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About CPAP Continuous Positive Airway Pressure

Source: American Sleep Apnea Association

The American Sleep Apnea Association (ASAA) is dedicated to reducing injury, disability, and death from sleep apnea and to enhancing the well-being of those affected by this common disorder.

Choosing a CPAP

CPAP, or Continuous Positive Airway Pressure, therapy is the most common form of treatment for sleep apnea. There are several CPAP manufacturers that offer different types of machines with different features. Once you have been diagnosed with sleep apnea and have been prescribed CPAP therapy, you may be able to choose one machine among the many offered.

Talk to your physician and your home care company representative about which machine is best for you, and keep in mind any restrictions on cost and/or provider which your insurance company may impose. In deciding which CPAP machine to use, think about what features you want or need. Options include a carrying case, the ability to convert to foreign currents, an attached heated humidifier, ramping (which allows for a gradual increase in pressure), DC (direct current) operations via a car or boat battery, and the capability to adjust for different altitudes. Bi-level devices with two different pressures--one for inhalation and one lower pressure for exhalation--are also available. In addition, the Food and Drug Administration has recently approved a few auto-adjusting devices for the market; these machines are to change the pressure automatically as needed.

In addition to features, the mask fit will be critical to you. Again, talk to your physician and home care company representative about your choices, and keep in mind that the mask may be manufactured by one company and the CPAP by another. For more on this topic, read Choosing A Mask And Headgear, which appears below.

Just as there are several CPAP manufacturers that offer different types of machines with different features, there are different masks and headgear styles within manufacturers' lines. The mask may be manufactured by one company and the CPAP by another as virtually any mask will fit the standard air hose size (or can be adapted easily). It is also possible to have masks custom-made, so ask your doctor or home care company's representative about all options. Before selecting a mask, try using it with the CPAP machine and under the most realistic conditions possible (for example, turn from side to side while wearing the mask). As with any medical expense, keep in mind any restrictions on cost and/or provider your insurance company may impose.

If you have difficulty using CPAP that may be unrelated to the mask fit (such as nasal congestion), you may be interested in obtaining a reprint of the article "CPAP and the Nose" from the October-November 1995 WAKE-UP CALL The Wellness Letter for Snoring and Apnea. Contact the ASAA for ordering information, but don't hesitate to talk to your doctor about your situation.

CPAP is considered a generic term, not a brand name. As a non-profit organization, the American Sleep Apnea Association does not endorse or recommend any company or products.

Choosing a Mask and Headgear

Once you have chosen to use Continuous Positive Airway Pressure (CPAP) therapy, you will need to be fitted for a mask and headgear that is both comfortable and that provides a proper seal for the airflow. In fact, the proper air pressure level cannot be established unless the mask and headgear fit is correct. Thus to obtain the optimal benefits of CPAP treatment, it is essential that both mask and headgear fit well. Moreover, a comfortable mask that fits well will make using CPAP easier.

The hard plastic body and softer silicon seal of the mask are worn over your nose while the adjustable straps of the headgear hold the mask in place. Straps that are too loose will permit air to leak. In some cases, straps that are too tight can break the seal and create leaks; any strap pulled too tightly can cause pain. Headgear straps must be tight enough for a good fit in all sleeping positions (back, side, and front) but no tighter.

CPAP machines compensate for the "built-in leak" in the mask system that, by allowing for exhalation, keeps the air supply fresh. However, too much leaking reduces the set pressure. Masks that are too large tend to leak more easily than those that are snug, so as a rule of thumb, select the smaller size. If you extend your hosing, be sure the total length is less than twelve feet as longer hoses generally will not maintain the proper pressure. If you must use one that is longer, measure the pressure at the mask, not at the machine.

In cases of chronic nose, lip, or facial discomfort caused by repeated nightly use of the same mask, varying the style or type of mask can reduce site irritation. However, some insurance carriers resist paying for more than one CPAP mask, so purchasing additional masks may be an out-of-pocket expense.

Dry skin and facial hair can also compromise the effectiveness of CPAP masks. Skin moisturizers may help with the problem of dry skin, and although they slightly reduce the life of the mask, an improved facial seal may very well be worth it. As for facial hair, some masks are made with moustache and beard wearers in mind.

An allergic reaction to mask materials can also be a problem. If you are allergic to the silicone, ask for a mask made from synthetic rubber or vinyl. The nasal pillows may also be a solution to this problem as the pillows fit directly to the nostrils and do not rest on the nose, upper lip, or cheeks. In addition, some people, especially people with a beard or moustache, simply prefer the nasal pillows to the triangular mask.

Ask the Doctor

[Reprint from: Wake-up Call: The Wellness Letter for Snoring and Apnea, from the American Sleep Apnea Association]

Can using the CPAP machine for a prolonged period of time be too much for your body? Is there an average age when sleep apnea is diagnosed? Are females less frequently affected? - JoAnn Marti, Orlando, FL

Using CPAP even for prolonged sleep periods is not associated with any detrimental effects. Just the opposite: CPAP is protective for the apnea patient, preventing the low oxygen levels and arousals that accompany apnea events. When it comes to a properly prescribed CPAP system, you can't get too much of a good thing.

As for your other questions, sleep apnea can be seen in infants as well as the elderly. However, apnea is most often recognized in middle-aged adults [30-60 years]. Frequently, the emergence of apnea is preceded by a history of ten or more years of noticeable snoring.

As a woman with sleep apnea, you are not alone. Current epidemiologic studies indicate that in middle-aged adults the ratio of men to women with apnea is 3:1.

What are the positive and negative aftereffects of laser surgery to relieve obstructive sleep apnea? - T.M., Mesa, Arizona

Laser-assisted uvulopalato-pharyngoplasty is currently being recommended by some physicians as a treatment for obstructive sleep apnea. There are no well-controlled studies in the medical literature that support the fact that this type of surgical intervention is effective for the treatment of this condition.

Laser surgery may, however, be useful in the treatment of snoring. Its benefits include that it can be performed without a hospitalization, in an out-patient clinic. Frequently, one to five visits are required by the otolaryngologist performing these procedures.

The negative effects of this surgery may be related to one or all of the following:

  1. The surgery may not work
  2. The surgery, despite the claim of some otolaryngologists, can result in significant postoperative pain.
  3. While snoring may be diminished or eliminated, upper airway obstruction may occur without the warning signs of loud, irregular snoring in the affected individual.
  4. Finally, some surgeons feel that previous laser surgery may complicate performing a subsequent conventional uvulo-tonsillectomy due to scarring related to the laser procedure.

After beginning CPAP, I developed problems from nasal restriction. l have since had an operation to open my nasal passages which vastly improved the uses of CPAP. Is there any study to indicate a nasal restriction causes sleep apnea? I have also heard laser surgery is used to firm up restrictive throat passages. Is this successful? - Edward Meyers, Allan, PA

In the vast majority of cases, sleep apnea is not caused by discrete anatomic problem such as nasal restriction. However, in certain patients an isolated anatomic abnormality may cause sleep apnea. A few studies have been published on this topic. Therefore, a careful examination of the nose and oral cavity is always indicated in patients with sleep apnea.

For patients on CPAP via a mask, identifying and treating nasal restriction is especially important. If the restriction is allergic in nature, treatment with nasal steroid sprays can be particularly effective. If this does not work, surgery may improve nasal airflow and comfort with the mask.

Laser surgery is currently being advertised as treatment for snoring and has been performed in patients with mild sleep apnea. There are few published results, but what data are now available suggest this procedure is no better than conventional uvulopalatopharyngoplast for mild sleep apnea.

Dr. Patrick Strollo, associate director of the Pulmonary Sleep Evaluation Center at the University of Pittsburgh Medical Center, answers Ask the Doctor questions. Please send your questions to ASAA, 2025 Pennsylvania Avenue, NW, Suite 905, Washington, DC 20006. We regret that the volume of mail makes personal replies impossible.