What Is Bi-Level Positive Airway Pressure (BiPAP) Therapy?

What is BiPAP, when is it used for COPD, what are the benefits, and how does it compare to CPAP?What is BiPAP, when is it used for COPD, what are the benefits, and how does it compare to CPAP?
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In This Article

Bi-level positive airway pressure (BiPAP) is a type of noninvasive ventilation that helps keep the upper airways of the lungs open by providing two levels of pressurized air delivered through a face mask. If you have a medical condition that affects the lungs, your doctor may recommend that you start using BiPAP to breathe easier and reduce the burden on your lungs, heart, and airways.

While most often recommended for use at night, as that is when breathing can be particularly challenged, BiPAP may be used during waking hours as well, if needed.

Purpose of BiPAP

The process of normal breathing (respiration) involves the lungs and diaphragm. When the diaphragm contracts, the lungs expand and take in air (inhalation). When the diaphragm relaxes, the lungs contract and push air out of the body (exhalation). Several medical conditions can interfere with this process and make it hard for you to breathe, especially when sleeping. In particular, this is often seen in people with COPD, obstructive sleep apnea, or obesity.

At night, weakened throat muscles can collapse, worsening the airway obstruction that may be already occurring. When this happens, it can be hard for patients to keep their airways open enough to keep their oxygen saturation levels up, and at the same time keep their carbon dioxide levels in their blood down (avoiding hypercapnia, or CO2 retention).

BiPAP can help with respiration by delivering constantly pressurized air. This decreases the work that must be done for adequate gas exchange of oxygen and carbon dioxide to take place in the alveoli, air sacs within the lungs.

It's thought that it may also help by allowing already weakened respiratory muscles to relax for a period of time at night.


Conditions that may benefit from BiPAP use include:

  • Chronic obstructive pulmonary disorder (COPD)
  • Obesity hypoventilation syndrome
  • Sleep apnea
  • Asthma flare-up
  • Pneumonia
  • Poor breathing post-operation
  • Neurological conditions that affect respiration

BiPAP can make a positive difference in life expectancy and has been found to significantly reduce the risk of death from certain conditions and diseases.

The use of BiPAP for COPD, for example, when indicated, may reduce the number of COPD exacerbations someone experiences and may decrease the need for mechanical ventilation (respirator support).

BiPAP may also be used as a transitional tool for people coming off of other breathing support methods.


If you are in severe need of breathing support, a BiPAP may not be effective for your condition. You may need supplemental medical oxygen, a mechanical breathing tube inserted into your throat, or a tracheostomy—a procedure that creates an airway in your windpipe (trachea).

How It Works

A BiPAP machine continuously pushes air into your lungs using positive air pressure on inhalation and exhalation.

The air is pressurized to force your lungs to open up without a lot of reliance on the body to help, then delivered to a face mask through long, plastic tubing.

The air may be pressurized at two different levels:

  • A higher pressure is used when breathing in (called inspiratory positive airway pressure, or IPAP).
  • A lower pressure is used when breathing out (called expiratory positive airway pressure, or EPAP).

These unique levels are determined by your doctor or pulmonologist.

In contrast to a BiPAP, continuous positive airway pressure (CPAP) provides air at the same amount of pressure on both inhalation and exhalation. Your doctor will help determine whether you'd benefit more from BiPAP or CPAP.

BiPAP machines used to be only accessible via in-patient services in hospitals, but are now available to purchase for at-home use (as are CPAP machines).

Risks and Contraindications

Using a BiPAP machine usually has very few risks. There may be some minor side effects, including:

  • Slight skin irritation from wearing the face mask
  • Dry mouth and/or dry nasal passages
  • Sinus congestion or pain
  • Eye irritation
  • Mild stomach bloating

If the mask is ill-fitting, leakage may occur, resulting in less air pressure being administered. This, of course, can make treatment less effective.

There is also a small chance of infection developing, but the risk is minimal compared to using other mechanical ventilation procedures.

BiPAP should not be used in people who are medically unstable, have a current infection, or are at risk of serious infection.

Choosing Your Machine

Work with a medical equipment professional to help you pick a mask and machine that best fit your unique needs. You'll need to decide if you want a full-face mask or simply a nasal mask or nasal plugs, and you'll also need to have the mask fitted to avoid leaks. The mask should form a tight seal around your nose and/or mouth, but not be too tight.

If information on proper care and cleaning techniques are not offered to you, it's worth asking for instructions.

Cost and Health Insurance

The cost of a BiPAP machine may vary, with lower-end models running around $800 to higher-end machines costing upwards of $2,800. Prices vary depending on which features and add-ons are included, such as a heated humidifier attachment, Bluetooth connectivity, etc. Face masks and air humidifiers are often sold separately, which can run anywhere from $40 to $160.

There's also the option to purchase cleaning supplies, a sterilizer unit, and travel cases, which could add several hundred dollars to the cost of the machine and face mask. You'll also need to regularly buy distilled water if you're using a humidifier, which is available in most drugstores and about $1 a gallon.

Luckily, most insurance plans—including Medicare—cover PAP therapy, whether CPAP or BiPAP, so you'll only likely be paying out of pocket for any extras you choose to buy. You'll need a prescription for a BiPAP machine in order for it to be covered under your insurance, though you don't need a prescription to buy a machine if you're covering the cost yourself.

Some insurance companies cover PAP therapy for just the first three months, or longer if recommended by your doctor.

Renting a machine may be a good option to look into and, in fact, some insurance companies may require you to rent a BiPAP machine for a certain period of time from a medical supply company before purchasing one outright. Additionally, check around for refurbished machines, which are certified to be in excellent working order (and cost a fraction of the price of new machines).

Before Use

Prior to use, a respiratory therapist or doctor from your healthcare team will calibrate the machine and check the pressure levels. Your provider will also tell you if you need to wear the BiPAP machine only while sleeping or at other times during the day.

At first, wearing a nose or face mask to sleep may feel awkward and the pressurized airflow may feel strange, but you'll slowly get accustomed to it.

If you feel like you can't breathe while wearing the BiPAP mask, speak with your provider about adjusting the pressure levels. If the noise of the machine keeps you awake at night, earplugs may be helpful.

Follow-up and Other Considerations

After starting on a BiPAP machine, check-in with your doctor regularly to monitor how your condition is progressing. If things are improving, you may be able to reduce the air pressure on either inhale or exhale or both.


For COPD patients, BiPAP is the preferred method of treatment over CPAP (continuous positive airway pressure) because it's easier for these patients to exhale against the lower pressure. It can be difficult for anyone to exhale against pressure (this is why BiPAP is sometimes used instead of CPAP for sleep apnea), but this can be particularly difficult with COPD, in which exhalation is more of a problem than inhalation. BiPAP also allows for adjustments in time, which is very helpful for those with COPD in which exhalation is slowed.

A Word From Verywell

BiPAP is a noninvasive treatment method that can make a world of difference for many people with sleep apnea, COPD, and other conditions, although it might not be helpful for everyone. It shouldn't be used if you have a weakened immune system, low blood pressure, severe acidosis (low blood pH) or a rapid heart rate (tachycardia). Talk to your doctor about whether BiPAP is right for you.

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Article Sources

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