🫁 Chapter 103: Nosocomial Pneumonia (VAP / HAP)

Ventilator-associated pneumonia · Hospital-acquired pneumonia · CPIS score · BAL / mini-BAL · Empiric antibiotics (early vs late) · MDR pathogens · Prevention bundles

🔍 Core Concepts: Nosocomial Pneumonia (VAP/HAP)

📌 Definitions
HAP: ≥48h after admission, non-intubated. VAP: ≥48h of mechanical ventilation (or within 48h of extubation). HCAP: risk factors for MDR pathogens.
🦠 Pathogens (Early vs Late)
Early (<4d): S. pneumoniae, H. influenzae, MSSA. Late (≥5d): P. aeruginosa, MRSA, Acinetobacter, ESBL, Stenotrophomonas.
📊 CPIS Score
≥6 suggests VAP. Combines fever, WBC, secretions, radiography, culture, PaO2/FiO2.
🔬 Diagnostic Sampling
BAL (>10⁴ CFU/mL), PSB (>10³ CFU/mL), mini-BAL. Tracheal aspirate (>10⁵ CFU/mL) but less specific.
💊 Empiric Antibiotics
Early VAP: ceftriaxone, ertapenem. Late VAP/MDR risk: antipseudomonal beta-lactam + aminoglycoside + MRSA coverage (vancomycin/linezolid).
🛡️ VAP Prevention Bundle
Head of bed elevation (30-45°), oral care with chlorhexidine, sedation vacation, spontaneous breathing trial, DVT/peptic ulcer prophylaxis.
⏱️ Duration
8 days for early VAP, 10-14 days for late or MDR. De-escalate based on cultures.

🩺 Stepwise Management of Suspected VAP/HAP

1
Clinical suspicion & CPIS score
New or progressive infiltrate + fever, leukocytosis, purulent secretions, worsening oxygenation. CPIS ≥6 supports VAP diagnosis.
2
Obtain lower respiratory tract sample before antibiotics
Endotracheal aspirate (least invasive) or BAL / mini-BAL (more specific). Send for Gram stain, culture, and sensitivity.
3
Risk stratification: early vs late VAP, MDR risk factors
Prior antibiotics >5 days, hospitalization >5 days, immunocompromised, high local resistance rates → late VAP/MDR protocol.
4
Start empiric antibiotics
Early VAP: ceftriaxone, ertapenem, or ampicillin-sulbactam. Late VAP/MDR: antipseudomonal beta-lactam (cefepime, meropenem, pip-tazo) + aminoglycoside + vancomycin/linezolid.
5
De-escalate at 48-72h based on cultures & clinical response
Narrow to pathogen-directed therapy. Stop antibiotics if alternative diagnosis (e.g., pulmonary edema, atelectasis). Duration 8 days for early VAP, 10-14 days for MDR.
6
Implement VAP prevention bundle
Head of bed elevation, daily sedation holiday, spontaneous breathing trial, oral care with chlorhexidine, stress ulcer prophylaxis, DVT prophylaxis.