Doctors prescribe BiPap machines, also called bilevel CPAP machines, for patients who have trouble breathing at night. A BiPap machine includes a component that generates pressure, some tubing, and a mask that the patient puts over his or her face when going to bed. During sleep, the machine uses pressure to move air into the lungs and keep them open so the patient can best use the oxygen taken in.
The typical user of a BiPap machine is a patient who has used a CPAP machine at night but needs more breathing assistance or greater comfort than a CPAP provides. The CPAP machine also includes a unit that provides steady air pressure plus the tubing and mask found with a BiPap. The main difference between the machines is that, while the CPAP focuses on inhalation pressure and can pose a challenge for breathing out against the pressure, the BiPap offers more pressure adjustability to make both breathing in and out more comfortable.
The BiPap machine works by producing positive pressure for breathing in and a separate positive pressure for breathing out. If a patient using a CPAP machine needs a high pressure setting for overnight breathing, he or she will be exhaling against a fairly high pressure because of the design of the machine. For some CPAP patients, a high exhalation pressure is too much to manage.
By using a BiPap machine instead, a patient can still set his or her inhalation pressure as high as needed, but the exhalation pressure automatically is lower to make breathing out easier. On some BiPap machines, the prescribed exhalation setting can be changed to adjust the exhalation pressure even lower. This can provide additional ease and comfort during nighttime exhalation.
Before prescribing a BiPap, typically, a doctor orders a sleep study to understand why a patient is not breathing properly at night. The causes can include obstructive sleep apnea, chronic obstructive pulmonary disease, coronary artery disease, or heart failure. Once the cause of difficult nighttime breathing is discovered, a doctor recommends pressure settings to be used with the BiPap machine at home.
A variety of BiPap machines are on the market. Some adjust automatically while the patient sleeps. Some add humidity to help with dry nose and throat symptoms, which can be caused by the moving air of these machines. A few machines offer digital tracking of breathing data and alarms in case of machine failure.