Apnoea a major cause of road accidents
Apnoea a major cause of road accidents
During sleep the muscles of upper part of the breathing passages in the nose but particularly the throat relax. This can cause narrowing of the air passages and lead to a reduction in airflow which becomes noisy and turbulent. This manifests as snoring. If the throat area around the tongue and soft palate, the wobbly bit in the throat, obstructs completely, the breathing ceases as does the snoring. During this silence the patient may be observed to struggle for breath but no sound is audible. This closure is called an Obstructive Sleep Apnoea (OSA) and if lasting 10 seconds or more is classified as a significant event. In some patients the apnoea may be 15, 30 or even 40 seconds plus.
During the apnoea the oxygen levels in the blood will dip and in some people to worryingly low levels. The brains eventually kick starts the breathing and the patient gasps, and may even wake up and then starts rebreathing only for the event to occur again. In mild cases these occur up to 15 times an hour, in moderate cases 15-30 events and in severe cases 30 or more events every hour of sleep. Individuals with 60-100 events per hour are not uncommon. Not surprisingly this leads to an extremely disrupted sleep pattern.
The dire consequences of apnea
In the UK it is estimated that 4 percent men, middle aged and 2 percent of post-menopausal women have OSA with symptoms, with these percentages being even higher in older people. In the Kingdom these figures may be higher due to the higher incidence of obesity in the population. Obesity is a major risk factor for developing OSA. In the UAE OSA in children is likely to be higher, again due to the weight issue, probably running at 4-5 percent. In children large tonsils play a major role and an operation may be curative, which is usually not the case in adults suffering from OSA.
Usually it is the spouse or the parents in children who are aware of a problem. Not only do they hear the snoring but will witness the cessation in breathing with its associated struggle. Adults may suffer nocturia, the need to get up and pass water during the night and children may bed wet.
For the person suffering OSA they will suffer during the day due to their lack of refreshing sleep. The person wakes up tired, sometimes with an early morning headache. Daytime sleepiness is very common with adults falling asleep at meetings, watching TV, during conversation and most alarmingly while driving. They have difficulty concentrating, with memory not as sharp as previously and frequently noted to be short-tempered and irritable. Their ability to work is affected. Some patients become so depressed that they are directed for psychiatric testing, which clearly is inappropriate. Many will have a loss of their sex drive. Children usually present with poor school performance, poor behavior and hyperactivity is not unusual.
Death and major heart problems associated with apnoea
Untreated or inadequately treated OSA is associated with major medical problems. If one considers the OSA event as a strangulation leading to poor oxygen levels to every cell in the body it is easy to understand the detrimental consequences. It may lead to high blood pressure, cause a pre-diabetic state and make existing diabetes more difficult to manage. There is an increased incidence of heart problems such as heart attacks and heart rhythm disorders. There is also an increased likelihood of suffering a stroke and the kidneys can also be damaged. Studies reveal untreated severe OSA will lead to death in 15% of patients and a major heart event in 30 percent over a 12-year period.
Road traffic accidents and apnea
There is an increasing awareness of the relationship between OSA and falling asleep during the boredom of driving, particularly on long straight roads. This is an issue for all road users but is likely to be a much greater problem in the haulage industry.
Assessment and diagnosis of Obstructive Sleep Apnoea
Adults can be assessed quickly by completing a STOP BANG questionnaire. The acronym represents:
• Snoring loudly;
• Tiredness during the day;
• Obstruction, usually observed by partner;
• Pressure, suffering high blood pressure;
• BMI, Body Mass Index greater than 35;
• Age, 50 years or above;
• Neck, collar size greater than 16 inches and
• Gender, if male score one.
Each yes answer is scored as one and a score of 4 or above indicates a very high chance of OSA and the individual should have a sleep study to confirm the diagnosis.
The treatment of Obstructive Sleep Apnoea
Treatment is dependent on the severity of OSA and the symptoms suffered by the patient. CPAP, Continuous Positive Airway Pressure is recommended for adults with moderate or severe OSA. CPAP delivers air under a pressure needed to keep the airway open, via a facial mask over the nose or nose and mouth. If it is correctly used it can have a dramatic improvement within two to three days. Intense clinical support is required to ensure the best results.
In about 7 percent of adults who have very large tonsils surgery is generally curative but other operations on the palate and tongue are generally ineffective and can result in significant complications. However, in children over 90 percent have massive tonsils which if removed provide a cure. Surgery is usually not recommended in children suffering facial deformities or Down’s Syndrome.
A small number of adults with a receding jaw or where the OSA is of a mild grade may benefit from a Mandibular Advancement Device (MAD). This is similar to a mouth guard, but must be specially made and fitted and is worn at night to pull the jaw forward and prevent the tongue blocking the airway.
A number of lifestyle measures will also assist in managing the OSA. The most significant is to lose weight. It is best to avoid alcohol and sedatives and meals just before sleeping.
• Professor Ram Dhillon is the consultant surgeon at Middlesex University, School of Health and Social Sciences, London. Michael Oko, consultant surgeons and Department of Health Adviser on Sleep Apnea, UK National Health Service, also contributed to this report.