Obstructive Sleep Apnoea

Question 1

What is obstructive sleep apnoea?

Answer 1

recurrent prolapse of the pharyngeal airway + apnoea (cessation of airflow for > 10 s) during sleep, terminated by partial arousal

Question 2

What is the aetiology of OSA?

Answer 2

Occurs due to narrowing of upper airways because of the collapse of soft tissues of the pharynx
Due to decreased tone of the pharyngeal dilators during sleep

Question 3

What are 7 risk factors for OSA?

Answer 3

Obesity
Male gender.
Middle age (55-59 in M, 60-64 in F).
Smoking.
Sedative drugs.
Excess alcohol consumption.
FH

Question 4

List 8 symptoms of OSA

Answer 4

Excessive daytime sleepiness.
Impaired concentration.
Snoring.
Morning headache
Poor sleep quality
Irritability/personality change.
Nocturia.
Decreased libido.

Question 5

What is the epidemiology of OSA?

Answer 5

Common

Increases with age

Question 6

List 6 possible signs suggestive of OSA

Answer 6

Obesity.
Large neck circumference 
Large tongue  
Enlarged tonsils  
Long or thick uvula  
Retrognathia (pulled back jaws)

Question 7

What is the gold standard investigation for diagnosing OSA? What does this consist of?

Answer 7

Polysomnography
Monitoring while asleep:
EEG
EOGs (measure horizontal + vertical eye movements)
Electromyogram to monitor muscle movement.

Question 8

What blood tests may be useful in excluding other diagnoses?

Answer 8

TFTs: hypothyroidism
ABG: Cor pulmonale

Question 9

How many episodes of apnoea per hour sleep are considered indicative of moderate and significant sleep apnoea?

Answer 9

> 5

>15

Question 10

What is used to assess daytime sleepiness?

Answer 10

Epworth Sleepiness Scale