Sleep apnea is a common condition affecting more than 12 million Americans, according to the National Institutes of Health. People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer.
The vast majority of cases remain undiagnosed and therefore untreated, despite the fact that this disorder can have significant consequences. Left untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, impotency, and headaches. Moreover, it may be responsible for job impairment and motor-vehicle crashes. Fortunately, sleep apnea can be diagnosed and treated.
Several treatment options exist, the most common of which is continuous positive airway pressure (CPAP) therapy. A CPAP machine is usually about the size of a shoebox but can be smaller. A flexible tube connects the machine with a mask or other interface device that is worn over the nose and/or mouth.
CPAP works by gently blowing air through the airway at a pressure high enough to keep the throat open. The pressure is set according to the patient’s needs at a level that eliminates the apneas that cause awakenings and sleep fragmentation.
Choosing a CPAP Unit
Because CPAP is a medical device, all units must have U.S. Food and Drug Administration (FDA) approval before they can be sold, and you must have a physician’s prescription in order to obtain a CPAP.
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. A CPAP, typically covered by insurance as a durable medical equipment benefit, is most often rented or purchased through a home health care company.
CPAPs may also be purchased over the Internet. However, before buying a machine, it is generally a good idea to rent one first (on a rent-to-own plan if possible) for several weeks to make sure that the machine has all the features you need, and to determine if it is working as it should.
Talk to your doctor and your home care company representative about which machine is best for you and your lifestyle. Keep in mind that some insurance companies will cover only certain types of CPAP devices. In deciding which machine to use, think about what features you want or need. Options may include the capability to adjust for different altitudes, a heated humidifier, ramping (which allows for a gradual increase in pressure), and DC (direct current) operations via a car or boat battery.
Bi-level devices with two different pressures —one for inhalation and a lower pressure for exhalation — are also available. In addition, the FDA has approved some auto-adjusting devices for the market; these machines are designed to sense varying pressure needs as you sleep and to change the pressure automatically as needed.
The latest type of machine to receive FDA approval is equivalent to a CPAP with continuous or constant pressure for inhalation, but with flexible lower exhalation levels. The exhalation pressure is determined partly by the machine, which responds to the user’s exhalation patterns, and partly by the user, who selects one of three settings.
More sophisticated machines with higher costs are not always automatically covered by insurance but may be covered with a specific physician prescription and documented failure to respond to standard CPAP treatment.
Some machines can monitor how often you use the CPAP, while others can record any apneas that occur while using the machine (which may indicate a need to adjust the pressure). Your doctor may want to download this data periodically to verify the adequacy of your treatment, and the compliance monitor can also be an important feature if you need an objective verification that you are obtaining sufficient amounts of sound sleep.
Choosing a Mask
Once you have been prescribed CPAP therapy, you will need to be fitted for a connection to your nose and/or mouth, along with tubing and headgear. The mask is attached to tubing that, when connected to the CPAP machine, delivers the pressurized air that prevents apneas from occurring.
It is very important that the mask is comfortable and provides a proper seal for the air flow; the proper air-pressure level cannot be established unless the fit is correct. Moreover, a comfortable mask that fits well will make using CPAP easier.
Most masks are triangular in shape and worn over the nose (or the nose and mouth, with a full-face mask for mouth breathers) while the adjustable straps of the headgear hold the mask in place. Headgear straps must be snug enough for a good fit in all sleeping positions (back, side, and front), but not tight. If you breathe through your mouth, you may also want to consider using a chin strap to help keep your mouth closed or a mask designed for mouth breathers.
CPAP machines compensate for a ‘built-in leak’ in the system, usually near the exhalation port of the mask, that is necessary to keep the air supply fresh. One mask includes over its exhalation port a small plastic piece filled with sound-absorbing material that muffles the sound and dissipates or spreads the exhalation flow that may bother a bed partner.
Too much leaking, though, may occur if the mask does not fit properly; excessive leaking reduces the set pressure and must be corrected (not to mention that leaks can irritate your eyes). Masks that are too large tend to leak more easily than snug ones, so as a rule of thumb, if in doubt, select the smaller.
Many masks have a hard plastic body and softer silicone seal that touches the face and may have varying features. For example, a mask may include an adjustable pad that rests on the forehead. The seal may inflate once the machine is turned on, so the straps do not need to be as tight. If the mask has a lower profile and does not sit too high at the nose’s bridge, it can typically accommodate eyeglasses better.
Another new mask that works only with a specific headgear has inside the silicone seal a soft, foam-like material with memory for facial contours. This mask also includes a thin plastic piece that glides from side to side across the mask as the person moves in sleep: this is to allow the headgear, but not the mask, to move with the user and alleviates mask leaks.
Some triangular masks have two openings or connection ports so, when necessary, oxygen can be used with the CPAP machine. If allergic to silicone, try a mask made from materials like synthetic rubber or vinyl. In addition, several masks now on the market are made out of a gel-like material. They are intended to mold to each person’s face in order to alleviate pressure points and to be more comfortable. However, because some of these masks are larger and heavier than traditional types, some people find them less comfortable. Another mask has an inflatable cushion that lets the wearer adjust the fit and prevent leaks.
A more recent variation of the gel-type masks, marketed as one-size-fits-all, has a soft, flexible shell and gel cushion with a pliable wire molded into the shell that allows the mask to be shaped to adjust for individual differences.
In addition to the masks described above — the standard mode of CPAP delivery — an oral mask, designed for mouth breathers, is now available. This delivers the pressurized air through the mouth, and while it uses no headgear, it requires heated humidification. Because the mask touches only the skin around the mouth, it can also accommodate eyeglasses. Not all patients can use this mask; for example, people who grind their teeth and some people who have had surgery for sleep apnea are not good candidates.
Nasal pillows are another option. Instead of wearing a triangular mask, the user inserts into the nostrils two small flexible pieces (shaped somewhat like mushroom caps) that are attached to a plastic adapter that is in turn attached to the tubing. However, people with higher pressures sometimes experience discomfort with the pillows.
Another new interface that is not a mask instead has two tubes that fit snugly inside the nostrils. No headgear is necessary — and hence this interface can also accommodate eyeglasses — as the tubing loops from the nose around the ears. The two tubes join together near the chest and then, as one tube, attach to the CPAP. There is also a strap that goes behind the head to keep the tubing around the ears in place.
Before selecting any interface, try using it with the CPAP on and under realistic conditions (for example, lying down and moving from side to side). The wearer should be happy with the fit. If you have discomfort with any mask, try other ones. However, keep in mind any restrictions on cost and/or provider your insurance company may impose.
This article was prepared by the American Sleep Apnea Assoc.