OSA

Question 1

What is sleep apnoea?

Answer 1

Absence of airflow during sleep

Can be central or obstructive

Question 2

What is central sleep apnoea?

Answer 2

Reduced or absent efferent activity from brainstem respiratory control neurones

Question 3

What is obstructive sleep apnoea?

Answer 3

Partial or complete occlusion of upper airway with paradox breathing

Question 4

What happens in OSA in the night that induces symptoms?

Answer 4

Lying down
Respiratory muscles have decreased muscle tone
Upper airway collapse
Tongue collapses and reduces size of lumen
Also increased adipose tissue pushes airway closed too

Question 5

What is apnoea?

Answer 5

Cessation of breathing

Intermittent hypoxia

Question 6

What does apnoea cause?

Answer 6

Arousal 
Fragmented sleep 
Sleepiness and cognitive dysfunction
Compensated respiratory acidosis
HTN
Daytime somnolence

Question 7

What does OSA do to sleep?

Answer 7

Arousals
Reduced deep sleep
Reduced REM

Question 8

How do you measure sleepiness?

Answer 8

Epworth sleepiness scale

Question 9

Describe the progression of OSA

Answer 9

Snoring
Upper airway resistance syndrome
Mild obstructive sleep apnoea (5-15 events/hr)
Moderate obstructive sleep apnoea (15-30 events/hr)
Severe obstructive sleep apnoea (>30 events/hr)

Question 10

What are the treatments for OSA?

Answer 10

Lifestyle measures -weight loss

CPAP for moderate to severe

Question 11

What are alternative to CPAP treatments?

Answer 11

Mandibular advancement splint (reduces tongue blocking)
Positional therapy for supine avoidance
Centralised sleep therapy
Goal setting and Expectation management

Question 12

What are predisposing factors for OSA?

Answer 12

Obesity
Macroglossia (acromegaly, hypothyroidism)
Large tonsils
Marfan’s

Question 13

When should the DVLA be informed of OSA?

Answer 13

causing excessive daytime sleepiness