THE USE OF
EXPIRATORY POSITIVE
AIRWAY PRESSURE
TO TREAT
OBSTRUCTIVE SLEEP APNEA
The historical thought in treat-
ing obstructive sleep apnea
(OSA) was that to be effective,
the treatment should address
the process of inspiration. This
thinking has expanded with
the development of both Oral
Appliance Therapy (OAT) and
Expiratory Positive Airway
Pressure (EPAP) devices like
Provent. While OAT manipu-
lates the protrusion of the jaw
to maintain a patent upper air-
way during sleep, Provent uses
pressure created during expi-
ration to keep the airway open.
During inhalation, microvalves
within the mesh structure of
Provent, open to allow in air.
These valves close during expi-
ration, creating a resistance. It
is thought that this build-up of
pressure created during expi-
ration has several physiological
effects.
While the exact mechanism of
how Provent works is unclear, it
is believed that exhaling against
a resistance causes the lungs
to reach a level of function-
al residual capacity. The the-
ory is that the inflation of the
lungs created by breathing out
against a resistance pulls upon
the structures within the chest
which in turn pull on the up-
per airway causing it to open.
Just as oral appliances advance
the mandible to keep the upper
airways open, Provent expands
the lungs through expiratory
pressure which pulls upon the
upper airway in order to keep
it open. Not only is the paten-
cy of the airway improved at
the start of the next cycle of in-
halation with Provent, but it is
believed that the airway itself is
now larger. During the next in-
spiration cycle, the valves of the
Provent device will again open,
releasing pressure. The airway
passage is not likely to collapse,
RUTH PEARSON
however, as the airway passage
has not only been forced open
during expiration, but the ca-
pacity of the lungs and the size
of the airway have been ex-
panded.
In a future article, we will dis-
cuss the results of studies ex-
amining the effectiveness of
Provent on obstructive sleep
apnea and its impact on oxygen
desaturation and the Apnea-Hy-
popnea Index. We will also look
at how the combined thera-
pies of OAT and Provent may
improve a patient’s outcome.
In the meantime, please visit
www.sleepwellrested.com for
more information on Provent.
Ruth Pearson
Ruth Pearson is an attorney who
lives in Philadelphia with her fam-
ily. She has practiced in the area
of workers’ compensation for
over twenty years. As a work-
ers’ compensation attorney, Ms.
Pearson has questioned numer-
ous medical professionals on the
mechanism of an injury sustained
as well as the best treatment plan
available. This work with injured
workers has led Ms. Pearson to
author a series of articles on the
use of Durable Medical Equip-
ment following an injury, sur-
gery or other medical diagnosis.