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.

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.

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.