CPAP, BiPAP, and APAP are all various types of positive airway pressure (PAP) therapies used to treat sleep apnea. Even though they all work based on the same principle, there are slight differences.
In our comprehensive PAP guide, you will get a general overview of PAP and learn about each type and its use cases.
What is sleep apnea?
But before we delve into the specifics, let’s talk about why PAP therapy exists. The reason is called sleep apnea, a disorder causing episodes of breathlessness during sleep.
Sleep apnea has two types. Obstructive sleep apnea (OSA) results from a narrowing of airways due to various mechanical reasons. Central sleep apnea (CSA), on the other hand, stems from a dysfunction in the basal ganglia, the part of the brain that regulates breathing.
While the underlying causes are different, both forms of the condition cause sudden stops in breathing, followed by the brain waking the body up to readjust. Because of this, sleep apnea can disrupt healthy sleeping patterns, leading to excessive daytime sleepiness, depression, anxiety, and other health problems.
Sleep apnea is a chronic condition with no known cure yet, so treatment efforts focus on lessening symptoms. This is where PAP therapy comes into the picture.
What is PAP therapy?
Positive airway pressure therapy is a common and highly effective treatment method for sleep apnea. It utilizes a specialized device that delivers a stream of pressurized air into the airways, keeping it open and unobstructed during sleep and ensuring a continuous flow of oxygen.
This consistent airflow helps eliminate breathing interruptions and other symptoms associated with sleep apnea.
How does a PAP machine work?
A PAP machine usually consists of a main unit, a hose, and a mask.
The main unit uses a motor to pressurize air and push it through a filter, then the hose, and into the airways via the mask. Most PAP machines use various computer technologies to monitor feedback from the user and adjust pressure and airflow accordingly.
Depending on the design, the mask can cover your nose, mouth, or both.
While the base principle seems simple, these machines require precision and reliability in order to provide safe usage. They are often equipped with various safety features as well.
To use a PAP machine, you need to attend a sleep study in a sleeping center, where they will determine your optimal pressure settings. This process is called titration.
What’s the difference between CPAP vs BiPAP vs APAP?
If you look into PAP therapy, you will come across various terms like CPAP, BiPAP, APAP, and more. These are all different forms of positive airway pressure therapy, based on the same principle but with slight differences in their adjustability and how they deliver pressurized air.
CPAP – Continous Positive Airway Pressure
Continuous positive airway pressure, or CPAP, is probably the most well-known type of PAP therapy.
As the name suggests, CPAP machines deliver a consistent and unvarying flow of pressurized air, keeping the airways open. Airflow and air pressure stay constant during use regardless of your breathing patterns. For some people, this might cause discomfort.
CPAP is the most basic form of PAP treatment that doesn’t involve complicated delivery technologies, making it an affordable yet effective solution. Another reason why doctors often recommend this form of PAP therapy is because it’s the most well-studied and proven to be safe and effective.
BiPAP – Bilevel Positive Airway Pressure
BiPAP machines are a more advanced version of CPAP, where you can adjust the pressure settings individually for inhalation and exhalation.
BiPAP provides a smoother breathing experience because the pressure is lower when you breathe out and higher when you breathe in. People with unusual breathing patterns or complex sleep apneas usually find it more comfortable than CPAP.
Every BiPAP machine has the bilevel setting for two different pressure levels, but more advanced ones can also adjust automatically to your breathing patterns in real-time. One other thing to note about BiPAP machines is that they can provide higher pressure ranges than other machines.
Since BiPAP machines use more complex technology, they are usually a bit pricier than simple CPAP machines.
Some manufacturers use the terms VPAP (variable positive airway pressure) or BPAP. These three are essentially the same.
APAP – Auto-adjustable Positive Airway Pressure
APAP machines are the most advanced of the three. They work on a breath-to-breath basis and adjust pressure settings throughout your sleep.
Since our breathing patterns, sleeping position, and the frequency of apneas can change during the night, different pressure levels can provide a better breathing experience. APAP machines can perceive changes in your breathing and adjust pressure levels just enough to return to normal breathing during apnea episodes.
Naturally, these more advanced devices cost more than CPAP machines.
Other types of PAP machines
CPAP, BiPAP, and APAP are the three most well-known forms of PAP therapy, but they are not the only ones that exist. Let’s take a brief look at some others.
- Adaptive Servo-Ventilation (ASV) – ASV is similar to APAP as it adjusts to your breathing patterns and is often used for treating sleep apnea, but its main focus is to treat Cheyne-Stokes breathing.
- Average Volume-Assured Pressure Support (AVAPS) – AVAPS is a mode of ventilation that adjusts settings based on tidal volume per breath. The technology is often used to treat hyperventilation, but some PAP machines utilize it as well.
- Smart PAP machines – While not a separate type of PAP, it’s worth mentioning smart PAP devices. These newer, more advanced devices can connect to mobile applications through Wi-Fi, which usually adds some extra settings, usage statistics, and more.
Differences in treating OSA and CSA with PAP therapy
While PAP therapies proved to be safe and effective treatment methods for sleep apnea in general, it’s important to note the differences in various forms of sleep apnea.
Obstructive sleep apnea (OSA) – when the cause of apneas is the narrowing of the airways – is typically easier to treat, as the underlying cause is purely mechanical. In most cases, OSA responds well to the simplest form of PAP therapy, CPAP.
Treating central sleep apnea (CSA) – when the underlying cause is a neurological dysfunction – on the other hand tends to be more complicated. Not all cases of CSA respond well to simple CPAP treatments, and more adaptable BiPAP and APAP therapies seem to be more efficient in treating CSA.
We should also mention therapy-induced central sleep apnea, also known as complex sleep apnea, a form of central sleep apnea that surfaces after treating OSA with PAP therapy. Treating complex sleep apnea requires a personalized treatment plan adjusted to individual needs by doctors.
Which machine should you choose? CPAP, BiPAP, or APAP?
While it’s good to learn about your potential options, ultimately, you shouldn’t choose a PAP therapy machine on your own. Each case of sleep apnea is different, and these machines must be calibrated individually.
You should always consult with your healthcare provider before purchasing a PAP machine. Doctors typically determine the needed machine and individual pressure settings during a sleep study, which is a vital part of Positive Airway Pressure treatments.
The side effects of CPAP machines
Some might be curious about the potential side effects. While PAP therapy is a well-researched and well-documented treatment method deemed safe and effective by experts, some individuals might experience the following side effects.
- Difficulty falling or staying asleep
- Dry mouth
- Runny nose
- Skin irritation from wearing the mask
- Nausea or bloating due to air in the stomach
- Infections if the machine is not clean
As mentioned above, in some rare cases, treating OSA with PAP therapy might lead to the development of treatment-induced central sleep apnea.
The cost of CPAP machines
PAP machines can be a pricey investment, and the prices can vary highly, depending on which type of PAP treatment you need.
CPAP is typically the cheapest option, as it uses simpler technology, APAP machines are usually a bit pricier, and BiPAP machines are the most expensive ones. While the low price of CPAP machines might sound intriguing, in some cases, CPAP treatment doesn’t bring the desired results, and patients might need to resort to other forms of PAP therapy.
Let’s see the ballpark price ranges for each type of PAP machine.
- The cost of CPAP machines – Between $500 and $1000
- The cost of BiPAP machines – Between $1000 and $4000
- The cost of APAP machines – Between $800 and $2000
Some machines might cost more than these, but those usually include various extra features, like mobile phone connectivity or usage statistics. Typically, CPAP therapy and other forms of PAP machines are partially or fully covered by insurance if you have been diagnosed with sleep apnea and got a prescription from your healthcare provider. However, you should always consult your insurance company about your individual case before making a purchase.