SLEEP DISORDERS

Question 1

What is obstructive sleep apnoea?

Answer 1

a sleep-related breathing disorder characterized by recurrent episodes of complete or partial obstruction of the upper airway during sleep, causing apnoea

Question 2

Whats the difference between OSA syndrome and OSA?

Answer 2

OSA is a term used to describe people with irregular breathing at night but without daytime sleepiness
OSA syndrome causes excessive daytime sleepiness

Question 3

Whats the epidemiology of obstructive sleep apnoea?

Answer 3

Can affect all age groups with an increasing prevalence with age and obesity

Question 4

What are risk factors for developing obstructive sleep apnoea syndrome?

Answer 4

Increasing age
Male sex
Obesity
Neck circumference >40.6cm
FH
Smoking
Alcohol
Sleeping supine
Hypothyroidism
Adenotonsillar hypertophy or macroglossia
Craniofacial abnormalities
Type 2 diabetes
Down’s syndrome
Acromegaly
PCOS
CHF
Asthma
Stroke or TIA
Cardiac arrhythmias
Non-arteritic anterior ischaemic optic neuropathy

Question 5

What are risk factors for OSAS for children?

Answer 5

Adenotonsillar hypertrophy.
Obesity.
Craniofacial abnormalities such as retrognathia (abnormal jaw positioning with mandible set back from the maxilla); micrognathia (undersized lower jaw); cleft palate.
Neuromuscular disease such as cerebral palsy (decreased tone in upper airway).
Other (such as Down’s syndrome due to both anatomical abnormalities and decreased muscle tone; achondroplasia; and Prader-Willi syndrome).

Question 6

What are symptoms of OSAS?

Answer 6

Excessive daytime sleepiness
Snoring
Fatigue
Witnessed apnoeas, gasping or choking
Unrefreshing sleep
Impaired concentration
Unexplained morning headache
Frequent nocturnal awakenings

Severe cases - hypertension, HF

Question 7

What screening questionnaires can be used for OSAS?

Answer 7

STOP-Bang
Epworth sleepiness scale
Multiple Sleep Latency Test

Question 8

What are DDx for OSAS?

Answer 8

Snoring
Sleep deprivation e.g. due to pain or shift work
Other sleep disorders - insomnia, narcolepsy, parasomnias
Daytime sleepiness could be caused by hypothyroidism, depression, drugs, neurological disorders
Nocturnal gasping - GORD, asthma, HF, panic attacks
Reduced concentration in children could be ADHD

Question 9

Why does OSAS sometimes cause hypertension?

Answer 9

Not fully understood but several theories:
- repeated episodes of oxygen desaturation and arousal from sleep causes activation of SNS which increases HR and causes vasoconstriction
- during sleep apnoea decrease oxygen in blood which promoters production of renin and angiotensin II = vasoconstriction
- OSAS can cause inflammation and oxidative stress = damage blood vessels = increases risk of developing hypertension

Question 10

What is the Epworth sleepiness scale?

Answer 10

a scale intended to measure daytime sleepiness that is measured by use of a very short questionnaire. This can be helpful in diagnosing obstructive sleep apnoea syndrome

Question 11

what is there multiple sleep latency test?

Answer 11

measures the time to fall asleep in a dark room (using EEG criteria)

Question 12

When should you arrange an urgent referral to a sleep clinic for suspect OSAS (within 4 weeks)?

Answer 12

If they have excessive sleepiness impacting on their role as a professional drivers or safety-critical worker e.g. pilot
If they have a comorbid condition e.g. COPD, arrhythmia, nocturnal angina, HF, resp failure etc
If pregnant
If undergoing pre-operative assessment for major surgery
If they have non-arteritic anterior ischaemic optic neuropathy

Question 13

What sleep studies can you do for OSAS?

Answer 13

Polysomnography - often used to measure sleep-wake state and apnoea/hypopnoea episodes to confirm the diagnosis of obstructive sleep apnoea syndrome
Oxygen desaturation index

Question 14

Whats the diagnostic requirement for OSAS from Polysomnography? And how is this severity graded?

Answer 14

At least 5 episodes of apnoea, hypoapnoea or both events lasting a minimum of 10 seconds per hour of sleep

Mild: AHI 5–14 per hour.
Moderate: AHI 15–30 per hour.
Severe: AHI more than 30 per hour.

Question 15

How do you manage confirmed sleep apnoea?

Answer 15

Modify risk factors and advise on lifestyle measures
Encourage adherence to any specialist treatments
Monitor for and manage any associated conditions
Provide advise on driving regulations and encourage Pt to check with their insurer whether they are still insured to drive under their current policy

Question 16

What are the options for specialist treatment of OSAS?

Answer 16

CPAP therapy
Intra-oral mandibular advancement devices
Upper airways surgery e.g. tonsillectomy

Adenotonsillectomy may be used in children who have adenotonsillar hypertrophy to correct the anatomical obstruction causing symptoms

Question 17

What is CPAP?

Answer 17

Airway pressure may be delivered through a nasal or face mask for airflow delivery at night, and the pressure acts to splint the upper airways to prevent collapse during inspiration.

Question 18

What are mandibular advancement devices?

Answer 18

devices consist of plates made to fit the upper and lower teeth to be worn during sleep, and vary in complexity and cost. They provide forward advancement of the mandible and attached tongue during sleep, to maintain an open upper airway and reduce airway collapsibility.

Question 19

When may upper airways surgery be indicated for OSAS?

Answer 19

if there is evidence of nasopharyngeal obstruction causing symptoms.

Question 20

What advice should you give about driving for pt with OSAS?

Answer 20

Group 1 and 2:
Mild - Must not drive until satisfactory symptoms control and if this cannot be achieved within 3 months the person must notify DVLA
Moderate/severe - must not drive and must notify DVLA. Subsequent licensing will require control of condition, improved sleepiness and treatment adherence

Advise a person that they may continue to drive and do not need to notify the DVLA if they have suspected or confirmed OSAS but do not have excessive sleepiness which is having, or is likely to have, an adverse effect on driving.