Treatment of CRAB VAP with Polymyxin B Combinations

Guideline Recommendations

• The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) provides a conditional recommendation for ampicillin-sulbactam in CRAB VAP when the organism is sulbactam-susceptible, and suggests double-covering combination therapy for severe CRAB infections 1, 2
• The Chinese guidelines recommend polymyxin combination therapy as preferential over monotherapy for CRGNB infections requiring polymyxin treatment (strong recommendation, moderate-quality evidence) 3

Antibiotic Dosage and Administration

• A loading dose of 2.5 mg/kg IV polymyxin B is recommended, with maintenance doses adjusted for renal function and therapeutic drug monitoring when available 6, 3
• High-dose sulbactam (9g/24h) as a continuous infusion is the preferred regimen for optimal pharmacodynamics 1, 2

Treatment Duration and Monitoring

• Treatment duration is typically 7 days for good clinical response, but may be extended to 10-14 days for severe infections with septic shock 8
• Daily serum creatinine and creatinine clearance calculation are recommended to monitor for nephrotoxicity 7

Contraindications and Caveats

• Polymyxin B/carbapenem is strongly recommended against for CRAB due to increased mortality (aHR 3.27) 9
• Polymyxin B/rifampin is also strongly recommended against due to no survival advantage and high-certainty evidence 1, 9
• Tigecycline monotherapy should never be used for CRAB pneumonia 10