Sleep Services- What to Expect

What to Expect During
Your Sleep Study

What should I bring with me?
Prepare yourself for your night in the sleep laboratory as if you were going to spend a night in a hotel. Please bring with
you everything you would need to spend the night away from home. This should include: all medications, your pajamas,
toothbrush, books to read, etc. If you wish you may bring your own pillow. You will not need to bring an alarm clock, as
the technician will wake you in the morning. Please keep in mind that cell phones and pagers should be turned off so as
not to disrupt your study or another patient's study.

What happens when I get there?
You will check in at the facility and proceed to the Sleep Center where you will be greeted by a sleep technician. You
will be asked to change into your nightclothes and prepare for going to bed. A technician will then begin to apply various
sensors and electrodes for the sleep study.

What is a sleep study?
A sleep study, or polysomnogram, is similar to an EEG or ECG study, but makes 16 different measurements in your brain
or body for the entire time you are asleep. This test is not invasive; the electrodes are resting on the skin attached by a
special adhesive and tape. These tests begin at night and last through the morning, as would a normal night of sleep.

What do the sensors tell the sleep technician?
From the electrodes that are placed on different points on the body, the computer receiving the information can measure

Up to 16 different body movements at the same time. Usually, these include the following:

Brain Waves or EEG. Usually 6 electrodes are attached to your scalp with a water-soluble paste or adhesive. Your
hair is not cut or shaved. Needles are not used. The adhesive is removed when your sleep study is over. Brain waves
allow us to determine the different stages of sleep.

Eye Movements. Usually 2 or 3 electrodes are attached with tape near your right and left eyes. They do not touch your
eye in any way. Eye movements help us identify specific sleep stages.

Muscle Activity. Usually 2 electrodes are attached with tape on your chin or under your chin. Muscle tone plays a
large role in determining your sleep stage throughout the night.

Electrocardiogram (ECG). Usually 3 electrodes are attached with tape to the upper chest to record your
heart's activity.

Leg Movements. Usually, a small belt or cuff is placed around each ankle to record leg movements. Occasionally, 2
electrodes are attached with tape to your lower legs to measure leg muscle activity.

Breathing. Your breathing is measured in several ways. First, a sensor is attached with tape to your upper lip to measure
airflow. Second, lightweight belts are placed around the chest and abdomen to measure how much effort you are
making to breathe. These belts are not tight or restrictive; they are sensitive to the motion of breathing.

Oxygen Levels in the Blood. A sensor is attached to one of your fingers or your ear with tape to measure the oxygen
levels in your blood.

Other Sensors. Depending on your particular problem other types of sensors may be used. Please feel free to ask the
technician about any of the equipment used in the sleep laboratory.

Why is it necessary to record so many different things?
Your brain and your body function very differently during sleep than during the day. Even if your heart, breathing, and
brain activity are completely normal during the day they may be different or abnormal during sleep. The only way to
determine the degree of the sleep problem is to take a variety of measurements.

How can I possibly sleep with all those things attached to me?
Almost every patient who comes for a sleep study asks this question. However, most patients find it is not as bad as it
sounds. Most patients have a similar night's sleep as they do in their own homes.

Can I sleep in my usual position and can I turn over?
All electrodes and sensors are attached so they should not come off during sleep. You should be able to sleep as you do at
home and turn over as usual. If you feel you cannot sleep normally because of the electrodes, please call the sleep technician
to help you. Also, if an electrode or sensor does come off, the technician on duty will simply adjust the sensor.

Will you give me any medication to help me sleep?
No - this might change your sleep and prevent us from identifying the source of your sleep problem. However, you may
take whatever medication you usually take before bedtime. Just be sure to tell the technician what
you're taking.

What happens if I need to go to the bathroom during the night?
All electrodes and sensors are "plugged in" to a portable box. The box is simply unplugged and the patient is able
to go - electrodes and all - to the bathroom. This is an easy process and can be done in a few seconds.

Will anyone else be in the sleep laboratory when I am there?
A technician will greet you when you arrive at the sleep laboratory and show you to your room. A member of our technical
staff will be present - and awake - in the control room all night long. Most sleep rooms have an intercom that is
left on all night. You may call the technician at any time by simply speaking. Depending upon lab location, there may be
other patients having sleep studies in their own rooms.

When can I leave?
Usually the technician will wake you at 6:00 a.m. If you need to be up earlier, please notify the technician. The technician
will remove all leads and sensors. There will be a short questionnaire to fill out. As soon as you are unhooked, you
are free to leave. Many patients bring their clothing for the next day and leave directly for work or other daily activities.

What is a MSLT?
Some patients are scheduled to stay through the day for daytime testing or Multiple Sleep Latency Test. This test monitors
your daytime functioning. When you awaken in the morning from your sleep study, the technician will remove the
respiration monitors and leg electrodes but will leave the head and EKG electrodes attached. These will stay on all day.
At two-hour intervals beginning at 8:00 am, you will be asked to lie down in bed and close your eyes for twenty minutes.
These naps will continue throughout the day at the following intervals 11am, 1pm and 3pm. When each nap is over, you
will be asked questions about your sleep, and evaluate how tired or alert you feel. Between the napping periods, you will
be able to watch television, read, etc. but you will not be allowed to lie down or take additional naps. After the last nap,
the technician will remove the electrodes and you will be allowed to leave sometime around 5:00 pm.

How and when do I get the results?
All sleep studies contain 1,000 pages or more of data that must be analyzed and interpreted. Analyzing a sleep study is a
time consuming process. Each page of the recording is examined for sleep stage, breathing abnormalities, cardiac
arrhythmias, movements, arousals, as well as many other variables. Often the technician must review the same page of
data 3 or 4 times to identify all significant data. The fully analyzed data is then reviewed by a certified sleep specialist
who will provide an interpretation (what the results actually mean). This information is entered into the final sleep study
report and prepared for your doctor. This process usually takes approximately 14 working days. Results will be faxed and
mailed to the physician who ordered the sleep study for you. The Sleep Center Technician and scheduling staff will not
be able to provide your results. You will need to follow up with your physician to obtain your sleep study test results.

Copyright: Sleep Services of America

Greater Baltimore Medical Center | 6701 North Charles Street | Baltimore, MD 21204 | (443) 849-2000 | TTY (800) 735-2258
© 2014  GBMC. This website is for informational purposes only and not intended as medical advice or a substitute for a consultation with a professional healthcare provider.