What is the treatment for hospital-acquired pneumonia?

Treatment for Hospital-Acquired Pneumonia

For hospital-acquired pneumonia, the recommended treatment is combination therapy with an antipseudomonal β-lactam (piperacillin-tazobactam 4.5g IV every 6 hours, cefepime 2g IV every 8 hours, or meropenem 1g IV every 8 hours) plus either an aminoglycoside or a fluoroquinolone, with additional MRSA coverage (vancomycin or linezolid) when risk factors are present. 1

Initial Empiric Therapy

Antipseudomonal Coverage (choose one):

• Piperacillin-tazobactam: 4.5g IV every 6 hours 1, 2
• Cefepime: 2g IV every 8 hours 1
• Meropenem: 1g IV every 8 hours 1

Plus Second Agent for Double Gram-negative Coverage (choose one):

• Fluoroquinolone: Levofloxacin 750mg IV once daily 1
• Aminoglycoside: Based on weight and renal function 1

Plus MRSA Coverage (if risk factors present):

• Vancomycin: 15 mg/kg IV every 8-12 hours (target trough 15-20 mg/mL) 1
• Linezolid: 600 mg IV twice daily 1, 3

Risk Factors Requiring Double Gram-negative Coverage:

• Prior IV antibiotic use within 90 days 1
• Septic shock 1
• High risk for mortality 1

Risk Factors for MRSA:

• Prior MRSA colonization or infection
• Recent hospitalization
• Recent antibiotic exposure
• High local MRSA prevalence

Treatment Duration:

• Standard duration: 7-10 days for uncomplicated pneumonia 1
• Minimum duration: 5 days if clinical improvement occurs 1
• Longer courses (2-4 weeks) for cavitary pneumonia 1

Treatment Modifications:

1. Culture-directed therapy: Once culture results are available, narrow therapy appropriately:

   • For MSSA: Switch to oxacillin, nafcillin, or cefazolin 1
   • For susceptible Gram-negative pathogens: De-escalate to narrowest effective agent

2. Clinical monitoring:

   • Expect clinical improvement within 48-72 hours 1
   • If no improvement, reassess diagnosis and consider changing antibiotics 1
   • Monitor vancomycin trough levels (target 15-20 mg/mL) 1

Special Considerations:

• For nosocomial pneumonia, the FDA-approved dosage of piperacillin-tazobactam is 4.5 grams every six hours 2
• Linezolid has demonstrated efficacy in nosocomial pneumonia with cure rates of 57% compared to 60% for vancomycin, with potentially better outcomes in ventilator-associated pneumonia (47% vs 40%) 3
• Adjust dosing in patients with renal impairment 2
• Obtain blood cultures if bacteremia is suspected 1
• Identify and address any source of infection, such as empyema requiring drainage 1

Common Pitfalls to Avoid:

1. Delaying treatment: Administer the first antibiotic dose while still in the ED 1
2. Inadequate initial coverage: Failure to cover likely pathogens including Pseudomonas and MRSA when risk factors present
3. Failure to de-escalate: Not narrowing therapy once culture results are available
4. Inappropriate duration: Treating too long or too short
5. Overlooking source control: Failing to identify and drain empyema if present

The Infectious Diseases Society of America recommends this approach to hospital-acquired pneumonia to ensure adequate coverage of common pathogens while minimizing the development of resistance through appropriate de-escalation once culture results are available.