Overnight Sleep Studies
Table of Contents
A visit to a sleep disorders facility for a sleep study is likely to be a new experience for you. A sleep study, or polysomnogram, (somnus = sleep) is a recording that includes measurements used to identify different sleep stages and classify various sleep problems. We urge you to learn more about sleep testing procedures before you arrive at the sleep disorders center so that your experience there will be easy and interesting.
Sleep is not a simple process. Many parts of the brain control it and influence 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.
During sleep testing, the activities that go on in your body during sleep (brain waves, muscle movements, eye movements, breathing through your mouth and nose, snoring, heart rate, and leg movements) are monitored by small metal discs (called electrodes) applied to your head and skin with an adhesive. Flexible elastic belts around your chest and abdomen measure your breathing. A clip on your index finger or earlobe monitors the level of oxygen in your blood and your heart rate. Your sleep will also be videotaped for later review of any abnormalities observed during the study.
None of these devices are painful and all are designed to be as comfortable as possible. If you have questions or concerns about the application of the electrodes (if, for example, you use a hearing aid or wear a hair piece), contact your doctor or speak with the technician before you arrive at the center.
In order to fully understand your sleep and any problems with it, we need to look at various brain activities and body systems and their relationships throughout the night. After the study, a sleep specialist will review and interpret the record to help you with your specific sleep patterns. Treatment recommendations will be made if evidence of a sleep disorder is found.
The sleep study and its' analysis and interpretation are part of a complex process. Specially trained professionals, including sleep technologists who process or "score" the large amount of data recorded during the study, require many hours of works. A sleep specialist with special knowledge of sleep and its' disorders then interprets the information. A typical sleep study involves more than 800 pages of data and various kinds (for example, brain waves, and muscle movements). 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 center should be able to give you an idea when the results will be available.
This is the question asked most frequently by patients prior to their sleep studies. Many people expect their sleep center to be cold, bright, technical and impersonal-looking. At most sleep centers, however, the surroundings (and especially the bedroom) are homey and comfortable, like a hotel room.
The technical equipment and technicians will be in a room separate from your sleeping room, and the electrode wires will be gathered together in a kind of ponytail behind your head so that you will be able to roll over and change positions as easily as you would at home.
On the day of your sleep study, avoid caffeine (coffee, tea, cola, chocolate) after 2:00 p.m., and try not to nap. Before coming to the sleep center, wash and dry your hair, and do not apply hair sprays, oils or gels.
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 recognizes that your sleep in the center maybe not be exactly like your sleep at home. This usually does not interfere with obtaining the necessary information from your study.
Before coming to the center, you should pack an overnight bag, as you would for an overnight stay at a hotel or friend's house. You may wish to include extra clothing. We require that you do NOT bring any pillows or blankets from home for health reasons. If you have special needs, advise the sleep center personnel so they can accommodate you.
When you arrive at the center, usually between 9:00 and 9:30 p.m., 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 technicians of any changes in your sleep or specific difficulties you have not already discussed with your healthcare professional. You will have time to change into nightclothes and get ready for bed as you do at home. There may be a waiting period before the technician applies the electrodes, and you can read, watch TV or relax during this time. If you have a commitment in the morning (if, for example, you have to work at a certain time), be sure to inform the sleep technician prior to your study, so a wake-up call can be arranged. Your wake-up time should also be confirmed when you arrive at the sleep center.
While you are sleeping, various important body functions and measurements are recorded. The technician will monitor your sleep throughout the night from a nearby room. 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, you will be notified before you go to bed, and the use and purpose of the device will be explained.
This device, called a positive airway pressure (PAP) device, includes a small mask that fits around your nose or your nose and mouth. You can find out whether you will be having a PAP trial during your study by asking your healthcare professional or sleep center staff. If you will be trying PAP during your sleep study night, the technician will adjust the mask in advance to make sure it fits comfortably, and will usually give you a chance to practice with the device before you go to bed.
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 center for most 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 decisions about specific sleep disorders and treatments.
Be sure to find out specific breakfast and lunch arrangements and the approximate time you will be able to leave.
It is important for your sleep professional to know if you are taking any prescribed or over-the-counter medication, since certain medications can affect the sleep and the interpretation of a sleep study. Sometimes certain medications need to be discontinued gradually prior to a sleep study so that the results can be interpreted correctly. Do not discontinue any prescription medication without first talking with your healthcare professional. Be sure to avoid coffee and alcohol on the day/evening of the study, unless directed otherwise by your physician.
You will have a consultation visit with a sleep medicine specialist to discuss the results and recommendations for treatment. Be sure to inquire before your study about scheduling a consultation visit. Sleep study results are not generally discussed over the telephone because of their complex nature.
To fully understand the results of your sleep study, their implications, and any treatment recommendations that are made, you should meet face-to-face with a sleep specialist. Additional procedures are occasionally needed to establish a diagnosis or evaluate a treatment. Your sleep specialist will inform you if this is the case.
We hope that your experience at our clinic will be a good one. Understanding the sleep process and the evaluation will help you take an active and positive role in your own care.
Courtesy of the American Academy of Sleep Medicine (http://www.aasmnet.org)