Sleep Apnea
Description of Sleep Apnea:
Sleep apnea (or sleep apnoea in British English) is a sleep disorder
characterized by pauses in breathing during sleep. Each episode, called an apnea
(Greek: ἄπνοια (ápnoia), from α- (a-), privative, πνέειν (pnéein), to breathe),
lasts long enough so that one or more breaths are missed, and such episodes
occur repeatedly throughout sleep. The standard definition of any apneic event
includes a minimum 10 second interval between breaths, with either a
neurological arousal (a 3-second or greater shift in EEG frequency, measured at
C3, C4, O1, or O2), a blood oxygen desaturation of 3-4% or greater, or both
arousal and desaturation. Sleep apnea is diagnosed with an overnight sleep test
called a polysomnogram, or a "Sleep Study".
Clinically significant levels of sleep apnea are defined as five or more
episodes per hour of any type of apnea (from the polysomnogram). There are three
distinct forms of sleep apnea: central, obstructive, and complex (i.e., a
combination of central and obstructive) constituting 0.4%, 84% and 15% of cases
respectively. Breathing is interrupted by the lack of respiratory effort in
central sleep apnea; in obstructive sleep apnea, breathing is interrupted by a
physical block to airflow despite respiratory effort. In complex (or "mixed")
sleep apnea, there is a transition from central to obstructive features during
the events themselves.
Regardless of type, the individual with sleep apnea is rarely aware of having
difficulty breathing, even upon awakening. Sleep apnea is recognized as a
problem by others witnessing the individual during episodes or is suspected
because of its effects on the body (sequelae). Symptoms may be present for years
(or even decades) without identification, during which time the sufferer may
become conditioned to the daytime sleepiness and fatigue associated with
significant levels of sleep disturbance.
Specific Sleep Apnea Information
Articles, questions and answers.
