Obstructive Sleep Apnoea

Question 1

Define obstructive sleep apnoea

Answer 1

irregular breathing at night due to intermittent closure/collapse of the pharyngeal airway causing apnoeic episodes during sleep WITHOUT daytime sleepiness

Question 2

Define Obstructive Sleep apnoea/hypopnoea syndrome (OSAHS)

Answer 2

Sleep-related breathing disorder characterised by recurrent episodes of complete or partial obstruction of the upper airway airway during sleep, causing apnoea (complete airflow obstruction with temporary absence or cessation of breathing) or hypopnoea (decreased airflow)

Question 3

Aetiology of sleep apnoea

Answer 3

An episode will be caused by dynamic narrowing of the upper airway during sleep.
This can be triggered by neuromuscular mechanisms within an anatomically small upper airway
Anatomical narrowing may be mediated by maxillomandibular anomalies or adenotonsillar hypertrophy
Increases in lateral pharyngeal, soft palatal and tongue tissue mass is commonly seen in obesity, which would also narrow the airway

Question 4

Risk factors for obstructive sleep apnoea

Answer 4

Increasing age
Male sex
Neck circumference >40.6
Family history
Smoking
Obesity
Type 2 diabetes
Adenotonsillar hypertrophy
Craniofacial abnormalities e.g. Retrognathia (abnormal jaw positioning with mandible set back from the maxilla), Micrognathia (undersized lower jaw), Cleft palate
Neuromuscular disease e.g. cerebral palsy
Down’s syndrome, achondroplasia, Prader-Willi syndrome

Question 5

Symptoms of obstructive sleep apnoea

Answer 5

Night:
Loud snoring
Apnoeic episodes (episodic cessation of breathing terminated by a loud snore)
Gasping or choking during sleep
Poor sleep quality
Nocturnal enuresis
Restlessness and sudden arousals from sleep, laboured breathing, unusual sleep posture (for example with neck hyperextended)

Daytime
Daytime somnolence or fatigue
Morning headache
Reduce cognitive performance, behavioural problems, hyperactivity
Impaired concentration, reduced school performance
Mouth breathing

Question 6

Investigations for obstructive sleep apnoea

Answer 6

Ask carers to record a video of sleep
STOP-Bang questionnaire: 8 items to assess snoring, sleeping, apnoea etc.
Epworth Sleepiness Scale: 8 items that assesses daytime sleepiness

Polysomnography (PSG): >15 episodes of apnoea/hypopnoea during 1 hour of sleep
- Monitors oxygen saturation airflow at the mouth, ECG, EMG chest, and abdominal wall movement during sleep

Question 7

Management for obstructive sleep apnoea

Answer 7

Routine referral to sleep clinic

Conservative:
- Weight loss
- Diet and exercise
- Stop smoking
- Stop drinking
- Avoid sleeping supine
- DVLA:
– Suspected/mild: do not drive
– Moderate/severe: do not drive and must notify DVLA

→ CPAP therapy
Intra-oral mandibular advancement devices may be appropriate for people who snore or have mild OSAS with normal daytime alertness

Question 8

When is urgent referral required for obstructive sleep apnoea

Answer 8

(Within 4 weeks)
Has excessive sleepiness impacting on their role as a professional driver or other safety-critical worker (for example pilot, bus or lorry driver, or operator of dangerous machinery). Advise the person not to drive until they have been assessed by a specialist
Comorbid condition e.g. COPD, arrhythmias, pulmonary HTN
Pregnant
Undergoing pre-operative assessment for majory surgery
Optic neuropathy