CPAP, and what to do when it is not going well
Positive airway pressure holds the airway open during sleep and is the most effective treatment for obstructive sleep apnea. Most difficulty with it is a mask or settings problem rather than a reason to give up.
How it works
Positive airway pressure holds the upper airway open during sleep by delivering pressurised air through a mask, preventing the collapse that causes obstructive apneas. It treats the mechanical problem directly, which is why it remains the most effective treatment for obstructive sleep apnea.
The AASM’s 2019 guideline gives a strong recommendation for positive airway pressure over no treatment in adults with sleep apnea and excessive sleepiness, and conditional recommendations where the problem is impaired sleep-related quality of life or coexisting high blood pressure.
CPAP or APAP
People arrive convinced one is better. The guideline says either.
Twenty-six randomised trials found no clinically significant difference between auto-titrating and fixed-pressure therapy in adherence, sleepiness or quality of life. Treatment may be started either with a home auto-titrating device or with an in-lab titration in adults without significant other conditions, and either device may be used for ongoing treatment. Bilevel is not the routine choice for straightforward sleep apnea; it is reserved for other indications.
Masks
Most trouble with this treatment is trouble with the mask, not the machine. The usual interfaces are a nasal mask, nasal pillows, and a full-face or oronasal mask, and the choice is individualised around leak, mouth breathing, nasal obstruction and comfort.
At a group level, meta-analysis favours nasal interfaces over oronasal for both adherence and reduction in breathing events. That is a tendency across populations rather than a rule about you: one large analysis found the opposite at thirty days, and its authors judged the difference not clinically meaningful. It is a starting point for a conversation, not a reason to refuse a full-face mask.
Heated humidification reduces dryness and some other side effects. Expiratory pressure relief features did not show clinically significant outcome differences against standard therapy in the same review.
Two different numbers get confused constantly
You will read that a third of people cannot use CPAP. That figure is a misreading.
Across 66 studies, mean nightly use was about 4.6 hours. The often-quoted 34 per cent is the proportion of unused hours measured against a seven-hour night, not the proportion of patients who fail. Those are different statistics and they should not be swapped for each other.
Separately, most insurers define coverage adherence the way Medicare does: use of at least four hours a night on 70 per cent of nights, in a consecutive 30-day window within the first 90 days. That threshold is a coverage rule. It was expert opinion rather than an outcome-validated optimum, and there is a dose–response between hours used and benefit, so more is better and the four-hour line is not a finish post.
What does help is support at the start. The guideline gives a strong recommendation for educational intervention when therapy begins, and conditional recommendations for behavioural support, troubleshooting and telemonitoring in the early period. Behavioural intervention improved use by roughly an hour a night on average.
If it is not working
Leak, pressure intolerance, nasal congestion, a dry mouth from mouth leak, claustrophobia, skin breakdown, swallowing air, machine noise, disturbing a partner, and untreated insomnia are all common and all addressable. Most are a fitting or a settings problem rather than a verdict.
If it genuinely cannot be made to work, there are other options, and needing them is not a failure. See CPAP alternatives.
Given up on a machine that is in a cupboard?
That is an extremely common call and not an embarrassing one. Bring the machine and the mask to the appointment if you still have them.
Call (614) 898-9340Sources
- Patil SP et al. Treatment of adult obstructive sleep apnea with positive airway pressure: an AASM clinical practice guideline. J Clin Sleep Med 2019;15(2):335–343. https://doi.org/10.5664/jcsm.7640
- Patil SP et al., accompanying systematic review. J Clin Sleep Med 2019;15(2):301–334. https://doi.org/10.5664/jcsm.7638
- ATS policy statement on positive airway pressure adherence, 2023. https://doi.org/10.1164/rccm.202210-1846st
- Rotenberg BW et al. Trends in CPAP adherence over twenty years. J Otolaryngol Head Neck Surg 2016;45:43. https://doi.org/10.1186/s40463-016-0156-0
- CMS local coverage determination L33718, positive airway pressure devices. https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?LCDId=33718