Nasal mask interface tied to better CPAP adherence
Using the nasal mask interface was associated with better adherence during continuous positive airway pressure (CPAP) therapy initiation compared with other mask interfaces, according to a local study on Asians.
“Mask tolerability is a major determinant of adherence and mask switching is associated with abandoning CPAP therapy. Therefore, identifying the most suitable interface at initiation of CPAP therapy is important in enhancing patients’ adherence,” said the researchers led by Dr Ken Goh Junyang from Singapore General Hospital, Singapore.
In the prospective, crossover trial, 85 patients (mean age 46 years) with newly diagnosed moderate-to-severe obstructive sleep apnoea (OSA; AHI* ≥15) were randomized to receive CPAP therapy with either one of the three mask interfaces: nasal mask, oronasal mask, or nasal pillow. Participants underwent CPAP with each mask interface for 1 month before crossing over to the other mask interfaces. [Respirology 2018;doi:10.1111/resp.13396]
Among the three interfaces, adherence to CPAP was the greatest with nasal mask, as indicated by an average nightly use of 3.96 hours compared with 3.26 hours for oronasal mask (p<0.001) and 3.48 hours for nasal pillow (p=0.007).
In addition, oronasal mask led to a higher residual AHI (mean, 7.2) compared with nasal mask (mean, 4.0; p<0.001) and nasal pillow (mean, 4.1; p<0.001).
“Nasal masks should therefore be the preferred mask interface during initiation of CPAP therapy,” suggested Goh and co-authors.
Nonetheless, 22 patients (25.9 percent) adhered to CPAP best with oronasal masks than the other interfaces. Compared with the rest of the participants, these patients used oronasal masks for a significantly longer duration nightly (average use, 2.93 vs 4.22 hours/night; p=0.016).
“Significantly better CPAP adherence was found with oronasal masks compared to nasal interfaces despite the higher residual AHI and leak with oronasal masks,” noted the researchers.
When these patients were analysed for characteristics associated with adherence to CPAP with oronasal masks, the researchers found that they have a lower NOSE** score (15 vs 40) as well as a larger distance between chin-lower-lip and midface width (menton-labrale inferioris/biocular width ratios, 31 percent vs 28 percent) compared with the rest of the patients. After adjusting for gender, age, BMI, and AHI, both lower NOSE score (odds ratio [OR], 0.891; p=0.045) and greater distance between chin-lower-lip and midface width (OR, 1.22; p=0.013) were found to be associated with better adherence with oronasal mask.
The lower NOSE score indicates less symptomatic nasal obstruction, and the finding was contrary to the common belief that higher NOSE score was linked to better CPAP adherence with oronasal mask. “These suggest that the presence of nasal obstruction should not preclude the use of nasal interfaces. This is an important consideration especially with the high prevalence of upper airway and nasal abnormalities in patients with OSA,” according to Goh and co-authors.
“We do not recommend selecting a mask interface based on craniofacial features alone because the benefits of improved adherence must be carefully weighed against the negative effects of an increased residual AHI and mask leak that is associated with oronasal masks,” they advised.