This is a brief explanation of the procedure for sleep apnea testing and the methods that may be used to treat it. CPAP therapy is described and images of the most common devices are provided.
If daytime sleepiness is a common occurrence, there is the potential that sleep apnea may be the culprit. Although the incidence of this disorder is more common in men, women are also affected. Some other contributing factors can be aging, obesity or just having a shorter and/or thicker neck, however some patients present with none of these factors
There are two types of sleep apnea. The central type and the more common obstructive type. In central apnea, there is usually a neurological cause, for during sleep, there are pauses in breathing with no inspiratory effort. Fortunately this is not seen often. More commonly, the patient will experience obstruction of the airway during sleep, especially during periods of REM. REM or Rapid Eye Movement sleep is a stage of sleep that can occur several times during the night but is most prolonged in the last hour or two. The brain waves change during REM sleep and vivid dreams may be reported. The body becomes paralyzed and the eyes can be seen twitching. If a person has sleep apnea, it will be at its worst during the stage of REM.
In obstructive sleep apnea, the tongue and other soft tissues relax and block the airway. When a person is awake, muscle tone keeps the airway open, but during sleep, airflow is blocked. The affected person will unconsciously try to take a breath, at first shallowly but stronger with each effort until the obstruction is overcome, usually with a loud snort. This can happen hundreds of times during a night and can effectively disturb sleep, often without a person's knowledge. All they know is that they are tired every day and don't understand why. Chronic sleep apnea, if allowed to persist, can result in other health problems down the road.
Fortunately there is treatment for this condition which is helpful for most sufferers. Is is called CPAP or BIPAP therapy. CPAP stands for Continuous Positive Airway Pressure and BIPAP is Bilevel Positive Airway Pressure. CPAP is sufficient most of the time. It is administered via a bedside machine that delivers air through a corrugated tube which attaches to a mask made from plastic and silicone. The system is pressurized and holds the airway open during sleep.
There are several types of masks available for CPAP therapy and many different manufacturers. The most common masks or treatment devices are the full face mask, the nasal mask and the nasal pillows. Because each person's facial anatomy is different, it may be necessary to try several sizes and types to find the right fit.
Full Face Mask with Headgear
Nasal CPAP mask
Nasal Pillow CPAP Device
In the United States, CPAP equipment requires a prescription. If a physician suspects sleep apnea, the person will be referred to a sleep lab or clinic. The patient will be expected to spend at least one night but it more often takes two.
The patient will arrive at the appointed time and be assigned a bedroom in the clinic. A trained sleep technician or respiratory therapist will then take the history and ask appropriate questions to be aware of any medical conditions, allergies or concerns the patient may have. Some patients are accustomed to taking a sleep inducer prior to bedtime. The doctor may or may not want this and should be consulted prior to the study.
The preparation for the study consists of electrodes placed on the head to monitor the brain waves, on the chest to monitor EKG and on the extremities for detection of movements during the night. Two other monitors will be strapped around the chest and abdomen so that respiratory effort can be seen. A flow sensor will be taped below the nostrils to detect depth of breathing. A blood oxygen sensor will be worn, usually on a finger. Patients may be concerned about not being able to sleep with so many wires attached, but the majority are able to relax and fall asleep. An infrared camera is kept in the room so the technician can see the patient and a speaker is always on so the patient can communicate anytime of the night.
Usually the first night will serve for monitoring purposes. Many physicians prefer to see a full night of sleep without any breathing augmentation. Sometimes this is required for insurance purposes as well. A record will be made of the study which will be reviewed by the doctor. The second night, the patient will again be outfitted the same way but in addition, will wear a CPAP or BIPAP device to bed. It is important that the device be comfortable but also conform snugly to the patient's face so that there are no leaks. Elastic straps with velcro are used to hold the mask on.
The pressure will be set on low at first until the patient falls asleep, then will be adjusted by the technician outside of the room. Sometimes very little increase is needed but some patients with severe sleep apnea will require more. If, during the night, a large leak develops, it will be necessary for the technician to come in the room to adjust the mask or try something different.
By morning, the optimal pressure should have been reached and the results will be sent to the physician. After everything is reviewed, the physician will order the equipment and the patient can go pick it up, usually at a store that deals in medical equipment. The patient needs to understand how to care for the equipment and should ask for instructions at the time of purchase. Some machines have humidifiers. This is optional and should be discussed with the ordering physician.
Most patients successfully using CPAP therapy say they feel better and have more energy. Their sleep partners, where applicable, also rest better because they are no longer being awakened by loud snoring and thrashing throughout the night. By alleviating sleep apnea, it is possible that other potential long-term health problems may be avoided as well.
by Marilyn Eisele, Registered Respiratory Therapist
Reference: personal experience working in sleep lab