The patient sleeps with a comfortable, close fitting nasal mask which is connected by flexible tubing, to a CPAP machine that provides varying levels of pressurised air, typically 4 – 20 cm/H2O.
The patient breathes in fresh air from the flow generator and breathes out via an exhaust port on the mask.
Snoring and obstructive sleep apnoea are abolished immediately and for as long as the patient wears the mask and the CPAP pressure remains adequate. Excessive daytime sleepiness often resolves within a few days of using CPAP.
When To Try CPAP
Following the diagnosis of obstructive sleep apnoea (OSA) your hospital Consultant will arrange for a trial of CPAP. The trial is usually for a period of up to 14 nights. You will be fitted with a mask and shown how to use the CPAP machine. This allows you to experience CPAP and for reports to be prepared to assess the appropriate pressure setting for your home system.
The CPAP System Consists of:
A CPAP machine to produce the pressurised air.
A flexible length of tubing to carry the air to you.
A mask worn over the nose or nose and mouth with ports or a device to allow the exhaled air to escape.
Head straps to hold the mask in place.
The CPAP Machine
The CPAP machine is a flow generator which consists of a pump that sucks air in from the room through a dust filter and blows it out under a pre-set pressure. This pressure varies from person to person.
Some CPAP machines have a delay timer or an inbuilt “ramping system”. This allows you to become accustomed to a low pressure of air whilst falling off to sleep. The machine will then gradually build up to the pre-set treatment pressure when you are sleeping.
The CPAP Mask
The standard mask fits over the nose leaving the mouth free. People who mouth breathe can use a mask known as a full face mask which fits over the nose and mouth. Mask designs vary between manufacturers but they share a number of common features.
A flexible cushion which rests against the face. Some masks may have a second, very thin membrane in addition to this.
A hard plastic shell with attachment points for the head straps that keep the mask in place during sleep.
An inlet tube, which allows CPAP tubing to attach to the mask.
Outlet port(s) which allow the exhaled air to escape. Some newer designs have a swivel feature built in to this port to allow directional control.
Using The CPAP System
Fit the mask with the CPAP machine turned on to make sure the cushion fills with air and forms a comfortable seal. It is a good idea to fit the mask while lying down in the position you like to sleep in. With many masks the angle of the frame can be altered to fit the shape of your face and helps to prevent the mask rubbing on the bridge of the nose or leaking around the eyes or under the nose or mouth.
Adjust the head straps but try not to have them too tight.
When you wake in the morning you may well feel much more refreshed than before treatment but some people take a few nights to really begin to feel effects of the CPAP treatment.
What To Expect When Using CPAP at Home
Position your CPAP machine and tubing to suit your preferred sleeping position. Some people prefer to bring the tubing over the top of the headboard whilst others run it over their shoulder. Try both ways and select whichever is more comfortable for you.
When using your nasal CPAP for the first time you will notice an unusual sense of pressure when breathing. It is normal to feel some resistance to breathing out as you are having to breathe out against the incoming air flow but you will soon become used to this.
It is advisable to keep your mouth closed when wearing the mask. If you open your mouth air will leak out and this may feel uncomfortable, as if you cannot get your breath. If you always breathe through your mouth you will probably have been offered a full face mask which goes over your nose and mouth.
Some people experience nasal congestion when first using CPAP. Your GP may prescribe nasal sprays if this persists.
If you wake in the night and feel uncomfortable with the pressure of the machine, try using the ramp feature which will reduce the pressure and allow it to build up gradually while you settle back to sleep.
Common Problems & Solutions for CPAP Users
When using your CPAP system for the first time you will notice an unusual sense of pressure when breathing. You will need to consciously push out when you breathe. This is normal and will occur automatically when you are asleep. If you open your mouth, air will leak out. This may feel a little unpleasant. You should try to keep your mouth closed. A full face mask may be the answer as it will allow you to breathe out through your mouth.
A delay timer or “ramping system” on your CPAP system can help overcome these problems. The pressure will build up gradually over the period of time you select, from a comfortable level to your prescribed pressure.
High pressure (typically 10 – 20 cm/H2O) cause ribcage and abdominal discomfort and can cause discomfort from air swallowing. Your GP may be able to offer advice should such problems arise.
If you or your partner find the machine too noisy then it can be safely put in a cupboard or box as long as there is sufficient room around it for air to circulate. Longer tubing may assist in moving the machine further away from the bedside – contact the Lung Function Unit for advice.
The Nose Mask
It is not uncommon to take a while to get used to wearing the mask at night. A tightly fitting mask is not necessary. A well balanced, comfortable fit without undue tightness will still provide an efficient air seal. A minor leak around the upper part of the face is sometimes preferable to over tightening the mask but you should eliminate any air leaks blowing in the direction of your eyes as this may cause eye irritation.
Pulling the headgear straps too tight can lead to sensitivity of the bridge of the nose or the upper lip, and occasional skin irritation. Setting the final tension is best done when lying down. Pressure ulceration on the bridge of the nose may result if not corrected.
Common Nasal Problems
Occasionally the CPAP treatment causes irritation to the nasal lining which results in sneezing and nasal streaming (similar to hay fever). This may settle down on its own but if it does not then nasal sprays which reduce the inflammation of the nasal lining and dry up the nose are the best treatment.
If your nose becomes blocked or congested during the night then it will be difficult to use the CPAP. system. If you have a cold stop using the system until recovered. Nasal decongestants may help to clear your nose but do not use them on a long term basis. Consult your doctor if problems persist.
Coldness/Dryness of the nose
Some people experience a continuing dryness of the nose and throat. If this occurs it may be helpful to keep the bedroom a little warmer and try to increase the humidity in the room with a tray of water above the radiator. It may also help to run the CPAP tubing under the bedclothes so that it stays warm. CPAP humidifiers are also available from the Lung Function Unit.
When Using CPAP
If any of the symptoms of Sleep Apnoea recur during the course of your CPAP treatment, consult the Lung Function Unit.
If you experience an infection of the upper respiratory tract, middle ear or sinus, you should consult your GP before continuing your CPAP treatment. You may be advised to stop CPAP until the infection has cleared.
If you are admitted to hospital or are prescribed any other form of medical treatment, always inform the medical staff that you are being treated with nasal CPAP.
Do not stop your CPAP treatment without the approval of your GP.
If you experience any unexpected symptoms during the course of your CPAP treatment, consult your doctor immediately.
Treatment with CPAP may act as a catalyst to weight loss and the sleep Apnoea may then improve significantly to allow discontinuation of the CPAP.
If you are admitted to hospital for any reason take your CPAP machine to use overnight.