What is sleep apnea and how is it treated?
Sleep apnea is a class of breathing disorders identified by the respiratory arrest and cessation of the lung ventilation during sleep for more than 10 seconds. Usually, it lasts for 20-30 seconds but in severe cases, it can last for 2-3 minutes and take up to 60% of the whole night's sleep time.
In regular apnea that usually occurs not less than 10-15 times per hour, it causes a violation of the sleep quality and daytime sleepiness, memory and other cognitive functions impairment, loss of productivity and chronic fatigue.
There are two main types of sleep apnea – obstructive and central apnea. There are also mixed forms.
Central apnea description
Central apnea occurs as a norm, usually when falling asleep and during the REM sleep phase (rapid eye movement or desynchronized sleep phase). In healthy individuals, central apnea episodes are rare and are not supplemented by other pathologies or symptoms. If there are violations of the functioning of the central mechanisms of breathing regulation, there is likely to be obstructive sleep apnea with the respective picture of symptoms.
Obstructive sleep apnea (OSA)
The constriction of the upper respiratory ways during sleep predisposes to OSA. This type of apnea is defined by the physical obstruction of the airways during sleep repeating multiple times per night and resulting in lowered saturation of the blood with the oxygen.
The episodes of stopped breathing are called “apneas”. If the duration of apnea is more than 10 seconds, hypoxia (low oxygen content in the body or individual organs and tissues) and hypercapnia (excess CO2 in the blood; carbon dioxide intoxication) with metabolic acidosis (shift of the acid-base balance of the body with an increased acidity) followed by the progression of changes as the duration of apnea increases.
At a certain moment of these changes, a person wakes up or shifts to the light sleep stage of sleep in which the tone of the muscles of the pharynx and mouth increases with the restoration of patency of the pharynx. This is followed by a series of deep breaths, usually, with intense snoring. As the blood gas composition normalizes, a deeper sleep phase begins.
The arterial pressure of people with OSA does not lower during sleep. On the contrary, during apneas it can sharply increase making the condition especially dangerous for people with arterial hypertension, ischemic heart disease, and diabetes, who are, commonly, exactly the people who develop OSA.
In some cases (up to 10%), obstructive apnea results in pulmonary hypertension with right ventricular failure, chronic high level of CO2 and low level of oxygen and generalized bronchial obstruction. Combined with obesity (one of the risk factors for the condition development) and drowsiness, the condition is called obesity hypoventilation syndrome (OHS), also known as Pickwickian syndrome.
Diagnosis of OSA
The basis for the diagnosis of OSA is the following parameters and tests:
- Excessive body mass with the body mass index around 30.
- Arterial blood gas measurement shows high content of carbon dioxide, over 45 mmHg or 6.0 kPa. (prior to this test, due to its difficulty, a preliminary test of venous blood for bicarbonate levels can be done and if it shows the elevated level (27 mmol/l or higher) then arterial blood is tested).
- If there are no other reasons for the reduced inflow of oxygen in the lungs (for instance, use of drugs, thyroid diseases, or others).
If all of these parameters comply, a doctor then appoints the tests for the diagnosis confirmation:
- Lung tests such as X-ray or CT to exclude other lung conditions that can result in lowered oxygenation and high CO2.
- Sleep analysis tests such as Polysomnography and multiple sleep latency test to identify the pattern of sleep, number of apneas per sleep, and other important indicators to determine the severity of the condition.
Treatment of OSA
The main therapeutic method of OSA is Constant Positive Airway Pressure (CPAP) therapy implemented with the use of special devices that can be used at home. These devices push the air down the airways creating constant positive pressure. It ensures the prevention of respiratory arrests during sleep.
There are also data on the elimination of snoring, daytime sluggishness, and sleep apnea in people who play an Aboriginal people traditional wind instrument didgeridoo that is believed to train the upper airways because of the specific breathing technique needed for playing the instrument.
Besides this main treatment method of OSA, there are no medicines that can solve the problem of the obstruction of the airways during the night. However, there are drugs that are approved for the management of sleepiness due to the condition. They can improve the professional and personal lives of people affected by the condition. These medicines were initially designed to cope with sleepiness in narcolepsy. These drugs are amphetamines (Adderall) and wakefulness-promoting medicines based on Modafinil (Provigil, Nuvigil, and generics, for instance, Modalert).
You can buy these medicines with a prescription in the U.S. and in Europe but you can get them without a prescription and at a lower price online. Check our comparison with the medicines in the table below.