CPAP 101: Treating Sleep Apnea With Continuous Positive Airway Pressure

If you’ve been diagnosed with obstructive sleep apnea (OSA), you’ve probably received a prescription for continuous positive airway pressure (CPAP) therapy.

“Continuous positive airway pressure is considered the gold standard for treating obstructive sleep apnea due to its ability to maintain the airway, ensuring a free flow of air in and out of the lungs and preventing the airway from collapsing,” says Madhat Arnouk, MD, a board-certified sleep medicine physician and the chief of medicine and division chief of pulmonary medicine at the University of Maryland St. Joseph Medical Center in Towson.

For new users, there’s a lot to learn about how this treatment works and how to get the most from it.

Not all CPAP devices work the same way. There are three main types:

• CPAP This is the most commonly prescribed device for OSA. It delivers the same constant pressure all night to keep the airway open, Dr. Arnouk says.
• Automatic Positive Airway Pressure (APAP) An APAP device uses an algorithm to learn your breathing patterns. This allows the machine to adjust the pressure within a range to match your changing needs during sleep, such as increasing pressure if you’re sleeping on your back.

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• Bilevel Positive Airway Pressure (BiPAP) “BiPAP is often used for patients who aren’t able to tolerate CPAP or APAP, or those requiring higher pressures,” Arnouk says. It delivers a higher level of pressure as you inhale and a lower level as you exhale, he says.

• Nasal Mask A nasal mask covers just your nose and may be recommended if you move a lot when you sleep.
• Nasal Pillow Mask This option covers only your nostrils, allowing you to wear glasses comfortably while using CPAP.
• Full Mask A full mask covers your nose and mouth. This type tends to work best if you breathe through your mouth while you sleep or have a nasal blockage.
• Hybrid Mask This mask type sits over your mouth and closes your nostrils without covering your entire nose.

Starting with CPAP involves more than simply putting on a mask. You’ll go through a series of steps in the first few months that set you up for long-term use.

Ashtaad Dalal, MD, a board-certified sleep medicine physician with PMA Health in Falls Church, Virginia, and a spokesperson for the American Academy of Sleep Medicine, outlines the typical timeline from prescription to follow-up care:

• Weeks 1 and 2 Your doctor sends the prescription, office notes, and sleep study results to a durable medical equipment (DME) company, which supplies the CPAP machine. The DME company submits the information to your insurance company for approval. It typically takes 7 to 10 days to receive the device. At that point, the DME company schedules a setup appointment — either in person or virtually — during which a technician walks you through how to use the CPAP machine. If your doctor fitted your mask and set your ideal pressure beforehand, the machine will be programmed to your specifications.
• Weeks 2 to 4 This is the adjustment period, when you use the machine to get used to the mask and the feel of the airflow.
• Months 1 to 3 After trying out the machine for a few weeks, you’ll return to see a respiratory therapist (either at a sleep clinic or through the DME company) to assess how the machine is working. About a month or two later, you’ll follow up with your prescribing doctor to review your progress and fine-tune settings if needed.

Getting used to CPAP takes time. The device has many components — mask, tubing, and machine — and you may go through some trial and error before you find the right fit and pressure settings.

Understanding the most common hurdles — and how to address them — can make the difference between giving up and getting the sleep you need.

Mask Discomfort

One size or style does not fit all when it comes to CPAP masks. You may need to experiment with a few options before you find one that feels good to you.

“For patients who are struggling with discomfort when wearing a mask, a mask-fitting session is very helpful to get the patient the mask of choice,” Arnouk says.

Feelings of Claustrophobia

The sensation of wearing a mask over your nose or both your nose and mouth can be disorienting at first. “The first few nights of using CPAP can be a struggle for some patients,” Arnouk says. He suggests wearing the mask while you’re awake — without connecting it to the machine — before you try to sleep in it. “Many patients find this technique very helpful, and usually after a few nights, patients have no trouble tolerating the mask,” Arnouk says.

If that doesn’t work, Maha Alattar, MD, a neurologist with VCU Medical Center and the chief of the sleep medicine division at Virginia Commonwealth University Medical School in Richmond, says that your doctor may recommend a smaller mask that fits under your nose, lowering the pressure, or switching from CPAP to BiPAP.

Dry Mouth, Sore Throat, or Skin Irritation

Dry mouth and throat are common complaints with CPAP therapy. To combat dryness, CPAP machines have a built-in humidifier that can be adjusted to your comfort level. “It is very important to use distilled water for the humidifier to prolong the life of the CPAP machine,” Arnouk says.

Using a room humidifier while you sleep can also help, Dr. Alattar says.

If you’re still waking up with a dry mouth or sore throat, check that your mask isn’t leaking air. If it is, you’re likely leaking water and humidity, too, Alattar says.

Irritation of the skin that touches the mask is less common but still possible. To prevent or resolve skin irritation, Arnouk recommends these practices:

• Choosing a mask made from hypoallergenic materials or with a gel cushion
• Finding a mask type that fits your facial structure
• Ensuring that the mask fits well but not too tightly
• Cleaning the mask daily with soap and water

“Over-the-counter hydrocortisone cream can help reduce inflammation and soothe the affected area,” he says. “Aloe vera or barrier creams containing ingredients like zinc oxide can also help calm the skin and create a protective layer.”

Modern CPAP machines don’t just treat OSA — they track it, transmitting data to your care team and insurance company.

The newer CPAP machines have a cellular modem built into them, so the data is automatically uploaded to a cloud platform, Dalal says. That gives care teams the ability to “log in and evaluate different metrics — nightly usage hours, mask leak, how well it's controlling the sleep apnea, and the residual AHI," he says.

The DME company also has access to the data, which is reported to your insurance company to monitor compliance.

Understanding how insurance covers CPAP — and what’s required to keep that coverage — can save you from a frustrating surprise down the road.

"Most insurance companies, including Medicare, cover CPAP through a rent-to-own model,” Dalal says. You pay a copay each month, and usually after 13 months, the ownership transfers from the DME company to you.

If you don’t meet these requirements, the insurance company may have the DME company take back the CPAP machine, “or tell the person to pay out of pocket for it,” Dalal says.

You can gauge whether your CPAP is doing its job by checking the data your device collects. AHI values are particularly helpful, since these measure how many times your breathing is interrupted per hour during sleep. The lower the number, the better your treatment is working.

"We want the residual AHI on the CPAP compliance data to be less than five,” Dalal says. “At that point, you can say this is effectively treating this person's obstructive sleep apnea."

• Reduced snoring
• Greater daytime alertness
• Improved mood

• Continuous positive airway pressure is considered the gold standard treatment for obstructive sleep apnea, delivering mild air pressure through a mask to keep your airways open while you sleep.
• CPAP use can significantly lower the number of times your breathing is interrupted while you sleep, leading to short- and long-term health benefits.
• Your healthcare provider will guide you through the steps involved in starting CPAP therapy, from receiving a prescription to fine-tuning the fit and settings.
• You’ll know that your CPAP machine is working when it records fewer than five breathing disruptions an hour, and you notice improvements in mood, daytime alertness, and snoring.