CPAP Therapy

Detailed analysis and reporting of your CPAP study takes several days.  A Sleep Physician will review the study data, CPAP machine settings and mask which were used on the night of your study to determine the optimal settings for your CPAP therapy.  These recommended settings will be documented on a CPAP Prescription.

The Sleep Disorders Unit will contact you within several days of your study to issue your CPAP Prescription and discuss how you can obtain a rental CPAP machine for an initial 1-2 month trial period.  This initial rental trial allows you to determine whether you are able to use CPAP on a long-term basis and to ensure you obtain symptomatic benefit from this therapy, before you commit to purchasing your own machine.

There are a number of different companies (listed below) which hire/sell CPAP machines. The CPAP supplier will require your CPAP Prescription to set the machine to your recommended settings.  They will also confirm your mask fits comfortably and seals effectively, and provide you with education about the operation and care of the CPAP machine and mask.  Once you have decided on your preferred company, the Sleep Disorders Unit will forward your CPAP Prescription to the company which will contact you to arrange an appointment.

CPAP Australia

16 Belmore Street
Surry Hills 2010
P 1300 69 27 27


Sydney CBD or
Bondi Junction
P 1300 925 387

Air Liquide Healthcare

Unit 5 / 476 Gardeners Road
Alexandria NSW 2015
P (02) 9364 7474

Breathe Easier Physiotherapy
Sleep & Lifestyle Solutions

Suite 902
St Vincent’s Clinic
P (02) 8382 6935

Philips Sleep Easy Centres

803 Anzac Parade
Maroubra 2035
P 1800 701 822

Benchmark Sleep Services

39 Hume Street
Crows Nest
P (02) 8068 8264
Casula, Bankstown, Miranda, Bella Vista

Fisher & Paykel

Distribution through pharmacies
P 1800 653 881 or
M 0411 425 251 for details


Most companies have outlets or distributors located throughout NSW.



Most suppliers hire CPAP machines at a reduced rental rate for the first 1-2 months (this initial rental cost is generally deducted from the machine purchase price). Initially a short-term rental is a good idea to ensure you are happy to continue using CPAP long-term.

Some features to consider when selecting a CPAP machine are:

1.  Heated Humidification

Humidification increases the temperature and moisture content of the air delivered by the CPAP machine. Humidification makes CPAP more comfortable (especially in winter), and can also prevent the development of secondary airway symptoms including rhinitis (runny nose), dry nasal passages and dry mouth. Humidification may also help to reduce the effects of mouth leak. Machines with humidifiers often cost more than basic CPAP models and whilst not everyone NEEDS a humidifier, humidification will certainly make therapy more comfortable. If you are not sure if humidification is for you, most brands of machine are “upgradable” to attaching a humidifier later if nasal symptoms develop.

2.  Machine Noise

Make sure you have the opportunity to listen to different CPAP machines operating at the pressure you require. Some machines are louder than others and the noise level of all machines will increase slightly as the pressure of the machine increases. Bear in mind that all CPAP machines are quite noisy when the mask is disconnected. When your mask is on and is sealing there should be a significant reduction in the operating noise of the machine.

3.  Delay Timer or Ramp

Most CPAP machine models have a delay timer or ramp feature which allows the machine to start a comfortable low pressure and gradually increase over a set time period (generally 20-30 minutes) until it reaches your prescribed pressure.  This feature is optional and is designed to make it easier to fall asleep at the lower pressure. 

4.  Pressure Reduction during Exhalation

Initially, many patients find breathing out against the incoming CPAP air pressure difficult.  To overcome this, some CPAP models are able to reduce the set pressure slightly when you breathe out (during exhalation).  Different brands of machines have their own proprietary name for this type of feature:  For example, on ResMed brand machines it is called EPR (Expiratory Pressure Relief), on Respironics machines it is called C-Flex.

5.  CPAP vs. APAP

CPAP delivers a single pressure (e.g. 10 cm H20 – ‘centimetres of water pressure’), determined during your CPAP Titration, to your airway to hold it open regardless of sleep stage or sleeping position. 

Automatic Positive Airway Pressure (APAP) is a form of PAP in which the machine automatically adjusts the air pressure up and down across the night to maintain an open airway.  Rather than setting a single pressure, as for CPAP, a pressure range (e.g. 4-10 cm H2O) over which the machine can operate is set.  The APAP machine uses mathematical algorithms to detect snoring, and periods of airflow limitation or cessation (indicating a partially or completely closed airway) and automatically increases pressure to prevent these events.  Once the APAP machine detects an open airway it begins to lower the pressure to maximise patient comfort. The main advantage of APAP is that it generally delivers a lower overall pressure across the night.  APAP, however, costs significantly more than a fixed CPAP machine. 

In studies comparing the two modalities, CPAP and APAP have been shown to be equally effective in treating OSA and equally effective in improving OSA symptoms.  No significant difference in long-term patient usage between the two types of therapy has been demonstrated.  We therefore recommend you start on a fixed CPAP machine and only consider APAP, in consultation with your Sleep Physician, if you continue to experience difficulty tolerating the air pressure after a few weeks of CPAP usage.


Some CPAP suppliers require you to purchase the CPAP mask and air tubing when you hire a CPAP machine. Most suppliers, however, include rental of the mask during the initial machine rental period. The mask model and size that you wore during your overnight CPAP study are provided on the attached CPAP Prescription. This is provided for your own information and intended as a guide. You are not required to purchase that mask.

The main considerations when selecting a CPAP mask are:

1.  Air Leakage

One of the most important features of the CPAP mask is that it seals well against your face and that no air leakage occurs. Air leaks reduce the effectiveness of the CPAP treatment by reducing the amount of pressure being delivered to your airway. Air leakage can also cause irritation and discomfort and lead to sleep fragmentation. Air leaks into the eyes can cause serious irritation to the conjunctiva. Common places for air to leak from the masks are over the bridge of the nose and near the cheek folds between the mouth and nose.

2.  Comfort

It is very important that your mask feels comfortable against your face when you are wearing it. There should not be any parts of the mask that feel like they are pressing against your skin much harder than the rest of the mask. CPAP masks are worn nightly. Therefore any areas of irritation may cause chronic redness or even pressure sores.

The choice of CPAP machine and mask is up to you and will depend on personal requirements and preference.  Remember that it is not necessary for the CPAP machine and mask to be the same brand.


Please ensure you have arranged a follow-up appointment with your referring Physician within the next 2-4 weeks so that you will be able to tell your doctor how you find the CPAP therapy and discuss whether any adjustments to your treatment plan are required.  Most machines record data which can be downloaded by the CPAP supplier or your Physician to provide information about the effectiveness of your treatment.  Remember, it takes most patients several weeks to become comfortable sleeping with CPAP and, in turn, start to experience the benefits.  If you have any difficulties, or need advice, please contact the Sleep Unit on (02) 8382 3593.