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.

Abstract

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. 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. 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. 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. 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.