
What is an Overnight Polysomnogram?
Doctors call this study a polysomnogram (PSG). It charts your brain
waves, heart beat, and breathing as you sleep. It also records your eye
and leg movements as well as muscle tension. Sensors are placed on your
head, face, chest and legs. They send tiny electrical signals to a
computer.
The signals show when you are asleep and awake during the
night. The brain-wave and eye-movement detectors show when you are in
REM sleep. This stands for rapid eye movement sleep. This is a stage of
sleep where your eyes twitch and your brain waves are very active. It
is also the stage of sleep when you have most of your dreams.
The breathing monitors show the number of times you stop
breathing. They can also detect low air flow and minor changes in
oxygen level.
The leg sensors show both minor twitches and major movements that occur during the night.
A clip will also be placed on your finger to note changes in the
level of oxygen in your blood. The clip monitors the color of your
blood. As blood loses oxygen, it turns from red to blue.
Who gets it?
A polysomnogram is often used in the following cases:
- To look for sleep-related breathing disorders, such as sleep apnea
- To set the correct levels of continuous positive airway pressure (CPAP) in patients with sleep related breathing disorders
- To go along with a daytime nap study to see if someone has narcolepsy
- To look for behaviors during sleep that can be violent or could be harmful to the patient or others
Your doctor will want to order a polysomnogram if he or she thinks
you have any of these problems. You might also have a sleep study if
you are already being treated for a sleep disorder but you are not
getting better. The sleep study can help your doctor see why the
treatment is not working.
What happens when I have it?
Our Technologist will go out of their way to make
you feel relaxed. You will be asked to come to the clinic in the
evening. Some time will be given for you to make yourself at home in
the bedroom. No other patients will be in the room with you.
You will not feel any pain during the polysomnogram. The
sensors are gently placed on your skin and connected to a computer. The
wires are long enough to let you move around and turn over in bed. You
will be asked to move your eyes, clench your teeth and move your legs.
This will make sure that the sensors are working.
You are free to read or watch TV until your normal bedtime.
Then the lights are turned out and it is time for you to try to fall
asleep. A low-light video camera allows a technologist to see you from
a nearby room. He or she will have to enter your room if a sensor comes
loose. He or she will also have to detach the wires if you need to go
to the bathroom during the night.
The polysomnogram is not a test that you can fail. Nearly
everyone falls asleep during the study. Most people do not sleep as
well as they do at home. This will not affect the results. In most
cases, you do not need to sleep for a full eight hours to find the
source of your problem.
In the morning the sensors will be tested again, and then they
will be removed. This will complete the study, and you will be free to
go. You may be tired if you did not sleep well during the night.
Otherwise, you can return to normal activities on the day after a sleep
study.
Who reads it?
Our chief technologist is the first one to look over the data from all sleep study. First, he will chart your sleep stages. Then, he
will look for any events of abnormal breathing or leg movement. The
results will be given to Dr. Clerk. He will then review the study to
find out what kind of sleep problem you may have.
Sleep Medicine Services is accredited by the American Academy of Sleep Medicine (AASM). The AASM sets strict standards for centers to maintain. This is to
make sure that patients with sleep disorders get the highest level of care. In
this center, the results of all Sleep studies are always reviewed by our sleep specialist
(Dr. Clerk) who is certified by the American Board of Sleep Medicine.
How do I get the results?
It will usually take two to three working days to get the results of a Sleep study. The doctor who ordered the study will discuss the results with you and the next best course of action. If
your primary care doctor ordered it, then the results are sent to him or her. If
you met with Dr. Clerk in the sleep center, he will tell you the
results on your follow up visit.