Nascimento J.A.1, Carvalho T.S.1, Silva A.C.2, Fernandes P.H.3, Barroso L.P.4, Genta P.R.3, Lorenzi-Filho G.3, Nakagawa N.K.1
1Faculdade de Medicina da Universidade de Sao Paulo, Physiotherapy, São Paulo, Brazil, 2Faculdade de Medicina da Universidade de Sao Paulo, Pathology, São Paulo, Brazil, 3Heart Institute - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Pulmonology - Sleep Laboratory, São Paulo, Brazil, 4Mathematical and Statistics Institute, Universidade de São Paulo, Statistics, São Paulo, Brazil
Background: Oronasal masks are used as a first choice for CPAP treatment in self-reported oral/oronasal breathers with severe obstructive sleep apnoea (OSA) with or without nasal obstruction. We hypothesized that independently of having oral/oronasal airflow via, nasal mask would have more advantages in severe OSA patients with nasal free airflow of obstruction.
Purpose: The objective of this study was to investigate the effects of nasal and oronasal CPAP titration on CPAP level, polissonographic variables and biomarkers of the airway defense in severe OSA patients (recent diagnosis and no previous OSA treatment) with nasal free flow of obstruction. Additionally we determined the effects of a 30-day period of CPAP treatment.
Methods: Twenty subjects (~46 years, 13 male) with severe OSA were randomly assigned to CPAP titration with nasal and oronasal mask, 14-day period apart. The outcome variables were CPAP level, PSG variables, and airway defense biomarkers. Patients were treated with CPAP during 30 days using the best interface determined by full night of manual titration and were assessed also for adherence, airway symptoms and airway defense mechanisms.
Results: Among 20 patients with severe OSA, 15 patients showed complete agreement of airflow via between self-report and laboratory analysis. Ten patients (50%) had oronasal airflow via during awake. However, independently of the airflow via, 100% of patients had better CPAP titration outcomes using nasal mask, such as lower residual AHI (p=0.030), lower CPAP level (p 0.001), longer restorative sleep (p=0.006) and inflammation reduction observed by increased number of goblet cells (p=0.034) and decreased expression of myeloperoxidase (p=0.006) in nasal lavage fluid. The use of oronasal CPAP during titration induced significant nasal inflammation observed by increased number of neutrophils (p=0.009), macrophages (p 0.001) and ciliated cells (p 0.001) as well as increased expression of intercellular adhesion molecule-1 and vascular adhesion molecule (p=0.041 for both) in nasal lavage fluid. After 30 days, nasal CPAP had 85% adherence, lowered airway symptoms and improved sleep quality and airway defense biomarkers (nasal mucociliary clearance, mucus properties and cytokines).
Conclusion(s): Independently of self-report of oral or oronasal airflow preference, nasal mask showed significant advantages over oronasal mask in patients with nasal free-airflow of obstruction and severe OSA.
Implications: The clinical message is that for patients with severe OSA and nasal free airflow of obstruction, nasal mask should be used independently of their airflow preference or via. Oronasal mask may be harmful in a sub-group of patients with nasal free airflow of obstruction.
Funding acknowledgements: Fundação de Amparo à Pesquisa do Estado de São Paulo (Research grant 13/13598-1).
Topic: Cardiorespiratory
Ethics approval: Ethical Committee of Faculdade de Medicina da Universidade de São Paulo number of the process: 102/13.
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