Effect of Proportional Assist Ventilation (PAV) versus Pressure Support Ventilation (PSV) on weaning outcomes in patients with difficult and delayed weaning: a multicenter, prospective, randomized controlled trial
Patients requiring invasive mechanical ventilation
Current interventions as of 16/01/2026: Participants are randomly divided using a random number table into the experimental group (PAV+ group) and the control group (PSV group). The participants in the experimental group (PAV+) will be ventilated in PAV+ mode and use PAV+ for a spontaneous breathing test. The participants in the control group (PSV) will be ventilated in PSV mode and use PSV mode for a spontaneous breathing test. The PAV+ group will be set to PAV+ mode and the support level will be adjusted to meet the patients' ventilation needs. Using PAV+ for a spontaneous breathing test, the definition of success is that the subject can tolerate 25% support. If the patient does not tolerate PAV+ mode, they are changed to pressure-controlled ventilation (PCV) assist-control (A/C) mode support. The PSV group will be set as PSV mode respiratory support, and the support level will be adjusted to meet patients' ventilation needs. PSV is used for a spontaneous breathing test (PSV 5 cmh2o+peep 5 cmh2o). If the patient does not tolerate PSV mode, they are changed to PCV-A/C mode support. When the patient reaches the weaning criteria (when the condition is stable), they start weaning for half an hour per day using one of the two weaning modes. Patients are observed during hospitalization and follow-up will be needed. _____ Previous interventions: Participants are randomly divided using a random number table into the experimental group (PAV+ group) and the control group (PSV group). The participants in the experimental group (PAV+) will be ventilated in PAV+ mode and use PAV+ for a spontaneous breathing test. The participants in the control group (PSV) will be ventilated in PSV mode and use PSV mode for a spontaneous breathing test. The PAV+ group will be set to PAV+ mode and the support level will be adjusted to meet the patients' ventilation needs. Using PAV+ for a spontaneous breathing test, the definition of success is that the subject can tolerate 25% support.
Current inclusion criteria as of 08/05/2026: 1. Age ≥18 years old, <90 years old 2. Patients with mechanical ventilation ≥48 h 3. Failed SBT (Spontaneous Breathing Trial) mechanical ventilation duration ≥ 48 hours; or successful SBT plus mechanical ventilation duration ≥ 7 days. 4. Volunteer to participate in this study and sign the informed consent form. If the subject is unable to read and sign the informed consent form due to incapacity and other reasons, or the subject is a minor, his guardian is required to represent the informed process and sign the informed consent form. If the subject is unable to read the informed consent form (e.g. illiterate subjects), the witness is required to witness the informed process and sign the informed consent form _____ Previous inclusion criteria as of 11/09/2025: 1. Age ≥18 years old 2. Patients with mechanical ventilation ≥48 h 3. Failed SBT (Spontaneous Breathing Trial) mechanical ventilation duration ≥ 48 hours; or successful SBT plus mechanical ventilation duration ≥ 7 days. 4. Volunteer to participate in this study and sign the informed consent form. If the subject is unable to read and sign the informed consent form due to incapacity and other reasons, or the subject is a minor, his guardian is required to represent the informed process and sign the informed consent form. If the subject is unable to read the informed consent form (e.g. illiterate subjects), the witness is required to witness the informed process and sign the informed consent form _____ Previous inclusion criteria: 1. Age ≥18 years old 2. Patients with mechanical ventilation ≥48 h 3. Patients with mechanical ventilation who meet the first SBT failure (excluding iatrogenic factors) 4. Volunteer to participate in this study and sign the informed consent form. If the subject is unable to read and sign the informed consent form due to incapacity and other reasons, or the subject is a minor, his guardian is required to represent the informed process a
Current key exclusion criteria as of 16/01/2026: 1. Airway/Pleural pathology: Pneumothorax, bronchopleural or bronchotracheal fistula 2. Concomitant neuromuscular disease 3. Severe chronic obstructive pulmonary disease 4. Contraindications to EIT (e.g., chest wall wounds or implanted pacemakers) 5. Other: Advanced malignancy (Stage IV) or withdrawal/discontinuation of treatment before extubation _____ Previous exclusion criteria as of 11/09/2025: 1.Neuromuscular diseases (e.g., myasthenia gravis) 2.Tracheoesophageal fistula, tracheomediastinal fistula, etc. _____ Previous exclusion criteria: 1. Myasthenia gravis and other neuromuscular diseases 2. Tracheoesophageal fistula, tracheomediastinal fistula 3. Patients with high endogenous peep