Sleep Study: What To Expect During Your Nap

Sleep studies, also known as polysomnography, are used to help diagnose sleep disorders such as sleep apnea, restless legs syndrome, narcolepsy, and insomnia. They are typically performed overnight in a sleep lab or hospital, and involve monitoring various body functions during sleep, including brain activity, eye movement, heart rate, and breathing patterns. The process involves attaching sensors to the patient's head and body to record information while they sleep. The data is then evaluated by a doctor to determine the presence of any sleep disorders.

Preparation: Avoid caffeine and alcohol, don't nap, and follow your usual routine

Preparation for a Sleep Study

If you are scheduled for a sleep study, there are a few things you should do to prepare. Firstly, avoid consuming any caffeine or alcohol. Caffeine should be avoided from the afternoon onwards, or at least eight hours before your sleep study. Alcohol should not be consumed on the day of your sleep study. Both substances can disrupt your normal sleep patterns and affect the results of the study.

Secondly, do not take any naps during the day. Napping will make it harder for you to fall asleep during the study, which is crucial for accurate results.

Thirdly, try to stick to your usual daily routine as much as possible. This includes following your regular diet and daily activities. However, there are a few exceptions to this: besides avoiding caffeine and alcohol, you should also refrain from using any hair products, such as hair gel or hairspray, as these can interfere with the monitoring equipment. Additionally, if your healthcare provider has instructed you to stop taking any medications, be sure to follow their instructions.

Packing List

When preparing for a sleep study, you should also pack certain items, just as you would if you were staying the night at a hotel. Here is a packing list to help you prepare:

• Medications that you usually take at night or in the morning, which your healthcare provider has approved for continued use during the test
• Comfortable sleepwear, such as pyjamas, and slippers or non-skid socks
• Clothes to change into the next day
• Your favourite pillow or blanket, if desired
• A bedtime snack (there may be a small refrigerator in your room)
• A book or other reading material, if it is part of your nighttime routine
• Breakfast, as coffee or juice may be provided, but food may not be
• Your usual toiletries, such as a toothbrush and toothpaste

Other Considerations

It is important to note that you will not be able to have anyone stay with you overnight during the sleep study. However, exceptions may be made for parents of children undergoing the study or patients with conditions that make it unsafe for them to be alone, such as dementia.

Additionally, you will not be able to bring pets, with the possible exception of service animals, which require proper documentation.

Remember to follow any specific instructions provided by your healthcare provider or sleep centre, as there may be additional preparations or restrictions to consider.

Arrival: Check-in, get set up with sensors, and relax before bed

When you arrive for your sleep study, the check-in process will be similar to checking in for a doctor's appointment. There may be some paperwork to fill out, including a consent form, and you may need to present your health insurance card.

Once you're checked in, a sleep technician will take you to your bedroom for the night. They will show you the bathroom and where you can put your things. You will then change into your sleepwear and go through your regular bedtime routine of brushing your teeth and washing your face.

The technician will then spend about 45 to 60 minutes setting you up with sensors for your sleep study. This involves attaching sensors to your head and body to monitor your brain activity and other selected information from your body. The sensors are attached with a sticky, electrically conductive gel coating or medical-grade glue or tape. The technician will also apply a mild abrasive paste to your skin to help the sensors adhere properly.

The sensors may include:

• Electrodes on your head to measure brain activity
• A flat, plastic microphone taped to your neck to record snoring
• Sticky pads on your chest to monitor your heart rhythm via an electrocardiogram (EKG)
• Stretchy cloth belts across your chest and stomach to measure breathing
• Sticky pads or electrodes on your shins or forearms to monitor muscle movements via electromyography (EMG)
• A peripheral capillary oxygen saturation monitor (usually clipped to a finger) to measure continuous oxygen saturation
• An electro-oculogram (EOG), which uses electrodes placed near the eye to measure eye movements
• A nasal cannula (plastic tubing that sits in the nose) to measure airflow while you sleep
• A thermistor, a pronged wire that sits in the nostrils and measures temperature changes

The wires from these sensors will be connected to a small, portable box that you can carry with you if you need to get out of bed. The technician will then test the equipment by asking you to open and close your eyes, move them around, snore, breathe in and out, and move your arms and legs.

Once you're all set up, the technician will leave you to relax, read, watch TV, or listen to music until it's your bedtime or you feel drowsy enough to sleep.

Sensors: Electrodes monitor brain waves, breathing, movement, and more

Sleep studies, also known as polysomnography, involve the use of sensors and electrodes to monitor various aspects of an individual's sleep. These sensors are placed on the body and head to record multiple systems, including brain activity, eye movement, heart rate, breathing patterns, and body movements. The data collected provides valuable insights into sleep patterns and quality, aiding in the diagnosis and treatment of sleep disorders.

Electrodes and Sensors: Monitoring Brain Waves, Breathing, and Movement

During a sleep study, electrodes—small metal discs with wires attached—are strategically placed on the sleeper's head and body. These electrodes are essential for monitoring brain waves and various body functions. Here's a closer look at what they track:

• Brainwave activity and sleep stages: Electroencephalograms (EEGs) are used to measure electrical activity in the brain. The electrodes are placed at specific points on the scalp and face, allowing technicians to record brain waves and identify different sleep stages.
• Breathing: Sensors are applied to detect air movement through the mouth and nose. Respiratory inductive plethysmography (RIP) belts are also used to measure the expansion of the torso during breathing.
• Heart rate and rhythm: Electrocardiograms (EKG or ECG) are employed to monitor the electrical activity of the heart and detect any issues with its beating pattern and internal electrical system.
• Eye movement: Electro-oculography (EOG) uses adhesive sensors placed around the eyes to track eye movements during sleep.
• Muscle movement: Electromyography (EMG) sensors are attached to the skin, typically on the face and legs, to monitor muscle movement without activating them.

These sensors and electrodes work together to provide a comprehensive view of an individual's sleep, helping healthcare providers diagnose and treat a range of sleep disorders and related conditions. The data collected can reveal insights into sleep patterns, disruptions, and potential underlying issues, contributing to a better understanding of sleep health.

Overnight: A technician monitors you and can assist if needed

A sleep study, or polysomnography, is an overnight test that monitors brain and body activity while you sleep. The test is conducted by a technician who monitors your sleep and can assist if needed. Here's what you can expect during the overnight study:

Before the Study

On the day of your sleep study, it is recommended to follow your regular diet and daily routine with a few exceptions. Avoid caffeine and alcohol after lunchtime, as they can interfere with your sleep. Also, refrain from taking naps during the day. Wash your hair to remove any styling products that may interfere with the monitoring equipment. If instructed by your healthcare provider, stop taking any regular medications. Pack comfortable sleepwear, toiletries, and other personal items, just like you would for an overnight stay at a hotel.

During the Study

When you arrive at the sleep center or lab, a sleep technician will take you to your room for the night. They will show you the bathroom and where to place your belongings. You will then change into your sleepwear and go through your regular bedtime routine. The technician will spend about 45 to 60 minutes setting up the equipment for the study. They will measure your head and mark the spots where electrodes will be attached. These electrodes are small metal discs with wires that monitor your brain waves, breathing, and body movement during sleep. In addition to the electrodes, the technician may also set up the following:

• A microphone to record snoring
• Sticky pads on your chest to monitor heart rhythm
• Elastic belts across your chest and stomach to measure breathing
• Sticky pads or electrodes on your shins or forearms to monitor muscle movements
• A peripheral capillary oxygen saturation monitor, usually clipped to a finger, to measure oxygen levels
• An electro-oculogram (EOG) to measure eye movements

All these wires will be connected to a portable box that you can carry if you need to get out of bed. The technician will help you into bed and connect the box to a computer so they can monitor you from another room. There will be a small infrared camera and a two-way speaker in the room for communication and assistance.

During Sleep

If a wire or sensor comes loose during your sleep, the technician will come in, wake you, and reattach it. They will also check on you if they observe any signs of a serious problem, such as a seizure or medical emergency.

After Sleep

In the morning, the sleep lab personnel will help disconnect and remove the sensors. You can then change into your clothes and leave the sleep lab. The data collected during your sleep will be evaluated by your doctor, and you will receive the results within a few days to a few weeks.

The sleep study is a non-invasive procedure that helps diagnose various sleep disorders, including sleep apnea, restless leg syndrome, and narcolepsy. It is important to follow the instructions provided by your healthcare provider and the sleep technician to ensure accurate results.

Results: A doctor interprets the data and discusses results and treatment

After the sleep study, a doctor will interpret the data and contact you to discuss the findings. They will determine whether your results indicate a sleep disorder and recommend next steps. This may take up to two weeks, and they will likely discuss treatment options with you at a follow-up appointment.

Sleep studies can be used to diagnose many sleep disorders, including sleep apnea, restless legs syndrome, narcolepsy, insomnia, and nighttime behaviours like sleepwalking and REM sleep behaviour disorder. Sleep studies can also be used to monitor a patient's response to treatment.

If you are diagnosed with a sleep disorder, your doctor will discuss treatment options with you. For example, if you are diagnosed with sleep apnea, your doctor may recommend continuous positive airway pressure (CPAP) therapy. This involves wearing a breathing mask at night to help keep your airways open.

Your doctor may also recommend lifestyle changes to improve your sleep, such as avoiding caffeine and alcohol, maintaining a consistent sleep schedule, and establishing a relaxing bedtime routine.

If you have been previously diagnosed with a sleep disorder and are undergoing a follow-up sleep study, your doctor will interpret the data to determine whether your current treatment is effective and make any necessary adjustments.

Frequently asked questions