Obstructive Sleep Apnoea (OSA): Definition
Obstructive sleep apnoea (OSA) (or apnoea) is the most common type of sleep apnoea and is caused by obstruction of the upper airway. It is characterized by repetitive pauses in breathing during sleep, despite the eﬀort to breathe, and is usually associated with a reduction in blood oxygen saturation. These pauses in breathing, called “apnoeas” (literally, “without breath”), typically last 20 to 40 seconds (AASM 2001).
“Obstructive Sleep Apnea Syndrome (780.53-0)”. The International Classiﬁcation of Sleep Disorders (PDF). Westchester, Illinois: American Academy of Sleep Medicine. 2001. pp. 52–8. Retrieved 2010-09-11.
Signs and Symptoms
A key problem with OSA, is the fact that the sufferer may not be aware of their breathing difficulties because they are often only partially awoken (only partially conscious) when their airway becomes restricted/ closed off. So, OSA is most often noticed by a partner or friend who shares the same sleeping space as the sufferer. Sleep partners therefore have a pivotal role in helping an OSA sufferer gain the medical assistance they need. Which is why a partner questionnaire can be a very useful screening device.
The actual episodes may be noticed or it may be more due to the affect on the body (sequelae) in the morning. Snoring is a key clue, as OSA sufferers often snore )however not all people who snore have OSA).
Daytime sleepiness associated with OSA is sometimes referred to as obstructive sleep apnoea syndrome.
When can OSA develop?
It is very possible for symptoms of OSA to be around for decades before a sufferer or their partner actually realises there is a real issue. Commonly there appears to be a general acceptance that increased age and reduced fitness will lead to fatigue in the morning, however there may actually be an underlying clinical picture, that if resolved can make a definitively positive impact. In contrast if OSA is left unresolved the impact on the sufferer can be extremely detrimental, due to high incidence of other related health problems and greater chance of falling asleep at the wheel (etc.).
Please Note: Individuals who generally sleep alone are often unaware of the condition, without a regular bed- partner to notice and make them aware of their symptoms.
What happens to the body in OSA?
During sleep the muscle tone in our bodies reduces (the muscles relax), this can allow the muscles that normally support the soft tissues in your throat to lose tone, sometimes called ‘patency’. This may lead to a reduction in the airway volume, possibly even causing a complete collapse. So, during sleep this collapse often increased if a person is lying down on their back (supine) and can cause the airway to become completely obstructed.
Levels / Severity of OSA
A very minor degree of OSA is considered acceptable within the normal bounds of sleep, and furthermore, many individuals experience episodes of OSA at some point in their life. Importantly however a small percentage of people develop a chronic more severe type of OSA. There are essentially considered to be 4 diagnoses/ levels;
- No Sleep Apnoea
- Mild Sleep Apnoea
- Moderate Sleep Apnoea
- Severe Sleep Apnoea
Is OSA permanent?
It is possible to experience OSA for only a short period of time. Which can be the result of several issues, including (but not limited to);
- An upper respiratory (throat/ nose) infection that causes nasal congestion, along with swelling of the throat.
- Tonsillitis that temporarily produces very enlarged tonsils. (e.g. the Epstein-Barr virus (EBV) is known to be able to dramatically increase the size of lymphoid tissue during acute infection, and OSA is fairly common in acute cases of severe infectious mononucleosis).
- Temporary spells of ‘OSA syndrome’ may also occur in individuals who are under the inﬂuence of a drug (such as alcohol) that are associated with an excess relaxation in their body (muscle) tone and may also interfere with normal ‘arousal from sleep’ mechanisms.
Benefits of Treating Obstructive Sleep Apnoea (OSA)
The benefits of treating obstructive sleep apnoea can often be seen and experienced very quickly as a reduction in daytime tiredness and fatigue. The long-term implications are far reaching however, including but not limited to;
- Reduced chance of diabetes.
- Reduced obesity (often related to an increased ability to exercise and other associated lifestyle changes).
- Healthier blood pressure.
- Reduced risk of heart attacks and strokes.
- Increased daytime alertness reduces the chance of accidents (often fatal in road collisions).
- Improved concentration.
- Awake feeling more refreshed.
- Reduced depression and improved mood.
- Improved libido.
- Raised energy levels.
- Reduced snoring and bedtime sleeping movement.
Clearly, successful OSA treatment has a far-reaching effect beyond the patient to include bedtime sleep partners and even those they interact with during the day.
Life simply becomes a whole lot more pleasant for everyone.