What is sleep apnoea?
Snoring and the disturbance it causes used to be regarded as a joke. However, we now know that snoring can indicate that there are problems with breathing at night which may harm the snorer. Also there are things that can be done to help alleviate snoring.
During sleep all the body’s muscles become less active and more floppy. In most parts of the body this does not matter and indeed helps one to relax and sleep comfortably. When the muscles that help hold open the throat behind the tongue relax, this leads to partial collapse and narrowing in this area.
Even in normal people this increases the resistance to the flow of air when breathing in, but this is usually of no significance. When this narrowing that occurs with sleep is more than normal, then the airway behind the tongue collapses much more.
To start with, this causes snoring and then, when the collapse is complete, it causes apnoea, which means “without breath” – actually stopping breathing. Fortunately, the body is able to sense this increased obstruction to breathing (thank goodness it does!) and the sufferer wakes briefly, before suffocation can occur, takes a few deep breaths, followed by a rapid return to sleep.
This obstruction and waking often becomes a continuous cycle, every minute or so, that can go on hundreds of times a night, every night. Usually though, the individual does not remember all these episodes of waking.
What causes sleep apnoea?
The things that cause sleep apnoea do so by increasing the normal narrowing of the throat during sleep. Anything that makes the throat narrower to start with (for example enlarged tonsils or a set-back lower jaw) means that it is easy for the throat to close off a bit more and block the airway.
A partially blocked nose generates lower pressures in the throat whilst taking a breath in, which tends to suck the walls of the throat together. Probably the most important factor is being overweight with a big neck. Extra fat in the neck squashes the throat from outside, particularly when the throat muscles become floppier with sleep.
Who gets sleep apnoea?
The sort of person we see most commonly with heavy snoring and sleep apnoea is a middle-aged man who is overweight with a big neck, usually taking a size 17 inch collar or more. However there are many patients with sleep apnoea who are not particularly overweight.
In some patients we simply do not understand why they have sleep apnoea. In children the commonest cause is enlarged tonsils. Nowadays sleep apnoea is a common reason for recommending that a young child has a tonsillectomy. Sleep apnoea and heavy snoring, severe enough to interfere with sleep quality, is probably much more common than is realised. At least three in every thousand men have severe sleep apnoea.
Symptoms of sleep apnoea
Because sleep can be so disrupted by the body having to wake up briefly to reverse the upper airway obstruction, sufferers experience severe daytime sleepiness. To start with this occurs only during potentially boring activities such as reading, watching television or driving on motorways. However when the sleepiness gets worse it begins to interfere with most activities, with patients falling asleep talking or eating. Poor work performance can lose the sufferer his job and of course sleepiness whilst driving can be fatal (sleep apnoea sufferers are about seven times more likely to have car accidents). Snoring will usually have been present for many years, and have gone well beyond a joke within the family. There are many other symptoms that one would predict in someone seriously sleep deprived (irritability for example) but the twin symptoms of snoring and daytime sleepiness are the best pointers to the diagnosis.
Diagnosis of sleep apnoea
The presence of significant sleep apnoea may be strongly suspected from the history. Often the patient’s partner has read an article about sleep apnoea and recognises that this must be what their partner has. Once sleep apnoea is suspected then a sleep study is done to confirm the diagnosis. A variety of signals can be measured during sleep, without having to use any painful needles or devices. Oxygen levels in the blood can be continuously measured from a clip on the finger and breathing monitored from belts around the chest and tummy. Sleep quality itself can be estimated from electrodes on the head, or from the number of body movements made during sleep. Video recordings with sound are often used so that the doctor can actually see how badly the breathing is obstructed and the sleep disturbed. Although such sleep studies usually involve a night’s stay in hospital, research is underway to develop reliable tests that can be done in the patient’s own home.
When sleep apnoea (and snoring) are not severe then simple approaches can help. Losing some weight, not drinking alcohol after 6.00 pm (alcohol relaxes the upper airway muscles even more), keeping the nose as clear as possible, and sleeping on one’s side or semi-propped up can all help. There are now simple dental devices worn at night, some of which are like sports-type gum shields, that can greatly reduce snoring.
When snoring is very objectionable, with the patient and his partner desperate for a solution, then an operation on the back of the throat may help – but this is a last resort and should only be done when a sleep study has shown snoring alone with very little, or no, sleep apnoea. The only really effective treatment currently used for bad sleep apnoea is nasal continuous positive airway pressure (nasal CPAP). Because the throat is collapsing, it can be held open by slightly pressurised air. To deliver this air a mask is worn during sleep just over the nose and connected to a little quiet pump beside the bed. Breathing is then able to return to normal during sleep with the air gently blowing through the nose, holding open the throat. The response is usually dramatic with greatly improved sleep and disappearance of the daytime sleepiness. Although these devices are cumbersome to wear, and hardly improve one’s appearance, the benefits far outweigh the disadvantages with the vast majority of patients deciding to use their machines every night at home after a one night trial in hospital.
‘Nocturnal hypoventilation syndrome’
Nocturnal hypoventilation syndrome is related to sleep apnoea, but is due to the brain’s respiratory control centre not sending out enough nerve impulses to the breathing muscles. So, rather than the breathing being stopped by obstruction to the upper airways behind the tongue (as with OSA), there simply is not enough breathing and sometimes complete cessation of breathing.
It is less common than OSA, snoring is not a feature of this kind of sleep apnoea, and it is usually results from a variety of neuromuscular diseases or chest wall deformities. The treatment consists of overnight ventilation using a nose or face mask system, very similar to those used in nasal CPAP for the treatment of OSA.
What is Obstructive Sleep Apnoea?
OSA is a more extreme manifestation of the condition, which typically causes snoring. In snoring, relaxation of the jaw and tongue backwards during sleep constricts the airway. Breathing becomes harder and faster to compensate, and this causes the snoring vibrations.
OSA occurs when the airway becomes completely blocked. The sufferer will stop breathing, and oxygen levels in the blood will drop. This stimulates the body to ‘reset’ itself, and the sufferer will wake briefly, although they are unlikely to remember this. A deep inhalation may be accompanied by one loud snore, and the cycle starts again. The sufferer will tend to snore in-between the cessations of breathing.
People with OSA are unable to sleep properly. Their sleep is constantly disrupted by snoring and obstructed breathing to the extent that they briefly stop breathing. This can happen several hundred times each night.
Who has Obstructive Sleep Apnœa?
It is estimated that about 80,000 people in Britain suffer from OSA. They are mostly (but not all) men, mostly (but not all) overweight, especially around the neck, and they all snore. They feel tired and sleepy during the day and at night are often observed to stop breathing.
How can you spot OSA?
Although there are exceptions, many sufferers are middle-aged or older, and have the following physical characteristics:
- Small chin
- Large neck
The sufferer’s spouse can usually verify that the sufferer is stopping breathing periodically during the night.
Other symptoms include:
- Frequent need to urinate during the night
- Choking during sleep
- Excessive day time sleepiness, irresistible urge to nap
- Morning headaches
- Limbs jerking during sleep
- Waking up tired or thirsty
- Poor memory
OSA and Snoring Treatments
Treatment of OSA and snoring depends largely on the severity of the condition.
For severe OSA:
- The preferred method of treatment has been a nasal CPAP machine (continuous positive airway pressure). This consists of a mask attached to a ‘fan’ machine, which keeps the airways open. Whilst this method of treatment is highly effective, only 70% of patients can actually tolerate it.
- Various surgical procedures or laser treatments may be carried out to reduce tissue causing the blockage, or an osteotomy performed to reposition the jaw. Not all patients would choose surgery if there were other effective treatments.
- Devices such as the TheraSnore can provide an effective solution, for patients, by preventing the jaw from dropping back and keeping the throat open, and is a very effective alternative to surgery and for patients who can’t tolerate CPAP. This treatment may also be given for milder cases of OSA and snoring.
For milder OSA and snoring:
- Many GPs recommend weight loss as an initial method of combating snoring and mild apnoea. This can be very effective, but most patients find it difficult to achieve.
- Snoring and apnoea are aggravated by alcohol: just one pint can have a significant effect on soft palate tone, and abstinence may be advocated.
- Snoring may be affected by sleep position, and patients can benefit from sleeping on their side in cases of simple snoring. Investigating sleep position may also help detect OSA, as the patient will typically snore when sleeping on their side or front in these cases.
Posiform is an anti-snoring pillow, designed specifically to encourage side sleeping rather than lying on your back. Supporting you on your side, the pillow’s Apex design allows the head to rest comfortably in a slightly forward titling position, which encourages the tongue to move forward, making it easier to breathe.