None listed
Conditions
Brief summary
Noninvasive ventilation (NIV) has been found to reduce ventilator associated pneumonia, total duration of mechanical ventilation, length of intensive care unit (ICU) and hospital stay and mortality in patients with respiratory failure when they are connected after extubation. However, this benefit will be annihilated if NIV cannot be tolerated by the patient. Because NIV is delivered through an interface prone to leakage in a conscious but not necessarily cooperative patient, there could be more problems in patient-ventilator synchrony as compared to invasive positive pressure ventilation (IPPV). NAVA was found to be able to improve patient-ventilator synchrony through its benefits in better ventilator triggering and cycling off using the electrical activity of the diaphragm (Edi) signal instead of pressure or flow changes in the ventilator circuit. This could translate into a reduction in the work of breathing (WOB) as has been found in an animal study using NAVA in IPPV, but detailed analysis of WOB in NIV-NAVA has not been reported. We hypothesized that patient-ventilator asynchrony and WOB would be reduced using NAVA-NIV. The aim of this study is therefore to find out whether there would be a reduction in asynchrony and WOB using NIV-NAVA compared with standard NIV-PS, and to find out its comparative benefits in post-extubation NIV.
Interventions
use of non-invasive ventilation in the neurally adjusted ventilatory assist mode (NIV-NAVA) with PEEP set at 5 cmH2O. NAVA gain level will be titrated to achieve an equivalent peak inspiratory pressure as in PSV (NAVA0). Another 2 levels will be set at 0.5 cmH2O/uV above and below NAVA0 (NAVA+1 and NAVA-1 respectively). Inspiratory trigger Edi will be set at 0.5uV above Edi min, while expiratory trigger is fixed by the manufacturer at 70% of Edi peak. The subject will breathe at each setting for
use of non-invasive ventilation in the neurally adjusted ventilatory assist mode (NIV-NAVA) with PEEP set at 5 cmH2O. NAVA gain level will be titrated to achieve an equivalent peak inspiratory pressure as in PSV (NAVA0). Another 2 levels will be set at 0.5 cmH2O/uV above and below NAVA0 (NAVA+1 and NAVA-1 respectively). Inspiratory trigger Edi will be set at 0.5uV above Edi min, while expiratory trigger is fixed by the manufacturer at 70% of Edi peak. The subject will breathe at each setting for 20 minutes as wash-out and recordings are obtained in the next 2 minutes.
Sponsors
Department of Intensive Care, Pamela Youde Nethersole Eastern Hospital
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Are currently or previously on mechanical ventilation for acute respiratory failure 2. Are considered fit for extubation (defined as hemodynamic stability without the need for vasopressor support and a heart rate less than 110 beats per minute (bpm), respiratory rate less than 30 per minutes, and a Glasgow coma scale of E4VtM6), or has been extubated already 3. Are indicated for NIV with >=1 of the risk factors for reintubation, including: chronic heart failure, COPD initially intubated because of an episode of acute hypercapnic respiratory failure, age >65, more than one consecutive failure of weaning trial before extubation, PaCO2 >45 mmHg (6 kPa) after extubation, weak cough 4. Expected to require NIV for >=2 days 5. Able to give consent to the study by him/herself.
Exclusion criteria
patients less than 18 years of age, pregnancy, with contraindications for insertion of nasogastric tube, or with contraindications for NIV (esophageal varices or obstruction, bleeding of the upper gastrointestinal tract, recent gastroesophageal surgery, hemodynamic instability or severe arrhythmia, facial surgery or trauma or deformity, severe upper airway obstruction, inability to cooperate or protect the airways, inability to cough or clear respiratory secretions, absence of a gag reflex and severe gastric distention), or contraindications to NAVA mode (known or suspected phrenic nerve dysfunction, and impaired respiratory drive).
Outcome results
None listed