TYPES AND SUBTYPES AAND CAUSES OF PNEUMONIA.pptx

Bacterial, viral, and fungal pneumonia

1. CBU-SOM/Ndola Teaching Hospital Internal Medicine JUNE 2022 PNEUMONIA Dr C Nyirenda

2. Learning objectives At the end of this unit the student will be able to: 1. Define Pneumonia 2. List the etiologic agents of Pneumonia occurring in different settings 3. Describe the mode of transmission of Pneumonia 4. Understand the epidemiology of Pneumonia. 5. Describe the pathophysiology of Pneumonia 6. Identify the clinical manifestations of Pneumonia 7. List the complications of Pneumonia 8. Describe the most common investigations for the diagnosis of Pneumonia 9. Make an accurate diagnosis of Pneumonia 10. Manage most cases of Pneumonia appropriately 11. Refer complicated cases of Pneumonia

3. Definition Pneumonia is an acute infection of the lung parenchyma including alveolar spaces and interstitial tissue. Involvement may be confined to an entire lobe -Lobar pneumonia A segment of a lobe-Segmental or lobular pneumonia Alveoli contiguous to bronchi - Bronchopneumonia Interstitial tissue - Interstitial pneumonia These distinctions are generally based on x-ray observations.  

4. Risk factors Predisposing factors for pneumonia include :-   Preceding respiratory viral infections Alcoholism Cigarette smoking Underlying diseases such as Heart failure, COPD Age extremes Immunosuppressive therapy and disorders Decreased consciousness, comma, seizure etc. Surgery and aspiration of secretions

5. Pathogenesis The usual mechanisms to develop pneumonia are either to inhale droplets small enough to reach the alveoli, or to aspirate secretions from the upper airways. Other means include hematogenous dissemination, via the circulation, or directly from contiguous infections.

6. Epidemiology CAP versus HAP Community-acquired pneumonia (CAP) is defined as an acute infection of the pulmonary parenchyma in a patient who has acquired the infection in the community, as distinguished from hospital-acquired (nosocomial) pneumonia (HAP ). CAP is a common and potentially serious illness . It is associated with considerable morbidity and mortality, particularly in older adult patients and those with significant comorbidities.

7. Pneumonia in special populations aspiration pneumonia, Hypostatic pneumonia Pneumonia in the immunocompromised patients, ventilator-associated pneumonia (VAP) etc.

8. Etiopathogenetic basis CAP; Streptococcus pneumonia, Haemophilus influenza and Mycoplasma pneumoniae. Others- Staph. Aureus, Legionella species HAP; Pseudomonas, Klebsiella, Bacteroides, Clostridia and also Staph aureus Aspiration e.g in stroke, oesophageal disease, myasthenia..; mainly oropharyngeal anaerobes but also gram positives and possibly negatives Immunocompromised; PJP, other fungal species, viruses (e.g HSV, CMV), Strep pneumonia, H. Influenza, M. Pneumonia also

9. Clinical presentation Subjective: fever, rigors, malaise, anorexia, dyspnoea, cough, purulent sputum, haemoptysis and chest pains Objective : febrile, cyanosis, confusion, tachypnoea, tachycardia, hypotension, reduced air entry, crepitations,bronchial breath sounds and increased vocal resonance

10. Investigations Laboratory; FBC/DC, U&E,LFT, CRP, blood cultures, sputum m/c/s, urine Ag –legionella and pneumococcus. Pleural fluid for culture?? Bronchoscopy and bronchoalveolar lavage Radiological; CXR, CT or MRI in case of complicated cases

11. Complications Pleural effusions, empyema, lung abscess, respiratory failure, septicaemia, brain abscess pericarditis, myocarditis etc

12. Severity scale CURB- 65 score C- confusion, U- urea> 7 mmol/l, R- rate >=30/min, BP < 90 systolic and /or 60 mmHg diastolic, age > 65 Scores 0-1; home treatment; 2 hospitalization, >=3 severe pneumonia Increased mortality in co-morbidity and reduced arterial partial pressure of oxygen e.g < 8 kpa

13. Management Oxygen therapy depending on severity; BLS as appropriate IV fluids e.g in dehydration and shock. Antibiotic therapy; oral in mild disease e.g CURB 0-1 or if not vomiting. IVs in severe disease Empirical options: CAP; mild-penicillins or macrolides or fluoroquinolones. Severe-Co-amoxyclav iv or cephalosporin iv . Erythromycin iv in case of Mycoplasma pneumonia

14. Management contn HAP; Aminoglycoside iv + penicillin or 3 rd generation cephalosporin iv Aspiration; Cephalosporin iv + metronidazole iv Others; PJP- high dose co-trimoxazole

15. END… Q/Cs??