Clinical Review: Paediatric obstructive sleep apnoea

Contributed by Mr Steven Powell, specialist registrar in otolaryngology, Freeman Hospital, Newcastle upon Tyne

Image of tonsillar hypertrophy, demonstrating the obstructed pharynx (Photograph: Author image)
Image of tonsillar hypertrophy, demonstrating the obstructed pharynx (Photograph: Author image)

Section 1: Epidemiology and Aetiology
Paediatric obstructive sleep apnoea is characterised by partial or intermittent complete airway obstruction during sleep which affects the child's ventilation and disrupts their normal sleep patterns. Generally, all of these patients will snore. It is possible to have habitual snoring without any airway obstruction and this is defined as primary snoring.

Sleep disordered breathing is a term which is used to cover a spectrum of airway problems from simple snoring to obstructive breathing.

In a UK cross sectional study, 12 per cent of children were found to be habitual snorers and 0.7 per cent were found to have obstructive sleep apnoea.1 Other studies from around the world have found the prevalence of obstructive sleep apnoea to be between 1 and 2 per cent.2,3 It can be extrapolated from this that one in 100 children on the average GP list will have obstructive sleep apnoea and this increases to approximately one in 10 of those who snore habitually.

Obstructive sleep apnoea occurs in three groups of children: those with adenotonsillar hypertrophy, those who are obese and those who have congenital abnormalities. The commonest cause is adenotonsillar hypertrophy. These are often children with no other medical problems who have hypertrophy of the adenoids and tonsils. This occurs most commonly between the ages of three and six years.

Children with congenital conditions, such as Down's syndrome, neuromuscular diseases or craniofacial abnormalities, have a much higher incidence of obstructive sleep apnoea.

The prevalence of obstructive sleep apnoea is increasing, partly due to the obesity epidemic in the paediatric population.

Pathophysiology
During sleep there are several phases. One of these is rapid eye movement sleep when dreaming occurs. Reduction in the body's muscle tone occurs during this phase, including the pharynx which has a natural resting muscle tone.

In isolation, this phenomenon is unlikely to cause any problems. When the tonsils are enlarged, however, they can meet in the midline to obstruct the airway as the pharynx relaxes and at the same time enlarged adenoids may obstruct the nose. This can result in obstructive sleep apnoea.

In children with anatomy where the airway may be abnormally narrow this may predispose to obstructive sleep apnoea. Abnormally lax muscle tone can result in excess pharyngeal relaxation and obstruction. Children with Down's syndrome have both reduced pharyngeal muscle tone and a narrow airway.

The consequences of partial or total intermittent obstruction are twofold. The child may wake from sleep frequently and there may be fluctuations in oxygenation. Both of these factors can result in neurobehavioural problems. Left undetected and untreated, and if the condition is serious, pulmonary hypertension and cor pulmonale may develop, although this is rare in developed nations.

Section 2: Making the diagnosis
Symptoms can be divided into night symptoms and day symptoms. The most common universal night symptom in these children will be the presence of habitual snoring. Many parents will describe 'choking' episodes or episodes where the breathing is obstructed.


The nasal cavity should be inspected to look for rhinitis (Photograph: SPL)

It is important to seek clarification of how often this occurs and how long the episodes last. Increasingly, parents are using mobile phone video technology to record the episodes and this can be useful in the clinic.

Parents will often report an exacerbation of symptoms during a URTI, which is likely to result in further adenotonsillar hypertrophy.

Enuresis may be more common in children with obstructive sleep apnoea.

In the daytime, children may experience problems with behaviour, concentration and attention. These are the manifestations of the neurobehavioural impairment from sleep fragmentation and hypoxia. The presentation of these may be most noticeable in poor school performers.

It is important to look for features of obstructive sleep apnoea when children are brought to the GP with possible related complaints, such as blocked nose, mouth breathing and upper respiratory or ear infections.

A history of sleep problems may not always be volunteered by the parent, but if sought, it may reveal features suggestive of obstructive sleep apnoea.

Examination
On examination, the children with adenotonsillar hypertrophy may have open-mouthed breathing if the nose is obstructed. A cold metal spatula held below the nose will reveal through its misting pattern whether there is asymmetrical or decreased airflow. The nasal cavity should be inspected, often with an otoscope to look for rhinitis.

Examination of the oral cavity will demonstrate tonsillar hypertrophy. The neck should be examined for lymphadenopathy. Glue ear may co-exist with adenoid hypertrophy so the ears should be examined. Calculation of the child's BMI may be appropriate.

Investigations
After referral to an ENT surgeon, the majority of diagnoses are based on clinical grounds alone, but investigations are indicated in some circumstances. These are outlined in a UK consensus document and cover children younger than two years old, weighing less than 15kg, those with serious comorbidity or an underlying diagnosis contributing to the problem.4

The investigations can take the form of overnight oximetry or a full sleep study.

Overnight oximetry involves the monitoring of heart rate and oxygen saturations. It is relatively non-invasive and can be done at home, but for practical purposes may involve an overnight stay in hospital.

The test has high positive predictive value as a large number of desaturations are diagnostic, but low negative predictive value as a lack of major desaturations does not exclude the child having obstructive episodes which resolve before desaturation can occur.

To detect these, a full sleep study or polysomnogram is required. This involves measurements of respiratory effort, ECG, video and sound so apnoeas can be reliably detected.

Polysomnograms can be useful to determine the severity of the sleep apnoea prior to treatment so provision for special care can be arranged for the most severe cases.

Section 3: Managing the condition
In primary care, children who have intermittent snoring only with no history of apnoeas, no underlying medical conditions and no daytime features, can be managed conservatively.


Post-operative image of tonsillectomy; this procedure is curative in the majority of children (Photograph: SPL)

Children with snoring and daytime symptoms or a history of night-time apnoeas in combination with suspected adenotonsillar hypertrophy should be referred in the first instance to an ENT surgeon.

Children with a history of apnoeas and underlying medical conditions, such as congenital or syndromal problems, should be referred to the paediatric team for care.

Obese children with obstructive sleep apnoea could be referred to respiratory paediatricians for assessment.

Adenotonsillectomy
The management of the condition depends largely on the underlying aetiology. The majority of cases occur in children with adenotonsillar hypertrophy and no underlying medical condition. For these children, adenotonsillectomy is completely curative in the majority of cases.

The procedure is usually undertaken in ENT departments with good paediatric anaesthetic support. Oxygen saturations are monitored overnight to check for any respiratory complications which can occur after the relief of the obstruction. The main risk of the surgery is a post-tonsillectomy bleed which occurs in 3 to 4 per cent of patients.

Children with underlying syndromes or airway abnormalities have a more complex cause of the obstructive sleep apnoea. They need to be assessed by their paediatric team as well as the ENT and anaesthetic teams. It may be decided that adenotonsillectomy is of benefit, but the multifactorial nature of the obstruction needs to be considered.

Children with obesity need assessment by a combination of the ENT and anaesthetic teams and weight loss should be encouraged.

Consideration can be given to adenotonsillectomy, but continuous positive airway pressure (CPAP) devices might be required.

Other treatments
Nasal steroid sprays can be used to treat rhinitis in children, if it is felt that this is making a significant contribution to the airway obstruction. However, it is important to remember that rhinitis could be secondary to adenoid hypertrophy.

CPAP devices are the standard treatment for adults with obstructive sleep apnoea, however, they are rarely required for children.

If adenotonsillar hypertrophy is not a significant contributor, if surgery is contraindicated or if there is a multifactorial aetiology, then CPAP may have a role in treatment.

Section 4: Prognosis
Without treatment, children with obstructive sleep apnoea are likely to have continuing problems resulting from sleep fragmentation and intermittent hypoxia. The most severe cases can develop cardiac or respiratory complications as a result of pulmonary hypertension, although this is rare.

Measuring outcomes
Outcomes can be measured by physiological measurements in sleep studies, or by quality-of-life scoring systems. After adenotonsillectomy in children with no significant comorbidity, a meta-analysis has shown improvement in breathing across all of the included studies and complete normalisation of night-time breathing in 83 per cent of patients.5

Quality of life in paediatric patients improved using a variety of both generic and disease specific questionnaires.6

The patients should be reviewed in the ENT clinic to ensure that there has been resolution of symptoms. Failure may represent untreated rhinitis. Rarely, children have central or neurologically based sleep problems. A repeat sleep study will help with diagnosis, and joint management with the paediatric team is encouraged.

Differences from adult obstructive sleep apnoea
Adults manifest obstructive sleep apnoea in different ways to children. While there may be similar night-time patterns of snoring and obstruction, adult daytime symptoms mostly relate to tiredness. This is the basis of the Epworth sleepiness score.

Paediatric patients exhibit their neurobehavioural problems in entirely different ways with behavioural and concentration problems being common. Adult patients are commonly overweight, while this is rare in the paediatric group.

Adult patients are treated by sleep teams with CPAP machines being the mainstay of treatment. In paediatric patients, adenotonsillectomy is curative in the vast majority of cases.

Section 5: Case report
J was an otherwise fit and well three-year-old child. He had been snoring habitually for around six months when his mother began to have some concerns about his breathing.

His breathing was very loud at night and his mother commented that even with the television turned up loud they could hear his snoring. He also began to have choking spells.

His mother described that he would take a loud snore, but then his breathing would stop for several seconds. His chest and abdomen would still move and then he would inspire with a loud snore. He slept with his head extended.

During the daytime his nose was blocked all the time and his speech was described as nasal. He also seemed to be unsettled since the difficulty with his breathing started.

Treatment
He was referred to an ENT surgeon by his GP who suspected a diagnosis of obstructive sleep apnoea. The ENT surgeon agreed with this diagnosis.

He found that J had large tonsils and a blocked nose consistent with adenoid hypertrophy. It was felt that no further investigations were required and treatment in the form of adenotonsillectomy was discussed with his parents.

He underwent an adenotonsillectomy. There were no complications and J maintained his oxygen saturations after the procedure. He was able to eat and drink well and went home a day after the surgery with analgesia.

J's night-time symptoms disappeared and at first his mother was concerned as she could no longer hear him breathing.

He did not snore and had no further apnoeas.

During the daytime his breathing through the nose improved and he did not sound like he had a URTI any more. His mother commented that he seemed much happier and more settled following the surgery.

He was seen once by the surgeon at six weeks and then discharged back to the GP.

Section 6: Evidence base
A summary of the evidence relating to this condition can be found in a recent article in the BMJ.7

Clinical trials
There are no RCTs of adenotonsillectomy in the treatment of obstructive sleep apnoea, but below are two meta-analyses of prospective non-randomised cohorts of children undergoing adenotonsillectomy that consider quality of life.

Guidelines

  • Robb PJ, Bew S, Kubba H et al. Tonsillectomy and adenoidectomy in children with sleep related breathing disorders: consensus statement of a UK multidisciplinary working party. Clin Otolaryngol 2009; 34: 61-3.

This consensus statement provides a guide to investigation.

Key texts

  • Clarke RW. The causes and effects of obstructive sleep apnoea in children. In: Graham JM, Scadding GK, Bull PD (editors). Pediatric ENT. Heidelberg, Springer, 2007: 141-51.

This text has a summary of obstructive sleep apnoea with discussion of the wider aspects.

Online
Patient information leaflets on tonsil and adenoid surgery are available from ENT-UK.

Reflect on this article and add notes to your CPD Organiser on MIMS Learning

CPD IMPACT: EARN MORE CREDITS

These further action points may allow you to earn more credits by increasing the time spent and the impact achieved.

  • Hold a clinical meeting with your colleagues, highlighting paediatric sleep apnoea.
  • Build a template on your clinical notes system to prompt clinicians to ask about symptoms of sleep apnoea, especially in a child with upper respiratory or behavioural problems.
  • Invite your local ENT consultant to your practice to discuss how you can investigate and manage children with potential sleep apnoea in primary care.

References
1. Ali NJ, Pitson DJ, Stradling JR. Snoring, sleep disturbance, and behaviour in 4-5 year olds. Arch Dis Child 1993; 68(3): 360-6.

2. Brunetti L, Rana S, Lospalluti ML et al. Prevalence of obstructive sleep apnea syndrome in a cohort of 1,207 children of southern Italy. Chest 2001; 120: 1930-5.

3. Bixler EO, Vgontzas AN, Lin H-M et al. Sleep disordered breathing in children in a general population sample: prevalence and risk factors. Sleep 2009; 32(6): 731-6.

4. Robb PJ, Bew S, Kubba H et al. Tonsillectomy and adenoidectomy in children with sleep related breathing disorders: consensus statement of a UK multidisciplinary working party. Clin Otolaryngol 2009; 34: 61-3.

5. Brietzke SE, Gallagher D. The effectiveness of tonsillectomy and adenoidectomy in the treatment of pediatric obstructive sleep apnea/hypopnea syndrome: a meta-analysis. J Otolaryngol Head Neck Surg 2006; 134(6): 979-84.

6. Mitchell RB, Kelly J. Behavior, neurocognition and quality-of-life in children with sleep-disordered breathing. Int J Pediatr Otorhinolaryngol 2006; 70(3): 395-406.

7. Powell S, Kubba H, O'Brien C et al. Paediatric obstructive sleep apnoea. BMJ 2010; 340: c1918.

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