Preparing for a sleep study

Overnight Sleep Studies

A visit to a sleep disorders facility for a sleep study is likely to be a new experience for you.

A sleep study is somewhat like spending a night in a hotel.  The difference is that for a sleep study you’ll have a bunch of sensors attached to your body and nurses and scientists will be there to monitor how you sleep – however they will not be present in your room while you sleep.  Most patients fall asleep quickly.  We hope that your experience at the sleep centre will be a good one.  Understanding the sleep process and the evaluation of sleep disorders will help you take an active and positive role in your own care.

What is a sleep study?

A sleep study, or polysomnogram, is a recording that includes various measurements used to help identify and diagnose sleep disorders. This brochure will help you learn more about sleep testing procedures so that your experience will be easy and interesting.

Why do I need a sleep study?

A laboratory sleep study is considered the “gold standard” to accurately diagnose sleep disorders. In order to fully understand your sleep, various brain activities and body systems and their relationships will be observed throughout the night. After the study a sleep specialist will review and interpret the data collected to help you and your healthcare professional understand your specific sleep patterns and sleep problems. Treatment recommendations will be made if evidence of a sleep disorder is found.

Sleep is not a simple process. Many parts of the brain control sleep and its different stages. These levels or stages of sleep include drowsiness, light sleep, deep sleep and dream sleep. It is possible to identify which stage of sleep a person is in by measuring different activities of the brain and body.

How should I prepare for my sleep study

On the day of your sleep study, avoid caffeine (coffee, tea, cola and chocolate) after 12 noon and try not to nap.  Avoid alcohol unless otherwise directed by your sleep specialist.  Before coming to the sleep centre, wash your hair with shampoo only, dry your hair and do not apply hair sprays, oils or gels as this may affect how the sensors adhere to you.

Should I take my medication as usual?

It is important for your sleep professional to know if you are taking any prescribed or over the counter medication since certain medication can affect sleep and the interpretation of a sleep study. Sometimes certain medications need to be discontinued gradually prior to a sleep study so that the sleep study results can be interpreted correctly. Do not discontinue any prescription medication without first taking with your healthcare professional.

Before coming to the centre you should pack an overnight bag as you would for an overnight stay at a hotel or a friend’s house. You may wish to include your own pillow and extra clothing. Bring your medications if your will need them in the time you are away from home. If you have special needs advise the sleep centre personnel so they can accommodate you.

What will happen when I arrive at the sleep centre?

When you arrive at the centre no later than 7.00pm the technician will greet you and show you to your bedroom. You will be shown the equipment that will be used and given a chance to ask questions. You should inform the technician of any changes in your sleep or specific difficulties you have not already discussed with your healthcare professional. There may be some paperwork for you to complete.

You will have time to change into sleepwear and get ready for bed as you do at home. There may be a waiting period before the technician prepares you for the sleep study and you can relax during this time. If you have a commitment in the morning (if for example, you have to be at work at a certain time), be sure to inform the sleep technician prior to your study so your wake-up time can be confirmed.

Next, approximately two dozen sensors which are generally small metal discs (called electrodes) are applied to the skin of your head and body using an adhesive. These sensors monitor the activation of your brain waves, muscle movements, eye movements, breathing, snoring, heart rate, and leg movements during sleep. Flexible elastic belts around your chest and abdomen measure your breathing. A clip on your finger or earlobe monitors the level of oxygen in your blood and your heart rate. None of these devices are painful and all are designed to be as comfortable as possible. The electrodes may feel strange on your skin at first, but most people do not find them uncomfortable or an obstacle to falling asleep. The sleep specialist recognises that your sleep in the centre may not be exactly like your sleep at home. This usually does not interfere with obtaining the necessary information from your sleep study in order to arrive at an accurate diagnosis.

If you have questions or concerns about the application of the electrodes (if for example, you use a hearing aid, wear a hairpiece or are sensitive to certain chemicals) contact your doctors or speak with the technician before you arrive at the centre.

How will I be able to sleep in a strange environment with all those wires on me?

This is the question asked most frequently by patients prior to their sleep studies. Many people expect the sleep centre to be cold, bright, technical and impersonal looking. At most sleep centres, however, the surroundings (and especially the bedrooms) are homely and comfortable, like a hotel room. Most patients fall asleep quickly. Some sleep disorders centres offer medication to patients who have significant difficulty falling asleep.

What happens during the sleep study?

The technicians will stay awake all night while you sleep to make sure that you are safe and also to monitor your sleep. They, and their technical equipment, will be in a room separate from your sleeping room. You will be able to roll over and change positions almost as easily as you would at home because the electrodes wires are gathered together behind your head. You should feel free to sleep in your customary position although during the night a sleep technician may ask you to try to spend some time sleeping on your back. Your sleep may also be videotaped for later review of any abnormalities observed during the study.

While you are sleeping various important body functions are measured, monitored and recorded. If a breathing problem is observed during your study the technician may awaken you to ask you to try a device that treats breathing problems during sleep. If this is a possibility for you, your sleep specialist or technician will generally discuss this with you before you go to bed and the use and purpose of the devise will be explained.

The device, called a positive airway pressure (PAP) device, includes a small mask that fits over your nose and mouth or soft silicone plugs that fit into your nostrils. If you will be trying PAP during your sleep study night, the technician will usually find a mask in advance that will fit comfortably and will usually give you a chance to practice with the device before you go to bed.

What if I need to go to the bathroom while I’m hooked up to all those wires?

This is actually a very easy task. Because all of the wires which are attached to you are generally plugged into a box, all you need to do is alert your technician that you need to go to the bathroom. The technician will come and unplug you from the box and you are then free to get up. Most patients have to get up at least once during the night.

What happens if I am scheduled for a daytime Nap study?

Sometimes an additional test, called a multiple sleep latency test (MSLT) is needed as part of the overall sleep evaluation. This test requires that you stay at the centre for most of the following day for a series of short naps beginning the morning after your overnight study. The naps are scheduled at set intervals throughout the day. Your sleep patterns will be monitored with most of the same recording equipment used the night before. The amount and type of sleep you get during naps can help the sleep specialist understand complaints of sleepiness better and make decision about specific sleep disorders and treatments.

Be sure to find out whether you will be staying at the centre the next day so you can plan ahead. Call the centre in advance to find out specific breakfast and lunch arrangements and the approximate time you will be able to leave. You may also want to ask about activites you may undertake between naps.

“Many hours of work are required by specially trained professionals in order to fully understand the significant amount of data gathered from you during the night”.

What happens after my sleep study?

The sleep study and its analysis and interpretation are part of a complex process. Many hours of work are required by specially trained professionals in order to fully understand the significant amount of data gathered from you during the night. A sleep technologist processes or “scores” the large amount of data recorded during the study. A sleep specialist with a special knowledge of sleep and its disorders then interprets the information.

A typical sleep study comprises approximately 1000 pages of data of various kinds (for example, brain waves, muscle movements and eye movements) that must be reviewed in detail. Because this is a time consuming and labor intensive process, sleep studies are usually not evaluated immediately and it may take some time to receive the results of your study. A representative from the sleep centre should be able to give you an idea when the results will be available.

The feedback you receive after your sleep study varies from centre to centre. You will likely receive feedback from your sleep disorders specialist in the form of a follow-up appointment or telephone call. If your sleep specialist is not your regular healthcare professional, you should also have a face to face appointment with your regular healthcare provider.