Obstructive Sleep Apnoea

Question 1

Define Obstructive Sleep Apnoea.

Answer 1

Intermittent, recurrent closure or collapse (may be partial or complete) of the pharyngeal airway, causing apnoeic episodes (>10s cessation of airflow) during sleep. These are terminated by partial arousal.

Question 2

What is the epidemiology of Obstructive Sleep Apnoea?

Answer 2

• More common in males
• Affects up to 20% males and 5% females ages 35+
• Prevalence increases with age

Question 3

Why does Obstructive Sleep Apnoea happen?

Answer 3

Collapse of airway due to collapse of soft tissue in pharynx – this is caused by decreased tone of pharyngeal dilator during sleep.

Question 4

Outline some risk factors of Obstructive Sleep Apnoea.

Answer 4

• Lifestyle: Increase in weight/smoker/alcohol
• Physical abnormalities: Macroglossia, Marfan’s, craniofacial deformities
• Children: enlarged tonsils/adenoids

Question 5

What might you find in the history of a patient with obstructive sleep apnoea?

Answer 5

Restless sleep, episodic gasping, loud chronic snoring, morning headache, excessive sleepiness in daytime, decreased cognitive performance, decreased libido

Question 6

What might you find on examination of a patient with obstructive sleep apnoea?

Answer 6

• Large tongue, enlarged tonsils, large uvula, retrognathia may be seen.
• Large neck circumference (>42cm in males and >40cm in females)
• Patient may be obese, HTN.

Question 7

How would you investigate obstructive sleep apnoea?

Answer 7

•Video recorded episodes

•Polysomnography – calculate the apnoea-hypoapnoea index or respiratory distress index
oMonitor airflow, respiratory effort, pulse oximetry and HR
o>15 episodes in an hour
o>5 episodes in an hour, with HTN/IHD/Hx of stroke/insomnia/excessive daytime sleepiness

•Bloods – TFTs (hypothyroid) and ABG

Question 8

How would you manage obstructive sleep apnoea?

Answer 8

• Mild: sleep on side, weight loss, smoking cessation, reduce alcohol intake
• Moderate: mandibular advancement splint
• Severe: CPAP during sleep – keeps airway patent by maintaining positive intraluminal pressure
• Surgery: in order to relieve pharyngeal obstruction

ADVISE PATIENT TO NOTIFY DVLA

Question 9

Outline some complications of obstructive sleep apnoea.

Answer 9

•CVS: ↑ Risk of disease - HTN, arrhythmia, stroke, CKD
oIncreased mortality due to this

• Brain: Cognitive dysfunction and depression
• Respiratory: ↑ Risk pulmonary HTN, Type 2 Resp failure
• Greater risk of occupational/driving accidents