APAP vs. CPAP

Exploring CPAP Machines — But Haven’t Been Tested Yet?

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How Is APAP Different From CPAP?

While APAP and CPAP machines are both types of PAP therapy used to treat obstructive sleep apnea, they differ in the levels of air pressure they release. CPAP releases air at a fixed rate, while APAP releases air at a rate that changes in response to the sleeper’s needs.

Technically, an APAP is a type of CPAP machine that includes technology allowing the machine to auto-adjust how much air it delivers at a given time. Traditional CPAP machines that don’t contain this technology are sometimes referred to as fixed-level CPAP devices, because they deliver air at a fixed rate of pressure.

In the past, fixed-level CPAP machines were most commonly prescribed, but in recent years, the use of APAP machines is increasing Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source .

Since APAP machines (aka auto-titrating CPAP or auto-CPAP machines) auto-adjust in response to a person’s breathing, the initial set-up can usually occur in a person’s home Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. View Source , using the machine itself. By contrast, the initial set-up of a fixed-level CPAP machine requires either an overnight sleep study in a lab or the temporary use of an APAP machine at home. 

However, certain factors, such as suspected air leakages or the presence of other health problems, may require a person to have their APAP titration in a sleep lab rather than at home.

While some studies show that people tend to use an APAP machine longer each night Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. View Source than they would a CPAP machine, more evidence is needed to determine which type of machine is more effective at reducing OSA symptoms. Current research suggests both types of PAP therapy are about equally effective.

Another type of PAP therapy sometimes prescribed to people with OSA is bilevel positive airway pressure (BiPAP or BPAP). Doctors usually prescribe BiPAP only to people who have another sleep disorder or who have tried CPAP and APAP therapies but could not tolerate them.

What Are the Pros and Cons of APAP Machines?

Using an APAP machine to treat obstructive sleep apnea may provide some advantages over other types of PAP therapy.

• In-home titration: While the set-up of BiPAP and fixed-level CPAP devices often requires an overnight stay in a sleep lab, an APAP device’s settings can be determined in a person’s home with the machine’s auto-adjusting feature. 
• Reduced average air pressure: Some people find it uncomfortable to breathe out against the constant pressure of a fixed-level CPAP. Compared to a CPAP, an APAP machine releases air at a lower average pressure throughout the night, making it easier to handle for some users.
• Adjusting to users’ needs: An APAP machine’s ability to automatically adjust air pressure could benefit a person as their needs change at different times. For example, drinking alcohol, gaining or losing weight, and changing sleep positions can all alter the pressure level a sleeper needs from their PAP machine.

However, there may be some disadvantages to using an APAP machine. For instance, APAP machines cost more on average than CPAP machines. The higher price can be a particular disadvantage if a person’s health insurance does not cover the full cost of their treatment. 

Although some people are sensitive to the fixed rate of air pressure from a CPAP machine, others may prefer it to the fluctuating rate of air pressure from an APAP machine. An APAP machine’s regular changes in air pressure during the night could cause brief sleep disruptions, which may lead to side effects.

APAP therapy may also cause the same side effects associated with other types of PAP therapy, including: 

• Stuffy nose
• Sore throat
• Dry mouth
• Nosebleeds
• Irritated eyes
• Chest discomfort
• Skin irritation from the mask
• Claustrophobia or feeling trapped

Most of these problems are minor and can be easily fixed Trusted Source Medline Plus MedlinePlus is an online health information resource for patients and their families and friends. View Source by trying a different mask type, cleaning the PAP machine, using a humidifier, or using nasal saltwater spray.

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APAP vs. CPAP: Which One Is Right for You?

Both APAP and CPAP machines are effective treatments for obstructive sleep apnea, but the best choice depends on how stable your pressure needs are, how you tolerate therapy, and what your doctor recommends.

Who Is APAP Best For?

APAP may be a good option if you:

• Need different pressure levels depending on sleep position, sleep stage, or nasal congestion
• Experience side effects from higher fixed CPAP pressures, such as bloating or difficulty exhaling
• Prefer lower average pressure during the night
• Did not complete an in-lab titration study and need at-home pressure adjustment
• Travel frequently or want a device that adapts to night-to-night changes

“APAP therapy is a very successful treatment option for sleep apnea because it delivers personalized and accurate air pressure to promote adequate breathing during sleep. Compared to conventional CPAP therapy, it gives patients more comfort and flexibility.”

Anis Rehman, MD

Internal Medicine Physician, MD

Who Is CPAP Best For?

CPAP may be a better choice if you:

• Have consistent pressure needs that don’t vary much during sleep
• Respond well to a single, stable pressure setting
• Prefer a simpler device with fewer adjustments
• Have certain medical conditions where a fixed pressure is recommended
• Are following insurance or compliance requirements that specify CPAP use

“In comparison to APAP devices, which constantly adjust pressure, CPAP machines offer a steady and fixed pressure, which is frequently more efficient in preserving a patient’s airway. Additionally, many individuals with sleep apnea choose CPAP machines since they are usually less expensive and simpler to operate.”

Anis Rehman, MD

Internal Medicine Physician, MD

How Do You Get an APAP or CPAP Machine?

Getting an APAP or CPAP machine starts with a diagnosis of obstructive sleep apnea from a healthcare provider. If you’re concerned about your nighttime breathing and think that you may have obstructive sleep apnea, make an appointment with your doctor. Common OSA symptoms include:

• Loud snoring
• Gasping or stopping breathing while asleep
• Daytime tiredness
• Trouble focusing
• Dry mouth
• Headaches
• Reduced sexual interest
• Nighttime awakenings to urinate

Based on your symptoms and health history, your doctor may refer you for a sleep study, which may be done either in a sleep lab or at home using an at-home sleep apnea test. Once sleep apnea is confirmed, a doctor will write a prescription that specifies the type of device and pressure settings (or pressure range, in the case of APAP).

With a prescription, you can obtain a CPAP or APAP machine through a durable medical equipment (DME) provider or an authorized online retailer. Many people use insurance, including Medicare, which typically covers PAP machines under specific conditions, such as meeting usage and compliance requirements. Your provider or supplier can help you understand coverage, setup, mask selection, and how to use the machine effectively.

If you use a CPAP machine and have difficulty tolerating the air pressure, you may want to talk to your doctor about switching to an APAP machine. Your medical provider can help you determine which OSA treatment is the best for you.

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