Effect of NAVA on Weaning Duration in Difficult to Wean Patients
Condition: Weaning
Study type: Interventional

Summary: 
      It has been showed that over assist and patient ventilator asynchrony often occur in
      mechanical ventilated patients, especially in patients who failed weaning, which are
      associated with a prolonged duration of mechanical ventilation.Neurally adjusted ventilatory
      assist (NAVA) improves patient-ventilator synchrony, prevents excessive assist induced
      diaphragm inactivation. So the aim of this study was to detect that whether NAVA compared
      with PSV has the ability to reduce the duration of weaning in difficult to wean patients.
    

Detailed description: 
      Intubated patients who were deemed ready for weaning by the clinical team but failed the
      first spontaneous breathing trials (SBT) or weaning were screened for eligibility. After
      enrollment, nasogastric tube eligible patient was replaced with a modified EAdi catheter.
      Then the patients were switched to a Servo-i ventilator. According to a random digits table,
      eligible patients were allocated randomly to ventilation with NAVA or pressure support
      ventilation (PSV). In PSV group, ventilator settings were determined by the physicians who in
      charge of the patients, and EAdi signals were not available for ventilator settings. In NAVA
      group, a daily NAVA level titration was performed to select the NAVA level which got
      approximate 50% unload, if the patients can't tolerate PSV or NAVA, PCV should be used to
      insure the ventilation safety. If the patients were under PCV mode, screening should be done
      by the researchers every 3 hours to make sure whether they will tolerate PSV or NAVA. In both
      group, daily measurement of diaphragmatic function was performed (only preformed in the first
      10 patients of each group), followed by a 30 minutes SBT with PSV 5-7 cmH2O. Patients who
      were able to tolerate the SBT were extubated. Patients who completed the SBT and remained
      extubated > 48 h were considered successfully extubated. Patients who failed SBT, or required
      noninvasive ventilation (NIV), or were re-intubated, or deceased within 48h post-extubation
      were considered extubation failure. Local sedation protocol including daily wakeup was
      performed during the research period. All continuous sedative infusions were discontinued at
      least 1 hour before the measurement of diaphragmatic function and SBT. Main end point was the
      duration of weaning, and second end point was extubation rate, diaphragmatic function and
      patient ventilator asynchrony.
    

Intervention name(s): NAVA
Intervention type(s): Device
Intervention description(s): Neurally adjusted ventilatory assist (NAVA) was delivered by a SVi ventilator. NAVA utilizes EAdi, a reflection of the neural respiratory output to diaphragm, as its primary source to trigger and cycle-off assist in synchrony with neural inspiratory efforts.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: weaning, mechanical ventilation