Sleep apnea defined
With sleep apnea, breathing pauses repeatedly occur during sleep (Apnea is a Greek word meaning calm). This can be associated with snoring but the two are not inherently linked. Those affected often do not notice their respiratory arrests. Often it is your partner or whoever sleeps in your general vicinity who will notice the breathing stops.
The stops in breathing disturb the quality of sleep so that symptoms such as severe tiredness during the day, and lack of concentration can occur. People with sleep apnea syndrome often nod off easily, especially in a quiet, boring environment. These interruptions in breathing can endanger one’s health overall. One such example is the established link between high blood pressure and lack of good sleep.
There are various therapeutic approaches. Treatment with a special breathing mask that patients wear at night has proven particularly effective.
What are the symptoms of sleep apnea?
In sleep apnea, breathing repeatedly stops during sleep. The gaps between breaths last at least 10 seconds, on average 20 to 30 seconds. However, they can also last for minutes.
Often it is your partner who notices these breathing pauses: In the typical case, the bedfellow snores loudly and regularly for a while until the breathing sounds suddenly stop entirely for a long time – only to start again with a loud snoring or breathing sound. However, sleep apnea also occurs without snoring sounds.
Snoring is not necessarily dangerous. And not every short pause for breath during sleep is alarming. Sleep apnea is defined by if more than five breathing stops occur in one hour, each lasting at least ten seconds.
If sleep apnea syndrome is suspected, a doctor should be consulted as a precaution. Untreated sleep apnea can have negative consequences – even shorten life expectancy.
Common symptom: daytime tiredness
Because those affected – often without realizing it – wake up again and again for a few seconds at night, sleep no longer provides the necessary recovery. A frequent consequence is severe daytime tiredness. Patients often feel listless, unfocused, and less able to perform. Their memory decreases. Libido and potency may be reduced.
Many patients with sleep apnea tend to nod off involuntarily and suddenly for a few seconds during the day (microsleep). This can be dangerous during work or in traffic.
Sometimes morning headaches and/or a dry mouth in the morning indicate sleep apnea.
What are the consequences of untreated sleep apnea?
If breathing stops during sleep, the body is temporarily put into a kind of alarm state. It activates the autonomic nervous system, and blood pressure and heart rate can rise.
If high blood pressure is detected, sleep apnea should always be considered as a possible trigger or factor. High blood pressure increases the risk of secondary diseases such as heart attack, heart weakness and stroke.
Because many patients with sleep apnea syndrome fall asleep easily during the day, the risk of accidents increases and performance decreases. The psychological well-being can also suffer.
What causes sleep apnea?
Doctors differentiate between two forms of sleep apnea according to the cause, sometimes a mixed form is also present:
1) Obstructive sleep apnea
The more frequent obstructive sleep apnea occurs because the airways are narrowed or blocked. The respiratory muscles receive the command from the brain to become active to take a breath. But the strength of the muscles is initially insufficient to get air through the blocked airways. The resistance in the airways is too great. A respiratory pause occurs.
The body does not receive any oxygen at this moment, so the oxygen level in the blood gradually decreases. Carbon dioxide accumulates in the tissue and blood. The body understands this and as a result, it virtually triggers an alarm and quickly regulates its activity – the person concerned shows a wake-up reaction and suddenly takes a deep breath. Respiration is once again secured – until the next respiratory arrest.
This can lead to numerous wake-up reactions per night. They are usually so short that the affected person cannot even remember them the next morning. Nevertheless, the constant interruptions to sleep are long enough to make restful sleep impossible and create restrictive daytime sleepiness.
Various factors can contribute to narrow airways or the airways being blocked:
- Anatomical peculiarities: A receding mandible can increase breathing resistance. Or an enlarged tongue or large tonsils narrow the throat.
- Obesity: Many patients with sleep apnea are overweight and a link has been demonstrated between weight and episodes of arrested breathing in the night.
- Supine position: During sleep, many muscles relax, so that in the supine position, for example, the tongue slides into the throat. As a result, it can temporarily block the airways.
- Increased muscle relaxation: alcohol, medication (e.g., sleeping pills) or drugs can contribute to muscle relaxation and thus promote sleep apnea
2) Central sleep apnea
In about one in ten cases of sleep apnea, the cause is not in the airways but in the brain – in the control center of the respiratory muscles. This form is called central sleep apnea. The respiratory muscles temporarily lack the command from the brain to become active. Only when the oxygen level in the blood drops below a critical level does the brain react and send the impulse to breathe again. Sometimes breathing is particularly shallow before the interruption (so-called Cheyne-Stokes breathing). Central sleep apnea with failure of the respiratory control unit can be caused by a stroke, for example.
How does the doctor make the diagnosis?
The doctor asks about the symptoms and personal medical history. The doctor should also examine the patient physically.
Is it possible to test for sleep apnea?
A simple orienting examination of sleep is suitable to get the first indications of sleep apnea. For this purpose, the doctor lends the patient measuring devices to take home. Before going to bed, the patient puts on measuring probes according to instructions. During the night, they register the airflow, breathing movements of the chest and abdomen, the pulse, the oxygen saturation of the blood, the body position, and sometimes snoring sounds. Possibly the results of this polygraph already point to the diagnosis of sleep apnea syndrome.
Examination in the sleep laboratory: polysomnography
The doctor can refer the patient to a sleep laboratory, where sleep is thoroughly analyzed (so-called polysomnography or a sleep-study). The patient spends one or two nights there. While the patient sleeps, many measurements are taken that are neither painful nor stressful: For example, brain waves, heart rhythm, oxygen content of the blood, and the respiratory flow to the mouth and nose are recorded. The sleeper also wears a stretching belt that registers breathing movements. By examining the eye movements, the doctor can distinguish the individual sleep phases. Blood pressure, muscle tension, body position, and snoring sounds are also evaluated.
If sleep apnea is diagnosed, further visits to the doctor are often advisable, such as examinations by an ear, nose and throat doctor, an oral surgeon or a neurologist.
The severity of sleep apnea can be measured.
The Apnea Index (AI) indicates how many breathing breaks of at least 10 seconds per hour of sleep time the patient has. In a healthy case, it is less than five per hour. The higher it is, the more severe the disease is.
The Apnea-Hypopnea Index (AHI) also includes phases of very shallow breathing. An Apnea-Hypopnea Index of 15 per hour or more is always considered pathological. An Apnea-Hypopnea Index between 5 and 15 is only considered pathological if symptoms such as tiredness exist during the day.
How is sleep apnea syndrome treated?
Sleep apnea syndrome can be treated with different methods. Which one is most suitable depends on the individual case.
In mild obstructive sleep apnea, even simple measures can help to reduce the number of breathing stops. For example, it is advisable to lose excess weight, as excess pounds can promote sleep apnea. Alcohol, smoking, and taking sleeping pills should also be avoided.
In some cases, aids that avoid lying on your back during sleep are also suitable. These include devices that send out an alarm as soon as the patient lies on his or her back or a tennis ball is sewn into the back of the pajamas. Sometimes a higher pillow can also help so that the upper body is positioned higher.
In lighter cases, or when other therapies are not effective, individually made bite splints that are worn at night (usually lower jaw protrusion splints) can be helpful.
The most effective way to treat obstructive sleep apnea syndrome is with a special breathing mask (see below). Surgery is possible in special cases.
In the case of sleep apnea syndrome, obstruction of varying severity (degree of obstruction, GdB) can be recognized depending on the case and further recommendations can be made by the physician.
Treatment of sleep apnea with a breathing mask
Often the doctor will recommend ventilation with a special mask: The patient puts on a breathing mask at night. It is connected to a device that blows room air into the nose and sometimes also the mouth with slight overpressure. This prevents the airways from collapsing and the air supply from being interrupted.
There are different types of masks. Which one fits best individually should be discussed with your doctor. There are also different ventilation methods, depending on the ventilation pressure:
- CPAP = Continuous Positive Airway Pressure
- BiPAP = Bilevel Positive Airway Pressure; the pressure is adapted to inhalation and exhalation.
- APAP = auto CPAP, the pressure is determined anew by the device with each breath
If patients suffer from a dry nasopharynx, the air may be enriched with water using a humidifier. In certain cases, often with the elderly, additional oxygen is added to the air.
Patients should learn how to use the mask under professional guidance. Instruction is usually given in a sleep laboratory by staff trained in sleep medicine. Many patients quickly get used to ventilation at night and soon feel more efficient and rested during the day. Others initially have difficulty coping with the form of treatment. It is then that good training and advice are particularly important. Sometimes it helps to test different models on masks or devices. It can also be useful to exchange experiences with other sufferers in a sleep apnea support group.
The doctor will carry out regular checks to ensure the success of the treatment.
When is surgery useful for sleep apnea?
If enlarged pharyngeal tonsils or nasal polyps are the cause of sleep apnea, these can possibly be removed surgically.
In selected cases, surgery can help to widen the airways. A variety of surgical techniques are available for this purpose. Some of them are minor surgery (minimally invasive) and are sometimes performed under local anesthesia. Others are more of a stress on the patient and require a general anesthetic.
If other therapeutic methods are not possible, a so-called tongue pacemaker may be helpful in certain cases. An implanted device stimulates the nerve that controls the tongue muscles and the so-called hypoglossal nerve. This is intended to keep the airways more open.
Doctor and patient should discuss together whether a surgical intervention appears to be sensible and which technique is the most suitable for the individual patient. Among other things, the strength and cause of sleep apnea play a role. The doctor should also provide detailed information on the possible risks of the operation, for example bleeding, infections or pain.
Areas of the upper airways are operated on. Oral surgery is also possible in some cases to treat malpositions of the upper and lower jaw.