CPAP stands for "continuous positive airway pressure." CPAP is a treatment that delivers slightly pressurized air during the breathing cycle. This keeps the windpipe open during sleep and prevents the episodes of blocked breathing in persons with obstructive sleep apnea and other respiratory problems.

WHO SHOULD USE CPAP

Continuous positive airflow pressure (CPAP), sometimes referred to as nasal continuous positive airflow pressure (nCPAP) is the best treatment for obstructive sleep apnea. It is safe and effective in sleep apnea patients of all ages, including children.

• After using CPAP regularly many patients report the following:
• Normal sleep patterns.
• Feeling more alert and less sleepy during the day
• Less anxiety and depression and better mood.
• Improvements in work productivity.
• Better concentration and memory.
• Improved sleep of a patient's bed partners.

A similar machine, called BiPAP (for bilevel positive airway pressure) is used as an alternative to CPAP.

These devices are useful for children with collapsible airways, small lung volumes, or muscle weakness that make it difficult to breathe.

CPAP or BiPAP may also be used for those who have acute respiratory failure, central sleep apnea, heart failure, or COPD.

HOW CPAP WORKS

CPAP works in the following way:

• The device itself is a machine weighing about 5 pounds that fits on a bedside table.
• A mask fits over the nose. A tube connects the mask to the CPAP device.
• The machine delivers a steady stream of air under slight pressure through this tube into the mask.

The doctor, nurse, or therapist will help choose the mask that fits you best. They will also help adjust the settings on the machine. The settings on the CPAP machine depend on the severity of your sleep apnea.

If you are using the CPAP machine, but your sleep apnea symptoms does not improve, the settings on the machine may need to be changed. Some patients can be trained to adjust the CPAP at home. Otherwise, you will need to make trips to the sleep center.

GETTING USED TO THE DEVICE

It can take time to become used to a CPAP device. The first few nights of CPAP therapy are often the most difficult. Some patients may actually sleep less or not sleep well at the start of treatment.

The patients who are having problems may tend not to use it for the entire night, or even stop using the device. However, it is important to use the machine for the entire night.

Common complaints include:

• Nasal congestion and sore or dry mouth
• Nosebleeds
• A feeling of feeling being closed in (claustrophobia)
• Irritation and sores over the bridge of the nose.
• Eye irritation
• Upper respiratory infections
• Chest muscle discomfort, which usually goes away after awhile

Many of these problems can be helped or eliminated by using a mask that is lightweight and cushioned. Some masks are used only around the nostrils. Chin straps, nasal salt water sprays, or humidifiers may also prevent side effects. Modern CPAP machines have many adjustments that can be made to make them more comfortable.

Basner RC. Continuous positive airway pressure for obstructive sleep apnea. N Engl J Med. 2007 Apr 26;356(17):1751-8.

Weaver TE, Maislin G, Dinges DF, Bloxham T, George CF, Greenberg H, et al. Relationship between hours of CPAP use and achieving normal levels of sleepiness and daily functioning. Sleep. 2007 Jun 1;30(6):711-9.

Patel NP, Ahmed M, Rosen I. Split-night polysomnography. Chest. 2007 Nov;132(5):1664-71.