Effect of NAVA on Duration of Weaning in Difficult to Wean Patients
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. 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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, China; Department of Critical Care Medicine St. Michaels's Hospital, University of Toronto, Canada|
- Duration of weaning [ Time Frame: 48h after extubation ] [ Designated as safety issue: No ]duration of weaning was defined as time from study enrollment to extubation.
- Extubation rate [ Time Frame: 48h after extubation or 30 day after enrollment ] [ Designated as safety issue: No ]Extubation rate was defined as the percentage of patients with successful weaning.
- diaphragmatic function [ Time Frame: At 8 am daily before extubatiuon ] [ Designated as safety issue: No ]Diaphragmatic function was measured by neuro-ventilatory efficiency (NVE), a ratio of tidal volume to diaphragm electrical activity (Vt/EAdi), and neuro-mechanical efficiency (NME), a ratio of airway pressure to EAdi(Paw/EAdi) during airway occlusion.
- Patient ventilator asynchrony [ Time Frame: At 8 am daily until extubation ] [ Designated as safety issue: No ]Time delay between neuro inspiration and ventilator delivery. Time delay between neuro expiration and ventilator cycle-off.
|Study Start Date:||December 2010|
|Estimated Study Completion Date:||December 2012|
|Estimated Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
No Intervention: PSV weaning
Patinens in the PSV group will be weaned using PSV mode.
Experimental: NAVA weaning
Patients in NAVA group will eb weaned using NAVA mode.
Device: Neurally adjusted ventilatory assist
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.
Other Name: NAVA
Intubated patients who were deemed ready for extubation 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 ( neurally adjusted ventilatory assist) 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. in both group, 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 frist 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 reintubated, 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 hrs before the measurement of diaphragmatic function and SBT. Main end point wast the duration of weaning, and second end point was extubation rate, diaphragmatic function and patient ventilator asynchrony.
|Nanjing Zhong-Da Hospital||Recruiting|
|Nanjing, Jiangsu, China, 210009|
|Contact: Ling Liu, MD. 86-25-83272201 firstname.lastname@example.org|
|Contact: Haibo Qiu, PhD.,MD. 86-25-83272200 email@example.com|
|Principal Investigator: Ling Liu, MD.|
|Principal Investigator: Lanqi Guo, MD.|
|Study Director:||Haibo Qiu, PhD,MD||Southeast University|