Continuous positive airway pressure (CPAP) therapy remains the gold standard treatment for obstructive sleep apnea (OSA), with demonstrated effectiveness in reducing symptoms while improving quality of life in patients with OSA. However, the success of this approach depends on the patient’s proper use and adherence, and findings have shown CPAP nonadherence rates between 46% and 83% among individuals with OSA despite ongoing improvements in the design of CPAP devices.1
An estimated two-thirds of CPAP users experience mask-related side effects (MRSEs) ranging from interface-related effects such as air leakage and skin rashes, pressure-related effects including nasopharyngeal symptoms and ocular complications, and other types of side effects such as infection and vocal changes. In rare cases, cerebrospinal fluid leak has been observed with nasal CPAP use, typically in the context of transsphenoidal surgery.1
Mask-related side effects have been cited as the most important factor influencing adherence to CPAP therapy.1 Researchers noted in one study that the number of MRSEs at 1 month independently predicted CPAP adherence at 12 months.2 Recognizing a dearth of similar data pertaining to patients on long-term CPAP therapy, the authors of a recent study published in Respiratory Research examined the relationship between MRSEs and CPAP nonadherence (defined in the study as usage <4 hours per day) in a sample of 1484 patients (72.2% men; median age, 67 years) with a median treatment duration of 4.4 years.
Their analysis revealed a nonadherence rate of 8.6% and a 16.17% prevalence of residual excessive sleepiness (based on an Epstein-Sleepiness-Scale [ESS] score ≥11).2 Patient-reported leaks represented the most common side effect, affecting 75.4% of participants. Other common MRSEs were dry mouth (70.6%), partner-disturbing leaks (69.4%), noisy mask (57.5%), and dry nose (54.4%). The results also showed an independent negative association between MRSEs and CPAP adherence, and a positive association between MRSEs and ESS scores.2
Of note, the patient-reported leaks were not predicted by leaks reported by the device software. “CPAP devices only record leak flows, whereas the patient’s perception of a leak is a complex phenomenon involving not only the strength of the leak-flow itself but also how it feels on his/her skin/eyes (if the mask is not properly adjusted), and associated noises,” the authors explained.2
In addition, device-reported leaks and apnea hypopnea index were not significantly associated with nonadherence or ESS scores. “Altogether, these results suggest that MRSE questionnaires should be included with CPAP-reported data during patient follow-up and particularly in long-term tele-monitoring programs,” the study authors concluded.2 Clinicians should closely monitor and address CPAP-related side effects early in treatment to encourage optimal adherence.1
To glean further insights and clinical recommendations regarding CPAP side effects and alternative therapies, we interviewed Richard J. Castriotta, MD, FCCP, FAASM, pulmonologist, sleep medicine specialist, and professor of clinical medicine at the Keck School of Medicine at the University of Southern California in Los Angeles.
What are the most common side effects of CPAP therapy, and what are the most serious potential side effects?
Most side effects of CPAP are caused by a suboptimal interface — for example, poorly fitting mask or nasal pillows — or inappropriate CPAP settings. Consultation for proper interface fitting is paramount.
A common side effect is nasal congestion, which may be treated after proper interface adjustment with optimal heated humidification, nasal steroids, antihistamines, nasal saline spray, or in the case of rhinorrhea, inhaled nasal ipratropium.1
Other potential side effects are oronasal dryness, skin abrasion or rash at the site of mask contact, aerophagia (treated with simethicone), sinus discomfort, and claustrophobia.1 Among the more serious side effects are epistaxis (usually with cold dry air at high pressure)1 and — very, very rarely — pneumothorax or pnemoencephaly.3
For patients who cannot tolerate side effects or refuse CPAP therapy, what alternative treatment approaches are available?
Alternative treatment options include a mandibular-advancing oral appliance, a hypoglossal nerve stimulator, upper airway surgery — for example, adenotonsillectomy or nasal septoplasty — when appropriate, maxillomandibular advancement (MMA) surgery, tracheostomy, positioning devices for supine-positional sleep apnea, expiratory airway pressure strips, and alternative positive airway devices such as bilevel positive airway pressure (BPAP) and auto-titrating positive airway pressure (APAP).4
What are some additional recommendations for clinicians who are treating patients with CPAP therapy, and what are the remaining needs in this area?
The only treatment modalities that have been shown to actually eliminate the excess mortality from OSA are CPAP and tracheostomy, when there are more than 20 apneas per hour.4 Most problems with CPAP can be solved with a proper choice of interface and machine, along with counseling, sometimes utilizing cognitive behavioral therapy or other adjunctive therapies.5
All of the above is intended for the use of CPAP in OSA. With central sleep apnea and complex sleep apnea, BPAP and APAP should not be used, as they may worsen central apnea. CPAP may also cause or worsen central apnea, and if this persists, it may be treated with adaptive servo-ventilation (ASV) if the left ventricular ejection fraction (LVEF) is more than 45%. Pure central sleep apnea may be treated with phrenic nerve stimulation (Remedē device) or oxygen, as well as ASV if LVEF more than 45%.6-8
There is a great need for both patient and physician education regarding this topic.9
1. Ghadiri M, Grunstein RR. Clinical side effects of continuous positive airway pressure in patients with obstructive sleep apnoea. Respirology. 2020;25(6):593-602.
2. Rotty MC, Suehs CM, Mallet JP, et al. Mask side-effects in long-term CPAP-patients impact adherence and sleepiness: the InterfaceVent real-life study. Respir Res. Published online January 15, 2021. doi:10.1186/s12931-021-01618-x
3. Rajdev K, Idiculla PS, Sharma S, Von Essen SG, Murphy PJ, Bista S. Recurrent pneumothorax with CPAP therapy for obstructive sleep apnea. Case Rep Pulmonol. Published online December 1, 2020. doi:10.1155/2020/8898621
4. Littner MR. Mild obstructive sleep apnea syndrome should not be treated. Con. J Clin Sleep Med. 2007;3(3):263-264.
5. D’Rozario AL, Galgut Y, Bartlett, DJ. An update on behavioural interventions for improving adherence with continuous positive airway pressure in adults. Curr Sleep Medicine Rep. 2016;2:166-179. doi:10.1007/s40675-016-0051-2
6. Central sleep apnea: causes and treatments. Sleep Foundation. Accessed February 25, 2021. https://www.sleepfoundation.org/sleep-apnea/central-sleep-apnea
7. Asp K. Pros and cons of adaptive servo-ventilation (ASV) for sleep apnea. American Association of Sleep Technologists. Published October 3, 2017. Accessed February 25, 2021. https://www.aastweb.org/blog/pros-and-cons-of-adaptive-servo-ventilation-asv-for-sleep-apnea
8. Joseph S, Costanzo MR. A novel therapeutic approach for central sleep apnea: phrenic nerve stimulation by the remedē system. Int J Cardiol. 2016;206:Suppl:S28-S34.
9. Hayes SM, Murray S, Castriotta RJ, Landrigan CP, Malhotra A. (Mis) perceptions and interactions of sleep specialists and generalists: obstacles to referrals to sleep specialists and the multidisciplinary team management of sleep disorders. J Clin Sleep Med. 2012;8(6):633-642.