gms | German Medical Science

Introduction: The use of nCPAP in the treatment of obstructive sleep apnea may lead to nasal and pharyngeal side effects. These side effects are usually addressed with airway humidification. Nevertheless, only limited data on the impact of nCPAP with our without humidifiers on the ciliary function is available. The integrity of the cilia is essential for mucosal clearance and regular nasal function.

Methods: Patients with obstructive sleep apnea (AHI>20) were included in this prospective, randomized, cross-over trial and were randomized to nCPAP therapy with or without airway humidification. The ciliary function was assessed by measuring ciliary beat frequency (CBF, via high-speed digital microscopyy) and the mucus transport time (MTT) immediately before and the morning after the first use of nCPAP. In addition, the ciliary function was assessed after a period of four weeks under nCPAP and a change in ventilation therapy was performed (cross over). Ciliary function was finally assessed after additional four weeks of use.

Results: CBF was 5.57±1.32 Hz and the was MTT 871±631 s at baseline. After one night of nCPAP, a small increase in ciliary function was detected, regardless the use of airway humidification (without humidification: CBF +1.41 Hz, MTT –119 s and with humidification: CBF +0.87 Hz, MTT –211 s.) Concerning long-term effects there was an additional increase in ciliary activity which was more pronounced in the group with airway humidification. In detail, the increase under nCPAP without humidification was CBF +1.81 Hz, MTT –323 s (p=0.13) and with humidification CBF +3.62 Hz, MTT –616 s (p=0.06) compared to baseline. The difference between the two groups was statistically significant.

Conclusion: After one night of nCPAP therapy, a limited and statistically non-significant increase in ciliary activity could be detected. This effect was independent from the utilization of a humidifier. However, under long-term treatment with nCPAP there was an increase in ciliary function, which was more pronounced in the humidifier group, which has not described to date. This long-term changes under nCPAP may indicate a slow but long-term, nCPAP induced change of the nasal epithelium.