This study intends to compare the effects of NAVA and PSV on weaning success rate and mechanical ventilation time in patients with tracheotomy patients through a randomized controlled study.

For patients with difficult weaning, NAVA can shorten the time of mechanical ventilation, but there is no large-scale study to explore the effect of NAVA on the weaning success rate and mechanical ventilation time of patients with gas resection. Therefore, this study intends to compare the effects of NAVA and PSV on weaning success rate and mechanical ventilation time in patients with tracheotomy patients through a randomized controlled study.

It is a prospective, multicenter, parallel group, single blind, randomized controlled tria。

Inclusion Criteria:

1. Tracheotomy and invasive mechanical ventilation is expected to be required for > 48h;
2. When support pressure ≤ 15 cmH2O, it can withstand pressure support ventilation (PSV) time > 1h;

Exclusion Criteria:

1. Age < 18 years or > 85 years;
2. Deep sedation.
3. Severe hemodynamic instability (norepinephrine or equivalent converted dose of other vasoactive drugs > 1ug / kg.min or map ≤ 65mmhg)
4. Severe respiratory center depression, high paraplegia, neuromuscular disease;
5. Esophageal obstruction, esophageal perforation, severe esophageal variceal bleeding, upper gastrointestinal surgery, diaphragmatic hernia and thoracic deformity;
6. Patients with chronic respiratory diseases requiring long-term home oxygen therapy;
7. Patients with severe coagulation dysfunction (INR > 1.5, APTT > 44s, history of leukemia);
8. Severe other organ dysfunction is expected to die in a short time (7 days) or palliative treatment.
9. The estimated survival time of advanced solid organ or hematological system tumors is < 30 days
10. Participate in other clinical studies within 30 days;
11. Failing to sign the informed consent form;