- What Is A Polysomnogram?
- Before Your Polysomnogram
- After Check-In
- While You Are Asleep
- Some Questions You Might Have
- In The Morning
Based on the outcome of your initial visit, you may require a polysomnogram. Other terms used for polysomnogram are PSG, sleep study, or sleep test. A night in the sleep center is necessary for evaluation of physical factors affecting sleep, commonly found in Restless Legs Syndrome (RLS), Periodic Limb Movement Disorder (PLMD), or Obstructive Sleep Apnea (OSA).
The good news is that a polysomnogram is noninvasive, painless, and lasts no more than a couple of nights. Think of it this way – you’re on your way to a diagnosis and treatment for your sleep problems.
Every sleep center is slightly different – some are private, while others are part of a hospital. In any case, you will be assigned to a testing area, and a private bedroom and bathroom. Although all sleep clinics do not perform the same tests or activities, there are consistent things to expect during your polysomnogram. Additionally, most sleep clinics will provide you with a detailed list of instructions that you should follow before your night in the clinic.
The following recommendations are standard practice before a polysomnogram:
- Do not take a nap the day before or the day of your study.
- Refrain from coffee or tea after 10 AM on the day of your appointment.
- Avoid stimulants, alcohol, or sedatives. Even though most sleep centers request that you maintain your regular medications, it is always wise to check first.
- On the day of your appointment you may shower and wash your hair.
- Avoid using any hair products, including conditioner, hair spray, or mousse. Refrain from using skin lotions and powders.
- Eat a normal evening meal before your arrival. If you normally eat a small snack before bed, check with the sleep center to see if you may bring one with you.
- Bring comfortable and modest nightclothes. If you do not bring your own nightclothes, a hospital gown will be provided for you.
- Bring any items that will help you feel at home, such as your own pillow, personal hygiene items, slippers, or a robe.
Most sleep centers require that patients complete a sleep questionnaire about their sleeping habits, the day’s events, medications taken, and so on. This may occur before your sleep study or shortly after your arrival at the sleep center.
After you check-in and get your belongings settled, a polysomnographic technician will ask you to change into your nightclothes or a hospital gown. Small sensors or electrodes will then be attached to parts of your head and body. (A glue-like substance called collodion is usually used; however, it can be removed easily and painlessly with fingernail polish remover after the procedure.) Flexible wiring is attached to the sensors, which is then connected to a central unit. A monitoring area is located close to your room. Once all of the sensors, electrodes, and belts are attached, the technician will take some initial readings while you are awake.
The attached sensors monitor and record various physical activities, such as heart activity and rate (EKG), eye movements (EMG), muscle activity, breathing, leg movements, and blood oxygen levels. More or fewer characteristics may be studied depending on your symptoms.
So, what are all the sensors for and what are they recording? Depending on the symptoms you have described to the sleep specialist, some or all of the following will be monitored:
- Brain activity – Multiple sensors attached to your head record your brain waves. This reading shows the technician which sleep stage you are in.
- Airflow – A sensor placed on your upper lip monitors the airflow and temperature from your nose and mouth. For patients that suffer from apnea, these sensors show a flat reading when there is no airflow. The temperature can determine when you inhale or exhale (inhaled air is cooler than exhaled).
- Neutral area – A sensor clipped to your ear is used as a neutral reading; the ear is a part of the body that does not move much during sleep.
- Rapid eye movements – One or two sensors placed near the eyes record rapid eye movements (REM), which are associated with dreaming and deep sleep.
- Breathing – Elastic belts around your chest and stomach will measure your respiratory effort.
- Muscle tone – Muscle tone and relaxation are measured with one or more electrodes attached to your chin. It is important that this reading is low during REM sleep, the period when your muscles should be paralyzed. This reading also helps technicians determine which stage of sleep you are in.
- Heart rate – Your heart rate and activity are monitored with multiple sensors attached to your chest or back.
- Oxygen level – An oximeter (or oxymeter), a device that measures oxygen levels, is clipped or taped to either your finger or earlobe. In patients with sleep apnea, this measurement can determine how serious the apnea episodes are.
- Leg movements – If RLS or PLMD is suspected, sensors will be placed on your legs, usually near the knee.
- Body position and movement – The last area observed is your body position and any other activities.
You may be videotaped while you sleep. In any case, one or more technicians will observe you the entire night while you sleep. Technicians note if you snore and how loudly, if you kick violently, or if you have periodic movements. They also chart your sleep stages and other measurements.
The next step is for you to get comfortable and go to sleep!
- Can I get shocked from the wires and sensors? No. It is impossible because the electrodes and sensors detect the electrical and physical signals that you produce. There is no electricity being sent through the wires to the sensors on your body.
- What if I need to go to the restroom during my sleep study? Don’t worry – disconnecting the wires to the nearby unit is a fairly quick process and a technician is always awake and available to help you. However, it is a good idea to avoid drinking any fluids after 6 p.m.
- Will I be able to sleep during my polysomnogram? This is a very common question. Most people doubt their ability to sleep in the lab, especially if they are unable sleep at home. However, polysomnographic technicians claim that most patients sleep better in the lab than at home. It could be due to the patient’s outlook that “I’m not going to be able to sleep here, so I’ll just stay awake,” which predictably leads to sleep, or the fact that some people feel more secure or less distracted in the lab than at home. Some individuals are simply relieved that someone is taking an interest in their problem, it will soon be diagnosed, and he or she is on the road to better sleep. Even if you do not sleep well in the lab, polysomnographic testing will still be able to determine a great deal of information.
After you wake up in the morning, the technician will help you remove the equipment and the glue-like substance. You may be asked to complete another questionnaire about your night’s sleep, such as how many hours you felt you slept, whether you slept well, or how long you think it took you to fall asleep. Some patients need to spend more than one night in the sleep lab. If that is the case, the patient will leave the center, perform his or her regular activities, and return later that afternoon to repeat the process. After your polysomnogram, you are able to resume your normal activities as soon as possible.
The technician and the sleep specialist review how long you spent in each stage of sleep, when and how long you dreamed, the amount and level of snoring, body movements, and a host of other activities. Because of the enormous amount of data collected from your sleep study, you will be asked to make a future appointment with the sleep specialist to discuss your results and treatment options.