Effects of long-term nasal continuous positive airway pressure therapy on morphology, function, and mucociliary clearance of nasal epithelium in patients with obstructive sleep apnea syndrome

Objectives/Hypothesis: The objective was to investigate the possible modification of nasal mucosa function and mucociliary clearance in a group of patients with severe obstructive sleep apnea syndrome receiving mechanical ventilation with long-term nasal continuous positive airway pressure (n-CPAP), without nasal diseases. Study Design: The study design was experimental. Eight (six male and two female) nonsmoker patients were selected on the basis of two sleep questionnaires, were identified as needing n-CPAP therapy, and showed normal values of mucociliary transport time, ciliary beat frequency, and anterior rhinomanometry. Methods: After a full polysomnographic examination, the authors recorded respiratory disturbance index (RDI), apnea/hypopnea index, nadir arterial oxygen saturation, and sleep stage. Every patient underwent pulmonary function test; arterial blood gas analysis; chest radiography; electrocardiography; ear, nose, and throat evaluation with rhinoscopy; anterior rhinomanometry; a saccharine test to measure the mucociliary transport time; and a brushing of nasal epithelium for study of ciliary beat frequency. All patients underwent polysomnographic examination in basal condition with overnight n-CPAP (without humidifier) and repeated this examination after 1 and 6 months with Auto CPAP (Autoset Res Care, Sidney, Australia) to titrate n-CPAP pressure and measure the new respiratory disturbance index. Results: The mean basal respiratory disturbance index (number of respiratory events during sleep per hour of recording time) was 53.7 ± 21.5 events/h; after 6 months of n-CPAP therapy (mean value, 7.5 ± 0.7 cm H₂O) the respiratory disturbance index was 5.7 ± 3.76 events/h. Values for nasal resistance, mucociliary transport time, and ciliary beat frequency were normal before and after the ventilatory treatment. Conclusion: In the study group of patients with severe obstructive sleep apnea syndrome, the nocturnal use of n-CPAP without humidifier did not modify the function and mucociliary clearance of nasal epithelium.