A study of outcome of noninvasive ventilatory support in acute respiratory failure

Introduction: Noninvasive ventilation (NIV) is often used in acute respiratory failure to prevent endotracheal intubation and its complications. Various factors influence favorable outcome for NIV. Aim: To assess the outcome of NIV in acute respiratory failure and to determine predictors of positive outcome. Patients and Methods: This was an observational study of 4 years where 110 patients with acute respiratory failure requiring NIV were included. Data of history, examination, investigations, and clinical outcome of all patients were recorded. The outcome was divided in two categories depending upon whether patients improved or required invasive ventilation. Results: Of 110 patients, there were 78 men with a mean age of 64.24 years and 32 women with a mean age of 56.59 years. The causes of acute respiratory failure were acute exacerbation of chronic obstructive pulmonary disease (COPD) (61.81%), bronchial asthma (9.09), pneumonia (22.72%), tuberculosis (2.72%), interstitial lung disease (1.81%), and pulmonary artery hypertension (0.9%). Among them, 81 (74%) patients improved. Patients who had acute respiratory failure due to COPD (P  3 days (P = 0.001). Conclusions: COPD patients with acute respiratory failure respond well to NIV. Improvement in pH, PCO2, and PO2 within or at 24 h of NIV predicts successful outcome. Requirement of prolonged NIV leads to poor outcome.