CAP Inpatient Diagnostics — Medical Practice MCQ

Correct answer: B — Sputum culture and blood cultures before antibiotics

This patient has community-acquired pneumonia requiring hospital assessment and is not low severity: confusion and raised urea/BUN are CURB-65 severity features, and age ≥65 would also add a point. In UK exam practice, moderate or high severity CAP should have microbiological investigation to guide later narrowing/escalation of antibiotics: obtain blood cultures and a good-quality sputum sample for culture before antibiotics, provided this does not delay prompt antibiotic treatment. Procalcitonin is not a standalone initial diagnostic test, CT and bronchoscopy are not routine first-line tests for CAP, and “no labs” is inappropriate in admitted moderate/high-severity disease.

Reference: NICE. Pneumonia: diagnosis and management (NG250), 2025, recommendations on CURB65, microbiological tests in hospital, and starting antibiotics: https://www.nice.org.uk/guidance/NG250/chapter/recommendations