Continuous Positive Airway Pressure
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Continuous Positive Airway Pressure



Continuous Positive Airway Pressure, or CPAP, is a method of delivering air to your lungs using a machine. Rather than breathing for you, the machine simply applies enough pressure to keep your airway open, allowing you to inhale completely. The air is delivered to your lungs by way of a tube connected to the machine and then to either a face mask covering your nose and mouth (called an oronasal mask) or nostril prongs.

Continuous Positive Airway Pressure Machine

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Parts of the Body Involved

  • Face and mouth
  • Nose/nostrils
  • Lungs
  • Esophagus
  • Head (to secure mask)

Reasons for Procedure

Although CPAP can be used in several different situations, CPAP treatment is most often used for obstructive sleep apnea or sleep disordered breathing. This is a condition in which breathing stops during sleep, often many times during a night. This can lead to daytime sleepiness and many other complications. CPAP helps to keep the throat and airway open and the tongue thrust forward. People suffering from sleep apnea can then breathe normally while sleeping. It is considered to be the most effective nonsurgical treatment for sleep apnea.

CPAP is also occasionally used in the case of preterm infants and in conjunction with general anesthesia. In both of these cases, CPAP is used to ensure that breathing remains steady.

Risk Factors for Complications During the Procedure

CPAP is a noninvasive, nonsurgical procedure and, therefore, is generally considered very safe. Talk to your physician about what, if any, risk factors may be applicable to you.

What to Expect

Prior to Procedure

In using CPAP for sleep apnea:

  • A complete physical examination will be performed.
  • Prior to prescribing a CPAP machine, your physician may require you to stay in a sleep lab in order to determine the correct amount of airway pressure for you and your condition.
  • You may see a pulmonologist, or an ear, nose, and throat specialist (otolaryngologist).
  • Depending on your situation, your physician may recommend that you make lifestyle changes, such as:
    • Quitting smoking
    • Losing weight
    • Exercising


CPAP may occasionally be administered in conjunction with general anesthesia. When CPAP is used to treat sleep apnea, no anesthesia is necessary.

Description of the Procedure

  • Following your stay in a sleep lab, you will be prescribed a CPAP machine.
  • The CPAP machine includes a ventilator (pump) and either a face mask or nasal prongs.
    • The pump will force air through your nasal passages to help keep them open.
  • Ongoing: You will wear the face mask, or nasal “pillows” system, to bed every night.

How Long Will It Take?

If you are undergoing CPAP treatment for sleep apnea, you will use the machine indefinitely.

Will It Hurt?

Some CPAP patients report chest muscle discomfort due to the increased lung volume. Talk with your physician about the best way for you to relieve any discomfort.

Possible Complications

Most patients who undergo CPAP report at least one side effect. Some reports indicate that up to 30% of users may eventually discontinue treatment because of side effects. Some of the first nights using a CPAP machine can be difficult; you may even experience poorer sleep at first. It is important to prepare for inconveniences until you become accustomed to the CPAP treatment. Talk with your physician about what steps you can take to minimize any discomfort, such as the use of saline sprays to moisturize nasal passages.

Some of the complications reported with the use of CPAP include:

  • A feeling of claustrophobia or suffocation from wearing the face mask
  • Rash or pressure sores in the area of the face mask
  • Difficulty exhaling
  • Nasal congestion
  • Sinusitis
  • Sore eyes, conjuncitivits
  • Sore or dry throat
  • Headaches
  • Abdominal bloating
  • Nosebleed
  • Chest muscle discomfort
  • Complaints of machinery being disruptive

Average Hospital Stay

In using a CPAP machine for sleep apnea, you must stay in the hospital for a “sleep study” to ensure that the correct amount of pressure is determined for your particular case. This could involve anywhere from a one night stay to a week.


Many patients who use CPAP for sleep apnea report relief from the following:

  • Decreased daytime sleepiness
  • Decreased high blood pressure
  • Improved heart function
  • Improved quality of life

It is important to note that in the case of CPAP for sleep apnea, discontinuing the use of the CPAP will most likely cause sleep apnea symptoms to return.

Call Your Doctor If Any of the Following Occurs

  • Shortness of breath
  • Chest pain
  • Dizziness or lightheadedness


American Academy of Otolaryngology

American Lung Association

American Sleep Apnea Association


The Canadian Sleep Society (CSS)

Canadian Society of Otolaryngology

The Lung Association


Barnes M, Houston D, Worsnop CJ, et al. A randomized controlled trial of continuous positive airway pressure in mild obstructive sleep apnea. Am J Respir Crit Care Med. 2002:165:773-780.

Bratzke E, Downs JB, Smith RA. Intermittent CPAP: a new mode of ventilation during general anesthesia. Anesthesiol. 1998;89(2):334-340.

Chowdhuri S. "Continuous positive airway pressure for the treatment of sleep apnea." Otolaryngology Clinics of North America. 2007; 40(4):807-27.

Montserrat J, Ferrar M, Hernandez L, et al. Effectiveness of CPAP treatment in daytime function in sleep apnea syndrome: a randomized controlled study with an optimized placebo. Am J Respir Crit Care Med. 2001;64:608-613.

Last reviewed May 2008 by Rosalyn Carson-DeWitt, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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