:3540 m2Causes:肺不张(atelectasis)肺实变(pulmonary consolidation)肺叶(fiy)切除(lobar resection)肺气肿(emphysema),25,第二十五页，共六十四页。,Area of alveolar-capillary membrane Thickness of the membrane,2.弥散(msn)障碍的常见原因Common causes of diffusion disorder,26,第二十六页，共六十四页。,Area of alveolar-capillary membrane Thickness of the membrane Shortening of the diffusion time 体力负荷增加(zngji)（劳动、运动）,2.弥散(msn)障碍的常见原因Common causes of diffusion disorder,27,第二十七页，共六十四页。,At rest-no changes.Only when the pulmonary blood stream speeds up-PaO2,PaCO2 normal or.,3.弥散(msn)障碍时的血气变化Blood Gas Changes in Diffusion Disorder,Type RF,28,第二十八页，共六十四页。,（二）肺泡通气(tng q)与血流比例失调Ventilation-perfusion imbalance,29,第二十九页，共六十四页。,Normal ventilation and blood flow distribution in lung,more marked,30,第三十页，共六十四页。,肺部疾病时，通气与血流比例严重失调，患者不能进行有效的换气(hun q)。这是肺部疾病引起呼吸衰竭最常见的机制。Ventilation/perfusion imbalance consists of 部分肺泡通气不足（功能性分流）Partial alveolar hypoventilation(Functional shunt/Venous admixture)部分肺泡血流不足（死腔样通气）Partial alveolar hypoperfusion(Dead space like ventilation),31,第三十一页，共六十四页。,部分(b fen)肺泡通气不足 Partial alveolar hypoventilation（VA/Q）,支哮、慢支、阻塞性肺气肿,部分肺泡(fipo)阻塞性通气不足,肺纤维化、肺水肿、肺不张等,部分(b fen)肺泡限制性