What Is Obstructive Sleep Apnea?
Obstructive sleep apnea (OSA) is a condition in which breathing stops involuntarily for brief periods of time during sleep. Normally, air flows smoothly from the mouth and nose into the lungs at all times. Periods when breathing stops are called apnea or apneic episodes. In OSA, the normal flow of air is repeatedly stopped throughout the night. The flow of air stops because airway space in the area of the throat is too narrow. Snoring is characteristic of obstructive sleep apnea. Snoring is caused by airflow squeezing through the narrowed airway space. Untreated sleep apnea can cause serious health problems such as:
- heart disease
Proper diagnosis and treatment are essential to preventing complications.
Sleep apnea causes episodes of decreased oxygen supply to the brain and other parts of the body. Sleep quality is poor, which causes daytime drowsiness and lack of clarity in the morning. People with sleep apnea may also experience the following symptoms:
- headaches that are difficult to treat
- feeling disgruntled (grumpy)
Other symptoms include:
- hyperactivity in children
- worsening depression
- poor job and school performance
- loss of interest in sex
- leg swelling (called edema, which can occur when sleep apnea is severe)
Daytime drowsiness puts people with sleep apnea at risk for motor vehicle crashes and industrial accidents. Treatment can help to completely relieve daytime drowsiness caused by sleep apnea.
There are several types of sleep apnea, but OSA is the most common. OSA is more likely to occur in older people and people who are overweight. Evidence shows that weight loss causes marked improvement in symptoms. Sleeping on your back can aggravate sleep apnea.
The three types of sleep apnea are:
- Obstructive sleep apnea: This is the most common type of sleep apnea, in which the airway has become narrowed, blocked, or floppy.
- Central sleep apnea: There is no blockage of the airway, but the brain doesn’t signal the respiratory muscles to breathe.
- Mixed sleep apnea: This is a combination of obstructive and central sleep apnea.
Risk for OSA increases if you have conditions or features that narrow the upper airway. Risk factors of OSA include:
- children with large tonsils and adenoids
- men with a collar size of 17 inches or more
- women with a collar size of 16 inches or more
- large tongue, which can block the airway
- retrognathia, which is when your lower jaw is shorter than your upper jaw
- a narrow palate or airway that collapses more easily
Heart disease is more common in obese people, and obesity is a risk factor of heart disease, high blood pressure, and sleep apnea.
A diagnosis of sleep apnea begins with a complete history and physical examination. A history of daytime drowsiness and snoring are important clues. Your doctor will examine your head and neck to identify any physical factors that are associated with sleep apnea. Your doctor may ask you to fill out a questionnaire about daytime drowsiness, sleep habits, and quality of sleep. Tests that may be performed include:
A polysomnogram usually requires that you stay overnight in a hospital or a sleep study center. The test lasts for an entire night. While you sleep, the polysomnogram will measure the activity of different organ systems associated with sleep. It may include:
- electroencephalogram (EEG), which measures brain waves
- electro-oculogram (EOM), which measures eye movement
- electromyogram (EMG), which measures muscle activity
- electrocardiogram (EKG or ECG), which measures heart rate and rhythm
- pulse oximetry test, which measures changes in your oxygen levels in your blood
- arterial blood gas analysis (ABG)
EEG and EOM
During an EEG, electrodes are attached to your scalp that will monitor brain waves before, during, and after sleep. The EOM records eye movement. A small electrode is placed 1 centimeter above the outer corner of the right eye, and another is placed 1 centimeter below the outer corner of the left eye. When the eyes move away from the center, this movement is recorded.
Brain waves and eye movements tell doctors about the timing of the different phases of sleep. The phases of sleep are non-REM (non rapid eye movement) and REM (rapid eye movement). Dreaming, decreased muscle tone and movement, and paralysis occur during REM sleep.
During the EMG, two electrodes are placed on the chin: one above the jawline and the other below it. Another electrode is placed on each shin. The EMG electrodes pick up the electrical activity generated during muscle movements. Deep muscle relaxation should occur during sleep. The EMG picks up when your muscles relax and move during sleep.
A 12-lead EKG can help your doctor determine if heart disease is present. Long-standing high blood pressure can also cause changes in an EKG. Monitoring heart rate and rhythm lets doctors see if any cardiac disturbances occur during episodes of apnea.
In this test, a small device called a pulse oximeter is clipped onto a thin area of your body that has good blood flow, such as the fingertip or earlobe. The pulse oximeter uses a tiny emitter with red and infrared LEDs to measure how much oxygen is in your blood. The amount of oxygen in your blood, or oxygen saturation, decreases during episodes of apnea. Normally, oxygen saturation is around 95-100 percent. Your doctor will interpret your results.
Arterial Blood Gas (ABG)
In this study, a syringe is used to obtain blood from an artery. Arterial blood gas measures several factors in arterial blood, including:
- oxygen content
- oxygen saturation
- partial pressure of oxygen
- partial pressure of carbon dioxide
- bicarbonate levels
This test will give your doctor a more detailed picture about the amount of oxygen, carbon dioxide, and the acid-base balance of your blood. It will also help your doctor know if and when you need extra oxygen.
The goal for treatment of sleep apnea is to make sure airflow isn’t obstructed during sleep. Treatment methods include:
Weight loss gives excellent relief from the symptoms of OSA.
Nasal decongestants are more likely to be effective in mild OSA. They can help relieve snoring.
Continuous Positive Airway Pressure (CPAP)
Continuous positive airway pressure (CPAP) therapy is the first line of treatment for obstructive sleep apnea. CPAP is administered through a facemask that’s worn at night. The facemask gently delivers positive airflow to keep the airways open at night. The positive airflow props the airways open. CPAP is a highly effective treatment for sleep apnea. A dental device may also be necessary to keep the lower jaw positioned forward.
Bilevel Positive Airway Pressure (BiPAP or BPAP)
Bilevel positive airway pressure machines are sometimes used for the treatment of OSA if CPAP therapy is not effective. BiPAP machines have settings, high and low, that respond to your breathing. This means the pressure changes during inhaling versus exhaling.
Since sleeping on the back (supine position) can make sleep apnea worse for some people, positional therapy is used to help those with sleep apnea learn to sleep in other positions. Positional therapy and the use of CPAP can be discussed with a professional at a sleep center.
Uvulopalatopharyngoplasty (UPPP) involves removal of extra tissues from the back of the throat. UPPP is the most common type of surgery for OSA, and it helps relieve snoring. However, this surgery hasn’t been proven to totally eliminate sleep apnea, and it can have complications.
Tracheostomymay be done as a procedure of last resort. Tracheostomy punctures an opening in the windpipe that bypasses the obstruction in the throat.
Other surgical procedures may be required to correct structural problems in the face and elsewhere when sleep apnea doesn’t respond to treatments such as CPAP. About 75 percent of children with OSA due to enlarged tonsils or adenoids get relief from surgery. The American Sleep Apnea Association (ASAA) says that the American Academy of Pediatrics has endorsed surgical removal of tonsils and adenoids as the treatment of choice for children with sleep problems due to enlarged tonsils or adenoids.
You should always talk to your doctor if you’re experiencing daytime drowsiness or consistently having problems sleeping. OSA has many different treatment options that can make symptoms manageable. Your doctor will create a treatment plan that combines lifestyle changes and other therapies.