Initial Treatment for Obesity Hypoventilation Syndrome

Understanding OHS

The American Thoracic Society defines Obesity Hypoventilation Syndrome (OHS) by the combination of obesity, sleep-disordered breathing, awake daytime hypercapnia (elevated carbon dioxide levels), and exclusion of other causes for hypoventilation, with awake daytime hypercapnia defined as PaCO₂ > 45 mm Hg at sea level 2
The diagnosis of OHS involves the exclusion of other causes for hypoventilation 3

For OHS with severe Obstructive Sleep Apnea (OSA), the American Academy of Sleep Medicine recommends Continuous Positive Airway Pressure (CPAP) as first-line therapy, which applies to approximately 70% of OHS patients who have concomitant severe OSA 4

The American College of Chest Physicians recommends that patients hospitalized with respiratory failure suspected of having OHS should be started on Noninvasive Ventilation (NIV) therapy before discharge, and undergo outpatient workup and PAP titration in a sleep laboratory within 3 months after discharge 4
Weight loss interventions, including sustained weight loss of 25-30% of body weight, should be considered as part of comprehensive management, and bariatric surgery may be considered for patients without contraindications who are unable to achieve sufficient weight loss through lifestyle interventions 4

Treatment should be guided by combined monitoring of oxygen saturation and carbon dioxide levels, and adjustments should be made if patients remain hypercapnic despite adequate adherence to CPAP therapy for 6-8 weeks, considering switching to NIV 4
Discharging hospitalized patients without arranging prompt outpatient sleep study and PAP titration should be avoided 4