Sound asleep - not quite

SLEEP disordered breathing consists of a spectrum of medical conditions from perfectly safe simple snoring to severe obstructive sleep apnoea (OSA) where the patient gasps, chokes and struggles for breath and its concomitant risks of heart failure, stroke and even death. Throw in sleepwalking, insomnia and other sleep-related conditions (parasomnias) into the milieu and we have an array of pathologies to keep us all on tenterhooks.

These conditions are not infrequently referred to the ENT surgeon for their opinion, with as many as 5-10 per cent of outpatient referrals associated with some measure of sleep-related complaints. Simple snorers by definition only snore and have no medical consequences but perhaps bear no dearth of consternation and angst from their bed partners and room companions.

Sleep apnoea is by definition a reduction in the amount of air breathed in and out with an episode lasting 10 seconds of breath holding and lack of air exchange. Hypopnoea is similar but here the cessation is only for 5 seconds and the combined number of episodes per hour of both these events provides a value called the apnoea-hypopnoea index (AHI) - the measure of severity of OSA.

Respiratory effort related arousals (RERAs) are characterised by increased respiratory efforts for at least 10 seconds when asleep, leading to arousals with no reduction in airflow ie no hypopnoeas or apneas. The combination of RERAs and AHI provides a further measure of sleeprelated oxygen deprivation called the Respiratory Distress Index (RDI).

When oxygen saturation drops below 3 per cent of the baseline, a further measure of oxygen deprivation is used - the oxygen desaturation index, ODI. At sea level, a value of 96-97 per cent oxygen saturation is considered normal, with a drop up to 90 per cent mild, between 80-90 per cent being moderate, and anything below 80 per cent, severe.

Children are not spared. Quite the opposite - they make up a good number of the cases and are quite high up the ENT surgeon's list of conditions requiring attention.

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Two classic cases, one adult and one child, come to mind and a walk through their medical odyssey perhaps can provide a better understanding of their respective conditions, treatment options and prognosis.

The adult

Typically, the impression of the adult sleep apnoeic is that of an overweight male with a short wide neck and receding chin. While the stereotype holds true in most instances, it isn't that uncommon to have the conversely slim athletic types too. Sleep apnoea is more common in men but should not be ignored in women who despite being smaller in build, demonstrate symptoms in keeping with the condition, namely: daytime fatigue, somnolence, irritability, memory loss, headaches and even depression. But no two patients are alike and treatment algorithms need to be titrated accordingly.

Most patients fill out a self-administered questionnaire such as the Epworth Sleep Score which provides a sense of severity due to potential for sleep apnoea. Their weight and height provide a measure of fat storage which is analogous to the bodymass index (BMI). Correlation of the BMI with OSA is high. Other medical conditions such as diabetes, thyroid disease, cardiorespiratory conditions and mental acuity are elicited.

Examination and diagnostics

Examination of the patient includes fibreoptic evaluation of the upper aerodigestive tract with video recording if possible, looking for potential causes for restriction and collapse of the upper airway. Thereafter, patients are recommended a domiciliary sleep study the same night of their visit at home. This study provides a fairly accurate gauge of the severity of OSA, including measures of the other parameters such as the ODI, RDI and loudness of snoring. Another feature related to the quality of sleep broken down to the electrical patterns within the brain when asleep are measured and tabulated. Sleep consists of several phases, each corresponding to a type of brain wave form - the most well known of which is rapid eye movement (REM). REM sleep is related to intense brain activity, dreaming, and restores the health of the brain. It is ideal to spend 20-25 per cent of sleep in REM and each REM cycle usually lasts longer than the preceding, increasing incrementally after each sleep cycle. We typically get through 3 sleep cycles a night.

Sleep nasendoscopy

This procedure is performed under sedation and is particularly useful in tailoring the treatment after assessing the patient while artificially asleep. As the patient drifts off to sleep, a flexible nasendoscope is inserted through the nose, which allows for direct views of the back of the nose, soft palate and throat. The effects of the falling tongue, flutter of the palate and constriction around the voice box are recorded to measure the contribution of each "level" of the upper aerodigestive tract to sleep apnoea and snoring.

Manoeuvres such as turning the head and body of the patient to the side, lifting the chin and jaw, are also performed in this quick, safe and dynamic study which is usually completed in less than 2-3 minutes and under the watchful eye of the anaesthetist.

Management options

With the relevant investigations done, the patient is then provided with the results along with an explanation of the findings, and the recommended course of action depending on the condition. Many simple snorers do well changing their position from being flat on their backs to sleeping on their sides. Cutting out smoking and alcohol, heavy meals and performing some mild activities before sleeping may help. Weight loss is important if the patient's BMI is high, and is a proven factor in reducing the severity of OSA. Improving sleep hygiene such as darkening the room, reducing noise, dimming bright gadgets, helps. In cases of moderate to severe OSA, continuous positive airway pressure (CPAP) treatment is considered the gold standard to help splint the collapsing airway using air pressure. This treatment, while previously bulky (machinery- wise), is now far more portable and less noisy. It does however involve using a face mask over the mouth, nose or both to deliver the positive air pressure. Many patients however find it too intrusive, somewhat claustrophobic, and drying to their mouth and nose.

Orofacial exercises to strengthen the tongue and cheek muscles may help as do devices that help to distract the lower jaw and tongue away from the back of the throat and larynx. Bespoke versions of mandibular devices can be helpful and I recommend many of my patients to dental surgeons who make these to measure.

Surgery for obstructive sleep apnoea is also an option, albeit one that has to be discussed with the pros and cons clearly laid forth. Risks including pain, bleeding and swelling with possible recurrence of OSA need to be explained as with inadequate or incomplete resolution of the problem. In the case of obvious nasal blockage contributing to snoring and sleep apnoea, surgical attention to the constriction in the nose may be enough to improve the simple snorer and mild apnoeic.

The child

Snoring in children isn't uncommon but regular snoring can be problematic. Sleep apnoea in childen without neurological and congenital conditions is almost entirely related to adenotonsillar hypertrophy. Unlike adults, many of these cases are managed with surgery, with very good results. Children tend to present from toddler stage with noisy breathing, somnolence, hyperactivity, snoring, disrupted sleep, irritability, poor concentration and behaviour. They may wet their beds, grind their teeth, sleep walk and/or talk.

Treatment

Most children tend to have enlargement of their adenoids and tonsils physiologically at a young age but this quickly improves with the reduction in volume as the child's head grows creating a relative increase in the space for breathing. In cases where the enlargement persists with symptoms, surgery is usually the primary treatment with excellent results. The risks of surgery are small with post-operative bleeding, infection and pain being most common.

Conclusion

Snoring and sleep apnoea affect children and adults with fairly dramatic consequences when not treated adequately. Treatment is tailored and varies between the two groups. Nonsurgical management such as CPAP has a major role in the management of these conditions and should be offered as primary treatment options prior to embarking on surgery in selected cases. Surgery, when correctly chosen, as in the case of children, provides an effective cure.

This article is produced in collaboration with Royal Healthcare Specialists Centre