The Underexplored Side Effect of EPAPIt’s good to have multiple treatment options for sleep apnea treatment. That way, people who are having difficulty with some treatment types can find ones that are better suited to them.

But it’s also important to make sure that the treatments we offer are actually positive ones for the people using them: they have to be capable of providing good results without serious side effects.

EPAP (Expiratory Positive Airway Pressure) is an FDA-cleared therapy for the treatment of sleep apnea, and it’s also used as a snoring treatment. In many ways, the treatment is good, but there is a potentially serious side effect that should be researched in more detail now that more people are using the devices.

The Good News about EPAP

EPAP works by trapping air in your body when you try to breath out. This creates an increased air pressure which can help to hold open your airways so that you are able to breathe more easily and not experience either snoring or apneic events.

There are two basic mechanisms used to trap your breathe. First, Provent (which has been cleared for sleep apnea treatment) uses one-way air valves to allow more air in than it allows out. Theravent uses a porous material that allows more air in than it allows out. This is not as effective as the air valves–only trapping up to half as much of your breath–and is recommended as a snoring treatment.

Both systems use a hypoallergenic adhesive to stick to the skin around the nostrils, creating a seal that helps trap the air.

Provent has been proven to treat sleep apnea. In clinical studies, Provent was able to reduce AHI (apnea-hypopnea index) by 38-70%. Theravent studies documented a reduction in snoring volume of up to 76%.

Unlike CPAP, the effect of these treatments isn’t entirely due to the physical effect of air pressure on the airway. Instead, there are three mechanisms that work to achieve the therapeutic effects:

  • Lower airway expansion and collapse resistance
  • Upper airway dilation
  • Hypercapnia (excess CO2)

It’s this final effect that is potentially of concern. Although an increase in CO2 levels is good because it can cause the body to want to breathe more, it does have some potentially disruptive side effects.

The Impact of Hypercapnia

In many ways, the body responds to excess CO2 more than it responds to a shortage of oxygen. That’s partly because the two are related (the more CO2 in the blood, the less “room” for oxygen), but also because CO2 can have toxic effects.

When CO2 is dissolved in liquid, it turns into an acid, and when the blood becomes acidic, it can be damaging to the body’s metabolism. It depresses the body’s metabolic rate, which may impact the body’s ability to rest during sleep.

In addition, some of the effects of excess CO2 are similar to what is seen in apneas. People experience mild fever, become flushed, get sweaty, and may experience an elevated heart rate.

But does EPAP create hypercapnia that’s severe enough to cause these effects? It seems so.

Hypercapnia is typically measured as a partial pressure of CO2, labeled PCO2. A PCO2 of around 90 Torr is potentially deadly for people breathing air at normal pressure. However, people may begin to experience the effects of hypercapnia once PCO2 exceeds 50 Torr. So, how high does PCO2 get when using EPAP? Clinical studies show that PCO2 averages about 50 Torr when using EPAP, although some people got as high as 59 Torr. This may potentially undermine the effectiveness of the device (although increases in oxygen levels could compensate somewhat).

The key is that we just don’t know the impact of this treatment side effect, so it should be studied more. In the meantime, EPAP should be considered only for certain candidates where the benefit exceeds the potential drawback of this side effect.

If you’re looking for more information about your sleep apnea treatment options in Omaha, please call (402) 493-4175 today for an appointment with a sleep dentist at the Advanced Dental Sleep Treatment Center.