NIV - NAVA vs NIV - PS for COPD Exacerbation

Number of Patients: Total no. of patients = 40 patients NIV-PSV group (Group A) = 20 NIV-NAVA group (Group B) = 20 Inclusion criteria a) Patients of Chronic obstructive pulmonary disease with acute hypercapnic respiratory failure (pH \45 mmHg) requiring noninvasive ventilation and with no indication for invasive mechanical ventilation. Exclusion criteria 1. Patient with any contra-indication for insertion of nasogastric tube (like recent gastrointestinal bleeding in previous 30 days, esophageal varices) 2. Patient with any contraindication of noninvasive ventilation (such as hemodynamic instability, active gastrointestinal bleed etc) 3. Patients with a known neuromuscular, central or peripheral nervous system disorder. 4. Patient not willing to give consent. Control(s): Patients receiving pressure support ventilation (NIV-PSV) will act as control Study design: Randomized interventional study Dosages of drug: None Duration of treatment: Till patient improves or requires invasive ventilation. Brief Methodology Patients of COPD with acute exacerbation will be randomized into two groups (group A and group B) to receive NIV-PSV or NIV-NAVA respectively. A special naso-gastric catheter (EAdi-catheter) will be placed in all patients. In each mode, NIV will be applied using a non-vented oro-nasal mask that will be fitted enough to avoid air leaks. Patients in Group A will receive NIV-PS and Group B will receive ventilation via NIV-NAVA. Pressure support and PEEP levels will be set by the treating physician to achieve a tidal volume (Vt) of 6 to 8 mL/kg of ideal body weight. NAVA level will be adjusted to match peak pressures of NIV-PSV using manufacturer-supplied software. After stabilization, a 30-min period of each NIV trial will be recorded and manually analyzed offline. Subsequent readings will be taken at 2, 6 and at 24 hours and then at 6 hourly interval from day 2 onwards. In each trial, patient-ventilator asynchronies (ineffective effort