Re-evaluating the nasal cycle by long-term rhinoflowmetry: most individuals demonstrate a “mixed” nasal cycle

Abstract

Background: The nasal cycle seems to be more complex than a strictly alternating swelling of the nasal mucosa. Long-term rhinoflowmetry (LRFM) allows continuous investigation of changes in nasal airflow over 24 hours (24h). We evaluated the various types of nasal cycle with LRFM over 24 hours and investigated the influence of age and gender. Methods: LRFM was continuously performed over 24h in 55 rhinologically healthy subjects (36 female, 19 male). The LRFM flow curves were examined for phases of the “classical”, “in-concert”, “one-sided” and “no-cycle” cycle types. Subjects were divided into 4 age subgroups (19-29; 30-49; 50-69; >70 years). Correlations of age and gender with the individual cycle forms were analyzed. Results: 85.5% of the subjects presented a “mixed” nasal cycle within 24h. The “classical” nasal cycle was seen most often (92.7% vs. “in-concert”; 56.4% vs. “one-sided”; 18.2% vs. “no-cycle”; 5.5%). Older age groups significantly more often presented the "no-cycle" type. A tendency was seen towards a mixed nasal cycle with increasing age. The mixed nasal cycle was significantly more often seen in the female subjects. Conclusions: LRFM is an easy-to-use measurement tool. The “mixed” nasal cycle predominates. However, all 4 different cycle types can be detected, alternating over 24h in each subject. Moreover, the cycle type varies with age.

Asymmetrical nasal high flow ventilation improves clearance of CO2 from the anatomical dead space and increases positive airway pressure

“…The phenomenon is characterized by periodically alternating resistance between nasal cavities caused by the obstruction of the nasal passages by erectile tissue ( 34 ). Most people exhibit a nasal cycle dynamically changing resistance every few hours, however the extent and pattern can vary and is often exaggerated during upper airway pathology ( 35 ). The asymmetrical occlusion depends on the cross-sectional area of the prongs relative to the vestibulum nasi, which is the area just inside the nostril at the entrance of the nasal cavity.…”

Biological sex as a modulator in rhinologic anatomy, physiology, and pathology: A scoping review

“…The nasal cycle describes the alteration of congestion and decongestion of the nasal cavities. The mixed nasal cycle, defined as multiple different nasal cycle types in 24 hours, was seen significantly more frequently in females than in males 12 . Baseline differences in the physiology of the nasal cycle and nasal contractility may contribute to pathology.…”

Assessing Nasal Epithelial Dynamics: Impact of the Natural Nasal Cycle on Intranasal Spray Deposition

“…However, it is believed that the autonomic nervous system plays a vital part in this process. The occurrence of nasal cycle can vary with age, physical activity, and specific medication [ 8 , 9 , 10 , 11 , 12 ]. Furthermore, factors that cause the widening of nasal blood vessels, thickening of the nasal mucosa, and alterations in nasal secretion levels, like allergic, nonallergic, or infectious forms of rhinitis, also affect the nasal cycle’s occurrence [ 13 , 14 ].…”