This type of device is commonly referred to as BiPAP, so this article uses that name as it's more familiar. The medical term for a two-level pressure device is bilevel positive airway pressure, or BPAP. This type of device separates the pressure during inhalation and exhalation.^[1] Unlike continuous positive airway pressure (CPAP) machines, which deliver a consistent, single pressure level as determined in a treatment plan.^[1]

Simply put, BiPAP has two pressure levels, while CPAP has a single, continuous pressure level. However, this difference doesn't mean BiPAP is better for everyone. This article will help you understand the principles and prepare questions to ask your healthcare team, but it shouldn't be used as a substitute for diagnosis, and you shouldn't use it to choose a machine or set the pressure yourself.

What is BiPAP?

BPAP stands for bilevel positive airway pressure, meaning it uses two levels of pressure: one level to assist during inhalation and another level during exhalation.^[1,6] This device belongs to the positive airway pressure (PAP) therapy group, just like CPAP.

In medical documentation, you may encounter the term "bilevel PAP," which refers to the same type of device. The name only indicates the pressure pattern; it doesn't specify what condition you have or which type of device you should use. If the cause of your symptoms is unknown, you should start with an evaluation.

What are inspiratory pressure airway pressure (IPAP) and expiratory pressure airway pressure (EPAP)?

Inspiratory positive airway pressure (IPAP) is the pressure the machine delivers during inhalation, while expiratory positive airway pressure (EPAP) is the pressure the machine delivers during exhalation.^[6]

Another frequently encountered term is noninvasive ventilation (NIV), which in this article refers to positive pressure ventilation without inserting a tube into the trachea. Generally, the machine delivers pressure through a mask that covers the nose, or both the nose and mouth.^[6,7]

Two other terms to know are chronic alveolar hypoventilation (CAH) and the stable phase. Chronic alveolar hypoventilation (CAH) refers to persistently insufficient breathing for an extended period, while the stable phase refers to a period when the condition is not deteriorating or experiencing an acute exacerbation. For individuals with chronic alveolar hypoventilation in the stable phase, the medical team will select the appropriate mask and pressure to suit their individual needs.^[6] These terms are meant to help you read documents and communicate with the healthcare team, not to be used to make up your own numbers.

How does BiPAP differ from CPAP?

CPAP delivers a continuous, single pressure level as predetermined in the treatment plan, while BiPAP separates the pressure during inhalation and exhalation.^[1] This is simply a difference in how pressure is delivered, so it's not enough to determine which machine is better for you.

The diagram compares a CPAP machine that delivers a continuous, single pressure level with a BiPAP/BPAP machine that separates pressure during inhalation (IPAP) and exhalation (EPAP), without showing numerical values or suggesting manual settings. — CPAP and BiPAP/BPAP differ in their pressure delivery methods, but this difference isn't enough to determine which machine is more suitable for each individual. The healthcare team must assess and configure the settings appropriately.^[1,6]

For the treatment of obstructive sleep apnea (OSA) in adults, the American Academy of Sleep Medicine (AASM) conditionally recommends that physicians should choose CPAP (auto-adjusting positive airway pressure) machines over BPAP, and specifies that diagnosis should be made through appropriate sleep studies and follow-up should be conducted after the start of treatment.^[2]

The term "conditional recommendation" sounds like technical jargon, but in simple terms, it's not a hard and fast rule. Doctors still need to consider each individual's case, and it doesn't mean BiPAP is prohibited.^[2] In some adult patients with OSA, physicians may consider BiPAP when a higher therapeutic pressure of over 20 centimeters of water (cm H₂O) is required, which conventional CPAP machines often cannot deliver, or when the patient cannot tolerate the high pressure of CPAP/APAP even after the medical team has helped resolve the issue and used an expiratory pressure reduction system.^[2] These numbers are for physicians to use as a guide, not values to be set on the device yourself. Having OSA (Obstructive Sleep Apnea) or loud snoring does not automatically make BiPAP the first choice. Physicians must consider test results, symptoms, comorbidities, and follow-up data. For more basic information, please see... What is CPAP?

How does BiPAP differ from CPAP?
Issue	CPAP	BiPAP/BPAP
Pressure pattern	Maintain a constant, single pressure level as specified in the treatment plan.^[1]	Separate the pressure during inhalation and exhalation.^[1]
The role of OSA treatment in adults in general.	The AASM has made a conditional recommendation that physicians should choose CPAP or APAP over BPAP.^[2]	It is not automatically the first choice for OSA in adults in general.^[2]
Things you shouldn't do	For OSA in adults, patients should not select modes or adjust pressure themselves. The healthcare team should monitor and help resolve the problem.^[2]	For chronic shallow breathing in the stable phase, do not adjust IPAP/EPAP yourself. This should be done by a trained team.^[6]

In what cases might a doctor consider BiPAP?

Doctors won't choose BiPAP based on a single symptom, but will consider the underlying condition, test results, what the machine needs to help with, and how the results will be monitored. Therefore, feeling uncomfortable with CPAP doesn't necessarily mean BiPAP is the next step.

Obstructive sleep apnea (OSA)

For the treatment of OSA in adults, the AASM generally recommends, conditionally, that physicians should choose CPAP or APAP over BPAP.^[2] If you experience discomfort while using CPAP, or if the machine's data isn't meeting your expectations, your healthcare team should investigate the cause before deciding to switch machines. For a small number of patients, your doctor may try BiPAP when the required pressure exceeds the limits of CPAP/APAP, or when you still cannot tolerate the high pressure even after your healthcare team has helped resolve the issue and used an expiratory pressure reduction system.^[2]

Obesity hypoventilation syndrome (OHS)

Obesity-related shallow breathing (OHS) requires examination and evaluation by a doctor; it cannot be judged based solely on weight, drowsiness, or snoring. The American Thoracic Society (ATS) explains that treatment plans may involve CPAP or NIV with two pressure levels, with the doctor choosing the most suitable option for each individual.^[1]

Chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) requires separate care for exacerbations from long-term care. During exacerbations, the UK's National Institute for Health and Care Excellence (NICE) states that physicians may use NIV (Non-Invasive Intensive Care) when carbon dioxide buildup and blood acidosis do not improve despite appropriate treatment. This care must be provided in a well-equipped facility by trained and experienced personnel.^[3]

For COPD patients with chronically elevated and stable blood carbon dioxide levels, ATS (Acute Rapid Transits) conditionally suggests that physicians may consider nocturnal NIV (Non-Invasive Medicine) in conjunction with routine treatment.^[4] For patients hospitalized due to disease exacerbation with respiratory failure and carbon dioxide retention, the same guidelines suggest that long-term NIV should not be initiated during the hospitalization, but rather the treatment team should reassess 2 to 4 weeks after the acute phase has subsided.^[4]

Therefore, having COPD does not mean everyone needs to use BiPAP. The doctor will choose the type of device, mode, and NIV settings based on each individual's situation. Patients should not start or adjust the treatment themselves.

OSA, OHS, and COPD mentioned above are just examples, not a self-diagnostic checklist. If a patient with COPD experiences a severe flare-up and difficulty breathing, seek emergency medical assistance immediately. Do not wait to adjust the breathing apparatus at home.^[3]

How should BiPAP be evaluated, set up, and monitored?

Before using BiPAP, the healthcare team must clearly understand what they are treating and what the device is intended to help with. For OSA in adults, diagnosis should be made through appropriate tests, and outcomes should be monitored after starting PAP.^[2] NIV adjustment in patients with chronic shallow breathing during the stable phase should be performed by a trained team with ongoing monitoring.^[6]

Before starting or changing a plan, prepare the following information for the medical team to review. Do not use it to select equipment or configure settings yourself.^[2,6]

Sleep study results, breathing test results, or documents used by a doctor for diagnosis.
List of pre-existing medical conditions, medications, ventilators, and oxygen currently being used.
Machine model, mode, and current values as per prescription or treatment plan.
Data from the device, such as usage hours, mask leaks, and events reported by the device.
Symptoms or problems that occurred after starting to use the product, along with the time they occurred.

For patients using NIV due to chronic shortness of breath in the stable phase, a trained team should monitor the use of the device, side effects, breathing, and oxygen levels.^[6] This guideline does not cover COPD patients and is not a criterion for who should start NIV.

The medical team may check for mask leaks, dryness, nasal congestion, and overall comfort while using the device.^[6] If you encounter a problem, note down what happened and when it occurred, and discuss it with the support team. Do not adjust the device settings or modes yourself.

For patients using NIV due to chronic shortness of breath during the stable phase, the medical team will assess oxygen levels separately from the machine, and not everyone requires oxygen.^[6] If your doctor has prescribed oxygen, connect the device and use the prescribed flow rate. Do not connect, increase, or change the flow rate yourself.

Limitations of BiPAP that you should know before expecting results.

For the treatment of OSA in adults, BiPAP is generally not the automatic first choice.^[2] For patients using NIV due to chronic shortness of breath during the stable phase, continuous monitoring by a trained team is required.^[6] Therefore, one should not expect the same results for everyone, nor believe guarantees that using it will definitely improve sleep, reduce fatigue, stop snoring, or prevent complications.

BiPAP is not a diagnosis and should not be chosen based on symptoms alone. For the general treatment of OSA in adults, the AASM also provides conditional recommendations that physicians should choose CPAP or APAP over BPAP.^[2]
For patients using NIV due to chronic shortness of breath during the stable phase, the medical team must monitor data from the device, side effects, breathing, oxygen levels, mask leaks, and discomfort.^[6]

Both the symptoms and the data from the device should be discussed with the support team. Deciding to replace the device or adjust settings based on only one side of the information is insufficient.

Before making a decision, what questions should you ask the medical team?

These questions will help you understand the treatment plan more clearly.

What was my diagnosis, and which test results were based on it?
What does the machine help with, such as opening the airway or helping with adequate breathing?
Why do doctors choose CPAP, APAP, BiPAP, or another method?
Who sets and reviews IPAP settings, EPAP settings, modes, and associated devices?
When should I follow up, and what information should I bring?
If your mask leaks, you feel uncomfortable, have dry mouth, or can't sleep, who should you contact, and what can you do safely while waiting?
What symptoms warrant an earlier appointment or require emergency assistance?
After a doctor confirms that it's necessary, you should check the details regarding the device, masks, warranty, and services.

The selection of a supplier concerns equipment and services, while diagnosis and treatment selection are the doctor's responsibility. These two aspects should be separated.

Frequently Asked Questions about BiPAP

Why does this article use both the terms BiPAP and BPAP?

This article uses the term BiPAP in its title because it is a term familiar to readers. BPAP stands for bilevel positive airway pressure, meaning a device that separates the air pressure during inhalation and exhalation.^[1,6] In medical texts, the terms BPAP or bilevel PAP are frequently encountered.

Is BiPAP better than CPAP?

One machine isn't always better than the other. The right machine depends on the problem being treated. For adults with obstructive sleep apnea (OSA), the American Society for Sleep Medicine guidelines prioritize CPAP (automatic pressure booster) over BPAP (biPAP), but this is a recommendation that a doctor must consider based on each individual case.^[2] A doctor may consider BiPAP when the required pressure exceeds the limits of CPAP/APAP, or when the high pressure cannot be tolerated even after the medical team has helped to resolve the issue and used an expiratory pressure reduction system.^[2]

Should I use a BiPAP if I only snore?

BiPAP should not be chosen based solely on snoring. Positive airway pressure (PAP) treatment should begin with a proper diagnosis and evaluation.^[2] If snoring is accompanied by other abnormal symptoms, it's better to note down the information and discuss it with your doctor instead of choosing a snoring device yourself.

Can I configure BiPAP myself?

Intra-endotracheal pressure (IPA), expiratory pressure (EPAP), mode, or other settings should not be manually adjusted for individuals using non-invasive ventilation (NIV) due to chronic shallow breathing during the stable phase. A trained team must monitor treatment goals, respiration, oxygen levels, symptoms, and data from the device.^[6] Chronic shallow breathing refers to persistently insufficient breathing for an extended period. A stable period is when symptoms are not deteriorating or acutely worsening. For other diseases or situations, a specific approach must be adopted.

If you find CPAP uncomfortable, should you switch to BiPAP yourself?

You shouldn't change it yourself. For adults with obstructive sleep apnea (OSA), your doctor may try BiPAP in some patients when they cannot tolerate the high pressure of CPAP, even after the treatment team has helped resolve the issue and used an expiratory pressure reduction system.^[2]

Does everyone using BiPAP also need to use oxygen?

No, for individuals using non-intubated ventilation (NIV) due to persistently insufficient breathing and in a stable condition, the medical team will assess oxygen levels separately from mechanical ventilation, and not everyone requires oxygen.^[6] Do not connect oxygen or change the flow rate yourself.

If using BiPAP, what information should I bring with me when I go for a follow-up appointment?

Bring your test results, previous treatment plan, data from the device, and symptom logs. If positive airway pressure (PAP) is being used to treat obstructive sleep apnea (OSA) in adults, follow-up after the start of treatment is recommended.^[2] For patients using non-intubated ventilation (NIV) due to chronic shallow breathing in the stable phase, monitoring of machine use, side effects, respiration, and oxygen levels is necessary.^[6]

summarize

BiPAP, or BPAP in medical terms, is a positive pressure device that separates the pressure during inhalation and exhalation.^[1,6] CPAP machines deliver a continuous, single pressure level. The difference in pressure patterns doesn't mean one machine is suitable for everyone.

For OSA in adults, the AASM generally provides conditional recommendations that physicians should choose CPAP or APAP over BPAP, but individual cases still need to be considered.^[2]

For OHS, the physician must first confirm the diagnosis before considering a 2-level pressure CPAP or NIV system suitable for each individual.^[1] In the case of COPD, the exacerbation period and the stable period are different situations.^[3] In patients with chronically and persistently elevated blood carbon dioxide levels, ATS (Acute Rapid Intravenous Thrombocytopenia) is conditionally suggested, and physicians may consider nocturnal NIV (Non-Invasive Vitro Fertilization) in conjunction with routine treatment.^[4]

The safe procedure is to discuss your test results, original treatment plan, data from the device, and symptoms with your treatment team. Clearly ask about the specific condition, how the device should assist, who configured the settings, and when follow-up will be conducted. Do not change the device, mode, pressure, or add oxygen yourself based on the information in this article.

What is BiPAP, how does it differ from CPAP, and when should doctors consider using it?