What is Sleep Apnoea?
The following article in the Autumn 2006 Newsletter from the Irish Post Polio Group is summarised from the Irish Sleep Apnoea Trust Website www.isat.ie
Recent studies have shown
that Polio Survivors are 30% more likely to suffer from sleep apnoea than the
rest of the population. A layman’s
definition of Sleep Apnoea is ‘the cessation of breathing during sleep’.
When breathing stops the levels of oxygen in the blood begin to drop. After a short time the lack of oxygen causes
a reflex response. This response forces
open the airway with a loud snort, maybe gasping breaths and loud snoring. There may also be kicking and flailing of the
arms. There are three different types of
sleep apnoea: obstructive, central and mixed.
Obstructive
Sleep Apnoea
Obstructive Sleep Apnoea
(OSA) is the most common. Central Sleep Apnoea and Mixed Apnoea are rare.
Obstructive sleep apnoea is caused by the obstruction and/or collapse of the
upper airway (back of throat), usually accompanied by a reduction in blood
oxygen saturation, and then an awakening (arousal) to activate breathing again.
This is called an apnoea event.
Why? There are a number
of factors:
Extra or loose tissue in the back of the throat, such
as large tonsils, large uvula, large tongue or long/floppy soft palate.
There
may also be an obstruction/obstructions at the base of
the tongue, turbinate problems or nasal blockages. A decrease
in the tone of the muscles holding the airway open.
Central
Sleep Apnoea
Central Sleep Apnoea is
defined as a neurological condition where there is a cessation of all
respiratory effort during sleep (the brain forgets to instruct the body to
breathe), usually with decreases in blood oxygen saturation levels. The person is aroused from sleep by an
automatic breathing reflex, so may end up getting very little sleep at
all. Note that Central Sleep Apnoea,
which is a neurological disorder, is very different in cause than OSA, which is
a physical blockage - though the symptoms are very similar.
Mixed Apnoea
Mixed Sleep Apnoea, is a
combination of Obstructive and Central Sleep Apnoeas’.
Breathing-assistance
devices
Continuous Positive Airway Pressure (CPAP)
“Nasal CPAP” is the treatment of choice for most people with
obstructive and mixed apnoea. It is the most reliable and effective treatment
in most cases. Hundreds of thousands of CPAP devices are now in use treating
obstructive sleep apnoea worldwide. An added advantage with this treatment is
the elimination of snoring.
It involves using a small
air blower device connected via a hose to a nose mask you wear while you sleep
- much like a regular oxygen mask, with straps to keep it in place. Essentially, this devices
blows air into your nose to keep your airway from collapsing and creating an
obstruction by increasing the air pressure in your airways. It isn’t as unpleasant as it sounds -
most people get used to the sensation fairly quickly. Admittedly, having to wear a face mask to bed
isn’t the most attractive thing in the universe. Most bed partners are usually happy to live
with that rather than snoring! And it is
infinitely preferable to the effects of apnoea, both the fatigue and the other
physical effects (additional strain on the heart). The exact results vary, but a great many
people report significant changes in their lives when they start using CPAP -
they feel more awake, more alive - “like a whole different person”,
in some cases.
People with sleep Apnoea have the
following:
Loud,
frequent and irregular snoring: The
pattern of snoring is associated with episodes of silence that may last from 10
seconds to as long as a minute or more.
The end of an apnoea episode is often associated with loud snores,
gasps, moans, and mumblings. Not
everyone who snores has apnoea, by any means, and not everyone with apnoea
necessarily snores (though most do).
This is probably the best and most obvious indicator.
Your
spouse/partner indicates that you periodically stop breathing or appear to be
choking during your sleep, or gasp for breath (witnessed apnoeas).
Excessive
daytime sleepiness: Falling asleep when
you don't intend to. This could be
almost anytime you are sitting down, such as during a lecture, while watching
TV, while sitting at a desk, and even while driving a car. You may have sleep apnoea or another sleep
disorder. Even if you don't literally fall asleep, excessive fatigue/tiredness
could be a positive indicator.
Body
movements often accompany the awakenings at the end of each apnoea episode, and
this, together with the loud snoring, will disrupt the spouse/partner’s
sleep and often cause her/him to move to a separate bed or room.
Forgetfulness, that is, effecting the short term memory, also a difficulty in
concentrating, focusing and completing repetitive tasks. Bouts of irritability
and depression are common.