Sleep apnoea

Question 1

What % of the population are affected by obstructive sleep apnoea?

Answer 1

1-2%

Most often fat, middle aged men

Can occur in children with enlarged tonsils

Question 2

What is obstructive sleep apnoea?

Answer 2

Irregular breathing and snoring patterns that cause apnoea (temporary cessation of breathing)

Leads to an inability to get a good nights sleep and therefore exhaustion

Question 3

Common signs and symptoms of sleep apnoea

Answer 3

• Loud snoring (95%)
• Daytime sleepiness
• Unrefreshed sleep
• Morning headache
• Nocturnal choking

Question 4

Why does the airway close in people with sleep apnoea during sleep but not during the day?

Answer 4

The opening muscles of the upper airway (geniglossus and palatal muscles) become hypotonic during sleep and the pressure of inspired air is enough to collapse the pharynx

Question 5

What are the correctable factors present in some cases of obstructive sleep apnoea?

Answer 5

There are correctable factors in ~1/3 of cases:

• Encroachment on pharynx: tonsils, obesity
• Nasal polyps/ adenoids/ deformity
• Respiratory depressant drugs

Question 6

How is sleep apnoea diagnosed?

Answer 6

• Relatives provide hx of snore-silence-snore cycle
• Epworth sleepiness scale (asks patients how likely they are to doze off during certain situations with overall score indicating normal, obstructive sleep apnoea and narcolepsy)
• Overnight pulse oximetry: shows o2 saturation falling in a cyclical manner producing a sawtooth appearance on the tracing *SA diagnosed if there are more than 10-15 apnoeas within an hr

Question 7

How is sleep apnoea managed?

Answer 7

• Correction of treatable factors
• CPAP delivered by nasal mask during sleep

*50% of OSA patients can’t tolerate CPAP

• Modafinil (CNS stimulant) is a useful short term alternative

Question 8

Predisposing factors for sleep apnoea

Answer 8

Obesity

Macroglossia: acromegaly, hypothyroidism, amyloidosis

Large tonsils

Marfan’s syndrome