Lung Abscess - Diagnosis and Management Summary Lung Abscess Etiology: • Necrosis of lung parenchyma by a polymicrobial infection • Most common cause: Aspiration pneumonia • DM risk factor for Klebsiella pneumonia • Chronic alcoholism • Periodontal disease/poor dentition/gingival disease • IV substance use • Esophageal dysmotility • Depressed consciousness • Large volume feeding tubes Lung Abscess Pathophysiology: 1. Inoculum 2. Pneumonitis 3. Tissue necrosis (7-14 days later) 4. Lung abscess Lung Abscess - Clinical Presentation: • 80% have fever ≥ 38 degrees • Chills, night sweats, fatigue, unexplained weight loss • Late disease: Pleuritic chest pain, hemoptysis, dyspnea, productive cough • Putrid sputum/sour-tasting sputum Lung Abscess - Physical Exam: • Poor dentition • Gingival crevice disease • Diminished breath sounds • Rales Lung Abscess Diagnosis: • CBC - Leukocytosis, anemia • Sputum/Blood cultures • CXR (non-diagnostic in early disease) • CXR upright or lat decubitus - air fluid level seen • Chest CT Lung Abscess Management: • Antibiotics: - IV Ampicillin-sulbactam - Piperacillin/Tazobactam - pseudomonas - Carbapenems - IV Clindamycin in case of PCN allergy - Switch to oral antibiotics once stable - 10-15% require lobectomy or pneumonectomy if fail antibiotics • Consider Surgical Intervention: - Fevers > 10 days - Hemoptysis - Cavitation > 6 cm - Neoplasm, or hemorrhage • Treatment duration: - 3 weeks or continue antibiotic treatment until the chest radiograph shows a small, stable residual lesion or is clear. This generally requires several months of treatment • Delayed response: Evaluate for foreign body, cancer, or bronchial stenosis Lung Abscess Pathogens: • Aerobic Bacteria: - Staph. Aureus - Legionella - H. Influenza - E. Coli - P. Aeruginosa - Strep. Pyogenes - K. Pneumonia • Anaerobic Bacteria: - Bacteroides - Fusobacterium - Peptostreptococcus - Prevotella • Fungal: - Aspergillosis - Blastomyces - Dermatitidis - Cryptococcus - Coccidioides • Parasite: - Entamoeba histolytica - Paragonimus westermani • Other: TB, M. avium, M. kansii Lung Abscess Differential Diagnosis: • Vasculitis (e.g., Granulomatosis with polyangiitis) • Malignancy • Aspirated foreign body • Bronchostenosis #Lung #Abscess #pulmonary #differential #causes #management #treatment #diagnosis
