Education and Resources

What is sleep disordered breathing?

The term Sleep Disordered Breathing (SDB) covers a range of disorders characterized by abnormalities in breathing during sleep.  Sleep-induced partial obstruction of the upper airway (at the throat) is the most common form of SDB, and is identified by the occurrence of snoring.  This well-known sound is generated when the partially obstructed airway vibrates during breathing efforts.  The severity of the obstruction that is indicated by snoring varies from mild to severe. Although snoring often occurs without any reduction in blood oxygen, it can be an important source of sleep disruption.

Obstructive sleep apnea (OSA) is the most serious form of SDB and typically occurs after long-standing snoring. In patients with OSA, the upper airway closes completely during sleep. This leads to arousals, disruption of sleep and diminished blood oxygen levels.  In the early stages of OSA the subject’s sleep is dominated by heavy obstructed snoring with only a few episodes of complete obstruction. As the disorder progresses there are typically repeated episodes of obstructive apnea throughout the night.

It is estimated that OSA affects up to 20% of the adult population, and is associated with hypertension, stroke, congestive heart failure and Type 2 diabetes. Snoring and obstructive apnea are also very common in childhood when adenotonsillar enlargement peaks in the 2 – 5 year old age range.  The American Academy of Sleep Medicine reports that the prevalence of OSA is approximately two percent in otherwise healthy young children. Chronic snoring occurs in almost 10% of children of both sexes.

“Apnea” means temporary absence or cessation of breathing. Obstructive apneas are caused by a physical obstruction, such as collapse of the upper airway when muscles relax during sleep. During an apnea the natural reaction of the body is to make bigger efforts to breathe.  Eventually this will cause the subject to wake up briefly, which causes the airway to return to normal again, allowing them to breathe, and then fall back to sleep. A person may have many obstructive apneic events during the night, leading to many arousals, disruption of sleep and diminished blood oxygenation.

Apneas may also be caused by a problem in the relay of breathing signals from the brain. These apneas are known as “central apneas”, as the problem relates to the central nervous system.  “Mixed” apneas are a combination of obstructive and central apneic events.

What causes OSA?

Enlarged tonsils and adenoids are a major contributor to the prevalence of OSA in infants and children, but other factors such as obesity, craniofacial structure, and upper airway muscle tone are important. Long-term nasal obstruction, for example in chronic hay fever,  may also contribute to OSA.

Recent research has linked asthma symptoms in children with snoring and troubled sleep (Pediatrics 2009;124:218-225).

What are the symptoms?

Snoring is usually the first and most obvious symptom of increased upper airway obstruction in sleep, and is extremely frequent in infants and children.  Snoring is an indication that the upper airway has partially collapsed. Other symptoms, as listed by the US National Sleep Foundation, are provided in the table below.

Symptoms of OSA in Infants and Children

During the night, a child with sleep apnea may:

  • Snore loudly and on a regular basis
  • Have pauses, gasps, and snorts and actually stop breathing. The snorts or gasps may wake them and disrupt their sleep.
  • Be restless or sleep in abnormal positions with their head in unusual positions
  • Sweat heavily during sleep

During the day, a child with sleep apnea may:

  • Have behavioural, school and social problems
  • Be difficult to wake up
  • Have headaches during the day, but especially in the morning
  • Be irritable, agitated, aggressive, and cranky
  • Be so sleepy during the day that they actually fall asleep or daydream
  • Speak with a nasal voice and breathe regularly through the mouth

Is OSA detrimental to the child’s health?

According to a recent study in CHEST, the official journal of the American College of Chest Physicians, children who snored loudly were twice as likely to have learning difficulties.  Following a night of poor sleep, children are more likely to be hyperactive and have problems paying attention.  These are also signs of attention deficit/hyperactivity disorder (ADHD).  Interruption of breathing during sleep may also be associated with delayed growth and cardiovascular problems.

The spectrum of disease and morbidity associated with SDB in children is expanding.  As such, degrees of severity (e.g. level of snoring) that might once have been considered clinically irrelevant are now recognised as having substantial developmental, behavioural and other health consequences.

What should I do if I suspect my child has OSA?

The symptoms should be discussed with the child’s paediatrician.

How is it diagnosed?

The diagnosis of OSA in children is usually based on the characteristic symptoms and evidence of adenotonsillar hypertrophy (enlarged tonsils and adenoids) and mouth breathing.  Children suspected of having OSA should usually be evaluated by a Paediatric ENT specialist for further evaluation.

If necessary, further testing might include a sleep study.  In most cases the sleep study must be performed during an overnight stay in a hospital or a specialised sleep clinic.  In some cases, the sleep study may be performed in the child’s home.
During a sleep study, various sensors will be attached to the child to measure sleep quality and breathing patterns.  After the study the results are analysed by a medical professional who will be able to determine if the child has sleep disordered breathing.

What are the treatments?

The first-line treatment for OSA in infants and children is surgical removal of tonsils and adenoids.  However, treatment with continuous positive airway pressure (CPAP) therapy is increasingly being used.

CPAP therapy involves the application of positive pressure to the upper airway via a face mask or nasal prongs.  The positive pressure acts as a ‘splint’ that keeps the upper airway open throughout sleep: much in the same way that a collapsed drinking straw can be opened by blowing into it.

CPAP therapy has been used to treat OSA in infancy and childhood for over twenty years, and is now recommended by the American Academy of Pediatrics as the second line of treatment after removal of tonsils and adenoids (American Academy of Pediatrics, 2002).

Until recently, CPAP therapy for children has been made difficult due to the unavailability of mask and nasal prongs interfaces designed specifically for children, especially those younger than 2 years.  However, this issue is being addressed as medical companies react to the increasing body of research showing the prevalence and the increasing diagnosis of OSA in children.

Other treatments options for OSA include:
• Weight loss
• Orthodontic braces
• Allergy treatment

Are there any side effects of CPAP therapy?

CPAP therapy has been used to treat OSA in infancy and childhood for over twenty years, and has been proven to be very safe.  The majority of side effects are local skin irritation by the mask, eye irritation from mask leaks, and nasal obstruction.  The latter can be resolved by humidifying the air supplied by the CPAP machine.  Humidifiers for use with CPAP devices are readily available for use with child patients.

The main concern in using CPAP on children is the potential of the mask and headgear to cause structural changes in the face with long-term use.  The bones in the face are not fused in children and so are malleable.  For this reason, children who require long term CPAP treatment should have an annual review by a specialist dentist or orthodontist.

Another potential side effect is gastric distension, caused by air entering the stomach.  This is more likely at higher CPAP pressures.  It is rarely observed in children possibly due to the fact that children on CPAP therapy are usually on lower pressure.

Is OSA genetic?

A recent report indicates that children have an increased risk of developing obstructive sleep apnea (OSA) if they have at least one sibling who has been diagnosed with the sleep disorder (Sleep, August 1, 2009)

According to the report’s authors, the increased risks for both OSA and adenotonsillar hypertrophy could be an expression of genetic or shared environmental mechanisms.  Recent genetic studies of both adult and pediatric patients with OSA indicate that genetic mechanisms do play an important role. Possible environmental factors include the increased medical awareness of sleep disordered breathing over time, both among parents and doctors.

The authors recommend that medical providers ask about sleep-related symptoms in siblings when children present with clinical signs or symptoms of OSA.