Does Noninvasive Ventilation Have a Role in Severe COPD?

Noninvasive ventilation (NIV) has long been theorized to offer benefit to patients with severe COPD. More than 30 years ago, nocturnal NIV (including negative pressure ventilators) was shown to reduce PaCO2 levels and improve respiratory muscle strength in such patients. The theories proposed that NIV would rest respiratory muscles at night, permitting improved strength and function during the daytime/ Others theorized that NIV might also improve the quality and quantity of sleep at night by preventing increases in PaCO2 and associated sleep fragmentation