A Guide to Sleep Aponea / Sleep Apnea (US spelling)
What is Sleep Apnoea ?
Sleep apnoea is a condition in which an individual experiences interruptions or obstructions in breathing, whilst sleeping. This condition is also known as obstructive sleep apnoea (OSA).
Sleep apnoea can be of two types.
Here, the throat muscles begin to relax causing the airways to become blocked. The condition lasts for about 5 seconds.
Here, the airways are blocked partially, and this decreases the amount of oxygen inhaled by as much as 50%. This condition too lasts for 10 seconds.
OSA is different from other more intense types of the condition, like central sleep apnoea where the brain forgets to inhale in a condition of deep sleep.
People who suffer from OSA may suffer a lack of oxygen, and this may cause them to come out of a situation of deep sleep into a lighter stage. They may even become awake for a short period of time to resume their regular normal breathing. When they go back into deep sleep, they can actually experience more apnoea and hypopnoea episodes. Thus, there may be repeated occurrences of these conditions during sleep.
These repeated episodes cause sleep to become interrupted, leaving the person fatigued and tired the next day. Usually, there is no recollection of any of the occurrences of the previous night. They don’t remember any periods of breathlessness, and so, they may not know the cause of their tiredness.
Prevalence of OSA
It is estimated that close to 3.5% of males and 1.5% of females in the UK suffer from OSA. The condition is seen more frequently in people aged 40 and above, although people of all ages including children, can experience this condition. People who are obese may find themselves more susceptible because extra body fat can strain the throat muscles, blocking the airways.
Risk factors for Sleep Aponea
Because people who suffer from OSA are not able to sleep properly they are more likely to be involved in a car crash. Evidence suggests that people with OSA are more likely to develop symptoms of hypertension, which is a leading cause of heart attack and strokes. The deprivation of sleep that OSA causes also impacts an individual’s judgment and reaction time.
Causes of Sleep Aponea
OSA is caused when the back muscles of your throat, that support your tonsils, tongue and soft palate relax during sleep. When these muscles are relaxed, it causes the airways to narrow down, or even get totally blocked. The supply of oxygen to the body is thus interrupted, and this sends a message to your brain to draw you out of the deep sleep stage, so that your airways can be unblocked, and you can resume breathing in a normal manner. At least 8 hours of sleep is the minimum requirement for most adults, and at least half of that should consist of the deep sleep stage. Because you end up having a limited amount of deep sleep, which is very important for your body to be fully rested and rejuvenated, you will end up feeling very lethargic the next day.
Risk factors for OSA
- Obese people are more at risk for OSA. Even a 10% increase in weight can increase your chances of developing OSA 6 times.
- It’s more common in men than women, although the reasons for this are not clear. People above 40 are more likely to suffer from OSA.
- It’s been noticed that people who suffer from OSA have a large neck circumference of 17” or greater.
- Individuals, who are in the habit of taking sleeping pills or other sedative medications, are more at risk for sleep apnoea.
- Some people have physical irregularities in the inner neck like large tonsils, a large tongue, narrow airways or a lower jaw that is positioned further in the back than in other people. These irregularities can increase the risk of sleep apnoea.
- People who smoke or drink alcohol before they go to bed are more likely to suffer from apnoea.
- Hormonal changes that occur during menopause may also cause the relaxation of throat muscles.
- There is even evidence that OSA is genetic and runs in families.
- Viagra has been found to cause relaxation of throat muscles.
Diagnosis of Sleep Aponea
If you have noticed unusual drowsiness in the day time or tiredness, ask someone to look for signs of breathlessness when you are asleep. If they notice any sleep interruption due to breathlessness, it can confirm an OSA diagnosis. Consult your GP who will enquire about your symptoms, conduct a physical check up and recommend tests to be conducted, including blood pressure tests and blood tests. A blood test is done to look for the presence of any other conditions that could be responsible for your tiredness, like hypothyroidism.
If the GP suspects OSA, he may refer you to a specialist sleep center that treats individuals who suffer from sleep disorders. You may have a number of tests conducted on you in a sleep center. You may be placed in a dark room in the day, and be asked to relax. Doctors will study the amount of time it takes for you to nod off. Other tests may include requiring you to try to keep yourself awake for the longest duration possible. If you manage to fall asleep quickly in the dark room test, and are not able to keep yourself awake for long in the second test, it could be an indication of OSA. The staff at the sleep center will enquire about your sleeping patterns – do you fall asleep when you are on a drive, or at the cinema theater etc.
After this, the staff will observe you in a state of sleep. For this, you will be asked to spend one night in the clinic, so that your sleep patterns can be observed. You may be hooked up to 2 special kinds of equipment that can monitor the changes in your body during sleep conditions. An oximeter makes use of a small sensor placed on your finger. This sensor transmits pulses of light, and an attached computer observes the absorption of pulses by your blood. In this manner, the computer can measure the amount of oxygen in your blood at any given time. You may even be asked to conduct the test when you are at home by providing you an oximeter.
A polysomnography (PSG) is also used to test for apnoea. Here, electrodes are placed on various parts of your body, and these are connected to a computer called a polysomnography. This equipment measures a number of factors including the amount of blood oxygen, breathing rate, your blood pressure, heart rate as well as the stages of sleep that you pass through.
A PSG can only be handled by an experienced technician, so this test can only be conducted in a sleep center. After these tests, your diagnosis of OSA should be complete. Depending on the number of apnoea and hypopnoea episodes you experience in an hour, the sleep center staff can determine the severity of the condition. In mild OSA, an individual may suffer between 5 & 14 episodes, in moderate OSA, there are anywhere from 15 to 30 episodes, and in severe OSA, there are more than 30 episodes of apnoea.
Treatment of Sleep Aponea
Life style changes
In case of mild and moderate OSA, life style changes like losing weight in case of obesity, avoiding consumption of alcohol just before bed time, avoiding smoking and use of sleeping pills and tranquilizers can treat the condition. You may also benefit from sleeping on your side instead of your back.
Continuous positive airway pressure (CPAP)
Continuous positive airway pressure (CPAP) is recommended in case of moderate or severe OSA. Here, a mask is used to provide a non stop supply of compressed air into your nose. This prevents relaxation of the throat muscles, and prevents blockage of the airway. CPAP is meant to be used when you go to sleep at night. Older models of CPAP were connected to nose bleeding, soreness of the throat and dryness in the nasal passages. Newer models come with a humidifier which can reduce these effects. Using the CPAP mask may feel cumbersome in the beginning, but people get used to the feeling of wearing the CPAP mask over time, leading to a dramatic improvement in the symptoms. If the mask causes discomfort, inform your sleep center staff. They may make modifications to the mask to increase comfort.
Inter oral devices (IOD)
These are not as effective as CPAP, but they can be used for mild OSA cases or in people who find using CPAP to be bothersome. These small devices are placed in your mouth, and work to keep the throat airway open in a sleep condition. Side effects may include increased production of saliva, and pain in the teeth and gums.
If you suffer from extreme sleepiness in the day time due to apnoea, your doctor may recommend a short term course of stimulants. These medications increase activity in your nervous system to increase alertness and wakefulness. A medication called modafanil may also be used to relieve extreme sleepiness in the day time. Side effects of this medication may include blurred vision and dizziness. Operating heavy machinery or driving a vehicle is also not recommended. Modafanil has also been found linked to depression and suicidal tendencies. If you notice these, discontinue use of the medication and consult your doctor. Stimulants are not recommended to be used over a very long period of time because of their addictive properties.
Surgery has not been found to be as useful as CPAP in elevating symptoms of sleep apnoea. This is usually used as a last resort method when all other options has been exhausted, or when the OSA is causing severe interruptions in your life. Surgical treatment usually involves conducting a tracheotomy. Here, a tube is inserted directly into the neck allowing you to breathe freely without obstructions. The tube enables breathing even when the upper throat airways are blocked.
Alternative treatments for Sleep Aponea
Playing the Australian wind instrument known as the didgeridoo has been found to reduce symptoms in case of mild or moderate OSA. This has been confirmed by studies which found that patients who took didgeridoo lessons and continued to practice daily for a period of at least 4 months found substantial decrease in the amount and severity of day time sleepiness. Playing the didgeridoo is known to strengthen the muscles in your throat’s upper airways, thus reducing the risk of relaxation of muscles during sleep.
Complications of Sleep Aponea
There are several complications that have been linked to OSA.
Patience who suffer from OSA has been found to develop symptoms of hypertension or high blood pressure. This in turn, leads to the development of heart disease, including strokes and heart attacks. However, it is not entirely clear whether hypertension is a result of OSA, or whether it is caused by obesity which is one of the causal factors of OSA.
People who suffer from severe OSA have been found to have their risk of being involved in a car crash increase up to 15 times. Causing an accident by nodding off at the wheel is considered a criminal offence, and can even result in a prison sentence. Individuals with OSA are required by law to notify the Driver and Vehicle Licensing Agency (DVLA) of this condition. If they fail to do so, they may be punished by a fine of 1000 pounds. You may not lose your license after you inform the DVLA of your OSA symptoms, as long as you are undergoing treatment for your condition. When your symptoms have been brought under control, you will be allowed to be back behind the wheel. If you operate heavy vehicles, then the DVLA will ask for some form of confirmation that your OSA symptoms are being treated by a specialist, and are under control.