Have you been told by your family members that you snore loudly or that you stop breathing in your sleep? Do you feel exhausted in the morning even after you have had a full nights sleep? If so, you may be suffering from a disorder known as sleep apnea which can lead to some very serious health problems. Your doctor may be able to refer you to a pulmonologist or a neurologist who can prescribe sleep apnea testing to help you determine whether or not you have this debilitating disorder.
There are several steps that are involved in sleep apnea testing, up to and including an overnight sleep study. Before referring you for any major testing, your doctor may require you to wear an oximeter at home for a night or two. An oximeter is simply a clip attached to a small machine that you wear on your finger while you sleep. It measures your blood oxygen levels to determine whether or not they stay within normal limits while you are asleep. Lowered oxygen levels can be an indication of sleep apnea. If the oximeter results do show that your oxygen levels fall below the normal range, your doctor will probably schedule an appointment for you with a sleep center for an overnight sleep study.
A sleep study is also known as a Polysomnogram. In short, a Polysomnogram records the way your body functions while you sleep through the use of multiple tests. In most cases, the sleep study requires the patient to spend one or two nights at a sleep center. These sleep centers can be independently located or they can be integrated into a hospital environment. The actual testing areas are made to be as comfortable and homey as possible. They are set up in a similar fashion to what you find in a normal bedroom with the exception of a video camera to visually monitor you while you sleep, a microphone to monitor any sounds and to communicate with you, and the computerized monitoring equipment that is set up. Depending on the sleep center, there may be a private bathroom as well as a television set.
You will be asked to arrive a few hours before the actual testing starts in order to acclimate to your to your new surroundings. When you are ready to go to sleep, the sleep technician will prepare you for the testing by attaching multiple electrodes as well as other equipment to your body. The Polysomnogram is actually a cluster of several tests in one. :
- An Electroencephalogram (EEG) monitors and records brain activity. This test requires a total of six electrodes which are attached to the scalp using a specialized paste.
- An Electromyography, or EMG, monitors and records the electrical activity of the muscles. It tracks the tension in the muscles as well as any movement in the legs. You will have a total of four electrodes attached to you for this test. Two of these electrodes will monitor the muscle tension in the chin area while the other two will monitor the muscle behavior of your legs.
- An Electrooculograph (EOG) monitors and records eye movement. By monitoring eye movement, this test can help determine when a person falls asleep. There are a total of two electrodes attached on either side of the eyes. One will be placed above one eye and the second one will be attached below the other eye.
- An Electrocardiogram (ECG or EKG) monitors and records the electrical activity of the heart. This helps identify any abnormalities that may be present or that take place while you are sleeping. This test requires the use of three electrodes that are attached to the collarbone area or the upper waist area.
- Pressure transducers that will monitor the airflow from your mouth and nose. This will help them identify any respiratory difficulties or lapses in breathing.
- An oximeter, which as discussed above, will measure your blood oxygen levels to determine if they fall within the normal limits.
- Chest bands which will measure your body’s movements while you breath.
Once everything is in place, the electrodes, oximeter, and chest bands will be plugged into a central machine that monitors and records all of the testing that will take place. You will then go to sleep like you would at home. If your doctor requested a split-night sleep study, you will be tested for the first half of the night and if the Polysomnogram indicates that you have sleep apnea, you will be equipped with a CPAP (Continuous Positive Airway Pressure) machine for the second half of the night. The CPAP machine forces the airways open by blowing a continuous stream of air through a hose that is attached to a face mask, nose mask, or nasal pillow. Once you are equipped with it, the technicians will monitor and adjust the airflow levels until they find the level that works best for you.
If your doctor did not request a split-night sleep study and the Polysomnogram indicates that you have sleep apnea, you will be asked to return for a second night to determine how to best treat your sleep apnea. In many cases, this second night will work the same as the second half of the split night study. You will be equipped with the CPAP machine and and the levels will be adjusted until they are optimal for you. The only difference is that you will be monitored for the entire night rather than just half the night.
Once the testing is complete, you will be allowed to shower, dress, and leave the sleep center. The sleep center will forward your test results to the referring physician who will then discuss your sleep apnea treatment options with you. If you do have sleep apnea, there is a good chance that your physician will prescribe a CPAP or BiPAP (Bilevel Positive Airway Pressure) machine for you to use at home.