Integrating the Divided Nasal Cannula Into Routine Polysomnography to Assess Nasal Cycle: Feasibility and Effect on Outcomes

Real-time observation of nasal cycle during sleep with polysomnography

PURPOSE

To investigate the nasal cycle (NC) during sleep in healthy individuals without nasal obstruction or obstructive sleep apnoea via a flexible wearable respiratory monitoring system in a continuous and real-time manner.

METHODS

NC during sleep was continuously measured in 30 healthy individuals (15 women, 15 men) via long-term sleep respiratory monitoring system, while sleep stage and body position were simultaneously recorded via polysomnography (PSG). The number of NC transitions and positional changes were documented each night. Additionally, time intervals between NC transitions and their closest positional changes during sleep were meticulously recorded to investigate potential correlations between them.

RESULTS

A total of 86.7% of the participants displayed the classic NC, with a mean duration of 6.43 ± 2.33 h. Nightly observations revealed an average occurrence of 2.19 ± 0.40 NC transitions, predominantly occurring during REM stage (68.4%), and 9.15 ± 7.77 postural changes. Analysis of the intervals between NC transitions and positional changes revealed an average absolute value of 27.72 ± 10.85 min, with a substantial 56.4% exceeding 30 min, indicating a non-obvious sequence order among them.

CONCLUSION

NC can be measured in a continuous and real-time manner, the transitions occur mainly during the REM stage. However, we have not identified a clear correlation between NC transition and positional change.

A Preliminary Report on the Correlation Between Nasal Function and the Different Phases of the Nasal Cycle

OBJECTIVE

To explore whether the different phases of the nasal cycle have a significant effect on nasal temperature, the nasal mucosal clearance rate, and levels of nasal nitric oxide (nNO) and to investigate the correlation between these nasal conditions.

METHODS

The study participants were divided into 2 groups: the control group and the rhinitis group. The participants' nasal temperature, cilia clearance rate, and nNO levels were measured during different phases of the nasal cycle (the congestion phase and decongestion phase) in the control group and before and after undergoing inferior turbinate ablation in the rhinitis group.

RESULTS

The temperature of the nasal cavity in the control group was significantly higher in the congestion phase than in the decongestion phase (P = .0025), while in the rhinitis group, the temperature of the nasal cavity decreased significantly after inferior turbinate ablation (P = .001). In the control group, the nasal mucosa clearance time was significantly shorter in the congestion phase than in the decongestion phase (P = .001), and in the rhinitis group, the clearance time of the nasal mucosa was significantly shortened after the operation (P = .0025). In the control group, the levels of nNO were significantly higher in the congestion phase than in the decongestion phase (P = .025), while in the rhinitis group, nNO levels decreased significantly after the operation (P = .005).

CONCLUSION

The function of the nasal cavity changes in different phases of the nasal cycle. Therefore, when evaluating the impact of various factors on nasal function, factors associated with the nasal cycle should also be considered. Inferior turbinate plasma ablation can improve the ciliary function of the nasal mucosa, reduce the temperature of the nasal cavity, and reduce nNO levels.