Comparison of Standard CPAP Therapy and the Racer Airway Device for the Treatment of Obstructive Sleep Apnoea: A Randomised Clinical Trial
Authors List
Alister M Neill, Angela J Campbell, James CD Miller
WellSleep, Sleep Investigation Centre, University of Otago, Wellington
Introduction/Aim
The nasal cycle is a normal ultradian physiological phenomenon where each nasal airway takes turns at conducting a greater proportion of tidal airflow through congestion /decongestion of nasal sinuses. The nasal cycle is affected by sleep stage, head position and can be measured in obstructive sleep apnoea (OSA) patients during sleep1. Conventional continuous positive airway pressure (CPAP) abolishes the nasal cycle2 and is not tolerated up to a third of OSA patients. Rest-Activity-Cycle positive airway pressure device (RACer-PAP)3 is a novel non-pharmacological OSA treatment that aims to maintain the innate nasal cycle - this could theoretically improve comfort, the need for humidification, reduce airway related side effects, improve adherence and quality of life.
Methods
Consenting PAP naïve patients with at least moderate OSA who were able to use a nasal mask interface were randomly assigned in a crossover design to 4 weeks RACer- PAP or a control humidified CPAP device (Fisher and Paykel Icon Premo) separated by a 3 day wash-out. The PAP treatment pressure was determined by in-lab Auto-titration (ResMed Tx). Outcome measures including objective PAP adherence, Epworth Sleepiness Score (ESS), quality of life (SF 36), nasal symptoms, PAP side effects and sleep quality were compared by mixed procedure SAS 9.4 (SAS Institute Inc, Cary NC) or Likert scale. Subjects were not blinded due to physical differences between machines but were asked their device preference.
Results
40 subjects (of 44 recruited) (29 M, 11 F) with a mean BMI 37.7kg/m2 aged 45 yrs (range 22-70 yrs) with severe OSA (mean AHI 56.4/ hr), ESS 13.6 (range 3-21) completed the study. Ethnicity included NZ Maori (17 %), NZ European (67%) and Pacific (12.5%). The prescribed mean pressure was 12.2 cmH2O (range 8-18 cmH20). Average PAP adherence was greater in the humidified CPAP control arm than the RACer- PAP arm (4:57h/night versus 4:14h/night p < 0.01). There was no order effect. Both devices similarly improved subjective sleepiness, quality of life and adverse upper airway symptoms. Humidified CPAP improved to a greater extent nasal symptom scores (baseline – final: control CPAP 2.8 vs. RACer 2.3, p = 0.03), sleep quality and was preferred (55% vs 22 %).
Conclusion
RACer PAP improved OSA symptoms and quality of life but adherence was lower and nasal symptoms more common when compared with humidified CPAP. This could be explained by not using humidification, technical issues with a prototype machine / mask or the use of set nasal cycle length. A number of practical improvements were suggested including redesign of button layout, and mask improvements to individualise airflow to each nostril. We recommend further research of nasal cycle traits in OSA & treatment studies that aim to maintain the natural nasal cycle.
Ethics approval (17/CEN/140); Clinical trials registry ACTRN12617001090303p
Acknowledge: Associate Prof David White AUT for providing equipment, research funding application. Funding Grant: MedTech CoRE Research Network Grant 2018/19
References:
(1) A. Neill, T. Lequeux2, A. Campbell. Nasal cycle – a novel trait. Can it be measured in obstructive sleep apnoea syndrome? Journal of Sleep Research 2019, 28: page 66
(2) White DE, Bartley J, Shakeel M, Nates RJ, Hankin RKS. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study. Journal of Biomechanics. 2016 49(9):1887-90.
(3) Crofts CAP, Neill A, Campbell A, Bartley J & White DE. Sleep architecture, insulin resistance and the nasal cycle: Implications for positive airway pressure therapy. J. insul. resist. 2018;3(1), a34. https://doi. org/10.4102/jir.v3i1.34
Alister M Neill, Angela J Campbell, James CD Miller
WellSleep, Sleep Investigation Centre, University of Otago, Wellington
Introduction/Aim
The nasal cycle is a normal ultradian physiological phenomenon where each nasal airway takes turns at conducting a greater proportion of tidal airflow through congestion /decongestion of nasal sinuses. The nasal cycle is affected by sleep stage, head position and can be measured in obstructive sleep apnoea (OSA) patients during sleep1. Conventional continuous positive airway pressure (CPAP) abolishes the nasal cycle2 and is not tolerated up to a third of OSA patients. Rest-Activity-Cycle positive airway pressure device (RACer-PAP)3 is a novel non-pharmacological OSA treatment that aims to maintain the innate nasal cycle - this could theoretically improve comfort, the need for humidification, reduce airway related side effects, improve adherence and quality of life.
Methods
Consenting PAP naïve patients with at least moderate OSA who were able to use a nasal mask interface were randomly assigned in a crossover design to 4 weeks RACer- PAP or a control humidified CPAP device (Fisher and Paykel Icon Premo) separated by a 3 day wash-out. The PAP treatment pressure was determined by in-lab Auto-titration (ResMed Tx). Outcome measures including objective PAP adherence, Epworth Sleepiness Score (ESS), quality of life (SF 36), nasal symptoms, PAP side effects and sleep quality were compared by mixed procedure SAS 9.4 (SAS Institute Inc, Cary NC) or Likert scale. Subjects were not blinded due to physical differences between machines but were asked their device preference.
Results
40 subjects (of 44 recruited) (29 M, 11 F) with a mean BMI 37.7kg/m2 aged 45 yrs (range 22-70 yrs) with severe OSA (mean AHI 56.4/ hr), ESS 13.6 (range 3-21) completed the study. Ethnicity included NZ Maori (17 %), NZ European (67%) and Pacific (12.5%). The prescribed mean pressure was 12.2 cmH2O (range 8-18 cmH20). Average PAP adherence was greater in the humidified CPAP control arm than the RACer- PAP arm (4:57h/night versus 4:14h/night p < 0.01). There was no order effect. Both devices similarly improved subjective sleepiness, quality of life and adverse upper airway symptoms. Humidified CPAP improved to a greater extent nasal symptom scores (baseline – final: control CPAP 2.8 vs. RACer 2.3, p = 0.03), sleep quality and was preferred (55% vs 22 %).
Conclusion
RACer PAP improved OSA symptoms and quality of life but adherence was lower and nasal symptoms more common when compared with humidified CPAP. This could be explained by not using humidification, technical issues with a prototype machine / mask or the use of set nasal cycle length. A number of practical improvements were suggested including redesign of button layout, and mask improvements to individualise airflow to each nostril. We recommend further research of nasal cycle traits in OSA & treatment studies that aim to maintain the natural nasal cycle.
Ethics approval (17/CEN/140); Clinical trials registry ACTRN12617001090303p
Acknowledge: Associate Prof David White AUT for providing equipment, research funding application. Funding Grant: MedTech CoRE Research Network Grant 2018/19
References:
(1) A. Neill, T. Lequeux2, A. Campbell. Nasal cycle – a novel trait. Can it be measured in obstructive sleep apnoea syndrome? Journal of Sleep Research 2019, 28: page 66
(2) White DE, Bartley J, Shakeel M, Nates RJ, Hankin RKS. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study. Journal of Biomechanics. 2016 49(9):1887-90.
(3) Crofts CAP, Neill A, Campbell A, Bartley J & White DE. Sleep architecture, insulin resistance and the nasal cycle: Implications for positive airway pressure therapy. J. insul. resist. 2018;3(1), a34. https://doi. org/10.4102/jir.v3i1.34
