S A N T È • LÖW E N S T E I N S L E E P T H E R A PY D E V I C E S
Appendix 9
pi i: jc- 00260 -15
ht tp: //dx.doi .org/10.5664/ jcsm.5590
Study Objectives: Pressure-relief features are aimed at improving the patient’s comfort during continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea. The objective of this study was to determine the effect of these therapy features on fixed CPAP and autotitrating CPAP (APAP) treatment efficacy. Methods: Seven pressure-relief features applied by three CPAP devices were included in our study (Remstar Auto: C-Flex 3, C-Flex+ 3, A-Flex 3, P-Flex; AirSense 10: EPR 3; Prisma 20A: SoftPAP 2 and 3). In fixed CPAP, the devices were subjected to a 10-min bench-simulated obstructive apnea sequence (initial apnea-hypopnea index, AHI = 60/h) with and without pressure-relief features. In APAP, the sequence was lengthened to 4.2 h (initial AHI = 58.6/h). The residual AHI and mean/median pressure were compared with and without pressure-relief features. Results: Compared to conventional CPAP, where pressure was adjusted to be just sufficient to control the simulated obstructive events, C-Flex+ 3, P-Flex, and EPR 3 failed to normalize the breathing flow and did not reduce the AHI. The mean pressures with the three features, respectively, were 1.8, 2.6, and 2.6 cmH 2 O lower than the conventional CPAP. Compared to conventional APAP, similar levels of control were observed with pressure-relief features, apart from P-Flex where the delivered mean pressure was lower and residual AHI greater. The device-reported mean/median pressures in APAP with A-Flex 3, P-Flex, EPR 3, and SoftPAP 3 were higher than that measured on the bench. Conclusions: Pressure-relief features may attenuate CPAP efficacy if not adjusted for at the time of their introduction. In clinical practice, efficacy can be ensured by increasing the therapeutic pressure delivered by fixed CPAP or by enabling the pressure-relief features prior to initial pressure titration. Device- reported pressures in APAP devices with pressure relief activated may overstate delivered pressures. Keywords: CPAP treatment, pressure-relief features, bench test Citation: Zhu K, Aouf S, Roisman G, Escourrou P. Pressure-relief features of fixed and autotitrating continuous positive airway pressure may impair their efficacy: evaluation with a respiratory bench model. J Clin Sleep Med 2016;12(3):385 – 392 . SCI ENT I F IC INVEST IGAT IONS Pressure-Relief Features of Fixed and Autotitrating Continuous Positive Airway Pressure May Impair Their Efficacy: Evaluation with a Respiratory Bench Model Kaixian Zhu, MS 1,2,3 ; Sami Aouf, MD 1 ; Gabriel Roisman, MD, PhD 2 ; Pierre Escourrou, MD, PhD 2,3 1 Air Liquide Healthcare, Gentilly, France; 2 Sleep Disorders Center, AP-HP Antoine-Béclère Hospital, Clamart, France; 3 Faculty of Pharmacy, Paris-Sud University, Châtenay- Malabry, France
I NTRODUCT I ON Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea (OSA). However, the effectiveness of treatment mainly depends on regular use of CPAP device and the patient’s tolerance to the treatment. Many factors are involved in CPAP adherence: side effects related to the equipment such as nasal discomfort and difficulty adapt - ing to the pressure, disease severity, patient characteristics and motivation, and other surrounding factors, such as family, phy- sician, healthcare professionals, and their interventions. 1–3 One side effect of CPAP treatment is the difficulty of ex - haling against a positive pressure, which is considered as a cause of reduced adherence to CPAP. As a solution, various CPAP delivery modalities have been developed on the basis that a lower expiratory pressure would be better tolerated. Auto-titrating CPAP (APAP) adjusts the pressure and main- tains the airway patency in real time during the therapy, and the adherence of APAP has been reported as same as that of conventional CPAP. 4 Bilevel PAP is designed to provide a lower expiratory pressure to reduce the average pressure level,
although no improvement in adherence has been reported. 4–7 Pressure-relief CPAP is another modality of pressure deliv- ery, which is proposed as an optional therapy feature for the patient’s comfort during the treatment and has been imple- mented in most fixed CPAP or APAP devices. This CPAP modality is aimed at reducing pressure during expiration to facilitate patient exhalation. Currently, almost all CPAP manufacturers provide their own proprietary versions of pressure-relief CPAP. However, there is no instruction or caution from the manufacturers regarding the use of these features, which are often added after the initial BRIEF SUMMARY Current Knowledge/Study Rationale: Pressure-relief features are aimed at improving the patient’s comfort during CPAP treatment for OSA. However, the effect of these therapy features on CPAP treatment efficacy is not well determined. Study Impact: Pressure-relief features may impair the efficacy of CPAP treatment. The treatment efficacy can be ensured by increasing the therapeutic pressure or by enabling the pressure-relief features prior to initial pressure titration.
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Journal of Clinical Sleep Medicine, Vol. 12, No. 3, 2016
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