Pneumonia and Lung Abscess Notes PDF

Pneumonia and Lung abcess Lower Respiratory Tract Infections Symptoms Noisy breathing: Wheezing, whistling Cough: Dry (irritation) or productive (mucus). Dyspnea: Difficulty breathing. Hemoptysis: Blood in sputum. General symptoms: Fever, headache, fatigue. Bronchitis...

Pneumonia and Lung abcess Lower Respiratory Tract Infections Symptoms Noisy breathing: Wheezing, whistling Cough: Dry (irritation) or productive (mucus). Dyspnea: Difficulty breathing. Hemoptysis: Blood in sputum. General symptoms: Fever, headache, fatigue. Bronchitis Acute: Viral infection, self-limiting. Chronic: Lasts for months; associated with COPD. Bronchiolitis (Common in infants) Symptoms: Dyspnea, wheezing, productive cough. Complications: Respiratory distress, cyanosis, dehydration, pneumonia. Pneumonia Definition & Epidemiology Infection of the lungs by bacteria, viruses, fungi, or mycobacteria.  Annual incidence: 3-5 million cases in the U.S., with 50,000+ deaths. High-risk groups: Elderly, infants, smokers, immunocompromised patients, diabetics, and those with chronic lung disease. Types 1. Community-Acquired Pneumonia (CAP): Acquired outside hospitals. 2. Nosocomial Pneumonia: o Hospital-Acquired (HAP): After 48 hours of hospitalization. o Ventilator-Associated (VAP): After 48 hours of intubation. Clinical Presentation Symptoms: Fever, cough (dry or purulent), dyspnea, fatigue, nausea. Severe cases: Respiratory distress Physical Examination & Diagnosis Findings: Fever, tachycardia, tachypnea, hypoxemia, crackles, wheezes. Laboratory: Leukocytosis, sputum culture. Pathogenesis: Bacterial presence in lungs (even in healthy individuals). Factors impairing defenses: Smoking, alcohol, aspiration, diabetes, aging. Virulent organisms impairing ciliary function, thickening mucus, destroying IgA. Morphology of Pneumonia Lobar Pneumonia Caused by: Streptococcus pneumoniae, Klebsiella. Stages: 1. Congestion: Lungs heavy, red, boggy. 2. Red hepatization: Firm, airless, liver-like consistency. 3. Gray hepatization: Grayish-brown color. 4. Resolution: Exudate cleared. Bronchopneumonia Causative agents: S. pneumoniae, H. influenzae, Pseudomonas. Gross appearance: Bilateral, basal, dry, granular lesions. Interstitial (Atypical) Pneumonia Causes: Viruses, Mycoplasma, Pneumocystis jirovecii. Symptoms: Dry cough, dyspnea. Complication: Lung fibrosis. Special Types of Pneumonia Community-Acquired Atypical Pneumonia Causes: Mycoplasma, Legionella, Chlamydia pneumoniae. Aspiration Pneumonia Occurs in: Patients with stroke, coma, vomiting Cause: Chemical damage + anaerobic bacterial infection. Complications Sepsis: Infection spreads to bloodstream, causing shock. Respiratory Failure: Alveoli fill with pus, impairing gas exchange. Pleural Effusion/Empyema: Fluid or pus in pleural space.  Lung Abscess: Pus-filled cavity in lung, requiring prolonged antibiotics or drainage. Lung Abscess Definition: Localized lung necrosis with pus formation. Causes: o Aspiration (most common in alcoholics, comatose patients). o Post-pneumonia abscess (S. aureus, S. pyogenes). o Cancer-associated secondary infection. o Septic embolism. Treatment: Long-term antibiotics, drainage, or surgery.