This is a small pilot study that will compare High Flow Nasal Cannula (HFNC) therapy to oxygen nasal cannula therapy on infants who have obstructive sleep apnea (OSA) and are scheduled for a clinically ordered sleep study called polysomnography (PSG). The HFNC procedure uses humidified room air delivered by nasal cannula at higher pressures and will test if HFNC can control OSA in infants better or as well as low flow nasal oxygen, the current clinical standard of care. All the infants in the study will have a brief test period of about 3 to 4 hours with the HFNC before participants begin their standard clinical PSG for titration of oxygen by nasal cannula for treatment of OSA.

The current standard of care for treating OSA in infants less than 6 months and frequently up to 12 months of age is with a continuous flow of oxygen by nasal cannula. This is generally referred to as nasal continuous positive airway pressure or NCPAP. A nasal cannula is used with oxygen at low flows of between 1/4 to 1 liter per minute (l/m) to deliver supplemental oxygen to reduce oxygen desaturations associated with apneic episodes and to provide a positive pressure flow to maintain an open airway.

High Flow Nasal Cannula (HFNC) therapy is a non-invasive treatment providing respiratory support. In this study, HFNC is designed to administer a heated and humidified mixture of air at a flow higher than the patient's inspiratory flow. There is currently no single, simple definition of high flow. In infants, it usually refers to a flow of >2 l/min and in children it is considered >6 l/min. High flow presents several advantages over conventional 'low-flow' oxygen therapy in terms of humidification, oxygenation, gas exchange, and breathing pattern. Several studies have shown that a flow higher than the patient's inspiratory flow provides better oxygen delivery than low-flow oxygen therapy or high-concentration oxygenation mask. This observation has been explained as the effect of a high flow on the oropharyngeal dead space, washing out oxygen depleted gas and reducing carbon dioxide (CO2) rebreathing. The extrathoracic dead space is proportionally two to three times greater in children than in adults. It may measure up to 3 mL/kg in newborns and becomes similar to the adult volume only after 6 years of age (0.8 mL/kg). Consequently, the younger a child is, the greater the effect of a high flow on oxygenation and CO2 clearance.

This pilot study is to compare standard of care low flow nasal oxygen to the effectiveness of HFNC therapy in infants aged 12 months and younger to treat OSA. The study intervention will occur for approximately 3 to 4 hours immediately prior to a scheduled clinical PSG. Subjects will be prepared for standard clinical PSG and after asleep, the intervention will be titration of room air at different pressure flows delivered by a HFNC system. At the end of the research portion of the PSG, the clinical PSG will begin with the standard of care treatment, the nasal oxygen titration for OSA. The results of the clinical PSG will serve as control comparison for the research intervention.

Inclusion Criteria:

• Infants ≤ 12 months
• Diagnosis of OSA from previous PSG

Exclusion Criteria:

• Infants who on previous PSG had central apneas > 50% of the AHI