How Do I Prepare for a Sleep Study?
Sleep clinics want you to stay as close to your night-time routine as possible in order to get the best results. Most sleep labs will give you check-in instructions a day or two before your study. This is the time to ask any questions you might have. Sleep labs will vary in what they expect from you. The following are common recommendations—however, check the instructions you are given by the sleep lab and your doctor before coming to the sleep lab.
Wash your hair before arriving to get off hair gel or other products that can interfere with the test equipment.
Arrive on time.
Pack a bag with all the items you would take for an overnight hotel stay including: Comfortable pajamas and slippers, Toiletries and Clean clothes for the next morning.
You usually can bring your own pillow and/or blankets.
Bring a bedtime snack if that is your routine and allowed by the lab.
Bring along your phone charger although you will be asked to turn it off once the sleep study starts.
Bring your medications. A nurse may call you before the study to verify your medications or to let you know to stop taking them for the test.
Make sure you have had dinner before arriving.
Bring something to eat for breakfast if you aren’t going home.
If you work nights, some facilities are able to do testing during the day.
What Happens During The Study?
To help you relax, many sleep labs try to make the rooms look more like a small hotel room instead of a hospital room. When you arrive for your sleep test, the process is often similar to checking in for any doctor's appointment. There may be paperwork to fill out, including a consent form, and you may need to present your health insurance card and/or co-pay if you have one.
Once you're checked in the sleep technician will take you to your bedroom for the night. You will be shown the bathroom and where you can put your things. You can settle in, put on your sleepwear, brush your teeth, take medications and do your usual nighttime routine.
The technician typically will then spend about 45 to 60 minutes setting you up for your sleep study. In order for your doctor to make a diagnosis of a sleep disorder and understand its severity, it is necessary to measure multiple aspects of your body’s functions during sleep—specifically, brain activity, breathing, heart rate, and leg movements. Therefore, the sleep study often includes measuring information from multiple sensors placed on your scalp (to measure brain activity and sleep), face (to measure eye movements, chin muscle activity and airflow), chest and belly (measuring breathing efforts and heart rate), finger (for oxygen levels) and legs (measuring leg movement). The specific sensors (discs, electrodes, bands) that are typically placed includes:
Wired electrodes taped around your eyes and chin to measure movements. Eye movements can help show sleep stages while chin movements might show that you grind your teeth.
Two elastic belts around your chest and stomach to measure breathing.
Small plastic tubing (like oxygen tubing) in your nose to also measure breathing.
Wire electrodes to your legs to monitor movement.
A sensor on your finger to show your oxygen levels during sleep.
EKG monitors on your chest to show heart rate and rhythm.
Each sensor or electrode will be put in place with a special sticky paste or tape. This keeps the sensors in place. Some of the wires on your face may be taped in place. If you’re sensitive to or allergic to medical tapes or glues, let the technician know ahead of time so that she can use a type that is less irritating.
The technician will help you into bed and connect the recording box to a computer so that she can monitor you from another room. To check the placement of the sensors, you may be asked to open and close your eyes, move them side-to-side, take breaths in and out and move your arms and legs.
Once you’re set up, the technician will leave you alone in your room. During the study, you may need assistance. The technician should instruct you on how to contact her. You can read, watch television, or listen to music before falling asleep. She will monitor you both using a infra-red video camera and through the information recorded on the sleep study machine (polysomnogram). If something comes loose during the night or you need to use the bathroom, the technician will come in to take care of the wires.
If the monitors show frequent breathing pauses during the first two hours of the sleep study (consistent with a diagnosis of sleep apnea), the technician may have you wear a CPAP device during the remainder of the study. During that period, she will adjust the CPAP pressure to find an optimal pressure that reduces the frequency of breathing pauses. This portion of the sleep study is called “titration”. A study where the first portion is for monitoring and the second portion for treatment is called a “split-night” study.
Sleeping During a Study
It may not be easy to get to sleep or stay asleep with all the wires and monitors hooked to your body. It may also not be easy to sleep knowing that someone is watching you. It might feel like you didn’t get any sleep at all! Even if you don’t sleep much during the study, it will be enough for the monitors to collect and return data.
However, keep these tips in mind.
Don’t worry about moving during sleep or worry about something slipping off. The sensors were placed to be secure. Even if something falls off, it usually can be easily replaced by the technician. Many times loss of a sensor doesn’t interfere with the ability of the doctor to make a diagnosis. Feel free to move to a position you find most comfortable.
With a little time, most people can get used to the feeling of the sensors. Try to think of relaxing images and not focus on the sensors or what is happening in the sleep lab. Know that this test is your first step towards getting good quality sleep—for a long time to come!
What Happens After a Sleep Study?
The sleep technician may wake you early the next morning depending on the lab’s schedule and how many hours of sleep you got. They will remove the monitors and have you do any final paperwork. Most sleep clinics have showers and changing rooms to use so you don’t have to hurry home before starting your day.
The sleep technician will not be able to share your results with you. If a sleep doctor is available there to read your results, you may be able to start any needed treatment quickly. Otherwise, results usually are provided back to your doctor over the next days—ask the technician when results usually become available to your doctor. If a sleep disorder such as sleep apnea is found, your doctor will discuss with you the treatment options available. If you did not have a split-night study, you may be asked to have another sleep study to try CPAP.
What About At-Home Sleep Studies?
In many cases, at-home sleep studies may be used to make a diagnosis of sleep apnea using equipment usable in your own home. These studies are recommended for patients with clear risk factors for obstructive sleep apnea who also do not have certain other chronic health conditions. While in-lab studies use information from changes in brain waves to determine when you are asleep and whether breathing pauses cause a sleep interruption (referred to as an “arousal”), home sleep studies don’t directly measure sleep (brain waves) but only use the recorded drops in oxygen to identify breathing pauses. In most cases, the information collected is enough to make a diagnosis. However, if you sleep poorly during the sleep study—did not get enough sleep—the study may underestimate the severity of the sleep apnea. Also, if you are a woman, not overweight, or otherwise have breathing pauses that interrupt sleep but doesn’t cause a drop in oxygen level, the study may underestimate sleep apnea. So, if you have a negative test, it is still important to discuss with your doctor the possibility needed for further assessment to make sure you are properly evaluated.
Equipment may be distributed a number of different ways (can pick up, have them delivered, etc.—depending on your insurance and local practices). In all cases you should be provided instructions on how to use the home equipment. You should ask any questions, including use of your medications during the test.
When ready to go to bed, attach the sensors as instructed. You may need to press a button on the device when you get into bed and may be asked to keep a sleep diary.
Home sleep studies are very variable in what they measure and how they work. Some include sensors that are very similar to those used in the sleep lab. Most home devices include an oxygen and heart rate monitor that is placed over your index finger. There may be other sensors used under your nose, on your chest or elsewhere.
Make sure the machines are working like they should and that all the sensors are in place. Like in a sleep lab, don’t worry about losing sensors. If you find one falls off during the night, just try to replace it when you notice it has fallen off.
When you wake up in the morning, you can remove the sensors and return them to the sleep clinic using the instructions provided. An appointment will still need to be made with your doctor in order to find out what the test results were and to discuss diagnosis and treatment options.
Cost and Health Insurance
Sleep Studies like the overnight polysomnogram used for sleepapnea can cost a lot of money. If you have insurance or Medicare they might cover most of the expense. What if finally ends up costign you will depend on the type of insurance you have and your deductible. Your insurance may also require that certain symptoms are present before the study will be covered. These are some the examples of sleep apnea symptoms that might be required:
Excessive Daytime Sleepiness
Sleep apnea episodes seen by a bed partner
Gasping or choking during sleep