Sleep Apnea Clinic – What You Need to Know

A sleep apnea clinic is a diagnostic facility designed to identify the presence of sleep apnea, narcolepsy and other sleep disorders such as periodic limb movement disorder. A sleep apnea clinic is often located inside a hospital but many free outpatient units also provide quality services.

If your doctor recommends that you visit a sleep apnea clinic and have a Polysomnography test, here’s what you can expect. First, a Polysomnogram (PSG)  test or sleep study measures body functions during sleep. Sleep studies can be performed during the day or night but most sleep apnea clinic work is conducted at night so your normal sleep patterns can be studied. Daytime, attended sleep studies which I’ll discuss late are usually administered to identify other sleep disorders such as narcolepsy. Here’s an excellent, short video that describes what happens at a sleep apnea clinic:

Sleep Apnea Clinic Diagnostics

As the video explains, when you report to the sleep apnea clinic on the evening of your sleep study, you will likely be assigned to a private room where you will sleep that night. A sleep technician will make sure you are comfortable and help get you ready for the test. The sleep technician will spend about one to two hours getting you ready and attaching a variety of sensors to your body. These sensors will measure a number of body functions including:

• Eye Movements
• Heart rate
• Brain wave Activity
• Levels of Oxygen in Your Blood
• Muscle movement
• Breathing (nose/mouth and chest movement)
• Movement of your arms and legs
• Video and audio monitoring

The sleep technician will be present throughout the night monitoring the various sensors and analyzing the data being collected while you sleep.

In the morning after the sleep study is completed, you will be able to clean up, leave the sleep apnea clinic and get on with your day. The data from the Polysomnography test will be collected and analyzed by the sleep technician and your physician. Here’s what they will be looking for.

Signs of sleep disruption and any episodes of abnormal breathing will be scrutinized and measured. An Apnea-Hypopnea Index (AHI) and a Respiratory Disturbance Index (RDI) will be calculated. The Apnea-Hypopnea Index measures the average number of apnea (suspended breathing) and hypopnea (very shallow or low number of breaths) events per hour of sleep. The Respiratory Disturbance Index measures other abnormal events (Respiratory Event Related Arousals or RERAs) that disrupt normal sleep and cause a sleeping person to arouse while also measuring the number of apnea and hypopnea events that occur. If you have an AHI score of between 5-15, it indicates you have mild sleep apnea. An AHI score of 15-30 indicates moderate sleep apnea and scores over 30 indicate you have severe sleep apnea.

Types of Sleep Apnea Clinic Studies

A sleep apnea clinic can conduct several types of evaluations and studies. These include a Diagnostic evaluation to determine the presence of sleep apnea, a CPAP or BIPAP Titration evaluation which is used after sleep apnea is diagnosed to calculate how much air pressure is needed using a sleep apnea machine to keep your airways open during sleep and a Split Night Study which is a combination of the Diagnostic and CPAP/BIPAP Titration studies.

Other Types of Sleep Studies Administered by a Sleep Apnea Clinic

Daytime Studies

As mentioned previously, a sleep apnea clinic can also perform sleep studies during the daytime. There are two specific studies that can be performed in the day by a sleep apnea clinic; the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test.

• Multiple Sleep Latency Test (MSLT)

The MSLT is primarily used to diagnose narcolepsy. A sleep apnea clinic will administer the MSLT to measure sleepiness  (how long it takes someone to fall asleep) and how fast you enter the REM stage of sleep.  This test has the patient undergo several periods of scheduled naps and measures the average time it takes the patient to fall asleep. While asleep during these scheduled naps, the patient is also analyzed to see if they fall into REM sleep, as most people must be asleep for a longer period of time than these naps allow before they enter REM. One feature of narcolepsy is rapid onset of REM sleep. If the tests indicate the occurrence of two or more episodes of REM sleep, this can be an indicator of narcolepsy.

• Maintenance of Wakefulness test (MWT)

Another test that can be performed at a sleep apnea clinic is the Maintenance of Wakefulness Test or MWT. Unlike the sleep latency test which measures your ability to fall asleep, the MWT measures and analyzes your ability to stay awake. This test is often performed at a sleep apnea clinic to determine how well a patient with a sleep disorder is responding to treatment. It can also be administered to test if the patient is safe to perform tasks such as driving or operating machinery.

A sleep apnea clinic performs a vital function in the identification and diagnosis of many sleep disorders. With the increased recognition and appreciation for the important role sleep plays in all of our lives, more doctors are turning to a sleep apnea clinic to help them successfully analyze and treat their patients sleep disorders. If you suspect you or a family member may have sleep apnea or other sleep related problems such as snoring, talk with a physician or a sleep specialist. Many hospitals have opened sleep clinics to better serve their patients. Find out if there is a sleep apnea clinic near you that can help.

Tags: continuous positive airway pressure, narcolepsy symptoms, obstructive sleep apnea, sleep apnea clinic, sleep apnea cures, sleep apnea machine, sleep disorder