Sleepiness is a killer. Approximately 770,000 people in the UK suffer from excessive daytime sleepiness. Obstructive Sleep Apnoea (OSA) is one of the most common causes.
Every night many of us stop breathing in our sleep. For some people this can happen many hundreds of times a night. Every time we stop breathing, known as an ‘Apnoea’, our brain instructs our body to briefly awaken. Most OSA victims have no memory of this all-night life-and-death struggle for breath. OSA robs its sufferers of restful sleep leaving them feeling ‘dog tired’ - sleepy and exhausted - during the day.
Recognition and treatment of Obstructive Sleep Apnoea is important because it increases the risks of having an irregular heartbeat, high blood pressure, heart attack and strokes.
Prevalence and statistics
Sleepy individuals exhibit symptoms of impairment - ranging from poor functioning at home, school or work, to vehicle crashes and industrial accidents. Poor performance occurs in all sleepy people, regardless of their education, occupation, or motivation to remain awake.
Sleep occupies approximately a third of our lives, but many people cannot get the good night’s sleep that they need. In the UK, sleep disorders affect about 770,000 people. Obstructive Sleep Apnoea (OSA) is one of the most common sleep disorders and occurs on a similar frequency as Type 1 diabetes and twice that of severe asthma.
Many people have OSA but are not aware of it!
It affects an estimated 4% of males and 2% of females in the UK.
A high level of undiagnosed OSA is suspected amongst long-distance lorry drivers, as the condition is more common in middle-aged men who are overweight. Obstructive Sleep Apnoea is more common in men aged 30 - 65 years, though it can occur in all age groups.
Research commissioned by the Government found a fifth of motorway collisions are caused by drivers falling asleep at the wheel and one in ten crashes on all of Britain’s roads - around 23,300 a year are also linked to fatigue.
Anyone affected by five or more of the following might be at risk of OSA:
1. Excessive daytime sleepiness
2. Loss of energy, fatigue
3. Restless sleep
4. High blood pressure
5. Overweight
6. Depression
7. Personality change
8. Irritability
9. Sexual dysfunction
10. Needing to pass water in the night
11. Trouble concentrating
Successful treatment for Obstructive Sleep Apnoea
Treatment of Obstructive Sleep Apnoea (OSA) is affordable, effective and uncomplicated with the most commonly prescribed treatment being Continuous Positive Airway Pressure (CPAP) therapy. The CPAP equipment delivers either a fixed or variable flow of gentle air pressure through mask that the individual wears while sleeping. The air pressure is adjusted so that it is just enough to prevent the airways in the throat from collapsing during sleep, acting as a “splint” eliminating airway collapse and allowing the individual to breathe normally. This permits uninterrupted and restorative sleep. For many individuals CPAP therapy dramatically improves their quality of life, daytime functioning and general health. CPAP is not a cure but is effective and the preferred therapy for managing OSA.
Obstructive Sleep apnoea can also be treated surgically, however the cost and success rates vary greatly depending on the individual and the chosen procedure. Non surgical dental appliances have also been tried by individuals. These work by bringing the lower jaw forward to increase the size of the airway. This approach is normally adopted in very mild forms of OSA or for individuals who snore but do not obstruct.
Diagnosing Criteria for Sleep Apnoea/Hypopnoea Syndrome (SAHS):
The awake baseline Oxygen saturation is above 90% and there are at least 15 4% dips in oxygen saturation per hour whilst asleep.
Polysomnographic (PSG) Criteria for Apnoeas:
Apnoeas were diagnosed on the basis of no airflow for at least 10 seconds and a desaturation of >4% in the following 30 seconds.
Hypopnoeas were defined as reduction in chest wall movement (>25%), reduced abdominal wall movement (>15%), and paradoxical movement with airflow reduction of >25%.
SAHS is diagnosed if PSG shows the apnoea/hypopnoea index >15/hour during sleep.
Ambulatory Sleep Study
Ambulatory or home sleep test is a diagnostic test that can determine whether or not you have obstructive sleep apnoea (OSA). It involves the use of a portable-monitoring system that is small enough for you to use at home. The system consists of a small recording device, sensors, belts and related cables and accessories.
The sleep recorder gathers important data as you sleep in your own bed. It receives information from sensors that are applied to strategic locations on your body. For example, sensors near your nose and mouth may measure your airflow. Other sensors around your chest and stomach may measure your breathing effort.
Each sensor sends a signal that is recorded on its own “channel.” Some home sleep tests collect more information than others. A system with a higher number of channels collects more data. A home sleep test can have as few as one or two channels, or as many as seven or more.
A home sleep test collects less information about your sleep and only detects OSA.
For some people a home sleep test may be nearly as effective at detecting OSA as an overnight sleep study.
The list below shows the information recorded by a standard overnight sleep study and a typical home sleep test:
Overnight Sleep Study:
Airflow
Breathing effort
Blood oxygen
Heart activity (ECG)
Brain waves (EEG)
Eye movements (EOG)
Chin movements (EMG)
Leg movements (EMG)
Snoring (Microphone)
Unusual behaviour (video)
Body position
Home Sleep Test:
Airflow
Snoring (Nasal Cannula)
Breathing effort
Blood oxygen
Heart activity (ECG)
Body position
Accuracy
Overnight sleep studies have been proven to be accurate with a low failure rate. A sleep technologist ensures that the equipment functions properly and records quality signals. He or she is able to correct any problems that may arise during the study.
A home sleep test can be as accurate as an overnight sleep study at detecting OSA. It is most effective for adults who have a high risk of OSA. Results are less accurate for people who have other medical problems or sleep disorders that affect sleep.