cessation of breathing, especially during sleep. The most common type is adult sleep apnea
. Central apnea in which there is failure of the central nervous system drive to respiration sometimes occurs in infants younger than 40 weeks after the date of conception.
adult sleep apnea
frequent and prolonged episodes in which breathing stops during sleep. Diagnosis is confirmed by monitoring the subject during sleep for periods of apnea and lowered blood oxygen levels. Sleep apnea is divided into three categories: (1) obstructive,
resulting from obstruction of the upper airways; (2) central,
caused by some pathology in the brain's respiratory control center; and (3) mixed,
a combination of the two (see above).
. Obstructive and mixed types are amenable to therapy. Since many sleep apnea patients are overweight, weight loss improves the symptoms. Central sleep apnea is the most difficult to control. Medications to stimulate breathing have not proven beneficial. Mechanical ventilation or administration of oxygen during the night may help some patients.
The most common treatment for obstructive sleep apnea is nasal continuous positive airway pressure
, which the patient uses during sleep; the positive pressure exerted prevents the airway from obstructing. Another method that may be tried is a dental appliance to move the jaw forward during sleep. In the most refractory cases, such as when an anatomical airway obstruction can be demonstrated, surgery to remove it may be performed after consultation with a surgeon experienced in evaluating and treating such obstructions. Another treatment that is occasionally used is insertion of a special type of tracheostomy tube
that can be plugged during the day for normal use of the upper airway and opened at night to bypass upper airway obstruction
deglutition apnea a temporary arrest of the activity of the respiratory nerve center during an act of swallowing.
initial apnea a condition in which a newborn fails to establish sustained respiration within two minutes of delivery.
late apnea cessation of respiration in a newborn for more than 45 seconds after spontaneous breathing has been established and sustained.
primary apnea cessation of breathing resulting when a fetus or newborn infant is deprived of oxygen; exposure to oxygen and stimulation usually restore respiration.
secondary apnea a period of time following primary apnea during which continued asphyxia of the fetus or newborn, with a fall in blood pressure and heart rate, necessitates artificial ventilation for resuscitation and reestablishment of ventilation.
transient periods when breathing stops during sleep; see adult sleep apnea
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
ob·struc·tive sleep ap·ne·a (OSA), [MIM*107650]
a disorder, first described in 1965, characterized by recurrent interruptions of breathing during sleep due to temporary obstruction of the airway by lax, excessively bulky, or malformed pharyngeal tissues (soft palate, uvula, and sometimes tonsils), with resultant hypoxemia and chronic lethargy. Sleep in the supine position predisposes apnic episodes. Compare: central sleep apnea
, sleep apnea
Obstructive sleep apnea (OSA), the most common type of sleep-disordered breathing, affects about 4% of men and 2% of women between the ages of 30 and 60. In addition, it occurs in about 2% of children, largely because of reversible adenotonsillar hyperplasia. It must be distinguished from central sleep apnea, in which apneic episodes during sleep result from impairment of the autonomic respiratory drive. Symptoms are loud snoring, recurrent apneic episodes during sleep followed by gasping inspiration with partial or complete arousal, nocturnal restlessness, and daytime sleepiness. Apneic episodes last 10-120 seconds and may be accompanied by sinus bradycardia or atrioventricular block. The cumulative effect of recurrent spells of apnea is hypoxemia and shallow, nonrefreshing sleep, which may lead to excessive daytime drowsiness, personality change, impairment of intellectual function, and heightened possibility of accidents. However, evidence establishing OSA as an independent risk factor for motor vehicle accidents, heart attack, stroke, and sudden death is weak. Obesity, hypothyroidism, cigarette smoking, alcohol, and some hypnotics (particularly benzodiazepines) predispose to OSA, and its prevalence increases with advancing age. About 35% of people with congestive heart failure and 50% of people with hypertension have this disorder, and 50% of those with this disorder have hypertension. There is also a statistical association between OSA and bilateral leg edema. Diagnosis is confirmed by polysomnography (continuous measurement of airflow, respiratory activity, chin electromyography, ECG, EEG, electrooculogram, and arterial oxygen saturation during sleep) and by evaluation of the shape and size of the upper respiratory tract. Interruption of normal breathing is quantified by the apnea-hypopnea index (AHI), computed by dividing the number of respiratory events (apnea, defined as cessation of air flow for at least 10 seconds, or hypopnea, defined as reduction of air flow by at least 50% for at least 10 seconds) by the total hours of sleep. An AHI of 15 or more indicates significant sleep-disordered breathing. Weight loss, smoking cessation, and avoidance of benzodiazepine hypnotics are advised for all patients. A mandibular advancement appliance worn inside the mouth at night reduces the symptoms in some patients. An effective if somewhat cumbrous treatment is the nightly use of continuous positive airway pressure (CPAP), which provides a steady flow of room air at low pressure through the nose to overcome intermittent upper respiratory obstruction. Selected patients benefit from surgical procedures such as uvulopalatopharyngoplasty (trimming and reshaping of the uvula and soft palate), which can be performed by laser or radiofrequency ablation under local anesthesia, and mandibular osteotomy with genioglossus muscle advancement.
Farlex Partner Medical Dictionary © Farlex 2012
obstructive sleep apnea Obstructive sleep apnea syndrome Sleep disorders A clinical complex due to the pathophysiologic response to anatomic defects of the nasopharynx, characterized by loud snoring, nocturnal oxyHb desaturation, disrupted sleep, hundreds of apneic episodes during sleep, resulting in upper airway closure for ≥ 10 secs Clinical Daytime drowsiness, especially in obese middle-aged ♂, cardiovascular Sx–eg, apnea-induced arrhythmia, bradycardia, ↑ ventricular ectopic activity Contributing factors Alcohol or sedatives before sleep, obesity, nasal obstruction, adenoid/tonsillar hyperplasia, macroglossia, retrognathia, acromegaly, hypothyroidism, HTN, pulmonary HTN Management Individualized–eg, surgery; uvulopalatopharyngoplasty is successful in 50%. Cf Snoring. Cf Narcolepsy, Sleep disorders.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
ob·struc·tive sleep ap·ne·a (OSA) (ŏb-strŭk'tiv slēp ap'nē-ă)
A disorder, first described in 1965, characterized by recurrent interruptions of breathing during sleep due to temporary obstruction of the airway by lax, excessively bulky, or malformed pharyngeal tissues (soft palate, uvula, and sometimes tonsils), with resultant hypoxemia and chronic lethargy.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Obstructive sleep apnea (OSA)
A potentially life-threatening condition characterized by episodes of breathing cessation during sleep alternating with snoring or disordered breathing. The low levels of oxygen in the blood of patients with OSA may eventually cause heart problems or stroke.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.