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 insufflation [TNI]) can treat OSA. The aim of this larger study was to find predictors for treatment responses with TNI.
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.
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.
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.