Dyspnea

1. Dyspnea Jin Yu-hua Dept. of Geriatrics

2. Definition • Dyspnea is defined as an awareness of difficulty in breathing. • Most patients suffer from actual difficulty, some patients just taste an awareness of hyperventilation(换气过度).

3. How to describe these sensations • Cannot get enough air • Air does not go all the way down • Smothering feeling in the chest • Tightness in the chest • Fatigue in the chest

4. Definition • Dilatation of nares(鼻翼扇动), cyanosis(紫绀), use of accessory muscles of respiration • Abnormalities of respiratory rate,depth or rhythm

5. Etiology • Respiratory disease • Cardic disease • Toxic • Nero-Psychogenic • Haematological disease • Increase of abdominal pressure (massive ascites(腹水), pregnancy(怀孕) etc)

6. Normal person may experience the physiologic dyspnea during heavy exercise • Environment short of oxygen

9. Respiratory dyspnea • Respiratory dyspnea is caused by abnormal ventilation and gas exchange. • Reduction in ventilatory capacity, hypercapnia(二氧化碳潴留) and hypoxemia(低氧血症) resulting from respiratory disease. • Three clinical types: inspiratory dyspnea, expiratory dyspnea, mixed dyspnea.

10. Inspiratory dyspnea • Clinical characteristics: visible indrawing over the sternal notch, the supraclavicular spaces, the intercostal spaces and the epigastrium in the inspiration(三凹症). • Accompanied by a coarse, low pitched inspiratory wheezing and dry cough. • Stenosis and obstruction of larynx, trachea, and bronchi

11. Expiratory dyspnea • Clinical characteristics: expiration is prolonged and laboured with wheezing. • Cause: the decrease of lung elasticity and spasm narrowing of the bronchioles and smaller bronchi. • Familiar diseases: emphysema(肺气肿), bronchial asthma(支气管哮喘) and chronic asthmatic bronchitis(喘慢支).

12. Mixed dyspnea • Clinical characteristics: breathing is difficult during both inspiration and expiration. Respiratory frequency increase and respiration superficial. • Cause: decrease of ventilators and gas exchange capacity • Familiar diseases: severe pneumonia(肺炎), pulmonary fibrosis(肺纤维化), massive atelectasis(大片肺不张) etc

13. Cardiac dyspnea • Cardiac dyspnea is usually attributable to pulmonary vascular congestion resulting from the left and/or right heart failure. • Dyspnea is the primary symptom of left heart failure.

15. Left heart failure Basal diseases: • Coronary heart disease • Hypertensive heart disease • Rheumatic heart disease • Congenital heart disease

16. Left heart failure Mechanism: • Lung congestion decrease gas dispersion • Alveoli are stiff and more work is needed to overcome elastic recoil • The high alveolar pressure stimulate stretch receptor • High pulmonary circulation pressure stimulate respiratory nerve center

17. Left heart failure Clinical representation: • Exhausted dyspnea(劳力性呼吸困难) • Orthopnea(端坐呼吸) • Paroxysmal nocturnal dyspnea(夜间阵发性呼吸困难)

18. Exhausted dyspnea • Difficulty in breathing when the patient is in activity relived when he relax. • Doing exercise impel more blood into pulmonary circulation. • More oxygen is needed for body demand, especially the heart.

19. Functional classification • Class Ⅰ– no limitation: Ordinary physical activity does • Class Ⅱ– slight limitation of physical activity • Class Ⅲ– Marked limitation of physical activity • Class Ⅳ– inability to carry or any physical activity without discomfort

20. Orthopnea Difficulty in breathing in the supine position relived by sitting up • Reduce the degree of pulmonary congestion by pooling blood in the lower extremities • Improve the diaphragmatic movement • Increase vital capacity

21. Paroxysmal nocturnal dyspnea • The patient awakes short of breath at night, but often obtain relief by sitting up for a period of time. • Physical examination: moist rales at the both lung bases, tachycardia, wheezing and bronchospasm (cardiac asthma心源性哮喘).

22. Paroxysmal nocturnal dyspnea Reason: • Supine posture for sleep impel more blood into pulmonary circulation, and decrease vital capacity. • Vagus excitement cause coronary artery constriction and bronchioles spasm.

23. Right heart failure Basal diseases: • Acute cor pulmonale(肺心病) which caused by pulmonary embolism(肺栓塞) • Chronic cor pulmonale which caused by chronic obstructive pulmonary disease(慢阻肺)

24. Right heart failure Mechanism: • The pressure of right atria and superior vena cava is the natural stimulus of respiratory center. • Hypoxemia and the accumulation of the acid metabolites stimulate respiratory center. • The restriction of the respiratory movement caused by enlargement of liver,ascites and pleural effusion.

25. Biventricular failure Left heart failure plus right heart failure may cause severe dyspnea?

26. Toxic dyspnea In the metabolic acidosis (uremia尿毒症 and diabetic acidosis糖尿病性酸中毒), the acid metabolites stimulate the respiratory center, causing deep and regular respiration (Kussmanul) with snoring.

27. Toxic dyspnea The overdose of morphine and pentobarbital can depress respiratory center causing slow respiration or Cheyne-Stokess respiration.

28. Neuro-Psychogenic dyspnea The respiratory center loses the blood supply or is compressed while patient suffering from cerebro vascular disease. The respiration becomes deep, slow and irregular.

29. Nero-Psychogenic dyspnea Patient suffer from hysteria will be seen repetitive deep, signing respiration with numbness of extremities or lips, cheiropedal spasm.

30. Haematologicl dyspnea • The decrease of oxygen-carrying capacity and oxygen content develop abnormal respiration and increase heart rate, such as severe anemia, carbon monoxide. • Hypotension can stimulate respiration when patient suffer from shock.

31. Accompanying symptoms Paroxysmal dyspnea with wheezing, It is present 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.

32. Accompanying symptoms Dyspnea with chest pain. It is frequently observed in lobar pneumonia(大叶性肺炎), pulmonary infarction(肺梗塞), 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).

33. 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 nervous system diseases.

34. 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 heart failure and organophosphorus poisoning(有机磷中毒).

35. 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.

36. 小结 呼吸困难的病因 • 肺原性 • 心原性 • 中毒性 • 神经精神性 • 血液病

37. 肺原性呼吸困难 • 吸气性 • 呼气性 • 混合性

38. 左心衰 • 引起呼吸困难的机制 • 临床表现(劳力性、端坐呼吸、夜间阵发性气急)及意义

39. 右心衰 引起呼吸困难的机制

40. 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

41. 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

42. X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

43. X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

44. X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

45. 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