Noninvasive ventilation (NIV), often referred to by the trade name “BiPAP®,” can prevent intubation and save lives in patients with COPD exacerbations or pulmonary edema due to heart failure. Its proven benefits and low risk have led to NIV being used for patients in respiratory failure in virtually every acute care setting in the developed world. Noninvasive ventilation reduces the work of breathing and increases the bulk flow of air, which may be why its benefits are especially pronounced in patients with