When and how do I qualify inpatients with acute on chronic hypercapnic respiratory failure for home noninvasive positive-pressure ventilation at the time of discharge? A 44-year-old woman with morbid obesity (BMI, 48) was brought to the hospital by her boyfriend for 1 day of confusion and reduced alertness. She had a history of chronic dyspnea on exertion and 10-pack-years of smoking. She also had history of well-treated diabetes and hypertension. In the ER, she was found to be somnolent but arousable and following commands appropriately. Her oxygen saturation was 86% on room air, and arterial blood gases indicated a pH of 7.16 with a Paco2 of 87 mm Hg, a Pao2 of 60 mm Hg, and a bicarbonate of 42 mEq/L. Chest radiograph showed mild pulmonary vascular congestion. She was started on continuous bilevel positive airway pressure and medical therapy, with clinical improvement.