Predictors for treating obstructive sleep apnea with an open nasal cannula system (transnasal insufflation)

Background: Obstructive sleep apnea (OSA) is a disorder that is associated with increased morbidity and mortality. Although continuous positive airway pressure effectively treats OSA, compliance is variable because of the encumbrance of wearing a sealed nasal mask throughout sleep. In a small group of patients, it was recently shown that an open nasal cannula (transnasal insuffl ation [TNI]) can treat OSA. The aim of this larger study was to find predictors for treatment responses with TNI. Methods: Standard sleep studies with and without TNI were performed in 56 patients with a wide spectrum of disease severity. A therapeutic response was defined as a reduction of the respiratory disturbance index (RDI) below 10 events/h associated with a 50% reduction of the event rate from baseline and was used to identify subgroups of patients particularly responsive or resistant to TNI treatment. Results: For the entire group (N = 56), TNI decreased the RDI from 22.6±15.6 to 17.2±13.2 events/h(P<.01). A therapeutic reduction in the RDI was observed in 27% of patients. Treatment responses were similar in patients with a low and a high RDI, but were greater in patients who predominantly had obstructive hypopneas or respiratory effort-related arousals and in patients who predominantly had rapid eye movement (REM) events. The presence of a high percentage of obstructive and central apneas appears to preclude efficacious treatment responses. Conclusion: TNI can be used to treat a subgroup of patients across a spectrum from mild-to-severe sleep apnea, particularly if their sleep-disordered breathing events predominantly consist of obstructive hypopneas or REM-related events but not obstructive and central apneas.