Expiratory Positive Airway Pressure (EPAP)

If you live in the United States and are between the ages of 30 and 70 years old, you may be one of the 26 out of 100 people that have sleep apnea. Rates of sleep-associated breathing disorders have been on the rise since 2000 as obesity becomes a larger issue. Sleep apnea occurs when your airway collapses during sleep; restricting breathing.

Man sleeping in his bed
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If you do not have any lung disorders, you can breathe in and out without any obstruction. However, if you gain weight, it is possible that as you breathe out, your upper airway will collapse. This can make it so that the airway does not automatically open back up when you breathe and you have an episode of apnea (a temporary cessation of breathing).

In the U.S., being overweight is one of the most common causes of sleep apnea but it should be noted that there are other causes of this condition. Enlarged tonsils or adenoids or neurological conditions can also cause you to stop breathing during sleep. Sometimes these structures need to be surgically removed to cure sleep apnea.

There are several devices that use positive pressure (pressure going towards the lungs) to assist with breathing as a treatment for sleep apnea. Examples include CPAP, BiPAP, and EPAP.

You should know that while we will discuss a treatment for obstructive sleep apnea, the best thing that you can do to treat your sleep apnea is to lose weight (unless your sleep apnea is not related to obesity).

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, continuous positive airway pressure, is one the most common methods for treating sleep apnea. With CPAP, positive pressure is applied by a machine constantly throughout both inspiration and expiration 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 machine for breathing) and BiPAP use both IPAP and EPAP.

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.

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3 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.
  1. American Academy of Sleep Medicine. (2014). Rising prevalence of sleep apnea in U.S. threatens public health

  2. Ho ML, Brass SD. Obstructive sleep apnea. Neurol Int. 2011;3(3):e15. doi:10.4081/ni.2011.e15

  3. Provent Sleep Apnea Therapy. About provent therapy

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