Efficacy and Safety of Intrapulmonary Percussive Ventilation in Patients With Pulmonary Infection Receiving Invasive Mechanical Ventilation

Inclusion Criteria: 1. age ≥ 18 years; 2. Meeting the diagnostic criteria for pulmonary infection, defined as follows: meeting the diagnostic criteria for hospital-acquired pneumonia and ventilator-associated pneumonia as defined in the Chinese Guidelines for the Diagnosis and Treatment of Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia in Adults, or meeting the diagnostic criteria for community-acquired pneumonia as defined in the Chinese Guidelines for the Diagnosis and Treatment of Community-Acquired Pneumonia in Adults; radiographic evidence of new or progressive pulmonary infiltrates plus at least two clinical criteria, including fever or hypothermia, leukocytosis or leukopenia, purulent respiratory secretions, or worsening oxygenation. 3. Oxygenation index (PaO₂/FiO₂) ≤ 300; 4. Currently receiving invasive mechanical ventilation and expected to require mechanical ventilation for ≥ 5 days; 5. Written informed consent provided by the patient's family member or legally authorized representative. Exclusion Criteria: 1. Presence of severe hemodynamic instability (norepinephrine dose \> 0.5 μg/kg/min); 2. Markedly elevated intracranial pressure (\> 25 mmHg) or a condition requiring strict intracranial pressure control; 3. Severe pulmonary bullae or untreated tension pneumothorax or undrained mediastinal emphysema; 4. Active massive hemoptysis; 5. Severe bronchospasm with inability to tolerate fluctuations in airway pressure; 6. Unstable chest wall, flail chest, recent thoracic surgery, or severe thoracic spine injury; 7. Receiving extracorporeal membrane oxygenation (ECMO); 8. Pregnant or breastfeeding women; 9. Inability to place the EIT chest belt (e.g., open thoracic surgical wounds or skin lesions at the belt placement site); 10. Concurrent participation in another clinical trial.