Shepard compares it to inflating a bicycle tube. CPAP usually brings immediate relief. A smooth breathing pattern is restored. Blood oxygen levels stabilize. During the first week of CPAP therapy, the sleep pattern may still be grossly abnormal, but with peaceful stretches of sleep gradually growing, as if the body is trying to catch up.
Sleep eventually settles down to a more normal pattern, often for the first time in years.
Unfortunately, many CPAP users never continue therapy beyond the first night, let alone the first week, because they find sleeping with a mask on the face uncomfortable. The typical approval process for any medical device involves the manufacturer submitting an application describing a product, and how it is similar to or different from devices that are already on the market. Newer CPAP devices cleared for marketing by FDA attempt to make the experience more pleasant by building air pressure slowly, moisturizing the air to stem the common complaint of dry throat, and filtering out dust and pollen. Choosing to live with a hole in the throat is a drastic measure, but several studies found that tracheostomy patients felt it was worth it to get complete relief from their apnea symptoms. Today, this procedure is used only in the most extreme cases, such as a person who cannot tolerate CPAP and who has severe hypertension with a high risk of heart failure due to apnea.