1、DyspneaDefinitionuDyspnea is defined as an awareness of difficulty in breathing.uMost patients suffer from actual difficulty, some patients just taste an awareness of hyperventilation(换气过度).How to describe these sensationslCannot get enough airlAir does not go all the way downlSmothering feeling in
2、the chestlTightness in the chestlFatigue in the chestDefinitionuDilatation of nares(鼻翼扇动), cyanosis(紫绀), use of accessory muscles of respirationuAbnormalities of respiratory rate,depth or rhythmEtiologyuRespiratory diseaseuCardic diseaseuToxicuNero-PsychogenicuHaematological diseaseuIncrease of abdo
3、minal pressure (massive ascites(腹水), pregnancy(怀孕) etc)uNormal person may experience the physiologic dyspnea during heavy exerciseuEnvironment short of oxygenRespiratory dyspneauRespiratory dyspnea is caused by abnormal ventilation and gas exchange.uReduction in ventilatory capacity, hypercapnia(二氧化
4、碳潴留) and hypoxemia(低氧血症) resulting from respiratory disease.uThree clinical types: inspiratory dyspnea, expiratory dyspnea, mixed dyspnea.Inspiratory dyspneauClinical characteristics: visible indrawing over the sternal notch, the supraclavicular spaces, the intercostal spaces and the epigastrium in
5、the inspiration(三凹症).uAccompanied by a coarse, low pitched inspiratory wheezing and dry cough.uStenosis and obstruction of larynx, trachea, and bronchiExpiratory dyspneauClinical characteristics: expiration is prolonged and laboured with wheezing.uCause: the decrease of lung elasticity and spasm nar
6、rowing of the bronchioles and smaller bronchi.uFamiliar diseases: emphysema(肺气肿), bronchial asthma(支气管哮喘) and chronic asthmatic bronchitis(喘慢支). Mixed dyspneauClinical characteristics: breathing is difficult during both inspiration and expiration. Respiratory frequency increase and respiration super
7、ficial.uCause: decrease of ventilators and gas exchange capacityuFamiliar diseases: severe pneumonia(肺炎), pulmonary fibrosis(肺纤维化), massive atelectasis(大片肺不张) etcCardiac dyspneauCardiac dyspnea is usually attributable to pulmonary vascular congestion resulting from the left and/or right heart failur
8、e.uDyspnea is the primary symptom of left heart failure.Left heart failureBasal diseases:uCoronary heart diseaseuHypertensive heart diseaseuRheumatic heart diseaseuCongenital heart diseaseLeft heart failureMechanism:uLung congestion decrease gas dispersionuAlveoli are stiff and more work is needed t
9、o overcome elastic recoiluThe high alveolar pressure stimulate stretch receptoruHigh pulmonary circulation pressure stimulate respiratory nerve centerLeft heart failureClinical representation:uExhausted dyspnea(劳力性呼吸困难)uOrthopnea(端坐呼吸)uParoxysmal nocturnal dyspnea(夜间阵发性呼吸困难)Exhausted dyspneauDifficu
10、lty in breathing when the patient is in activity relived when he relax.uDoing exercise impel more blood into pulmonary circulation.uMore oxygen is needed for body demand, especially the heart. Functional classificationlClass no limitation: Ordinary physical activity doeslClass slight limitation of p
11、hysical activitylClass Marked limitation of physical activitylClass inability to carry or any physical activity without discomfortOrthopneaDifficulty in breathing in the supine positionrelived by sitting upuReduce the degree of pulmonary congestion by pooling blood in the lower extremitiesuImprove t
12、he diaphragmatic movementuIncrease vital capacityParoxysmal nocturnal dyspneauThe patient awakes short of breath at night, but often obtain relief by sitting up for a period of time.uPhysical examination: moist rales at the both lung bases, tachycardia, wheezing and bronchospasm (cardiac asthma心源性哮喘
13、).Paroxysmal nocturnal dyspneaReason:uSupine posture for sleep impel more blood into pulmonary circulation, and decrease vital capacity.uVagus excitement cause coronary artery constriction and bronchioles spasm.Right heart failureBasal diseases:uAcute cor pulmonale(肺心病) which caused by pulmonary emb
14、olism(肺栓塞)uChronic cor pulmonale which caused by chronic obstructive pulmonary disease(慢阻肺)Right heart failureMechanism:uThe pressure of right atria and superior vena cava is the natural stimulus of respiratory center.uHypoxemia and the accumulation of the acid metabolites stimulate respiratory cent
15、er.uThe restriction of the respiratory movement caused by enlargement of liver,ascites and pleural effusion.Biventricular failure Left heart failure plus right heart failure may cause severe dyspnea?Toxic dyspnea In the metabolic acidosis (uremia尿毒症 and diabetic acidosis糖尿病性酸中毒), the acid metabolite
16、s stimulate the respiratory center, causing deep and regular respiration (Kussmanul) with snoring.Toxic dyspneaThe overdose of morphine and pentobarbital can depress respiratory center causing slow respiration or Cheyne-Stokess respiration.Neuro-Psychogenic dyspneaThe respiratory center loses the bl
17、ood supply or is compressed while patient suffering from cerebro vascular disease. The respiration becomes deep, slow and irregular. Nero-Psychogenic dyspneaPatient suffer from hysteria will be seen repetitive deep, signing respiration with numbness of extremities or lips, cheiropedal spasm.Haematol
18、ogicl dyspneauThe decrease of oxygen-carrying capacity and oxygen content develop abnormal respiration and increase heart rate, such as severe anemia, carbon monoxide.uHypotension can stimulate respiration when patient suffer from shock.Accompanying symptoms Paroxysmal dyspnea with wheezing, It is p
19、resent in bronchial asthma and cardiac asthma. Paroxysmal severe dyspnea is often seen in acute larynx edema(急性喉水肿), spontaneous pneumothorax(自发性气胸), massive pulmonary embolism. Accompanying symptoms Dyspnea with chest pain. It is frequently observed in lobar pneumonia(大叶性肺炎), pulmonary infarction(肺
20、梗塞), spontaneous pneumothorax, acute exudative pleurisy(急性渗出性胸膜炎), acute myocardial infarction(急性心肌梗死), and bronchial carcinoma(支气管肺癌).Accompanying symptoms Dyspnea with fever. It is commonly noted in pneumonia, lung abscess(肺脓肿), pulmonary tuberculosis(肺结核), pleurisy, acute pericarditis(急性心包炎), and
21、 nervous system diseases.Accompanying symptoms Dyspnea with cough and purulent sputum. It is often present in chronic bronchitis, obstructive pulmonary emphysema with infection, purulent pneumonia, and lung abscess; Dyspnea with large amount of foamy sputum is often seen in acute left ventricular he
22、art failure and organophosphorus poisoning(有机磷中毒).Accompanying symptoms Dyspnea with coma. It suggests cerebral hemorrhage(脑出血), pneumonia with shock, uremia, diabetic ketoacidosis(糖尿病酮症酸中毒), and acute poisoning.小结小结呼吸困难的病因u肺原性u心原性u中毒性u神经精神性u血液病肺原性呼吸困难u吸气性u呼气性u混合性左心衰u引起呼吸困难的机制u临床表现(劳力性、端坐呼吸、夜间阵发性气急)
23、及意义右心衰引起呼吸困难的机制复习思考题复习思考题严重吸气性呼吸困难最主要的特点是:A.端坐呼吸B.鼻翼煽动C.哮鸣音D.呼吸加快加深E.三凹征混合性呼吸困难的特点是A.呼气费力B.吸气费力C.可伴有干咳及高调吸气性喉鸣D.由于肺呼吸面积减少,换气功能障碍所致E.以上都不是X型题型题吸气性呼吸困难的特点是:A.吸气显著费力B.呼吸时间明显延长,常伴有吸气期哮鸣音C.严重者可见“三凹征”D.常见于喉部、气管、支气管的狭窄与阻塞E.由于肺呼吸面积减少导致换气功能障碍所致X型题型题呼气性呼吸困难的主要特点有A.呼气费力、呼吸缓慢、呼吸时间明显延长B.严重者有“三凹征”C.常伴有呼气期哮鸣音D.由于肺泡弹性减弱或（和）小支气管痉挛和炎症所致E.常见于重症肺炎、弥漫性肺间质病变等X型题型题左心衰竭引起的呼吸困难主要是由于A.体循环淤血B.肺淤血C.呼吸中枢功能障碍D.肺泡弹性减低E.肺循环压力减低呼吸变慢变浅伴有呼吸节律异常见于A.喉炎B.左心衰竭C.右心衰竭D.呼吸功能中枢障碍E.癔症
