1. Pneumonia Dr. Meg-angela Christi Amores

2. Definition infection of the pulmonary parenchyma often misdiagnosed, mistreated, and underestimated community-acquired pneumonia (CAP) or health care–associated pneumonia (HCAP) – hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP)

3. Pathophysiology proliferation of microbial pathogens at the alveolar level and the host's response aspiration from the oropharynx inhaled as contaminated droplets hematogenous spread

4. Pathophysiology Host defense: – hairs and turbinates of the nares – branching architecture of the tracheobronchial tree traps particles on the airway lining – gag reflex and the cough mechanism – normal flora adhering to mucosal cells of the oropharynx – resident alveolar macrophages

5. host inflammatory response, rather than the proliferation of microorganisms, triggers the clinical syndrome of pneumonia inflammatory mediators, such as interleukin (IL) 1 and tumor necrosis factor (TNF), results in fever

6. Pathology Edema – presence of a proteinaceous exudate Red hepatization – erythrocytes in the cellular intraalveolar exudate Gray hepatization – neutrophil is the predominant cell, fibrin deposition is abundant, and bacteria have disappeared Resolution

7. Etiology Typical: – S. pneumoniae, Haemophilus influenzae, S. aureus and gram-negative bacilli such as Klebsiella pneumoniae and Pseudomonas aeruginosa Atypical: – Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella spp. as well as respiratory viruses such as influenza viruses, adenoviruses, and respiratory syncytial viruses (RSVs

8. Risk factors CAP:alcoholism, asthma, immunosuppression, institutionalization, and an age of 70 years versus 60–69 years

9. Clinical Manifestations frequently febrile, with a tachycardic response, and may have chills and/or sweats and cough pleura is involved, the patient may experience pleuritic chest pain fatigue, headache, myalgias, and arthralgias Crackles, bronchial breath sounds

10. Management Diagnosis – CLINICAL – XRAY – suggests etiology pneumatoceles suggest infection with S. Aureus upper-lobe cavitating lesion suggests tuberculosis – Sputum Gram stain and culture – Blood culture

11. Management Treatment : CAP – Site of Care Home Hospital – Antibiotics Empiric Previously healthy and no antibiotics in past 3 months A macrolide [clarithromycin (500 mg PO bid) or azithromycin (500 mg PO once, then 250 mg od)] or Doxycycline (100 mg PO bid)