When sleep is steady, all is steady

What is CPAP?

One of the most common treatments for adults with obstructive sleep apnea (OSA) is continuous positive airway pressure (CPAP).  CPAP reverses the complete blockages or narrowing of the upper airway that occur during sleep in individuals who have sleep apnea. To keep the airway open, CPAP uses small amounts of air pressure and is almost always successful, when tolerated and used appropriately, to treat OSA.


Obstructive sleep apnea is a common sleep abnormality where breathing pauses occur due to narrowing of the upper airway. During sleep this causes a lack of air to enter the lungs resulting in less oxygen reaching vital organs. When the airway collapses or narrows during sleep,  the body tries to compensate to overcome the perceived obstruction (which is why it is called obstructive sleep apnea). A greater effort to breathe air through the narrower airway often causes snoring. CPAP is usually the best treatment for this kind of sleep apnea.

CPAP treatment consists of using a device that includes two main components, a mask and machine. The face mask is placed over the mouth, nose or both. A strap connected to the mask helps keep it in a fixed position while wearing it. The machine contains a motor that blows humidified air into a tube which extends to the mask. Light pressure produced by the CPAP machine eases the airway open and prevents it from collapsing or being blocked.

A sleep study called a CPAP titration can ensure that CPAP is effective to treat OSA in a given individual. During the study, each breath is observed for apneas while CPAP is being applied and adjusted to the right pressure. If an apnea is observed during the study then pressure is increased.  Using this method, the appropriate pressure is identified to ensure that airway collapse can be avoided in the future.

Ordering a CPAP device

Once the doctor prescribes CPAP using the pressure determined at the sleep study, a specialized provider known as a home equipment provider must be contacted to help select a machine. Home equipment providers are sometimes known as durable medical equipment (DME) companies. They will normally arrange to deliver a new CPAP device and mask and show you how to use them. Any problems with the machine or mask may be communicated to the doctor, who may make assist directly by troubleshooting the problems or indirectly through communication with your DME. Alternatively, DMEs may be contacted directly by patients to help troubleshoot a device. Many DME companies also will replace a mask within the first month (only within the first month) if you aren’t satisfied.

While alternative treatments such as oral appliances exist to treat OSA, CPAP therapy has several advantages. It is able to maintain open airways in severe cases of sleep apnea even when other alternatives cannot. In addition, it improves the duration and quality of sleep, decreases sleep apnea symptoms, and can even improve high blood pressure. After beginning CPAP treatment, patients usually report a higher quality of sleep and less difficulty breathing while asleep. Treatment also reduces snoring at night and improves focus during the day.

Who Needs CPAP?

Adult patients diagnosed with obstructive sleep apnea are initially prescribed CPAP. While obstructive sleep apnea can also be found in children, the preferred form of treatment for them is usually the removal of the tonsils and adenoids (adenotonsillectomy). The tonsils are the two oval shaped pads at the end of the throat, while the adenoids include a rectangular tissue at the rear of the nasal cavity.  CPAP becomes an option if there is no improvement post-surgery and is also considered when exam reveals small tonsils.

Diagnosing sleep apnea

Diagnosis of sleep apnea is confirmed by an overnight sleep study known as a polysomnogram (PSG) when it is in a sleep lab or a Home Sleep Study (HST) if conducted at home. For patients suspected of having obstructive sleep apnea, a PSG assesses sleep, breathing, oxygen levels and determines the type and severity of sleep apnea as well as any other sleep problems, if they are present. Sleep studies are important because they help determine the type of sleep condition a patient may have and that may change the type of treatment that is needed. A positive study is usually followed by a CPAP titration study. Sleep apnea is usually a life-long and chronic medical condition. If left untreated, it can cause disability in addition to decreased quality of life. Patients with sleep apnea can benefit greatly from having their condition managed by a sleep specialists, who specialize in the diagnosis and treatment of patients with sleep apnea and other sleep disorders.

Alternative Positive Airway Pressure (PAP) devices

There are various types of PAP devices including CPAP, Bi-level positive airway pressure (BiPAP) and Adaptive Servo-Ventilation (ASV). Some types of PAP machines are made to treat conditions that are slightly different than sleep apnea, such as chronic hypoventilation or central sleep apnea. Chronic hypoventilation is a condition where a patient breathes so slow, increasing carbon dioxide in the body and interrupting normal breathing. Central sleep apnea, where pauses to breathing occur in the absence of obstruction or narrowing is also treatable with different positive airway pressure devices such as BiPAP or ASV. Sometimes, when CPAP is not effective to treat OSA, such as when very high pressures are needed, BiPAP may be used.

What to Expect Before Using CPAP

Prior to the prescription of CPAP, a sleep specialist is likely to recommend a sleep study known as a polysomnogram  (PSG). A PSG is a study that is able to record data during sleep. It provides information about the activity in the brain, eye movements, blood pressure, heart rate and several other types of sleep data. Patients are required to sleep overnight in a sleep lab for this kind of study.

If there is strong suspicion for severe apnea, a doctor may conduct a split-night sleep study in which a technician will monitor a patient’s sleep for the first half of the night. If severe enough sleep apnea is diagnosed in the first half of the study, the patient will sleep with a CPAP machine for the latter half of the night. As with a standard CPAP titration study, a technician adjusts the settings until the patient is comfortably asleep without any apnea. A sleep specialist is responsible for determining what kind of sleep study is appropriate for a patient on a particular night and usually advises the attendant with specific instructions and information about the patient undergoing monitoring.

What to Expect After a Polysomnogram (PSG)

The results of the study will determine the type of treatment that is needed. Ideally, results of the studies should be discussed with patients at each stage, such as after the original sleep study and, if subsequently performed, after a CPAP titration. If CPAP is determined to be the most appropriate treatment, a doctor will determine the settings based on the CPAP titration study that is best.

Does insurance cover CPAP?

The majority of health insurance providers cover CPAP treatment. Providers often require documentation of sleep apnea by sleep study. They might also require documentation of symptoms from sleep apnea (eg sleepiness) or of comorbid medical conditions (eg high blood pressure). Health insurance providers can help to understand the kind of coverage possibilities they have. Physicians with experience as well as experienced DMEs can also help to ensure that you will be covered and that the necessary documentation is available for your insurance company. Follow up  with a physician is also important to document that the machine is being used. Generally, insurance companies may require you to be using CPAP at least 4 hours a night for a minimum of 21 days in a 30 day period. If not, insurance companies may ask you to return the device.

Selecting a CPAP Machine and Mask

Home equipment providers have a number of CPAP machines with different features to improve a patient’s comfort level. They can assist in selecting a machine according to the physicians prescription and personal preferences. There is even a possibility of using the CPAP machine on a trial basis. This allows the patient the opportunity to be sure they are satisfied with the CPAP machine.

Most masks fall into one of three categories, full face masks that cover the nose and mouth, a nasal mask or a nasal pillow interface, that look like little, flexible mushroom cones and fit into each nostril.. The most important factors in selecting a mask is fit and comfort. In addition to comfort, a good fit should prevent air from escaping. The correct choice of mask will produce consistent air pressure needed to ease any breathing problems. Fortunately, masks for CPAP machines come in a variety of shapes, sizes, and materials. Many cover the mouth and nose; while others simply cover the nose. Individuals who predominantly breath through their mouth (mouth breathers) or who have frequent allergies might do best with a full face mask that covers both. Finding the perfect mask is usually a matter of trial and error. But mask fittings by DME providers or during a CPAP titration are often helpful to guide in this decision. For individuals who sleep with supplemental oxygen (CPAP is pressure not oxygen), masks have attachments.

What to Expect While Using CPAP

If you’re one of the lucky ones, you will have no problem adjusting to CPAP and notice immediate benefits to your sleep. While some people get used to it right away, patience is important when it comes to CPAP. It can take a month and sometimes several months to get used to wearing a mask on your face when you are sleeping. A positive outlook has been shown to be beneficial in getting used to CPAP. Initially, some people feel discomfort or are bothered by air flow while they are trying to fall asleep. Other people will notice skin irritation or leaking of their mask. Many problems are easily fixed by experienced DMEs or physicians, so any problems should be promptly discussed with a DME or physician. Some people who have trouble sleeping with the device or notice that they are repeatedly ripping the mask off during sleep, can sensitize themselves to the machine by first wearing the mask on their faces for brief periods of time during the daytime. Gradually, once comfortable wearing the mask, they can turn the CPAP machine on during the datyime. When that is tolerable, using the machine at night may be easier. Some patients also have benefit from performing relaxation  techniques while wearing the mask. Breathing with a CPAP device may not come naturally for some, but motivated patients have great success.

Follow Up Care

The doctor may ask a patient to schedule a return visit after he or she has tried the CPAP machine for a month. The physician will monitor how the patient has adapted to the treatment. From there, follow-up care usually consists of visits every six months to a year. A patient should report any weight loss, persisting or recurring symptoms, or any new sleep apnea symptoms to his doctor. This will help doctors to readjust the settings of the machine according to a patient’s needs.

Studies find that many patients experience a recovery in focus and memory with CPAP therapy. Some studies have even reported that CPAP can reduce the chances of road accidents. Sleep partners also report positive feedback after their partners begin CPAP. Overall, patients usually feel much more attentive and the quality of their day time activity increases.

However, it is important to remember that it can take some time for a patient to properly adjust to CPAP. This adjustment period is usually a short term problem and diminishes as treatment progresses. CPAP requires some time to be effective, however the improvement in symptoms are significant.

What Are the Risks of CPAP?

Although most treatments can have side effects, doctors try to minimize these negative effects and maximize the benefits. . CPAP is considered efficient because it is associated with the minimal side effects. Despite this, some patients can experience troublesome side effects. It is important that patients contact their physician if this occurs so treatment can be adjusted to fix any problems.

Mask Allergies and Skin Irritation

Some patients experience irritated skin from their mask. Masks may cause an allergic reaction, irritate skin or provide pressure unevenly on part of the face (eg bridge of nose). In this case, a patient should try cleaning the mask thoroughly in addition to washing and appropriately moisturizing your face before wearing the mask. A patient can also try a mask made from a different material. Nasal pillows, which are little, flexible mushroom shaped cones that fit into each nostril—can also be used if the mask causes too many problems.

Dry Mouth

Dry mouth is very common in patients undergoing CPAP therapy. Sometimes, it can be caused by mouth breathing or the CPAP itself. Most CPAP machines have heated humidifiers that can be adjusted to reduce dry mouth. A faulty mask may cause air to leak leading to dry mouth and ensuring a proper seal in such cases may solve the problem.  If mouth dryness persists, a chin strap to keep the mouth closed at night or a different mask reducing the volume of air flowing through the mouth can be tried.

Congestion, Runny Nose, Sneezing, Sinusitis, and Nosebleeds

Other side effects of CPAP include nasal congestion, a runny nose, sinusitis, and even nosebleeds. CPAP machines with heated humidifier may decrease some of these effects. A saline-based nasal decongestant may be used to prevent these types of side effects. If these options are not effective, your doctor may suggest effective different nasal spray. Since these symptoms are common in those without CPAP, evaluation by a primary care doctor may be prudent.

Stomach Bloating and Discomfort

Patients rarely complain about bloating or burping that occurs from CPAP. This can occur if patients swallow air during the night.  Air will then enter the stomach and GI system resulting in bloating, abdominal discomfort and excessive belching. This phenomenon appears to be more common in patients with acid reflux. Adjusting CPAP machine settings can help decrease the incidence of this rare event. New users of CPAP machines may also experience burping shortly after starting therapy until they get used to the air pressure from the machine.

Problems With CPAP Treatment

Mask Leaks

CPAP masks are constructed to leak out some air, so that exhaled carbon dioxide can be replaced by fresh air. So leaking can be a good thing. But sometimes too much of a leak can be a problem. If the mask is leaking excessively, the required air pressure might not be reached to properly treat the sleep apnea.  Several things can cause a CPAP mask leak. To avoid any leakage, patients should read the instructions carefully before using their mask (thankfully if you can’t find the instructions that came with the mask, they can usually be located online in no time). The looseness or tightness of the mask may also cause a leak. Trying on the mask and adjusting it in front of a mirror to get a good fit can go a long way. This can first be done with the machine turned off and then with the machine turned on to ensure an adequate fit. The mask should be snug but not too tight.  A discussion with a sleep specialist can help determine if the mask is leaking excessively (a “large leak”). Although small leaks do not restrict the equipment from producing the appropriate amount of air pressure, they might also make noise that can impact the quality of sleep. Machine adjustments may fix the problem but making changes is best left to the device providers or health care practitioner. This is essential not only because they are more familiar with the equipment, but because their changes will be more permanent. Changes that are made to the machine by anyone other than the doctor (who should coordinate changes with the DME) have the risk of reverting back to the original settings, through their remote connection with the DME.

Air Pressure Problems

Even after getting used to CPAP, excessive pressure can sometimes stimulate choking or suffocating. One way to alleviate this is using a machines pressure relief system which decreases pressure when breathing out. The “ramp-up” feature on most CPAP machines can also help. This adjusts the air pressure beginning from low to high over time until it is at the recommended settings for the patient. Ideally, the machine is at a relatively low pressure while falling asleep and only increases to higher pressures after falling fast asleep. This feature allows the patient to slowly adjust to the the air pressure. If machines lacks the ramp up feature or a patient cannot adjust to the air pressure, a doctor can suggest another mode of treatment.

Mask Removal

The greatest benefit from CPAP therapy comes when it is always used. However, a common complaint is that the mask gets removed during sleep.  Choosing a good fitting mask and adjusting humidifier settings can help. Alternatively, a chinstrap can be used to keep the mask firmly in the required position. Several machines have a built-in alarm for when the mask is taken off during sleep but this feature may disturb the sleep of bed partners.


While newer machines are quieter than older models, some noise is usually present. Some patients find that the CPAP machine creates a gentle and serene noise, while others find it unpleasant. In addition, air filters in the machine can become clogged, creating an unpleasant sound. If this occurs, the air filters may need to be washed and reinserted.

Living With CPAP

To fully benefit from CPAP therapy, treatment has to be maintained consistently. The best results are achieved if CPAP is used whenever and wherever sleeping is taking place. That includes during short naps and using CPAP every night even when on vacation. Machine and mask maintenance is vital to the long-term efficiency of CPAP. Masks and components of the CPAP machine should be replaced every 3 to 6 months. A sleep specialist can be very helpful in managing your long term care. These specialists can help to troubleshoot problems with your device and ensure that CPAP pressures are adequate, as the CPAP pressure requirements often change over time.

Maintaining the CPAP Machine

After receiving a CPAP machine, it is best to read through the user manual and understand how the machine works. Home equipment providers will often send over a technician to teach you how to use the device. Some components of the machine requires regular cleaning. The humidifier is one such part that may need to be cleaned daily for best results.

Repairs and replacement of parts may become necessary over the course of the treatment. The home equipment provider will be able to provide these services. Attempting to repair the machine without the guidance of the certified provider should be avoided. If there is a small opening in the machine that may seem like a defect, it may be there for the exhalation of air and maintaining a fresh air supply.

Other uses for CPAP

CPAP ventilation is used as a medical treatment for conditions other than sleep apnea. It is often used for hospital patients in respiratory distress, patients with respiratory failure, premature babies and in newborns who have labored breathing. PAP ventilation can sometimes be used instead of intubation, which is more invasive. It may also be helpful in critical care settings to facilitate earlier extubation. Patients with neuromuscular diseases such as ALS or Myasthenia gravis with compromised respiratory function may also benefit from CPAP.

Getting Ongoing Care

It is important to have open dialogue with your sleep specialist and home equipment provider. Some doctors may be able to suggest an experienced home equipment provider. Regular visits with a doctor every six to twelve months is purdent. These check-ups can monitor the effectiveness of CPAP treatment and troubleshoot any CPAP problems that arise.

CPAP is not the only treatment option available to patients with sleep apnea, and will not satisfy all sleep apnea patients. If CPAP does not work despite efforts to acclimate to it, your doctor may suggest alternative treatments such as an oral appliance or, possibly, surgery.


1. Principles and practice of sleep medicine. 5th ed. St. Louis:Elsevier/Saunders; 2010.
2. http://www.resmed.com/int/products/swift_fx/swift-fx.html?nc=patients
3. Picture 1, Picture 2, Picture 3