A patient in the ICU on mechanical ventilation develops fever with purulent tracheal aspirate on day 5. Quantitative BAL culture grows >10⁵ CFU/mL of Acinetobacter baumannii. The most appropriate empirical therapy for suspected carbapenem-resistant Acinetobacter baumannii (CRAB) VAP, while awaiting final susceptibility, is:
- A Meropenem 2 g IV 8-hourly (extended infusion)
- B Colistin (polymyxin E) IV + high-dose extended-infusion sulbactam ✓
- C Tigecycline monotherapy
- D Piperacillin-tazobactam alone
Explanation
Carbapenem-resistant Acinetobacter baumannii (CRAB) VAP is a critical healthcare-associated infection. When CRAB is suspected/confirmed, the current recommended combination therapy is colistin/polymyxin B combined with high-dose sulbactam (which retains activity against Acinetobacter via PBP2 inhibition, independent of other resistance mechanisms). Cefiderocol or ampicillin-sulbactam (for sulbactam-susceptible strains) are newer options. Tigecycline alone has subtherapeutic serum/lung levels and high relapse rate. Carbapenems are ineffective against CRAB by definition.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.