Obesity Hypoventilation Syndrome: New Insights in Diagnosis and Management

Obesity hypoventilation syndrome (OHS) is a syndrome characterized by a constellation of obesity [body mass index (BMI) 30 kg/m 2 ], daytime hypercapnia (arterial carbon dioxide tension 45 mm Hg), and sleep-disordered breathing (SDB), provided other conditions leading to alveolar hypoventilation have been objectively ruled out. Delayed diagnosis can precipitate significant cardiorespiratory morbidity in the form of pulmonary hypertension, heart failure, and coronary disease. Sleep fragmentation, oxidative stress, and obesity-related deconditioning are the predominant mechanisms of the clinical predicament and the poor quality of life. The diagnosis requires a due awareness about its presence and a prone index of suspicion in the suitable clinical context. The diagnosis is conclusively established on basis of a sleep study and arterial blood gases (ABGs). Management requires a holistic approach focusing on weight reduction, lifestyle modification, treatment of comorbidities, and control of the SDB by means of continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV) and pulmonary rehabilitation. Opportune therapy facilitates an optimistic prognosis and improves the quality of life.