Obstructive
Sleep Apnea
Introduction
Obstructive
sleep apnea is a relatively common
disorder that was clinically
recognized only over the last 20 -
30 years. For many years, people
recognized that obese patients had a
tendency to snore while asleep.
This observation was made famous by
Charles Dickens in his collection of
short stories, The Pickwick Papers.
As the medical community recognized
snoring and obesity as a true
diagnosis, the term "Pickwickian"
came into usage to describe patients
with obesity and snoring.
However,
this only captures a portion of the
patients with the modern diagnosis
of obstructive sleep apnea. The
name is a descriptive diagnosis.
"Apnea" refers to the stoppage or
lack of breathing. A pause in
breathing of greater than 10 seconds
is considered an "apneic" event. A
breath that is less than 50% of a
normal breath is considered "hypopneas."
While your asleep, especially in
deep or REM sleep, the muscles of
your throat relax and the soft
tissues block off your airway,
producing the "obstruction."
Symptoms
Since the
airway is blocked off, the oxygen to
the brain is diminished. Once the
oxygen level drops to a certain
point, the brain "wakes you up;" and
the muscle tone to the throat is
returned, removing the obstruction.
Unfortunately, these micro-arousals
interrupt periods in REM sleep.
Adequate REM sleep is necessary to
feel rested. Over time,
interruptions of REM sleep produce
ineffectual sleep. Consequently,
patients awaken feeling tired and
tend to fall asleep easily during
the day.
The soft
tissue that blocks the airway can be
from the soft palate, base of the
tongue, or the soft tissues of the
throat (pharynx). Frequently,
patients with OSA breathe through
their mouths. Airflow along the
soft palate produces vibrations,
which produce the characteristic
noise of OSA: snoring. This
snoring can be so loud that it is
heard throughout the house, forcing
your sleeping partner to sleep in
another room.
Snoring is
the most common symptom of OSA.
Other symptoms include:
-
Gasping
for breath at night.
-
Restless sleep - one cannot lie
still at night, constantly
moving.
-
Getting
up frequently to use the
bathroom at night.
-
Awakening feeling tired.
-
Awakening with headaches.
-
Falling
asleep easily during the day.
-
Falling
asleep while driving.
Your physician
will discuss your symptoms with
you. Frequently, your sleeping
partner can give valuable insight
into how you sleep. The
Epworth
Sleepiness Scale
is a useful test to measure one's
degree of sleepiness.
Associated
Medical Problems
Your
physician will also ask you about
other medical problems in your
history. A few medical disorders,
e.g. hypothyroidism and gigantism,
can produce problems that promote
OSA. Some medical problems are very
common in patients with OSA, such as
hypertension, gastro-esophageal
reflux disorder (GERD), and
arrhythmias.
Anatomical
Problems
Your physician
will examine your upper airway
carefully to look for anatomic
reasons for sleep apnea. Probably
the most common finding in patients
with OSA is obesity. Obesity is
defined as a body mass index of
greater that 30 kg/M2.
You can
calculate your
BMI
by following this link.
Other
anatomical problems that increase
the chance of having OSA include:
Diagnostic
Tests
The most
important diagnostic test for OSA is
a sleep study. The medical term for
this test is polysomnography. This
test is performed on an outpatient
basis. The patient goes into the
testing facility at night. Several
different monitors are connected to
the patient, and the patient falls
asleep.
While the
patient sleeps, his or her sleep
pattern, oxygen saturation, heart
rate, breathing rate, etc are
monitored. The recording is then
evaluated, usually by computer, and
measurements such as frequency of
apnea and hypopnea, length of REM
sleep, heart rate, etc are
calculated.
Treatment
The
treatment for OSA is complex and
evolving. Generally speaking, there
are three forms of treatment for OSA.
-
Weight
loss. Clearly, for patients
that are obese, losing weight
will not only help to relieve
OSA, but it will improve one's
overall health. Having said
this, losing weight can be
difficult. Additionally, not
all patients with OSA are obese.
-
CPAP.
These letters stand for
Continuous Positive Airway
Pressure. In general, most
patients have a decrease in
apnea, hypopnea and snoring with
CPAP. The device uses a mask
that fits over the patient's
nose and delivers pressurized
air to keep the soft tissues
open.
-
Surgery.
For many patients, identifiable
anatomic problems can be
corrected with surgery. This
can include procedures such as
septoplasty
or
tonsillectomy,
but it might also include
procedures to correct
retrognathia or tracheostomy.
Your physician will discuss with
you if you might be a candidate
for one of these procedures.
Please follow the link to find
out more about
surgery
for obstructive sleep apnea.
Your
physician will discuss the options
that are appropriate for you. OSA,
when left untreated, can result in
several serious medical problems and
has been shown to shorten one's
lifespan. Once OSA is properly
diagnosed and treated, the
improvement in one's life can be
dramatic.
