Chapter 18 Fungal Diseases of the Lung

1. Chapter 18Fungal Diseases of the Lung

2. YLS M S AC Figure 18-1. Fungal disease of the lung. Cross-sectional view of alveoli infected with Histoplasma capsulatum.AC, alveolar consolidation; M, alveolar macrophage; S, Fungal spore; YLS, yeastlike substance.

3. Anatomic Alterations of the Lungs • Alveolar consolidation • Alveolar-capillary destruction • Caseous tubercles or granulomas • Cavity formation • Fibrosis of the lung parenchyma • Bronchial airway secretions

4. Etiology Histoplasmosis (Histoplasma capsulatum) • Most common fungal disease in the United States • Prevalence is especially high alone th major rive valleys of the Midwest • Ohio, Michigan. Illinois, Mississippi, Kentucky, Tennessee, Georgia, Arkansas • Histoplasmosis is also called Ohio Valley Fever

5. Etiology (Cont’d) Screening and Diagnosis—histoplasmosis • Fungal culture—considered the gold standard for detecting histoplasmosis • Fungal stain • A positive test result is 100% accurate • Serology • A relatively fast and accurate test

6. Etiology (Cont’d) Coccidioidomycosis (Coccidioides immitis) • Endemic in hot, dry regions: • California • Arizona • Nevada • New Mexico • Texas • Utah

7. Etiology (Cont’d) • Coccidioidomycosis is also known as: • California Disease • Desert Fever • San Joaquin Valley Disease • Valley Fever

8. Etiology (Cont’d) • Screening and diagnosis—coccidioidomycosis • Direct visualization of distinctive spherules in patient’s sputum • Tissue exudates • Biopsies • Spinal fluid

9. Etiology (Cont’d) Blastomycosis (Blastomyces dermatitidis) • Also called: • Chicago disease, • Gilchrist’s disease, • American blastomycosis • Occurs in people living in the south-central and midwestern United States and Canada.

10. Etiology (Cont’d) • Screening and diagnosis−Blastomycosis • Direct visualization of yeast in sputum smears • Culture of the fungus

11. Etiology (Cont’d) Opportunistic pathogens • Candida albicans • Cryptococcus neoformans • Aspergillus

12. Overview of the Cardiopulmonary Clinical Manifestations Associated with Fungal Diseases of the Lungs The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Alveolar Consolidation Increased Alveolar-Capillary Membrane Thickness

15. Clinical Data Obtained at the Patient’s Bedside

19. Clinical Data Obtained from Laboratory Tests and Special Procedures

23. PaO2 and PaCO2 trends during acute alveolar hyperventilation.

25. PaO2 and PaCO2 trends during acute or chronic ventilatory failure.

30. Figure 18-2. Acute inhalational histoplasmosis in an otherwise healthy patient. This young man developed fever and cough after tearing down an old barn. The study shows bilateral hilar adenopathy and diffuse nodular opacities. (From Hansell DM, Armstrong P, Lynch DA, McAdams HP, eds: Imaging of diseases of the chest, ed 4, Philadelphia, 2005, Elsevier.)

31. Figure 18-3. Histoplasmoma, showing a well-defined spherical nodule. The central portion of the nodule shows calcification.

32. Figure 18-4. Chronic cavitary histoplasmosis. Note the striking upper zone predominance of the shadows. Numerous large cavities.

33. General Management of Fungal Disease The antifungal agents are the first line of defense in treating fungal lung infections. In general, the drug of choice for most fungal infections is the IV administration of the polyene amphotericin B.

34. Table 18-1 Antifungal Agents

35. Table 18-1 Antifungal Agents (Cont’d)

36. Table 18-1 Antifungal Agents (Cont’d)

37. Table 18-1 Antifungal Agents (Cont’d) Modified from Gardenshire DS: Rau’s respiratory care pharmacology, ed 7, St. Louis, 2008, Elsevier.

38. Respiratory Care Treatment Protocols Oxygen Therapy Protocol Bronchopulmonary Hygiene Therapy Protocol Mechanical Ventilation Protocol