Severe Community Pneumonia

• Severe CAP means 1 major criterion (pressors/intubation) or ≥3 ATS/IDSA minor criteria (CURB-65/SMART-COP are separate scores): ICU admission plus β-lactam plus macrolide or respiratory fluoroquinolone.
• Obtain blood cultures ×2 and sputum before antibiotics; check urine antigens (legionella, pneumococcus) in severe cases.
• Consider systemic corticosteroids for severe CAP, excluding influenza pneumonia; review contraindications, glucose and infection risk. Septic shock/another steroid indication needs its own assessment.
• Switch to oral at clinical stability; the typical total course is 5–7 days.
• ATS 2025 updates severe-CAP steroids and retains a minimum 5-day antibiotic course for severe disease; its shorter non-severe courses do not apply to ICU severe CAP.
• Reassess at 48–72 hours against four questions — right diagnosis, right organism, right drug and dose, and a complication needing drainage — before widening the antibiotic; assess the pleural space for a drainable complication.

Severe community-acquired pneumonia

First tests: Chest X-ray, Full blood count, Sodium, potassium, bicarbonate, urea and creatinine, Blood cultures, Respiratory culture.

Only if indicated: Arterial blood gas, Respiratory viral NAAT, Legionella and pneumococcal urinary antigens, MRSA nasal PCR.

Repeat monitoring: Oxygenation and clinical response.

Pneumonia — acquisition not yet established

First tests: Chest X-ray, Full blood count, Sodium, potassium, bicarbonate, urea and creatinine.

Only if indicated: Arterial blood gas, Blood cultures, Respiratory culture, Respiratory viral NAAT.

Repeat monitoring: Oxygenation and clinical response.

• Severe Community-Acquired Pneumonia: Severity, Cultures and First Dose
• Community-Acquired Pneumonia Not Improving at 48–72 Hours