Comparing Heated Humidified High Flow Nasal Cannula and Continuous Positive Airway Pressure Therapy for Children with Obstructive Sleep Apnoea

The primary objective of this study is to compare the effectiveness of high flow nasal cannula (HFNC) therapy to gold standard continuous pressure airway pressure (CPAP) therapy in improving polysomnography (PSG) parameters of children with moderate or severe obstructive sleep apnoea (OSA) during a single night study. The secondary objective of the study is to compare patient tolerance and comfort of HFNC therapy to CPAP therapy. Children initially underwent a standard diagnostic overnight PSG. Those diagnosed with moderate-to-severe OSA who were not considered suitable candidates for therapeutic surgical intervention, such as adenotonsillectomy, were routinely referred for CPAP therapy as part of standard clinical care. These children would ordinarily return to the sleep laboratory for an overnight CPAP titration study. Participants who consented to the study were offered an additional overnight heated humidified HFNC titration study prior to their scheduled CPAP titration. HFNC was performed first, followed by the clinically indicated CPAP titration within four weeks. This additional study did not delay or alter routine clinical care, as CPAP titration is typically scheduled two to four weeks following diagnostic PSG because of patient scheduling and sleep laboratory availability. HFNC was delivered using the Fisher & Paykel AIRVO™ 2 system with warmed, humidified room air administered via appropriately sized nasal cannulae. Nasal prongs were selected to occupy approximately 50% of each nare. Initial flow rates were determined according to participant weight and titrated throughout the overnight study by an experienced sleep clinical nurse technologist to minimise obstructive respiratory events while maintaining participant comfort. Children weighing less than 10 kg commenced at 1 L/kg/min, with flow increased in 1 L/min increments to a maximum of 2 L/kg/min. Participants weighing 10 kg or more commenced at 10 L/min, with flow increased in 5 L/min increments to a maximum of 2 L/kg/min or 60 L/min, whichever was lower. CPAP titration was subsequently performed during a separate overnight attended PSG according to standard departmental protocols. Therapy was initiated at 4 cmH2O and increased in 1 cmH2O increments until obstructive respiratory events were adequately controlled or the maximum therapeutic pressure was reached. All intervention procedures were undertaken with close clinical supervision at all times within the sleep lab. All PSG studies were scored according to American Academy of Sleep Medicine paediatric scoring criteria and interpreted independently by sleep physicians blinded to the results of the alternate treatment study. Participant- or parent-reported comfort questionnaires were completed following each intervention to assess treatment tolerability and preference.