Community-acquired pneumonia — the severity and the empiric antibiotics

The CURB-65 score (the five criteria):

• Confusion — the new disorientation.
• Urea raised — above 7 mmol/L.
• Respiratory rate — 30 or above.
• Blood pressure — the systolic below 90 or the diastolic 60 or below.
• 65 — the age 65 or above.
• Each criterion is the one point.
• 0 to 1 — NICE: consider home-based care (low risk, under 3 percent 30-day mortality).
• 2 — consider hospital-based care (intermediate, 3 to 15 percent). Lim's exact score-2 mortality is 3 percent.
• 3 or above — consider intensive-care assessment (high risk, over 15 percent). Not automatic ICU and not an automatic hour-1 antibiotic unless there is shock.^[1][3]

Empiric antibiotics (ATS/IDSA 2019; local eTG for the ANZ product):

• Healthy outpatient — amoxicillin 1 g three times daily or doxycycline 100 mg twice daily or a macrolide if pneumococcal macrolide resistance is under 25 percent (not automatically amoxicillin plus a second agent).
• Inpatient non-severe — beta-lactam plus macrolide or a respiratory fluoroquinolone.
• Severe — beta-lactam plus macrolide or beta-lactam plus fluoroquinolone. MRSA/Pseudomonas only with locally validated risk factors. HCAP is abandoned.^[2]

Principles: CURB-65 plus judgement; atypical cover in hospitalised CAP; Legionella clues are hyponatraemia, GI and neurological features (not LDH as a rule); cultures must not delay the first dose; duration minimum 5 days plus clinical stability, not a default 14-day Legionella course.^[2][1]