Continuous positive airway pressure delivery interfaces for obstructive sleep apnoea

Background Continuous positive airway pressure (CPAP) is the mainstay of therapy for moderate to severe obstructive sleep apnoea (OSA). However, compliance with CPAP has been less than ideal. There are many different CPAP interfaces now available for the treatment of OSA. The type of CPAP delivery interface is likely to influence a patient's acceptance of CPAP therapy and long term compliance. Objectives This review aims to compare the efficacy of the various CPAP delivery interfaces available for the treatment of obstructive sleep apnoea. Search strategy Searches were carried out on the Cochrane Airways Group Specialised Register, CENTRAL, MEDLINE, EMBASE & CINAHL up to January 2006. Selection criteria All randomised, controlled trials comparing different forms of CPAP delivery interface for the treatment of OSA were considered for inclusion. Data collection and analysis Two reviewers independently assessed studies for inclusion into the review and extracted data. Attempts were made to contact study authors to obtain additional, unpublished data. Main results A total of four studies fulfilled the inclusion criteria. Two studies compared nasal mask with the Oracle oral mask and showed no significant difference in compliance at one month (mean difference [95% CI]: 0.17 hours per night [-0.54 to 0.87]). There were also no significant differences in any of the physiological parameters (e.g. AHI, arousal index, minimum oxygen saturation), Epworth Sleepiness Scale (ESS), or symptoms of OSA. A single study comparing nasal mask with nasal pillows showed a significant difference in compliance when expressed as the percentage of days used in favour of nasal pillows (nasal pillows mean +/- SD 94.1 +/- 8.3%; nasal mask 85.7 +/- 23.5%, P = 0.02), however there were no significant differences in the mean daily use for all days or when use was greater than 0 minutes per day. Nasal pillows were also associated with fewer overall adverse effects (P < 0.001) and greater interface satisfaction (P = 0.001). No significant differences in AHI, ESS or quality of life scores were seen. One study comparing nasal mask with face mask showed that compliance was significantly greater with use of a nasal mask (mean difference 1.0 hour per night [95% CI 0.3-1.8]). Nasal mask was also associated with significantly lower ESS scores and was the preferred interface in almost all patients. Authors' conclusions Due to the limited number of studies available comparing various interface types, the optimum form of CPAP delivery interface remains unclear. The results of our review suggest that nasal pillows or the Oracle oral mask may be useful alternatives when a patient is unable to tolerate conventional nasal masks. The face mask can not be recommended as a first line interface, but may be considered if nasal obstruction or dryness limits the use of a nasal mask. Further randomised studies comparing the different forms of CPAP delivery interface now available for the treatment of OSA, in larger groups of patients and for longer durations, are required.