Chronic Noninvasive Positive-Pressure Ventilation: Considerations During Sleep

Noninvasive ventilation (NIV) has become a proven and accepted treatment for respiratory failure from a variety of underlying causes. NIV during sleep can improve gas exchange in both acute and chronic respiratory failure. During sleep, numerous physiologic changes take place that increase the work of breathing and can therefore worsen sleep quality. These include decrements in tidal volume, worsening of gas exchange, and altered lung mechanics. While institution of NIV has been shown to improve nocturnal Paco2 and Pao2 levels and reduce the work of breathing, less is known regarding its effects on sleep and sleep quality. This article reviews data from case series, uncontrolled studies, randomized clinical trials, and meta-analyses. While there is some controversy, the predominance of data suggests that NIV can significantly improve several measures of sleep quality and duration in patients with chronic respiratory failure from numerous underlying causes. Studies have demonstrated improvements in total sleep time, sleep efficiency, subjective sleep quality, and overall quality of life in patients using NIV. In patients with the obesity hypoventilation syndrome, NIV is a cornerstone of therapy, improving daytime hypersomnolence as well as gas exchange. The data for NIV in patients with chronic obstructive pulmonary disease are conflicting and it is unclear if these patients have overall improvements with NIV use. Implementation of chronic NIV is discussed, along with indications and contraindications to therapy.