Expiratory Positive Airway Pressure (EPAP) for Sleep Apnea

Expiratory positive airway pressure (EPAP) is an emerging treatment for sleep apnea, which affects about one-quarter of U.S. adults between the ages of 30 and 70. It works similarly to continuous positive airway pressure (CPAP) but only provides pressure on the exhale.

Unlike CPAP, EPAP does not require any bulky or noisy machinery. EPAP is a disposable one-way resister valve that is affixed over the nostrils with adhesive. The valve provides minimal resistance on inhaling and positive pressure on exhaling. This opens the airway making it less likely to collapse during inhaling.  

Sleep apnea occurs when your airway collapses during sleep, restricting breathing. People with healthy airways breathe in and out without any obstruction. However, with sleep apnea, the upper airway collapses on exhale. As a result, the airway does not automatically open back up when you breathe, resulting in a temporary cessation of breathing, which is medically referred to as apnea.

Man sleeping in his bed
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The most common cause of sleep apnea is being overweight. Other causes of sleep apnea include enlarged tonsils or adenoids or neurological. Sometimes these structures need to be surgically removed to cure sleep apnea.

Positive airway pressure is used to assist with breathing as a treatment for sleep apnea. CPAP, BiPAP, and EPAP are examples of positive airway pressure.

Consequences of Sleep Apnea

  • Daytime sleepiness & fatigue
  • Impaired cognitive function
  • Metabolic dysfunction—your body doesn't breakdown or absorb nutrients normally
  • Heart disease
  • Death
  • Depression or mood swings

Differences Between EPAP, IPAP, CPAP, & BiPAP

CPAP is one of the most common methods for treating sleep apnea. CPAP uses positive pressure constantly applied by a machine throughout both inspiration (inhale) and expiration (exhale) phases.

Another treatment called BiPAP (bilevel positive pressure) applies positive pressure during both phases as well, but not as a continuous pressure.

EPAP is different from the previous two modes of breathing support because it does not deliver positive pressure during the inspiratory phase of breathing. It only delivers positive pressure when you are exhaling.

IPAP, inspiratory positive pressure, refers only to positive pressure when you breathe in. Ventilators (life support machines for breathing) and BiPAP use both IPAP and EPAP.

CPAP involves using a machine with tubes and a face mask to force air pressure. In contrast, EPAP is a disposable device that only covers the nostrils. It uses adhesive to affix a one-way resister valve on the end of your nose, like a sticker. The valve opens on the inhale and provides resistance on the exhale. This forces the airway to remain open, preventing episodes of apnea.

Expiratory Positive Airway Pressure

EPAP is an acronym that stands for "expiratory positive airway pressure." This mode of breathing support only applies positive pressure when you are exhaling. This is thought to work due to a belief that airway collapse and resulting sleep apnea are most likely to occur when you are breathing out.

One device that utilizes EPAP to treat sleep apnea is called Provent. This technology is known as nasal EPAP. According to the manufacturer, Provent uses a one-way valve that is placed over the nostrils at nighttime. The valve opens when you inhale but partially closes during exhalation forcing your exhaled breath out through small holes, creating positive pressure in the airway.

Unlike most CPAP devices, Provent does not use water or an electrical power source. It's also more portable. The manufacturer claims that this is an advantage and that their studies have shown greater compliance with EPAP than is typically seen in people using CPAP for the treatment of sleep apnea.

Frequently Asked Questions

  • What is positive airway pressure?

    Positive airway pressure (PAP) is a treatment for sleep apnea that uses pressure to keep the windpipe open during sleep. CPAP, EPAP, and BiPap all work in slightly different ways to keep the airway open while you sleep. 

  • What is the difference between CPAP and EPAP?

    CPAP provides continuous positive airway pressure on both inhalation and exhalation and EPAP provides pressure on the exhale only. The devices used for CPAP and EPAP are also very different.

  • Is EPAP as effective as CPAP?

    No, but it appears to be a suitable alternative for people with mild to moderate obstructive sleep apnea. While CPAP works better, patients have higher rates of compliance with EPAP because it is easier to use, compact, and does not require electricity.

  • What is APAP?

    Automatic positive airway pressure (APAP) is a device used to treat sleep apnea. During the night, an APAP machine automatically adjusts its pressure settings in response to a person's breathing.

  • What is a sleep apnea pillow?

    A sleep apnea pillow is a specially designed pillow made for people that use a ventilator. Some designs have indents for the CPAP hose to travel through while you sleep, while others may give more comfort when you're resting on your side. These can help prevent air leaks from your face mask.

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8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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