1. Bilevel positive airway pressure (BPAP) delivers two levels of positive airway pressure - a higher pressure during inspiration and a lower pressure during expiration - to reduce work of breathing and improve oxygenation.
2. BPAP is effective for acute exacerbations of COPD and cardiogenic pulmonary edema by reducing mortality, need for intubation, and treatment failure compared to standard care.
3. For pneumonia, outcomes are worse with post-obstructive pneumonia, pleural effusions, hypoxic hypercapnic respiratory failure with effusions, and over 24 hours on BPAP therapy.