Continuous investigation of the nasal cycle over 48 hours

Previous results on the nasal cycle refer to measurements over up to 24h. The long-term rhinoflowmetry (LRFM) allows continuous observations over a longer period. The aim of the study was to observe the nasal cycle for the first time over 48h under everyday conditions.

The LRFM was continuously applied to 30 rhinologically healthy subjects (20 female, 10 male) over 48h. The different types of nasal cycle were classified as follows: "classic", "in concert", "one-sided", "no-cycle" and "mixed". The focus of this study was on the results over the entire 48 hours. The comparison of the two consecutive days was also made.

A nasal cycle could be detected in 100% of the subjects over 48h. With 97%, the mixed type most commonly occurred as a combination of classical and in concert components. In all subjects, classical cycle components could be detected at least once. The no-cycle type was not observed. In the awake state, the mixed type dominated (80%), as a combination of classical and in concert parts. In the sleep state, the classical type was the most common type (97%). The average phase duration was 206 +- 83 minutes.

In the very first continuous 48-hour study on the nasal cycle, 100% of the subjects presented a nasal cycle. The LRFM method is the only one that offers the possibility to perform continuous measurements over a longer period during daily routine. The results of previous single-stage examination methods should thus be questioned.