Bacteriophage Cocktail Therapy for Multidrug-Resistant Gram-Negative Ventilator-Associated Pneumonia

Inclusion Criteria: 1. Diagnosed with ventilator-associated pneumonia (VAP); 2. Identified infection with MDR Klebsiella pneumoniae, Acinetobacter baumannii, or Pseudomonas aeruginosa via MROSE evaluation and antimicrobial susceptibility testing (AST) from this or other tertiary hospitals; 3. Aged 18 to 85 years; 4. Written informed consent obtained from the patient or legal guardian. Exclusion Criteria: 1. Pregnant or breastfeeding women; 2. FiO₂ ≥ 70% or PEEP ≥ 15 cmH₂O; 3. Hemodynamic instability (vasopressor dose increased by ≥30% in the last 6 hours or norepinephrine \> 0.5 μg/kg/min); 4. Known allergy to phage components.