Fig. 2From: Switch of noninvasive ventilation (NIV) to continuous positive airway pressure (CPAP) in patients with obesity hypoventilation syndrome: a pilot studyFlow chart. Definition of abbreviations: OHS: Obesity Hypoventilation Syndrome; FEV1: Forced Expiratory Volume in 1 s; FVC: Forced Vital Capacity; NIV: Non Invasive Ventilation; CPAP: Continuous Positive Airway Pressure; AHI: Apnea Hypopnea IndexBack to article page