Breathing disorders during sleep
Breathing in sleep is normal During sleep, many indicators of the body’s vital activity undergo noticeable changes, this is very indicative of the example of breathing. So, in perfectly healthy people in shallow NREM sleep and in REM sleep, repeated episodes of a decrease in the amplitude of respiratory movements ( hypopnea ) and even complete cessations of breathing (apnea) may be noted . These disorders can be obstructive or central in nature. Obstructive apnea / hypopnea , which occurs as a result of temporary closure (obstruction) of the upper airways, while maintaining the respiratory movements of the diaphragm. Sleep breathing disorders are called central when there is a decrease in amplitude or cessation of respiratory movements of the diaphragm. In this case, accordingly, there is no respiratory air flow. The acceptable amount of apnea / hypopnea is considered to be 5 episodes of apnea or 10 – apnea and hypopnea per hour of sleep. If the number of these disorders is equal to or exceeds the specified number, conditions are created for the formation of a symptom complex of sleep apnea syndrome, designated as obstructive or central, depending on the type of breathing disorders dominating during sleep.
Obstructive sleep apnea syndrome (OSAS) is the most clinically significant of the sleep-breathing disorders mentioned in the classification. This is due to both the very high prevalence of this disorder in the population (1-3% according to the most conservative estimates), and with a significant impact on the health and quality of life of patients. Men suffer from this disorder 3-8 times more often than women, and only after 50 years, with the onset of menopause, women begin to experience breathing problems almost as often. The most common symptom of OSAS (present in 95-100% of cases) is snoring. Snoring is usually loud and irregular, with prolonged episodes of silence consistent with obstructive sleep apnea or hypopnea . The patients themselves rarely complain of difficulty breathing during sleep or waking up from a feeling of lack of air. Frequent episodes of arousal apnea disrupt the normal course of sleep and lead to an almost complete absence of deep sleep stages in patients with OSAS. It is not surprising that the next characteristic feature of the syndrome is the absence of a refreshing effect of sleep and the presence of daytime sleepiness (in 70-90% of cases). Drowsiness attacks can take on an imperative character with falling asleep in transport, at work, while eating, etc. Other common manifestations of OSAS include: frequent urination at night, increased motor activity during sleep, morning headaches, and dry mouth. Each episode of sleep apnea / hypopnea is accompanied by activation of the sympathetic nervous system and changes in the cardiovascular system, primarily fluctuations in blood pressure and heart rate. This contributes to the development of various pathologies: arterial hypertension, cardiac arrhythmias, disorders of cardiac and cerebral blood supply. Other complications of OSAS include pulmonary hypertension, polycythemia, disorders of fat and water-salt metabolism. Obesity is the most common risk factor for OSAS. It has been shown that 2/3 of patients with this disorder are overweight. Obstructive breathing disorders during sleep are also observed in various forms of ENT pathology , which is accompanied by a narrowing of the lumen of the upper respiratory tract (rhinitis, tonsillitis, uvula hypertrophy). Diseases of the endocrine system (diabetes mellitus, hypothyroidism, acromegaly) and the nervous system (cerebral strokes, neuromuscular diseases, syringomyelia) are also often accompanied by the development of OSAS. If there is an obvious cause for sleep-disordered breathing, the underlying condition should certainly be treated. However, in many cases it is not possible to identify or eliminate this factor. Then pathogenetic methods of treatment are applied. The most effective of these is the use of special devices during sleep that create continuous positive air pressure in the airways ( CPAP , CPAP, English). At the same time, the air serves as a kind of “prop” for the walls of the respiratory tract, preventing them from collapsing and even fluctuating in the rhythm of snoring. Other methods of OSAS treatment are surgical (more effective for mild severity), with an artificial increase in the lumen of the pharynx and orthodontic with the selection of special devices (oral applicators) inserted into the mouth at night and allowing to maintain a certain configuration of the airways. Effective medications for correcting OSAS have not yet been developed.
Central sleep apnea syndrome (CASA) is a significantly rarer clinical condition. It accounts for less than 10% of the total number of cases of sleep apnea syndrome. The most typical manifestation of SCAS, in contrast to OSAS, is complaints of frequent nocturnal awakenings. As a consequence of this, patients develop daytime sleepiness. It was shown that SCAS, like OSAS, is accompanied by cardiovascular disorders, but less pronounced due to the absence of changes in intrathoracic pressure. Breathing disorders during sleep of a central nature are often detected in patients with congestive heart failure and various neurological diseases (cerebral strokes, multisystem atrophies, polyneuropathies). For the treatment of OSAS, assisted ventilation methods ( CPAP and its varieties) are also used (however, with less effect ). In some cases, drug therapy – acetazolamide or theophylline – can be very effective .
Central alveolar hypoventilation syndrome is a condition characterized by a decrease in blood oxygen saturation during sleep while maintaining the mechanical properties of the lungs. In this case, a violation of the sensitivity of the receptors to oxygen and carbon dioxide is often revealed. This condition is rarely diagnosed, since apnea is frequent with it, which makes it possible to attribute it to OSAS or SCAS. The main complaints of patients with central alveolar hypoventilation syndrome are frequent awakening from sleep, a feeling of ” sleep deprivation ” and headaches in the morning. There are primary (idiopathic) and secondary (most often due to neurological damage). The treatment of this disorder has not been sufficiently developed, and the methods used to treat SCAS are applied.
Congenital central hypoventilation syndrome is an even rarer condition, when ventilation disorders aggravated during sleep are observed from the first months of life. Such children often have other developmental defects ( neuroblastoma , Hirschsprung’s disease ). With age, there is a gradual “maturation” of the chemoreceptor systems and it is believed that from 4-5 years of age such children no longer require hospitalization for every respiratory infection.
Primary snoring – This phenomenon is also regarded as a breathing disorder and is defined as “a condition characterized by loud sounds from the level of the upper respiratory tract during sleep.” If snoring is present against the background of any pathology of the ENT organs, it is called secondary. The prevalence of the phenomenon of “habitual” (almost nightly ) snoring among women is about 10%, and among men – about 20%. Despite the fact that the sound of snoring, it would seem, should bother only others, in recent years it has been shown that the presence of habitual snoring contributes to the development of arterial hypertension, heart rhythm disturbances in the snoring people themselves. People with snoring are 2-3 times more likely to develop myocardial infarction and cerebral stroke. Most often, primary snoring is associated with obesity – 60% of overweight middle-aged men snore. The role of a hereditary factor is high, which apparently determines the configuration of the facial skeleton. Given the steady progression with age, it has been proposed to regard primary snoring and OSAS as stages of a single process called “heavy snoring disease.” Usually, in the initial period, snoring is noted sporadically, in the supine position, against the background of alcohol intake or overwork. Later, snoring becomes continuous, loud, almost constant. Further, obstructive breathing disorders join it and the OSAS symptom complex is formed. Therefore, snoring should be treated as early as possible, until the patient has ” snored ” serious complications. Uncomplicated snoring is quite effectively treated with surgical methods, when excess pharyngeal tissue (uvula, lateral ridges) is removed and the passage of air in the nasal cavity is improved. In this case, a variety of techniques are used using cryodestruction , laser coagulation, microwave destruction, sclerotherapy , etc. It can be used for the treatment of snoring of mouth applicators and nasal wings dilators.