Effectiveness of Bronchodilator Nebulization With and Without Noninvasive Ventilation in COPD

Effectiveness of Bronchodilator Nebulization With and Without Noninvasive Ventilation During Respiratory Failure in Chronic Obstructive Pulmonary Disease

The study aim to evaluate effectiveness of two bronchodilator nebulization strategies in patients with acute decompensated type 2 respiratory failure due to acute exacerbation of chronic obstructive pulmonary disease..

Decompensated type 2 respiratory failure during acute exacerbation of chronic obstructive pulmonary disease (COPD) is treated with non-invasive ventilation (NIV) and nebulized bronchodilators. Nebulization during NIV can be applied by two methods: in-line nebulization through NIV mask and off-NIV nebulization during which NIV mask is taken off for a short time and reapplied when nebulization is finished.

This study is a prospective randomized controlled trial to compare in-line nebulization through NIV versus off- NIV nebulization. After starting NIV in eligible COPD patients with type 2 respiratory failure, the baseline end-expiratory lung impedance (EELI) will be measured. Patient is randomized to receive either in-line or off-NIV nebulization. EELI will be measured again following completion of the nebulization, 15min after NIV is restarted (off-NIV group) or continued (in-line group). Ultrasound measurement of the thickness of the diaphragm will be recorded at baseline, 15min after NIV is restarted (off-NIV group) or continued (in-line group) and 48 hours after stopping the NIV. The main outcome measure, difference in mean end expiratory lung volume at 15min after NIV is restarted (off-NIV group) or continued (in-line group) between the two nebulization methods will be compared using independent sample T test. Thickness of the diaphragm and changes in the arterial blood gases (in terms of pH and carbon-di-oxide) will be compared between in-line nebulization and off-NIV nebulization.

Inclusion Criteria:

1. Age ≥21 years.
2. Known or suspected COPD (defined by a ratio of Forced Expiratory Volume in 1 second (FEV1) to Forced Vital Capacity (FVC) of less than 0.7).
3. Acute decompensated type 2 respiratory failure (ABG pH ≤ 7.35 and PaCO2>45mmHg).
4. Clinical decision made to start NIV.

Exclusion Criteria:

1. Other acute decompensated type 2 respiratory failure related conditions (e.g. neuromuscular, heart failure etc.).
2. Pneumonia present in the chest radiograph.
3. Other conditions which may change lung impedance (e.g. heart failure or lung fibrosis).