Winning The Fight For Breath
Philip Barron reports on Sleep Apnoea
A small minority of snorers suffer from a condition that is more troublesome and potentially more dangerous than snoring itself. This is the condition called Obstructive Sleep Apnoea (OSA), in which the walls of the throat collapse inwards during sleep. It occurs mostly in middle-aged men who are overweight.
A friend of mine has this problem. When it was at its worst (he is now recovering), he used to wake up as many as eight times a night, blue in the face, fighting for breath. Sometimes his wife had to call an ambulance and he would be taken to hospital. Once the patient is in a waking state, the condition usually subsides, making diagnosis difficult, but more cases are coming to light as doctors become more familiar with the syndrome.
OSA was first recognised as a specific syndrome in the 1960s but an effective treatment was not devised until the early eighties, when the bedside machine that brought relief to my friend came into use. The CPAP machine (the initials stand from Continuous Positive Airways Pressure) pushes air through a nose-mask at just the right pressure to keep the throat open and ensure that sufficient air enters the lungs while the sufferer sleeps.
Although the treatment sounds off-putting, it is painless and the benefits can be quite dramatic. The portable machine sits by the bed and after a night or two in hospital, the patient can use it at home without supervision.
The thickening of the neck that often goes with being overweight is a prime factor in OSA, because the tissues thicken inside the throat as well as on the outside. An increase in shirt-collar size is one of the clues to diagnosis.
An apnoea (literally 'without breath') starts when the subject falls asleep and the throat muscles relax. The walls of the throat collapse inwards, blocking the air passage. Then the victim struggles for breath until sooner or later (it is often 30 - 60 seconds) the brain arouses the sleeper enough to ensure that breathing resumes, usually with a resounding snore.
This is called a micro-arousal, as the snorer does not fully wake. However, repeated micro-arousals disturb the sleep pattern and so lead to a dangerous sequel: the sufferer tends to fall asleep during the day, lose concentration and become accident-prone.
Some unexplained car accidents may be caused this way. The sufferer's job performance is likely to be impaired and, of course, the strain on a bed-partner can be great.
In severe cases, lack of oxygen leads to raised blood pressure and this can affect the heart. But not all cases of sleep apnoea turn out to be serious. Simple advice sometimes solves the problem (for example, the patient may be advised to sleep on one side and avoid alcohol late at night).
The best way to confirm the diagnosis and assess the severity of the condition is for the patient to take a 'sleep test'. This test is available at the centres detailed on the back page of this magazine. A referral from one's GP is required.
Surgery on the back of the mouth and the throat, to widen the airway, sometimes helps in mild cases, but is used sparingly because all surgery carries some risk.
A CPAP machine was prescribed for my snoring friend three years ago, after his sleep test. At present he uses it every night but as he improves this may no longer be necessary. He has already reduced his weight by 30 kgs which is an important step on the road to recovery.
The machine costs several hundred pounds and should be available on the NHS, although these days one can't assume that all health authorities will readily provide one.
A new diagnostic technique is shortly to be given a clinical trial at Leicester General Hospital. It involves passing a bundle of fine fibre-optic strands (together only 2mm wide) into the nose and down the throat under local anaesthetic. Each strand is then used to measure air pressure at a different point. As these fibres are much smaller than other probes, the doctor can examine more places at the same time and minimise discomfort for the patient.
Dr Chris Hanning, who is testing the instrument at Leicester General, says: 'When an obstruction is present those strands which are below it will show a big change in pressure as the patient tries to breath in; those at the point of obstruction will show a variable change, and those above it no change. In this way we can establish the position and extent of the obstruction and assess whether the patient is suitable for surgery'.
In this late-night movie, you are the star!
A SLEEP TEST: WHAT IT'S LIKE
Sleep tests help doctors to diagnose the causes of snoring and sleep apnoea. Procedure varies from place to place, but the following routine is typical.
You will probably be asked to arrive at the hospital between 8.00 and 9.00 pm, to give you time to unwind before going to bed in a room of which you will be the sole occupant. As the purpose of the test is to see what breathing abnormalities occur during a NORMAL night's sleep, patients are asked not to change their routine during the day (eat and drink as usual).
Your behaviour while sleeping will be filmed throughout the night and watched on a screen in an adjoining room by the technician in charge of the test. Before you climb into bed, electrodes will be attached, with a special adhesive, to parts of your head and chest and a probe attached to a finger or ear to monitor your heart rate and the level of oxygen in your blood. All this is quite painless. Surprisingly, it is not difficult to get to sleep. No needles are involved.
The electrodes are linked to a computer; they identify the various stages of sleep and monitor your breathing. If you need to get up in the night, you can signal to the technician who will unplug you!
Early the following morning, you will be roused and the electrodes removed from your person. In due course, your consultant will study the results and you will be invited back to hear what he makes of them.
Be prepared to go home hungry. It seems that many sleep centres do not provide breakfast.