The Sleep Lab Experience

We spend about 1/3 of our life sleeping. For this reason we can deduce that sleep is a fairly important phenomenon that helps repair and restore our bodies. Often abnormalities in sleep can disturb our daytime lifestyle. Doctors may request a sleep study for a number of reasons but ultimately it is to try and determine if there is a problem occurring during a persons sleeping hours. This link is designed to help patients and their families understand what a sleep study is, why it has been requested and what might happen during their night in the sleep lab.

What is a sleep study and why might I need one?
What happens at the sleep Lab?
Sleep Techs, what do they do?
What happens now?
Frequently asked questions

What is a sleep study and why might I need one?

Following an examination and a thorough history by your doctor, you may be referred to a sleep disorders specialist. Your doctor might refer you to a sleep specialist for some of the following reasons:

You are very sleepy during the day, even after a long nights sleep
Your partner reports loud snoring or breathing pauses when sleeping
Your partner reports you thrashing about during the night (restlessness)
You experience choking sensations when sleeping
You wake with a morning headache
You feel depressed and/or your memory is poor

Before a diagnosis can be made on why you might experience some of these things a sleep study or polysomnography (PSG) should be performed.

A sleep study is an overnight procedure performed in a sleep unit/laboratory. The sleep study allows extensive monitoring of your bodies' activities while you sleep and allows a sleep specialist to determine whether any abnormalities are present in your sleeping pattern, muscle activity or breathing during the night. In some instances a sleep lab may have the ability to test people in their own homes or in other areas of the hospital with portable monitoring equipment.

What happens at the Sleep Lab?

The sleep unit consists of several private bedrooms outfitted with simple non-invasive monitoring equipment used to monitor brain, muscle, heart and breathing activity during sleep. Prior to sleep, the staff will attach several monitoring leads to you, then work through the night in an adjacent room to observe the recordings.

Some of the activities of the body monitored during a sleep study usually include the following:

Brain activity (electroencephalogram, EEG)
Muscle activity (electromyogram, EMG)
Heart activity (electrocardiogram, ECG)
Eye activity (electrooculogram, EOG)
Chest and stomach movements
Airflow at nose and/or mouth
Body oxygen level (light transmission through finger/ear-lobe)
Sleeping position

Picture of a patient wired up for a sleep study in preparation for being monitored

If the sleep technician easily confirms that you have sleep apnea in the early part of the night you may have what is called a ‘split-night study' (half diagnosis, half titration). After about 4 hours of observing how you sleep the technician will wake you to initiate CPAP. While on CPAP the technician will continue to monitor you and measure the effectiveness of this treatment. This process can be done over two full nights in some cases.

Sleep Techs, What do they do?

A Sleep Technician (sleep tech) is the person who works at the sleep lab and conducts the sleep study. Their job is to attach the monitoring equipment to you and then observe the recordings on a computer through the night. They are also there to ensure your safety throughout your stay and to answer any further questions you might have about the procedure.

What happens now?

Following your night in the lab, a qualified sleep specialist will analyze your sleep study. This involves isolating any irregularities in your sleep patterns or your breathing. Often they will be trying to determine if you stopped breathing while you were sleeping and if you did they will count how often this occurred. If you had a split night study they will compare your diagnostic portion to the treatment portion to determine how effective the CPAP was for you. A summary report will be prepared outlining these things and this will determine the severity of your condition.

Your sleep specialist will then contact you to outline their findings and discuss with you how you felt about the CPAP and what the most suitable treatment options for you.

Frequently asked questions

Does it hurt having all of these electrodes on?
The electrodes or monitoring devices are all placed on the surface of your body some are stuck on with a skin-friendly tape, others are wrapped around you with Velcro. These devices pick up either movement or your bodies' electrical activity. The procedure is in no way painful.

What do I need to bring with me?
As the procedure requires an overnight stay you should pack a bag containing any items you might require for the night such as bedtime clothing and toothbrush. You can also pack any items you might require to sleep better such as a favourite pillow.

What if I can't sleep?
Given that you are trying to sleep in a foreign environment while attached to equipment and being observed, it is understandable that you might fear that you will not sleep. It is important to accept that it may take longer than normal to initiate sleep but during a PSG almost everyone manages to fall asleep eventually. Just relax and don't worry about the wires, they are attached securely and will not come off with normal movement in bed.

What if I need to use the bathroom during the night?
This is not a problem. If you need to use the bathroom during the night you can call on the sleep technician. They will detach some of the equipment from you and group the wires together out of your way to allow you to go to the bathroom.

Can the sleep technician see what I'm dreaming?
No, although the sleep techs observe your brain activity they can only tell if you are awake or asleep. If you are asleep they can tell what stage of sleep you are in (light sleep or deep sleep) and whether you are dreaming or not but they do not know the make up of your dreams.