Definition:-
Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called apneas (Greek: ?p???a (ápnoia), from a- (a-), privative, p??e?? (pnéein), to breathe), lasts long enough so that one or more breaths are missed, and occurs 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.
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 (complex is a combination of central and obstructive) making up 0.4%, 84% and 15% of cases respectively. Breathing is interrupted by the lack of effort in central sleep apnea; in obstructive sleep apnea, breathing is interrupted by a physical block to airflow despite effort. In 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, 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.
Breathing Problems During Sleep
Many people consider snoring a minor annoyance, but it can signal a potentially serious condition called sleep apnea (temporary interruptions in breathing during sleep).
An article in the June 13, 2001, issue of The Journal of the American Medical Association reports an association between sleep-disordered breathing and a genetic marker called apolipoprotein E ?. The authors speculate that this marker may be one of many genetic factors that make someone susceptible to developing sleep-disordered breathing.
Sleep apnea is disturbed or interrupted breathing during sleep. For those affected by sleep apnea, there can be many temporary interruptions in breathing, each usually lasting about 10 seconds, throughout the sleep period. These interruptions in breathing can occur as often as 20 to 30 times per hour.
Symptoms of Sleep Apnea:-
Because some of the symptoms of sleep apnea occur during sleep, they may be recognized first by people with whom one shares living quarters.
* Heavy snoring, although not everyone who snores has sleep apnea
* Struggling to breathe during sleep
* Interruption in breathing during sleep followed by a snort when breathing begins again
* Being excessively sleepy during the day
* Falling asleep during activities that require attention and concentration, such as driving, working or talking
If you are experiencing these symptoms, see a doctor; you may have sleep apnea or some other condition that needs medical attention.
Causes of Sleep Apnea:-
* Obstructive — Partial or complete obstruction of the airway, which can be caused by relaxation of the muscles of the throat, soft palate, and tongue during sleep
* Central — Problems with signals from the brain that control breathing
Risk factors for sleep apnea include
* Being overweight
* Having a physical abnormality in the nose, throat, or other parts of the upper respiratory tract
* Having high blood pressure
Treatment
For mild cases of sleep-disordered breathing one can
* Sleep on one’s side instead of back
* Avoid drinking alcohol before sleeping
* Avoid using sleeping pills
* Avoid smoking or using other tobacco products
* Lose weight, if overweight
The most common medical treatment for sleep apnea is continuous positive airway pressure (CPAP), which is a therapy that uses pressure from an air blower to circulate air through the nasal passages and upper airway. The patient wears a mask over the nose that is connected to the air pressure hose, and the air pressure is adjusted to keep the airway open during sleep. Other therapies include dental appliances that change the position of the jaw and tongue, and various surgeries to keep the airway open during sleep.
Special situation: surgery and anesthesia in patients with sleep apnea syndrome
Many drugs and agents used during surgery to relieve pain and to depress consciousness remain in the body at low amounts for hours or even days afterwards. In an individual with either central, obstructive or mixed sleep apnea, these low doses may be enough to cause life-threatening irregularities in breathing.
Use of analgesics and sedatives in these patients postoperatively should therefore be minimized or avoided.
Surgery on the mouth and throat, as well as dental surgery and procedures, can result in postoperative swelling of the lining of the mouth and other areas that affect the airway. Even when the surgical procedure is designed to improve the airway, such as tonsillectomy and adenoidectomy or tongue reduction – swelling may negate some of the effects in the immediate postoperative period.
Individuals with sleep apnea generally require more intensive monitoring after surgery for these reasons.
Click for more information :-> www.nhlbi.nih.gov/about/ncsdr
Resources:
http://www.medem.com/medlb/article_detaillb.cfm?article_ID=zzzwt155mnc&sub_cat=593
http://en.wikipedia.org/wiki/Sleep_apnea
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