Sleep Apnoea

Question 1

Obstructive sleep apnoea is far more serious than simple snoring. Snoring is brought about by vibration of the pharynx during partial airway obstruction. This is typically worse when the patient is sleeping because pharyngeal muscles relax.

What is apnoea?

Answer 1

Cessation of airflow at mouth for 10 seconds

Question 2

What is obstructive sleep apnoea?

Answer 2

• apnoea caused by upper airway obstruction
• as pharyngeal muscles relax during sleep
• 5 or more episodes / hr

Question 3

What is obstructive sleep apnoea hypopnoea syndrome?

Answer 3

• OSA w/ daytime symptoms
• sleepiness, poor concentration + irritability
• 15 or more episodes / hr

Question 4

What causes OSA in children?

Answer 4

• apnoeas commonly noticed by parents
• daytime symptoms less common
• tonsillar enlargement → adenoids + tonsils
• obesity
• neuromuscular disorders
• craniofacial abnormalities

Adenotonsillectomy is almost always curative

Question 5

Adult OSA is often noticed by the partner and daytime symptoms are more prominent.

What are causes in an adult?

Answer 5

• obesity 50%
• more common in males than females
• rhinitis + nasal obstruction
• maxillomandibular abnormalities
• neck size >43cm
• age >40
• alcohol + smoking

Surgery is rarely effective

Question 6

OSA causes a brief period of hypoxaemia. The patient is then aroused from sleep; refreshing sleep is impossible.

What is the clinical presentation?

Answer 6

• Adults:
  
  • excessive daytime sleepiness
  • unrefreshing sleep
  • impaired concentration
  • irritability
  • decreased libido
  • at night → snoring, witnessed episodes of apnoea, choking
• Children:
  
  • often brought in by parents → snoring + witnessed apnoea
  • daytime sleepiness not prominent → may have XS activity + behavioural problems
  • performance at school suffering
  • pulmonary hypertension and cor pulmonale in severe cases

Question 7

Daytime sleepiness can be assessed by the Epworth Sleepiness Scale. Polysomnography is currently the most accepted test → sleep sutdies measuring several variables.

What is the management of adult obstructive sleep apnoea?

Answer 7

• stop sedative drugs if possible
• conservative → weight loss, limit alcohol/smoking
• medical → treat underlying cause, use mandibular advancement device for uncomplicated snoring + for established OSA use CPAP at night
• surgical → specialist, cost-limited, very difficult patient selection, dubious benefit