Urgent Care For Pneumonia 4 — Questions and Answers
Question 1: A 55-year-old alcoholic presents with a chest X-ray showing a cavitary lesion in the right upper lobe. Which organism is most likely responsible?
- Legionella pneumophila
- Klebsiella pneumoniae (Correct answer)
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
Correct answer: Klebsiella pneumoniae
Klebsiella pneumoniae classically causes cavitary pneumonia in alcoholics, often involving the upper lobes with 'currant jelly' sputum.
Question 2: Which of the following indicates the need for ICU admission in a pneumonia patient per ATS/IDSA major criteria?
- Temperature > 38°C
- Requirement for vasopressors or mechanical ventilation (Correct answer)
- BUN > 20 mg/dL
- Age > 65
Correct answer: Requirement for vasopressors or mechanical ventilation
ATS/IDSA major criteria for ICU admission include need for vasopressors (septic shock) or requirement for mechanical ventilation.
Question 3: A 30-year-old construction worker who worked at an excavation site presents with fever, cough, and mediastinal lymphadenopathy on chest X-ray. Which fungal infection should be suspected?
- Candida albicans
- Histoplasma capsulatum (Correct answer)
- Aspergillus fumigatus
- Cryptococcus neoformans
Correct answer: Histoplasma capsulatum
Histoplasma capsulatum is endemic in the Ohio and Mississippi River valleys and associated with disturbed soil or bird/bat droppings.
Question 4: Which finding on a pleural fluid analysis would indicate an exudative effusion requiring further workup for empyema?
- pH > 7.30, glucose 80 mg/dL, LDH 100 U/L
- pH < 7.20, glucose < 40 mg/dL, LDH > 1000 U/L (Correct answer)
- Protein < 2.5 g/dL, LDH < 100 U/L
- Clear fluid, no cells, specific gravity < 1.012
Correct answer: pH < 7.20, glucose < 40 mg/dL, LDH > 1000 U/L
Empyema or complicated parapneumonic effusion is suggested by pH < 7.20, low glucose, and markedly elevated LDH in pleural fluid.
Question 5: An immunocompromised patient with pneumonia has a CT chest showing a nodule with a 'halo sign.' Which organism is most likely?
- Streptococcus pneumoniae
- Aspergillus fumigatus (Correct answer)
- Pneumocystis jirovecii
- Mycobacterium tuberculosis
Correct answer: Aspergillus fumigatus
The halo sign — a nodule surrounded by ground-glass opacity — is the classic CT finding of invasive pulmonary aspergillosis in immunocompromised patients.
Question 6: Which vaccine is most directly recommended to prevent the most common bacterial cause of CAP in adults over age 65?
- Influenza vaccine
- Pneumococcal vaccine (PCV15 or PCV20) (Correct answer)
- BCG vaccine
- Hepatitis B vaccine
Correct answer: Pneumococcal vaccine (PCV15 or PCV20)
Pneumococcal vaccines (PCV15 or PCV20) protect against Streptococcus pneumoniae, the most common bacterial cause of CAP, and are recommended for all adults ≥65.
Question 7: A patient with CAP has been treated with azithromycin for 3 days with no improvement. Which scenario would best explain treatment failure?
- The patient drank coffee with the antibiotic
- Drug-resistant Streptococcus pneumoniae or an atypical organism not covered
- The patient's CAP was caused by influenza virus (Correct answer)
- The antibiotic was given with food
Correct answer: The patient's CAP was caused by influenza virus
Influenza causes viral pneumonia that does not respond to antibiotics, and failure of azithromycin should raise concern for viral etiology or resistant organisms.
Urgent Care For Pneumonia 4
A 55-year-old alcoholic presents with a chest X-ray showing a cavitary lesion in the right upper lobe.
Which organism is most likely responsible?