Obstructive Sleep Apnoea

Question 1

Define obstructive sleep apnoea

Answer 1

Complete or partial airway obstruction during sleep -> apnoea (cessation of airflow for >10s) followed by arousal from sleep

Question 2

What are the aetiology/risk factors of OSA?

Answer 2

• Obesity
• Smoking
• Alcohol
• Family history
• Sedative use
• Enlarged tonsils/adenoids/tongue
• Craniofacial abnormalities
• Endocrinopathies e.g. T2DM, acromegaly, PCOS, metabolic syndrome

Question 3

Describe the epidemiology of OSA

Answer 3

Common: 5-20% of men and 2-5% of women >35 years

Prevalence increases with age

Question 4

What are the presenting symptoms of OSA?

Answer 4

• Excessive daytime sleepiness
• Unrefreshing/restless sleep
• Morning headaches
• Dry mouth
• Difficulty concentrating
• Irritability
• Mood changes
• Snoring
• Nocturnal apnoeic episodes
• Nocturnal choking

Question 5

What are the signs of OSA?

Answer 5

• Macroglossia
• Enlarged tonsils
• Long, thick uvula
• Retrognathia (posteriorly displaced jaw)
• Increased neck circumference (>42cm ♂, >40cm ♀)
• Obesity
• Hypertension

Question 6

What are the investigations of OSA?

Answer 6

• polysomnography Apnoea-Hypopnoea Index (AHI) ≥15 episodes/hour
• portable multichannel sleep tests - Respiratory Event Index (REI) of ≥15 episodes/hour
• awake fibreoptic endoscopy - may see nasal polyps or tumours