What are the current guidelines for managing hospital-acquired pneumonia (HAP)?

Current Guidelines for Managing Hospital-Acquired Pneumonia (HAP)

The management of hospital-acquired pneumonia should follow a risk-stratified approach with empiric antibiotic therapy based on patient risk factors for multidrug-resistant organisms, local antibiogram data, and clinical severity. 1

Diagnosis and Initial Assessment

• HAP is defined as pneumonia occurring ≥48 hours after hospitalization in non-intubated patients, and should be diagnosed based on clinical criteria rather than biomarkers like procalcitonin, C-reactive protein, or CPIS 1
• Respiratory samples should be obtained noninvasively before starting antibiotics to guide targeted therapy and subsequent de-escalation 1
• Distal quantitative samples are preferred in stable patients with suspected VAP to reduce unnecessary antibiotic exposure and improve diagnostic accuracy 1

Risk Stratification for Empiric Therapy

Low Risk Patients

• For patients with early-onset HAP and no risk factors for multidrug-resistant (MDR) pathogens, narrow-spectrum antibiotics are recommended: 1
  • Ertapenem, ceftriaxone, cefotaxime, moxifloxacin, or levofloxacin 1
  • Consider local C. difficile rates when selecting third-generation cephalosporins 1

High Risk Patients

• Broad-spectrum empiric therapy is recommended for patients with: 1
  • Prior intravenous antibiotic use within 90 days 1
  • Hospitalization in a unit where >20% of S. aureus isolates are methicillin-resistant 1
  • Unknown MRSA prevalence in the unit 1
  • Septic shock or need for ventilatory support due to HAP 1
  • Recent prolonged hospital stay (>5 days) 1
  • Previous colonization with MDR pathogens 1

Empiric Antibiotic Recommendations

For Suspected HAP with Low Risk of MDR Pathogens

• Monotherapy with one of the following: 1, 2
  • Piperacillin-tazobactam 4.5g IV q6h
  • Cefepime 2g IV q8h
  • Levofloxacin 750mg IV daily
  • Imipenem or meropenem 1g IV q8h

For Suspected HAP with High Risk of MDR Pathogens

• Coverage should include S. aureus, Pseudomonas aeruginosa, and other gram-negative bacilli 1
• For MRSA coverage (when indicated): 1
  • Vancomycin (15-20 mg/kg IV q8-12h) or
  • Linezolid (600 mg IV q12h)
• For antipseudomonal coverage: 1, 2
  • Piperacillin-tazobactam 4.5g IV q6h, or
  • Cefepime 2g IV q8h, or
  • Meropenem 1g IV q8h, or
  • Imipenem 500mg IV q6h, or
  • Aztreonam 2g IV q8h (for patients with β-lactam allergies)

For Nosocomial Pneumonia with High Mortality Risk

• Initial combination therapy is recommended: 1, 3
  • Two antipseudomonal agents from different classes plus MRSA coverage if risk factors present 1, 3
  • For Pseudomonas aeruginosa pneumonia, combination with an aminoglycoside is specifically recommended 4

Duration of Therapy and De-escalation

• The recommended duration for HAP treatment is 7-14 days 1, 3
• De-escalate therapy based on culture results and clinical response when available (typically by day 3) 1
• If quantitative culture results are below the diagnostic threshold for VAP, consider withholding antibiotics in stable patients 1

Special Considerations

• For patients with renal impairment, dosage adjustments are necessary: 4
  • For creatinine clearance 20-40 mL/min: reduce piperacillin-tazobactam to 2.25g IV q6h for HAP 4
  • For creatinine clearance <20 mL/min: reduce to 2.25g IV q8h 4
• Extended or continuous infusions of β-lactams may be appropriate to optimize pharmacokinetics 1, 2
• For multidrug-resistant (MDR) Pseudomonas, combination therapy with polymyxins (colistin) may be necessary 3

Prevention Strategies

• Oral care and aspiration precautions may reduce HAP risk 5
• Avoid unnecessary broad-spectrum antibiotics to prevent emergence of resistant organisms 6

Common Pitfalls to Avoid

• Overdiagnosis of HAP occurs in approximately 35% of cases when objective radiological criteria are not applied 7
• The recommended MRSA prevalence threshold alone (>10-20%) has poor specificity and may lead to significant overtreatment 8
• Delaying appropriate antibiotic therapy increases mortality; start broad coverage in high-risk patients and de-escalate based on culture results 9
• Aminoglycosides should never be used as monotherapy for HAP, even when the isolate appears susceptible 2