Treatment
The common mainstays of management for sleep-disordered breathing include oxygen therapy and noninvasive ventilation (NIV) such as continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) or more advanced therapy. Oxygen therapy alone, however, should be looked at with caution in our patient population as it may worsen hypoventilation57. In children, therapeutic options include surgical options such adentonsillectomy as first line treatment for OSA. Additional options for OSA in adults include oral devices, glossopharyngeal nerve stimulation, myofunctional therapy and positional devices58-60. Pharmacologic therapies for OSA, such as montelukast and nasal steroids have shown mixed results in pediatric and adult populations, with some benefit to montelukast being seen in children but not adults61,62.
There are no clear guidelines or recent literature available for treatment of isolated nocturnal hypoxemia. Although there are studies evaluating use of oxygen therapy based on daytime hypoxemia, studies treating based on nocturnal hypoxemia are sparse.63Multiple older studies exist recommending caution with using oxygen therapy alone at night for treatment due to worsening hypercarbia.45,46 In a 12-month randomized prospective trial, Milross et al. studied the long term effects of NIV, with or without oxygen and low flow oxygen on event free survival in adults with CF already diagnosed with nocturnal hypoxemia by a PSG.57  Events were defined as development of hypoventilation, lung transplantation, or death.57They also followed for outcomes such as hospitalization, lung function, and health-related quality of life.57 Their aim was to determine if adults with CF and nocturnal desaturations were less likely to develop hypercapnia on low flow oxygen or non-invasive ventilation.57 They concluded that NIV with or without oxygen increased event free survival compared to treatment with oxygen alone.57 This emphasizes that CF providers need to use caution if prescribing oxygen therapy alone.
Noninvasive positive pressure ventilation is not completely new to the cystic fibrosis population, and has been successfully already been incorporated in the care plan for certain patients. In stable CF patients with awake hypercapnia, a six week trial of nocturnal noninvasive ventilation showed improved nocturnal hypoventilation and peak exercise capacity without improving lung function or awake hypercapnia64. Noninvasive ventilation has also been evaluated in cystic fibrosis patients as an adjunct to airway clearance techniques,65,66 particularly in patients having trouble expectorating sputum.65  The rationale is that in patients with severe lung disease, airway clearance therapy results in energy expenditure and use of noninvasive ventilation could allow for decreased work of breathing and fatigue.67  In addition, noninvasive ventilation is used pre- lung transplant, and has been shown to slow the decline in lung function in this patient subset65. It stands to reason that patients prescribed noninvasive ventilation for sleep-disordered breathing may also have additional benefits such as improved airway clearance, increased peak exercise capacity, and a slower decline in lung function; however, dedicated studies looking at these outcomes are necessary.