CPAP: complete guide to understand, choose and get equipped

VivaRespire is a specialist online CPAP shop. We do not offer INAMI/RIZIV reimbursement. For more information, see our page on CPAP reimbursement in Belgium.

CPAP (Continuous Positive Airway Pressure) is the reference treatment device for sleep apnea. In this complete guide, you will learn how a CPAP works, the differences between fixed CPAP, Auto-CPAP and BiPAP, how to choose your device and mask, and how the INAMI convention system works in Belgium.

What is a CPAP?

CPAP stands for Continuous Positive Airway Pressure. It is a medical device that delivers a continuous flow of pressurized air through a tube and a mask, keeping the upper airways open during sleep and preventing the apneas and hypopneas characteristic of obstructive sleep apnea (OSA).

Sleep apnea affects millions of people. The apnea-hypopnea index (AHI) measures its severity: an AHI above 15 events per hour generally indicates moderate to severe apnea requiring CPAP treatment. To learn more about the AHI, see our page on the AHI - apnea-hypopnea index.

A CPAP does not produce oxygen: it compresses ambient air to create the therapeutic pressure. It is not an oxygen concentrator.

How does a CPAP work?

The principle is simple: a turbine draws in ambient air, compresses it to a set pressure (in cmH₂O), and delivers it through a tube to the mask worn during sleep. This air pressure acts as a pneumatic splint, keeping the walls of the upper airway open and preventing collapse.

The essential components of a CPAP system are:

  • The CPAP device: the machine that generates and regulates pressure.
  • The tubing: carries air from the device to the mask (standard or heated).
  • The mask: the interface between the device and the patient's face (nasal, full face, nasal pillows).
  • The humidifier (optional but recommended): adds moisture to the air to prevent dryness.

Fixed CPAP, Auto-CPAP (APAP) and BiPAP: what are the differences?

Fixed-pressure CPAP

A fixed CPAP delivers a constant, single pressure throughout the night, prescribed by the doctor following a titration. It is particularly suited to patients whose pressure needs are stable and predictable.

Auto-CPAP (APAP)

An Auto-CPAP (APAP) automatically adjusts pressure in real time based on detected breathing events (apneas, hypopneas, snoring, leaks). Pressure varies within a range set by the doctor. Most modern devices are APAPs. This flexibility is especially useful when needs vary with sleep position or sleep stage.

APAP devices available at VivaRespire: see the Auto-CPAP category, including the AirSense 11 AutoSet, the DreamStation 2 and the Prisma SMART Auto.

BiPAP (bilevel ventilation)

BiPAP delivers two pressure levels: a higher pressure on inhalation (IPAP) and a lower pressure on exhalation (EPAP). It is generally reserved for specific indications - certain complex apnea forms, neuromuscular diseases or respiratory failure. Your doctor or sleep specialist will determine whether BiPAP is appropriate for your situation.

Type Mode of operation Typical use case
Fixed CPAP Single, constant pressure Stable apneas, well-known pressure
Auto-CPAP (APAP) Pressure auto-adjusted within a range Majority of cases, improved comfort
BiPAP Two pressure levels (IPAP / EPAP) Specific indications prescribed by doctor

How to choose your CPAP

1. Medical indication

This is always the starting point. Fixed CPAP or APAP? Your doctor or sleep clinic defines the device type and appropriate pressure range based on your AHI and characteristics. To estimate theoretical pressure, see our CPAP pressure calculator.

2. Connectivity and data monitoring

Modern devices transmit treatment data via a built-in cellular connection or Bluetooth. This allows tracking results night by night via an app like myAir (ResMed) or EncoreAnywhere (Philips). The AirSense 11 AutoSet features native cellular connectivity - no WiFi needed.

3. Comfort features

  • EPR (Pressure Relief): pressure reduction on exhalation for greater comfort.
  • Ramp: low starting pressure to make falling asleep easier.
  • SmartStart / SmartStop: automatic start and stop triggered by breathing detection.
  • AutoSet For Her: algorithm adapted to the female apnea profile (available on the AirSense 11).

4. Format and portability

If you travel frequently, compact devices like the ResMed AirMini are designed for travel. Our guide on travelling with a CPAP details best practices.

Choosing your CPAP mask

The mask is often the most decisive factor for comfort and adherence. A poorly fitted mask generates leaks, noise and nighttime awakenings - regardless of device quality. For a complete guide, see our page on how to choose a CPAP mask.

Full face mask

Covers the nose and mouth. Recommended for patients who breathe through their mouth during sleep or whose mouth opens despite a nasal mask.

Nasal mask

Covers only the nose. A good balance between seal and comfort. Suitable for the majority of patients who breathe through their nose.

Nasal pillows mask

Two small inserts placed directly in the nostrils. Very light and discreet. Ideal for those who feel confined with a larger mask, or who move around a lot during the night.

Masks available at VivaRespire

See the full selection in our CPAP masks category.

The humidifier: why and how?

Humidification adds water vapour to the air delivered by the CPAP. It reduces dry mouth and nasal dryness, throat irritation and the risk of congestion. Most modern devices include an integrated humidifier.

Water chamber humidifier

The water chamber is filled with distilled water before each use. It is essential to use only distilled or demineralized water - never tap water - to avoid limescale deposits and bacterial growth.

Heated tubing

A heated tube maintains the temperature and humidity of the air throughout its journey, reducing condensation ("rain-out"). Particularly useful in cool environments.

INAMI convention vs buying from VivaRespire

How does the INAMI convention system work in Belgium?

In Belgium, CPAP treatment for sleep apnea can be covered through the INAMI convention system. This system works by device loan: an approved sleep centre (accredited provider) lends the device to the patient. The patient does not buy the device - they use it for the duration of treatment and return it if necessary.

The INAMI convention is not a "reimbursement" for a purchased device: it is a loan system via an accredited provider. Devices provided in this framework do not belong to the patient.

Why choose VivaRespire?

VivaRespire is aimed at patients who wish to own their own CPAP device - outside the convention system. This approach offers several advantages:

  • Freedom to choose your device and mask according to your preferences.
  • The device is yours to keep permanently.
  • Freedom to travel without constraints related to the provider's equipment.
  • Access to the latest models available on the market.
  • Simple online purchase, fast delivery.

To understand all the implications of choosing outside the convention, see our dedicated page: CPAP reimbursement in Belgium.

Monitoring data: myAir and OSCAR

Data monitoring is essential to ensure treatment is effective. Modern CPAP devices record dozens of parameters each night: residual AHI, leaks, comfort index, hours of use, etc.

myAir (ResMed)

ResMed's myAir app allows patients with an AirSense 10 or AirSense 11 to view their results night by night on a smartphone or via browser. It also offers coaching features (Care Check-In, Personal Therapy Assistant on the AirSense 11). To learn how to read your myAir results, see our guide on reading your myAir results.

OSCAR (free software)

OSCAR is a free open-source software that allows in-depth analysis of CPAP data downloaded from your device's SD card. It offers far greater granularity than myAir and is favoured by patients who want to understand their therapy in detail. Our guide on OSCAR - CPAP software explains how to use it.

Maintenance and care

Regular maintenance is essential to preserve equipment hygiene and ensure treatment effectiveness.

  • Mask: daily cleaning (warm soapy water, thorough rinse) and cushion replacement every 3 to 6 months.
  • Tubing: weekly rinse, complete drying before use.
  • Water chamber: daily rinse, weekly disinfection, annual replacement recommended.
  • Filters: monthly check, replacement according to model (disposable fine filters, washable foam filters).

Find all consumables and spare parts in our CPAP accessories category.

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