Infectious Diseases of The Lungs

1. Infectious Diseases of The Lungs Hu Suping PulmonaryDepartment 1st clinical college, Wuhan University

2. Case A 35 y.o. M presents with 2d cough, productive of green-yellow sputum. He complains of fever, chills, and dyspnea PE: T 38.7℃, RR 26/min, BP 110/65 mmHg, HR 125/min

3. Examination of the lungs reveals increased fremitus and dullness at the right posterior base. Crackles and bronchial breath sounds are audible at the right base Gram stain of the sputum reveals gram-positive cocci and numerous neutrophils

5. 目的和要求 • 掌握肺炎的临床表现和诊断程序 重点掌握肺炎球菌肺炎的病因、发病机制和病理、临床表现、诊断、鉴别诊断和防治。熟悉其它病原体所致肺炎的临床特点和诊治 • 掌握肺脓肿的临床表现、诊断和鉴别诊断、治疗原则 • 熟悉支气管扩张症的临床表现、诊断要点

6. Overview of pneumonia • Pneumococcal pneumonia • Staphylococcal pneumonia • Mycoplasma pneumonia • Pulmonary mycosis • Lung abscess

7. Definition of pneumonia • Pathophysiology of pneumonia • Clinical manifestation & Categories • Microbiologic examination • Diagnostic procedure • Treatment and Prevention

8. Definition Inflammation of the distal lung terminal airways, alveolar spaces, and interstitium Causes: pathogen, physiochemical factors, allergy, etc

9. Definition of pneumonia • Pathophysiology of pneumonia • Clinical manifestation & Categories • Microbiologic examination • Diagnostic procedure • Treatment and Prevention

10. Pathophysiology of bacterial pneumonia Sources of bacteria Route of inoculation Response Outcome Colonization of Naso/oropharynx Microaspiration Sterile lung Inhalation Air Lung defenses Non-pulmonary infection Bloodstream Direct extension Contiguous infection Pneumonia

11. Usual routes of inoculation • Microaspiration：most bacterial pneumonia, anaerobic pleuropulmonary infections • The concentration of aerobic bacteria in upper respiratory tract secretions is about 108 organisms per milliliter, and that of anaerobic bacteria is about 10 times greater, aspiration of even small quantities of oropharyngeal secretions introduces an enormous bacterial challenge to the lungs

12. Ambient air: • Mycobacterium tuberculosis • Viruses， including influenza • plague and anthrax bacilli • Organisms that are present in large numbers • in contaminated air in confined spaces, such • as Legionella organisms

13. Bloodstream: Staphylococcal • endocarditis, septic emboli • Direct extension: Amebic liver abscess • (uncommon)

14. Pathogenesis

15. Definition of pneumonia • Pathophysiology of pneumonia • Clinical manifestation & Categories • Microbiologic examination • Diagnostic procedure • Treatment and Prevention

16. Symptoms and signs depending on the offending pathogen andthe state of the host

17. Previously healthy person with pneumococcal pneumonia(typical) • a brief prodromal upper respiratory illness • fever, chill • cough with purulent or “rusty” sputum • pleuritic chest pain • signs of consolidation

18. (2)Elderly confused patient maybe only deterioration of mental function rhonchi without signs of consolidation

19. (3) Predisposing factors old age, previous pulmonary diseases, smoking history A. a history of alcoholism, seizure disorder, previous stroke, recent dental procedures aspiration pneumonia or lung abscess caused by oral anaerobes and mixed aerobic/anaerobic flora

20. B. a history of intravenous drug use Staphylococcus aureus pneumonia with tricuspid endocarditis (sepsis) C. persons with depressed cell-mediated immunity increased incidence of bacterial, fungal, and tuberculous pneumonia

21. Categories Anatomy: lobar pneumonia; bronchopneumonia; interstitial pneumonia Causes: bacterial pneumonia; viral pneumonia; mycoplasma, chlamydia pneumonia; fungal pneumonia; radiopneumonitis; etc Contaminant source: community-acquired pn（CAP） hospital-acquired pn（HAP）

23. Lobar pneumonia: whole lobe(s) involved Fixed specimen, grey hepatization Lobar pneumonia

24. Bronchopneumonia, patchy involvement

25. → 间质性肺炎 病理切片

26. 间质性肺炎X片

27. 间质性肺炎 CT片肺窗

28. CAP an acute infection of the pulmonary parenchyma in a patient who is not hospitalized or residing in a long-term-care facility for the 14 days before the onset of illness Common pathogens:S. pneumoniae, H. influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae,Moraxella catarrhalis

29. HAP or nosocomial pneumonia Colonization of the upper respiratory tract with potentially pathogenic organisms, including gram-negative bacilli and S. aureus, commonly occurs in hospitalized patients The prevalence of colonization is proportional to the duration of hospitalization and the severity of underlying illness

30. Organisms most frequently involved in HAP • S. aureus, H. influenzae, K. pneumonia, • Pseudomonas species, Escherichia coli, • Enterobacter species, Acinetobacter, et al • often resistant to multiple antimicrobials • knowledge of the resistance patterns in a given hospital is essential

31. Chest radiograph Lobar consolidation with small pleural effusion —pneumococcal pneumonia Cavitation — S, aureus, gram-negative bacilli or mixed anaerobic infection, or Mycobacterium tuberculosis Multilobar or segmental consolidation with large pleural effusion — H. influenzae

32. Chest radiograph Upper-lobe air space consolidation, abscess formation, bulging interlobar fissure with the accumulation of large amounts of inflammatory exudate — K. pneumoniae

33. Definition of pneumonia • Pathophysiology of pneumonia • Clinical manifestation & Categories • Microbiologic examination • Diagnostic procedure • Treatment and Prevention

34. Sputum (1) before antimicrobial is instituted (2) a deep cough (3) be transported to the laboratory and processed within 2 hours (4) include Gram’s stain, cytologic evaluation, and aerobic culture

35. Cytologic criteria for sputum culture purulent, <10 squamous cells and >25 leukocytes/low power field Gram’s stain:predominated organism encapsulated gram-positive cocci – Pneumococci Quantitative culture Cp ≥107 cfu/ml definitive pathogen 104< Cp<107cfu/ml undetermined Cp≤104cfu/ml exclusive

36. 肺炎链球菌纯培养的 镜下形态 (革兰染色) 肺炎链球菌肺炎患者 痰标本直接涂片 (革兰染色)

37. 肺炎链球菌在血琼脂 平板上的菌落特征 (18~24h) 肺炎链球菌荚膜形态 (Hiss荚膜染色)

38. 金黄色葡萄球菌纯 培养的镜下形态 (革兰染色) 流感嗜血杆菌纯培养 镜下形态(革兰染色)

39. 军团菌纯培养的镜下 形态(革兰染色) 军团菌在荧光显微镜 下的形态(荧光染色) 军团菌在BCYE琼脂 平板上培养的菌落 特征(3~5d)

40. Limitation (1) difficulties in obtaining a proper specimen pneumococci: extremely fastidious (2) difficulties in interpreting the results overgrowth with less fastidious oral flora false positive diagnoses of GNB and S. aureus prior antimicrobial treatment false negative

41. Cultures of transtracheal aspirates, transthoracic needle aspirates, and bronchoalveolar lavage fluids or protected brush catheter specimens more sensitive and more specific

42. Blood cultures (1) not necessary when the patient does not require admission (2) should be obtained from all hospitalized patients before treatment is initiated

43. Pleural fluid cultures • Special tests • Antigen tests for viral pneumonia (influenza virus, respiratory syncytial virus, adenovirus, and parainfluenza viruese1,2, and 3) • Urine antigen assays for pneumococci and legionella pneumoniae: very specific (>90%) but low sensitivity(50%~60%)

44. Definition of pneumonia • Pathophysiology of pneumonia • Clinical manifestation & Categories • Microbiologic examination • Diagnostic procedure • Treatment and Prevention

45. Diagnostic procedure (1) Clinical diagnosis of pneumonia a chest radiograph, WBC count and DC, sputum examination, history and physical examination Differential diagnosis: pulmonary tuberculosis lung cancer lung abscess pulmonary thromboembolism noninfectious diseases

48. Diagnostic procedure (2) Identifying the etiologic pathogen (3) Assessing the severity of infection and need for hospitalization In general, hospitalization is needed if patients have multiple risk factors for a complicated course

49. Risk factors 1. Age over 65 yr 2. Presence of coexisting illnesses such as COPD, bronchiectasis, malignancy, diabetes mellitus, chronic alcohol abuse, malnutrition, cerebrovascular disease, and postsplenectomy 3. Certain physical findings: RR ≥ 30 /min; DBP≤ 60 mmHg or SBP < 90 mmHg; pulse ≥ 125/min; T< 35 ℃ or ≥ 40 ℃; confusion; and extrapulmonary infection 4. Laboratory findings also predict increased morbidity or mortality:

50. WBC < 4×109/L or > 30 × 109/L, or N <1 × 109/L • PaO2< 60 mm Hg or PaCO2 of > 50 mm Hg (room air) • c. Serum Cr >1.2 mg/dl or BUN > 20 mg/dl (> 7 mM) • d. Chest radiograph findings: multilobar involvement, presence of a cavity, rapid radiographic spreading and the presence of a pleural effusion • e. HCT of <30% or Hb < 9 mg/dl • f. Sepsis or organ dysfunction as manifested by a metabolic acidosis, or coagulopathy • g. Arterial pH < 7.35