What is the Difference Between CPAP and BiPAP?

There is one major difference between CPAP and BiPAP: CPAP machines are set at one single pressure while BiPAP machines are programmed with two distinct pressures—one for inhaling and one for exhaling. CPAP machines are primarily used to treat Obstructive Sleep Apnea (OSA) while BiPAP machines are used to treat Central Sleep Apnea, Complex Sleep Apnea, or COPD.

CPAP Machine: A CPAP machine only delivers therapy air to the wearer at one specific pressure and doesn’t vary unless manually changed by a sleep doctor. A CPAP machine pushes the same amount of air pressure throughout the night and is used to treat most cases of OSA.

BiPAP Machine: A BiPAP can be programmed to have two different values of air pressure: one for inhaling and one for exhaling. These are respectively called Inspiratory Positive Airway Pressure (IPAP) and Expiratory Positive Airway Pressure (EPAP). BiPAP therapy pressures are usually higher for inhale and lower for exhale. The lower pressure on the exhale can make it more comfortable to breathe ou

What Makes BiPAP Different from CPAP?

For the most part, CPAP machines have been the go-to treatment for obstructive sleep apnea. CPAP machines deliver a steady, continuous stream of pressurized air to patient’s airways to prevent them from collapsing and causing apnea events. After a CPAP titration study, your sleep technician and doctor will determine the pressure settings for your CPAP machine and set the machine to deliver that exact amount of pressure continuously.

CPAP machines can only be set to a single pressure that remains consistent throughout the night. However, many CPAP machines have a ramp feature that starts off with a lower pressure setting and gradually builds to the prescribed pressure. This comfort feature simply makes the pressure at the beginning more tolerable and less immediate, once the pressure builds to the required setting, it stays at that setting for the rest of the night.

What is BiPAP Good For?

One of the complaints about CPAP devices is that some patients find the constant singular pressure difficult to exhale against. For patients with higher pressure strengths, exhaling against the incoming air can feel difficult, as if they’re having to force their breathing out.

BiPAPs can also be set to include a breath timing feature that measures the amount of breaths per minute a person should be taking. If the time between breaths exceeds the set limit, the machine can force the person to breath by temporarily increasing the air pressure.

The main difference between BiPAP and CPAP machines is that BiPAP machines have two pressure settings: the prescribed pressure for inhalation (ipap), and a lower pressure for exhalation (epap). The dual settings allow the patient to get more air in and out of their lung

Who Would Benefit from BiPAP Therapy?

• BiPAP machines are often prescribed to sleep apnea patients with high pressure settings or low oxygen levels.
• BiPAPs are often used after CPAP has failed to adequately treat certain patients.
• BiPAPs can be helpful for patients with cardiopulmonary disorders such as congestive heart failure.
• Often prescribed to people with lung disorders or certain neuromuscular disorders.

Why Not Use CPAP with C-Flex Instead of BiPAP?

C-Flex is similar to BiPAP therapy in that it offers pressure relief as the patient exhales so that they don’t feel like they’re fighting against the incoming airflow during expiration. However, C-Flex is more of a comfort feature for CPAP machines that only offers pressure relief up to 3 cm, whereas BiPAP pressure relief starts at 4 cm and goes up. For those who need only a little pressure relief, a CPAP with C-Flex might be the right choice.

Another difference between BiPAP and CPAP with C-flex is that the pressure relief from C-flex is not a fixed amount, and the pressure drop can vary from breath to breath, whereas the BiPAP maintains a set, prescribed exhalation pressure.

Ask Your Doctor About the Benefits of BiPAP

Depending on the results of your CPAP titration study, more than likely your doctor and sleep technician will know outright if a BiPAP machine is right for you. However, if you’ve tried CPAP and find the pressure settings too difficult to manage exhaling against, talk with your doctor and see if a BiPAP machine is right for you.

The Alaska Sleep Clinic diagnoses and treats thousands of patients every year in Alaska suffering from sleep apnea. Often as a result of our diagnosis, patients are prescribed CPAP or even APAP machines for therapy. However, compliance is one of the keys to successful treatment, and if you’re finding that your CPAP pressure settings are too difficult to manage, give us a call and we’ll help you find the proper alternative, which may just be a BiPAP machine