Obstructive Sleep Apnoea
(OSA) is a condition in which
the upper airway collapses
repeatedly during sleep.
This creates an effect similar
to that of being repeatedly
choked throughout the night.
During these episodes, there are
recurrent dips in the blood oxygen
levels, putting stress on the heart.
As a result, sleep is unrefreshing and
patients typically feel sleepy and
irritable throughout the day.
What if OSA is left untreated?
In addition to causing sleep disruption
and daytime symptoms, OSA can
increase the risks of serious health
complications such as:
- Memory loss
- Stroke (Almost 70% of people who have had a stroke have OSA)
- Hypertension (>35% of people with sleep apnoea suffer from hypertension)
- Heart failure and heart attacks
(by 2 to 3 times)
- Risk of motor vehicle accidents
(by 7 times)
- Increased risk of work-related accidents
- Loud, frequent snoring
- Cessation of breathing or gasping
for air during sleep
- Excessive daytime sleepiness
- Unrefreshing sleep
- Frequent urination at night
- Erectile dysfunction
I sleep through the night without recurrent awakenings, does this mean I do not have OSA?
No. Often, the sleep disturbances
caused by OSA are short and
intermittent and are insufficient to
fully rouse the affected person from
sleep completely. These repeated
short arousals are however enough to
result in unrefreshing sleep and all the
adverse health consequences described
It is best to see a sleep specialist to confirm the diagnosis. In the initial consultation, a thorough sleep history will be taken to assess for OSA. If OSA is suspected, an overnight sleep study is recommended to confirm the diagnosis of OSA.
What is a sleep study?
A sleep study or polysomnogram
(PSG) is an overnight noninvasive
diagnostic test done in a Sleep
Laboratory. The PSG monitors
the different stages of sleep,
heart rhythm, muscle activity,
breathing effort and oxygen
levels during sleep. The severity
of OSA can also be determined.
A very effective treatment for OSA is
Continuous Positive Airway Pressure
(CPAP) therapy. CPAP therapy is
considered the gold standard and
most effective non-surgical treatment
for OSA. Depending on the severity of
OSA and the upper airway anatomy,
other treatment options include
weight loss, wearing of appliance
during sleep and surgery.
How does CPAP therapy work?
CPAP therapy works by quietly
delivering pressurised air through
the nose or mouth to keep the upper
airway open and maintain normal
breathing during sleep. There are two
important parts of the CPAP machine
that need to be decided on by careful
consultation with your sleep physician
prior to using CPAP.
1. The mask:
CPAP is administered through a mask that seals either the nose, mouth or both the nose and the mouth. There are a variety of masks that can be used. Most of these are made from a soft silicon or gel to maximise comfort. The mask chosen for you will be fitted by the sleep technician to suit your facial structure and breathing habits.
The first step in choosing the type of
mask is to establish how you breathe
naturally (through the nose, mouth
or both). There are different types of
masks to suit different needs, such as:
- Nasal masks (for nose breathers)
- Nasal pillows (for nose breathers)
- Full face masks (for nose and mouth breathers)
- Oral-nasal masks (for nose and mouth breathers)
- Oral masks (for mouth breathers)
In order to optimise the comfort and
success of CPAP therapy, it is important
to identify and treat any reversible
causes of nasal obstruction (e.g.
chronic rhinitis, nasal polyps or septal
deformities) prior to CPAP therapy.
2. The Machine:
Most CPAP machines today are small –
about the size of a bedside alarm clock –
quiet and relatively portable.
Modern CPAP devices can deliver
a fixed pressure or may have
sophisticated software that can
detect obstruction and self-adjust
the delivered pressure (auto-titrating
machines). Excessive pressure can
cause air leak and discomfort while
insufficient pressure will not effectively
treat the sleep apnoea.
Some devices have special modes that
allow you to breathe out more easily,
or can deliver a different pressure
depending on whether you are
breathing in or out.
The type and setting of each device
will need to be individualised for each
patient after consultation with your
What happens after OSA is treated?
OSA sufferers who start using
CPAP report sleeping better and
feeling more energetic and less
sleepy during the day. Some report
feeling better after the first day
of treatment while for others, the
improvement may only become
apparent after a few weeks of
sustained use. The benefits of
- Improved sleep quality with
reduction or elimination of
snoring and apnoea
- Feeling more rested and alert
during the day with improved
memory and cognition
- Improved blood pressure control
- Reduced risks of stroke, heart
failure and heart attacks