What is a CPAP Machine?

CPAP machine in use
CPAP machine in use

Are you wondering what a CPAP machine is and how to choose the one for you?

Choosing a CPAP machine may look like a minefield, but it depends on your therapy needs and to some extent, personal preferences.

The acronym C.P.A.P. stands for Continuous Positive Airway Pressure. A CPAP machine increases the air pressure in your throat to prevent your airway from collapsing when you inhale and can reduce your snoring.

CPAP therapy is a treatment for O.S.A. (Obstructive Sleep Apnoea). Sleep apnoea is a term for the collapsing of your airways while sleeping.

One thing to note at this time is that a CPAP machine is not a ventilator; it does not breathe for you. The CPAP machine generates only enough air pressure to keep your airways open.


Fixed Pressure CPAP Machine or Automatic CPAP Machine

There are two types of CPAP machine, fixed-pressure and automatic.

Fixed Pressure CPAP Machines stay at one pressure setting which should be provided by your sleep clinic, or possibly your doctor.

Automatic CPAP machines are for sufferers who do not have a specific air pressure requirement. What does that mean? Some people require different amounts of air pressure to stop the sleep apnea effect. Auto-CPAP or APAP machines have a range of sensors that allow them to calculate the correct air pressure.


CPAP Masks and your CPAP Machine

The CPAP Mask is critical to your therapy success and is used in conjunction with your machine to deliver the correct air pressure to your airways. We have an extensive FAQ section on our website about CPAP Masks if you want to learn more.

CPAP Machines and humidifiers

There are also CPAP machines which can have a humidifier as a separate piece of equipment added, or they can have the humidifier built-in. A humidifier heats water and adds moisture to the air from the CPAP machine to prevent drying in your nose, mouth and throat from the CPAP therapy; to improve comfort for the user.

Intus healthcare advice:

Before you can order a CPAP Machine from Intus Healthcare, you need to have written documentation to show you require CPAP therapy. Your documentation does not have to be a formal prescription; it could be a simple letter from your doctor. Intus healthcare also has a sleep test facility, which you can view here by clicking the link: The Sleep Test.

If you have done a sleep study but are unsure if you have any paperwork showing your need for CPAP, then please contact us. If you are yet to do a sleep study (either privately through our at-home service, or via the NHS) then your first step would be to read our Sleep Studies information page and progress from there – you could still be benefiting from CPAP therapy within a fortnight.


CPAP Machines – do I need fixed pressure or automatic?

The difference between the two types of machine

There are two types of CPAP (Continuous Positive Airway Pressure) machine, fixed-pressure or automatic.

Fixed Pressure CPAP Machine

A fixed-pressure CPAP machine is designed to stay at one pressure level during use; this pressure setting should be provided by your sleep clinic, or possibly your doctor. This setting is calculated for your requirements based on several factors.

If you have been provided with a fixed supply-pressure setting by your clinic or GP, then a fixed-pressure CPAP machine should do nicely.


Automatic CPAP Machine

If you do not have a specific pressure setting (most do not), then you will be advised to use an automatic machine instead, also known as Auto-CPAP or APAP. Automatic CPAP machines have a range of sensors built-in that allow them to calculate how much pressure you require at any given time. It can detect when you are about to stop breathing and raises the air pressure accordingly. Once the danger has passed, it will drop the air pressure down again. This means, on average, you will get less pressurised air throughout the night than you would with a fixed pressure machine.

The fixed pressure CPAP machine would be set at the highest setting you might need.

Intus healthcare advice:

Many people find automatic CPAP machine therapy to be more comfortable and more effective. We often find even those who have been provided a fixed-pressure setting opt for an automatic machine as a result.

However, there is often an adjustment period as you get used to the different way an automatic machine provides pressure compared to a fixed-pressure one. Initially, some find the lower pressure alarming, and it can seem like you are not getting enough air! You are, you do not need high pressure all of the time – particularly when you’re awake. Equally, the automatic CPAP machine may go higher than you’re used to if it determines you need more pressure.

It can take a little time to acclimatise when switching to an automatic initially, but in the long-term, your therapy should be more comfortable and more effective.

One thing to note is that the fixed-pressure setting you are prescribed will be accurate at that time. Unfortunately, over time your requirements can change. For example; gaining or losing weight, or drinking alcohol before sleep can affect the severity of your OSA and therefore the pressure you require. It is therefore essential to be assessed regularly by your sleep or respiratory clinician and make sure your pressure setting is still at the optimum level. Alternatively, you could choose an Auto-CPAP Machine which will always provide you with the exact pressure you need regardless of any changes.

So in short: If you have not been prescribed a fixed-pressure setting (for example, 12cmH2O), then you will need an Auto-CPAP Machine. If you have, you can either choose a fixed pressure CPAP Machine at that setting or choose an Auto-CPAP Machine anyway for the additional benefits it offers.


CPAP Machines – What is BiPAP

BiPAP (Bilevel Positive Airway Pressure) is similar to CPAP (Continous Positive Airway Pressure). Your sleep/respiratory clinician or the Intus Healthcare sleep test/sleep study will prescribe which therapy and machine you will need. BiPAP machines have two pressure setting. One pressure setting for inhalation (IPAP), and the second, a lower pressure setting for exhalation (EPAP).

The difference in inhalation and exhalation pressures reduces the work of breathing and allows the person to have a more restful sleep. These are some reasons BiPAP machines are sometimes used as a treatment method when CPAP has failed to treat their sleep-disordered breathing adequately.

Like CPAP, the BiPAP machine also increases the pressure when you inhale to keep the airways in the nose and throat from closing while you are sleeping and provide a lower pressure during exhalation that continues to maintain an open airway. If you have OSA but without any other respiratory, cardiac or other severe health conditions, then CPAP would be the best form of treatment for you. People with nerve and muscle problems may better benefit from the BiPAP machine rather than the CPAP machine. BiPAP machines can make sure users breathe a set number of times per minute.

If you think you may require BiPAP, then you should discuss this with your sleep or respiratory clinician first. Appropriate testing is essential to determine what treatment method would suit your needs better and what settings are appropriate for you.