Sleep Studies
Visiting
the SDC for an overnight sleep study must be a new experience to
you. Spending one night in the SDC is not like spending a night in
the hospital. You may be under the impression that the bedroom you
are going to sleep in is full of equipment, monitors and a medical
person who will be watching you the whole night. That is far from
truth.
You should look at it like spending one night in a hotel or in a
relative’s house. The room you are going to spend the night in is
a specially furnitured room. It will have a special cupboard to
keep your clothes and a private washroom with all accessories. You
can control temperature and light to your convenience.
What is an overnight sleep study?
Sleep is a complex process during which, many physiological and
pathological processes occur. In order to understand your sleep
and any problems with it, we need to monitor several physiological
parameters during sleep. During the sleep study, the following
parameters will be monitored; brain waves, muscle movements,
breathing through your mouth and nose, snoring, heart rate and
rhythm, leg movements, chest and abdominal wall movements, oxygen
level in the blood and carbon dioxide output. To monitor those
functions, we apply small metal discs to your head and skin using
an adhesive. Flexible elastic belts will be put around your chest
and abdomen to monitor your breathing. A small plastic tube (cannula)
will be put close to your mouth and nose to monitor your
breathing. Oxygen level in the blood will be measured via a clip
in your index finger or your ear lobe. None of the above devices
are painful and all are designed to be as comfortable as possible.
The equipment and the technician will be in a room separate from
your sleeping room. You will be able to roll over and sleep in any
position you like as easily as you would at home.
During the study, patient’s privacy is completely assured. You
will be able to call the technician via a microphone anytime
during the study.
What am I supposed to do before a sleep
study?
On the day of your sleep study:
• Avoid caffeine containing beverages (tea, coffee, Pepsi, coca
cola, chocolate) after 2
PM
• Avoid napping
• Before coming to the sleep center, wash and dry your hair to
make it easy to apply the
adhesives
• Pack a small bag that contains things you may need overnight
like medications,
toothpaste and brush, your nightclothes and a towel.
• If you have special needs, please advice the sleep center staff
before hand to be able
to help you.
What will happen when you arrive at the
sleep disorders center?
You will be asked to come to the sleep disorders center between 8
and 9 PM. On arrival, the technician will meet you, show you your
room and the equipment used in the study. After that, you can sit
in the waiting room to watch TV, read or relax. Before your
bedtime, the technician will apply the wires and electrodes
required to monitor your sleep. The technician will wake you up
around 7 AM. If you want to get up before that be sure to inform
the sleep technician before your study.
If you have breathing problems during sleep, the technician may
awaken you from sleep to use a device that delivers air under
positive pressure. The machine is called CPAP machine. Air is
applied through a soft mask that fits around your nose. Your
physician usually discusses the possibility of using this machine
with you in the clinic.
What will happen after the sleep study?
Analysis and interpretation of a sleep study is a complex process.
A typical sleep study involves 800-1000 pages of data. Its
analysis is time-consuming and labor-intensive. Therefore, the
results of the sleep study will not be available immediately. Your
sleep study will be reviewed and interpreted by your doctor (a
sleep specialist with special training in sleep disorders). When
you come for follow up your physician will discuss with you the
results and the management plan. The results of the sleep study
will not be given by the technician and usually cannot be
discussed over the telephone.
Sometimes an additional sleep test called multiple sleep latency
test (MSLT), is needed as a part of the overall sleep evaluation.
For this test, you need to stay in the sleep center for most of
the day following your overnight sleep study. If your condition
necessitates this test, your doctor will discuss that with you in
the clinic beforehand. The test is a series of short naps
beginning the morning after your overnight study.
Ahmed BaHammam, FRCP, FCCP
Professor of Medicine
Director, Sleep Disorders Center
College of Medicine, King Saud University
Associate Editor, Ann Thoracic Med
