Pneumonia Management Guide: CAP, HAP, and VAP Diagnosis and Treatment

🏥 Part 1: Community-Acquired Pneumonia (CAP)

🔍 Diagnostic Criteria

• Cough, fever, dyspnea, pleuritic chest pain
• Physical findings: rales, bronchial breath sounds, dullness to percussion
• Imaging: new infiltrate on chest X-ray

🧪 Severity Assessment (to guide IPD vs OPD)

• CURB-65:
• Confusion
• Urea > 7 mmol/L
• Respiratory rate ≥ 30
• Blood pressure (SBP < 90 or DBP ≤ 60 mmHg)
• Age ≥ 65

Score ≥2 → consider hospitalization

💊 Empiric Antibiotic Therapy (IDSA/ATS 2019)

A. Outpatient Treatment

1. Healthy patient, no recent antibiotics:
   • Amoxicillin 1 g TID PO
   • Doxycycline 100 mg BID PO
   • Macrolide (Azithromycin 500 mg Day 1, then 250 mg daily × 4 days) if local resistance <25%
2. Comorbidities (DM, CHF, COPD, CKD, etc.):
   • Amoxicillin-clavulanate 875/125 mg BID PO or cefpodoxime 200 mg BID PO
   • PLUS macrolide or doxycycline
   • Or monotherapy: Levofloxacin 750 mg PO daily or Moxifloxacin 400 mg PO daily

B. Inpatient (Non-ICU)

• Ceftriaxone 1-2 g IV q24h + Azithromycin 500 mg IV/PO q24h
• Or Levofloxacin 750 mg IV/PO daily

C. ICU Treatment

• Ceftriaxone 2 g IV q24h + Azithromycin 500 mg IV q24h
• Or Ceftriaxone + Levofloxacin

🏨 Part 2: Hospital-Acquired Pneumonia (HAP)

Definition:

• Occurs ≥48 hours after hospital admission without prior mechanical ventilation.

Risk Stratification:

• Low risk for MDR pathogens: No prior IV antibiotics in past 90 days
• High risk: Prior IV antibiotics, structural lung disease, or septic shock

Empiric Treatment:

1. Low risk for MDR:
   • Piperacillin-tazobactam 4.5 g IV q6h
   • Or Cefepime 2 g IV q8-12h
2. High risk/MDR suspicion:
   • Antipseudomonal β-lactam: Meropenem or Cefepime
   • PLUS anti-MRSA: Vancomycin 15 mg/kg IV q12h or Linezolid 600 mg IV q12h
   • Add second antipseudomonal agent if septic shock or >10% resistance

🛏️ Part 3: Ventilator-Associated Pneumonia (VAP)

Definition:

• Occurs ≥48-72 hours after endotracheal intubation

Pathogens to Cover:

• MRSA, Pseudomonas aeruginosa, ESBL GNB, Acinetobacter spp.

IDSA 2016 Empiric Regimens:

• 1 anti-MRSA agent:
  • Vancomycin or Linezolid
• 2 anti-pseudomonal agents from different classes:
  • β-lactam (e.g., meropenem, cefepime, piperacillin-tazobactam)
  • Non-β-lactam (e.g., ciprofloxacin, levofloxacin, or aminoglycoside like amikacin)

Duration:

• Typically 7 days (can be adjusted by clinical response)

🧼 Additional Management Steps

• Oxygen therapy (maintain SpO₂ > 92%)
• Fluids and antipyretics (e.g., paracetamol)
• Monitor vitals and oxygenation
• Sputum culture and blood cultures before antibiotics
• Consider Legionella urinary antigen and influenza testing in CAP

Would you like me to continue into Thai CPG adaptation, summarize these for OSCE pattern, or help simulate a case-based management?