Obstructive Sleep Apnoea

Question 1

Grading of Sleep Apnoea Severity

Answer 1

Use Apnoea Hypopnoea Index (AHI)

• OSA Diagnosis with >= 5 AHI events / hour
• Moderate-Severe Disease with >=15 AHI events / hour

Question 2

Risk Factors for Sleep Apnoea

Answer 2

• Obesity
• Adenotonsillar hypertrophy
• Age >= 50
• T2DM
• Alcohol or sedative use
• HTN that is difficult to control.

Question 3

OSA Screening Questionnaires

Answer 3

Berlin Questionnaire
- 3 categories asked
- Snoring and witnessed apnoeas
- Daytime sleepiness or fatigue
- Self-reported HTN and Obesity
-Sens 82% Spec 38%

OSA50
- Four items that best predicted moderate to severe disease
- Waist circumference
- Snoring
- Witnessed apnoeas
- Age >= 50yo
- Sens 94% Spec 31% in identifying mod-severe OSA

STOP-Bang
- Snoring
- Tiredness
- Observed Apnoeas
- High Blood Pressure
- BMI > 35
- Age > 50
- Neck circumference > 40cm
- Male Gender

Epworth Sleepiness Scale
- Measure of daytime sleepiness by asking patient to rate chance of dozing off in eight commonly encountered scenarios.
- ESS >= Presence of at least mild daytime sleepiness.

Question 4

MBS rules regarding primary care referral pathway for sleep study

Answer 4

OSA Screening Questionnaire
- OSA50>=5 or STOP-BANG >=4
+
ESS >= 8

If not met, can refer to respiratory physician to consider referral via specialist.

Question 5

Complications of untreated OSA

Answer 5

• Impaired neurocognitive function
• Daytime somnolence
• HTN
• Acute coronary syndrome
• CHF
• Stroke.