Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times a night. In the most common form, this follows loud snoring. There may be a choking or snorting sound as breathing resumes. Because the disorder disrupts normal sleep, those affected may experience sleepiness or feel tired during the day. In children, it may cause hyperactivity or problems in school.
Snoring is the vibration of respiratory structures and the resulting sound due to obstructed air movement during breathing while sleeping. The sound may be soft or loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of obstructive sleep apnea (OSA). Research suggests that snoring is one of the factors of sleep deprivation.
Apnea is the temporal cessation of breathing. During apnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. Depending on how blocked the airways are, there may or may not be a flow of gas between the lungs and the environment, but if there's sufficient flow, gas exchange within the lungs and cellular respiration wouldn't be severely affected. Voluntarily doing this is called holding one's breath. Apnea may first be diagnosed in childhood, and it is recommended to consult an ENT specialist, allergist or sleep physician to discuss symptoms when noticed; malformation and/or malfunctioning of the upper airways may be observed by an orthodontist.
Obesity hypoventilation syndrome (OHS) is a condition in which severely overweight people fail to breathe rapidly or deeply enough, resulting in low oxygen levels and high blood carbon dioxide (CO2) levels. The syndrome is often associated with obstructive sleep apnea (OSA), which causes periods of absent or reduced breathing in sleep, resulting in many partial awakenings during the night and sleepiness during the day. The disease puts strain on the heart, which may lead to heart failure and leg swelling.
Positive airway pressure (PAP) is a mode of respiratory ventilation used in the treatment of sleep apnea. PAP ventilation is also commonly used for those who are critically ill in hospital with respiratory failure, in newborn infants (neonates), and for the prevention and treatment of atelectasis in patients with difficulty taking deep breaths. In these patients, PAP ventilation can prevent the need for tracheal intubation, or allow earlier extubation. Sometimes patients with neuromuscular diseases use this variety of ventilation as well. CPAP is an acronym for "continuous positive airway pressure", which was developed by Dr. George Gregory and colleagues in the neonatal intensive care unit at the University of California, San Francisco. A variation of the PAP system was developed by Professor Colin Sullivan at Royal Prince Alfred Hospital in Sydney, Australia, in 1981.
Hypercapnia (from the Greek hyper = "above" or "too much" and kapnos = "smoke"), also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs. Carbon dioxide may accumulate in any condition that causes hypoventilation, a reduction of alveolar ventilation (the clearance of air from the small sacs of the lung where gas exchange takes place) as well as resulting from inhalation of CO2. Inability of the lungs to clear carbon dioxide, or inhalation of elevated levels of CO2, leads to respiratory acidosis. Eventually the body compensates for the raised acidity by retaining alkali in the kidneys, a process known as "metabolic compensation".
Upper airway resistance syndrome is a sleep disorder characterized by the narrowing of the airway that can cause disruptions to sleep. The symptoms include unrefreshing sleep, fatigue, sleepiness, chronic insomnia, and difficulty concentrating. UARS can be diagnosed by polysomnograms capable of detecting Respiratory Effort-related Arousals. It can be treated with lifestyle changes, orthodontics, surgery, or CPAP therapy. UARS is considered a variant of sleep apnea, although some scientists and doctors believe it to be a distinct disorder.
Polysomnography (PSG), a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek πολύς, the Latin somnus ("sleep"), and the Greek γράφειν.
A mandibular splint or mandibular advancement splint is a prescription custom-made medical device worn in the mouth used to treat sleep-related breathing disorders including: obstructive sleep apnea (OSA), snoring, and TMJ disorders. These devices are also known as mandibular advancement devices, sleep apnea oral appliances, oral airway dilators, and sleep apnea mouth guards.
Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask, nasal mask, or a helmet. Air, usually with added oxygen, is given through the mask under positive pressure; generally the amount of pressure is alternated depending on whether someone is breathing in or out. It is termed "non-invasive" because it is delivered with a mask that is tightly fitted to the face or around the head, but without a need for tracheal intubation. While there are similarities with regard to the interface, NIV is not the same as continuous positive airway pressure (CPAP), which applies a single level of positive airway pressure throughout the whole respiratory cycle; CPAP does not deliver ventilation but is occasionally used in conditions also treated with NIV.
Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction of the upper airway leading to reduced or absent breathing during sleep. These episodes are termed "apneas" with complete or near-complete cessation of breathing, or "hypopneas" when the reduction in breathing is partial. In either case, a fall in blood oxygen saturation, a disruption in sleep, or both may result. A high frequency of apneas or hypopneas during sleep may interfere with restorative sleep, which – in combination with disturbances in blood oxygenation – is thought to contribute to negative consequences to health and quality of life. The terms obstructive sleep apnea syndrome (OSAS) or obstructive sleep apnea–hypopnea syndrome (OSAHS) may be used to refer to OSA when it is associated with symptoms during the daytime.
Somnology is the scientific study of sleep. It includes clinical study and treatment of sleep disorders and irregularities. Sleep medicine is a subset of somnology.
Shallow breathing, thoracic breathing, costal breathing or chest breathing is the drawing of minimal breath into the lungs, usually by drawing air into the chest area using the intercostal muscles rather than throughout the lungs via the diaphragm. Shallow breathing can result in or be symptomatic of rapid breathing and hypoventilation. Most people who breathe shallowly do it throughout the day and they are almost always unaware of the condition.
Hypopnea is overly shallow breathing or an abnormally low respiratory rate. Hypopnea is defined by some to be less severe than apnea, while other researchers have discovered hypopnea to have a "similar if not indistinguishable impact" on the negative outcomes of sleep breathing disorders. In sleep clinics, obstructive sleep apnea syndrome or obstructive sleep apnea–hypopnea syndrome is normally diagnosed based on the frequent presence of apneas and/or hypopneas rather than differentiating between the two phenomena. Hypopnea is typically defined by a decreased amount of air movement into the lungs and can cause oxygen levels in the blood to drop. It commonly is due to partial obstruction of the upper airway.
Continuous positive airway pressure (CPAP) is a form of positive airway pressure (PAP) ventilation in which a constant level of pressure greater than atmospheric pressure is continuously applied to the upper respiratory tract of a person. The application of positive pressure may be intended to prevent upper airway collapse, as occurs in obstructive sleep apnea, or to reduce the work of breathing in conditions such as acute decompensated heart failure. CPAP therapy is highly effective for managing obstructive sleep apnea. Compliance and acceptance of use of CPAP therapy can be a limiting factor, with 8% of people stopping use after the first night and 50% within the first year.
The Apnea–Hypopnea Index or Apnoea–Hypopnoea Index (AHI) is an index used to indicate the severity of sleep apnea. It is represented by the number of apnea and hypopnea events per hour of sleep. Apnea is the complete absence of airflow through your nose and mouth. Hypoapnea is a partial collapse of your airway, limiting breathing. Apneas must last for at least 10 seconds and be associated with a decrease in blood oxygenation to be considered. Combining AHI and oxygen desaturation gives an overall sleep apnea severity score that evaluates both the number of sleep breathing disruptions and the degree of oxygen desaturation during said disruptions.
The respiratory disturbance index (RDI)—or respiratory distress Index—is a formula used in reporting polysomnography findings. Like the apnea-hypopnea index (AHI), it reports on respiratory distress events during sleep, but unlike the AHI, it also includes respiratory-effort related arousals (RERAs). RERAs are arousals from sleep that do not technically meet the definitions of apneas or hypopneas, but do in some way disrupt breathing during sleep and cause respiratory symptoms that may cause a alrosal.
Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation(ROHHAD) is a rare condition whose etiology is currently unknown. ROHHAD mainly affects the endocrine system and autonomic nervous system, but patients can exhibit a variety of signs. Patients present with both alveolar hypoventilation along with hypothalamic dysfunction, which distinguishes ROHHAD from congenital central hypoventilation syndrome (CCHS). ROHHAD is a rare disease, with only 100 reported cases worldwide thus far.
Central sleep apnea (CSA) or central sleep apnea syndrome (CSAS) is a sleep-related disorder in which the effort to breathe is diminished or absent, typically for 10 to 30 seconds either intermittently or in cycles, and is usually associated with a reduction in blood oxygen saturation. CSA is usually due to an instability in the body's feedback mechanisms that control respiration. Central sleep apnea can also be an indicator of Arnold–Chiari malformation.
Sleep surgery is a surgery performed to treat sleep disordered breathing. Sleep disordered breathing is a spectrum of disorders that includes snoring, upper airway resistance syndrome, and obstructive sleep apnea. These surgeries are performed by surgeons trained in otolaryngology, oral maxillofacial surgery, and craniofacial surgery.
