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

STUDY OBJECTIVES: Patients suspected to have sleep-disordered breathing underwent an overnight polysomnography using a divided nasal cannula to gain additional information about the nasal cycle during sleep.

METHODS: This was a prospective, observational cohort study replacing the undivided nasal cannula with a divided nasal cannula during routine polysomnography (n = 28).

RESULTS: Integration of the divided nasal cannula pressure transducer system into routine polysomnography was easy and affordable. Most patients (89%) demonstrated nasal cycle changes during the test. Nasal cycle changes tended to occur during body position changes (62%) and transitions from non-rapid eye movement sleep to rapid eye movement sleep (41%). The mean nasal cycle duration was 2.5 ± 2.1 hours. Other sleep study metrics did not reveal statistically significant findings in relation to the nasal cycle.

CONCLUSIONS: Replacing an undivided nasal cannula with a divided nasal cannula is easy to implement, adding another physiologic measure to polysomnography. Although the divided nasal cannula did not significantly affect traditional polysomnographic metrics such as the apnea-hypopnea index or periodic limb movement index based on this small pilot study, we were able to replicate past nasal cycle findings that may be of interest to sleep clinicians and researchers. Given the ease with which the divided nasal cannula can be integrated, we encourage other sleep researchers to investigate the utility of using a divided nasal cannula during polysomnography.