Obstructive Sleep Apnoea

Question 1

What is obstructive sleep apnoea/ hypopnoea syndrome?

Answer 1

recurrent episodes of complete or partial upper airway obstruction during sleep causing apnoea or hypopnoea

Question 2

What is apnoea?

Answer 2

complete airflow obstruction with temporary absence or cessation of breathing

Question 3

What is hypopnoea?

Answer 3

Decreased airflow

Question 4

What is the aetiology of OSA?

Answer 4

Occurs due to excessive collapsing forces around the pharynx that exceed the decreased muscle tone during sleep

Question 5

What are 6 risk factors for OSA?

Answer 5

Age
Male
Obesity +/ neck circumference >40cm
FH
Smoking.
Alcohol

Question 6

What 4 endocrine disorders are associated with OSAS?

Answer 6

T2DM
Acromegaly
Hypothyroidism
PCOS

Question 7

Give a cardio, resp and neurological condition associated with OSAS

Answer 7

Chronic HF
Mod-severe asthma
Stroke/ TIA

Question 8

List 4 symptoms of OSA

Answer 8

Excessive daytime sleepiness + fatigue
Unrefreshing sleep + impaired concentration.
Witnessed breathing pauses (apnoeas), gasping or choking during sleep
Snoring

Question 9

Give 4 symptoms that sometimes occur in OSAS

Answer 9

Morning headache (resolves within hours of waking)
Freq nocturnal awakenings
Unexplained nocturia.
Nocturnal GORD

Question 10

What should you examine the patient for if suspicious of OSAS?

Answer 10

Jaw abnormalities: micrognathia, retrognathia

Nasopharyngeal obstruction: mouth breathing, nasal speech (Enlarged tonsils)

Signs of COPD, resp failure, pulmonary HTN

BP, BMI, neck circumference
Large tongue

Question 11

How can OSA cause hypertension?

Answer 11

Increase in BP due to drop in blood O2 levels + rise in CO2 during apnoea

Question 12

Give 4 indications for urgent referral to a sleep clinic

Answer 12

Excessive sleepiness impacting role as safety critical worker: driver, pilot

Co-morbid: COPD, poorly controlled arrhythmia, HF, Tx resistant HTN

Pregnant

Undergoing pre-op assessment for major surgery

Question 13

What is the gold standard investigation for diagnosing OSA? What does this consist of?

Answer 13

Polysomnography
Monitoring while asleep:
EEG
EOGs (measure horizontal + vertical eye movements)
Electromyogram to monitor muscle movement.

Question 14

What blood tests may be useful in excluding other diagnoses?

Answer 14

TFTs: hypothyroidism
ABG: Cor pulmonale

Question 15

How many episodes of apnoea per hour sleep are considered indicative of severity in sleep apnoea?

Answer 15

> 5: mild
15: moderate
30: severe

Question 16

What is used to assess daytime sleepiness?

Answer 16

Epworth Sleepiness Scale

Question 17

What questionnaire assesses snoring, sleepiness, apnoeas and patient characteristics in OSAS?

Answer 17

STOP-Bang questionnaire

Question 18

What conservative management can be used for OSAS?

Answer 18

Weight loss
Smoking cessation
Alcohol reduction
Avoiding sleeping supine
Intra-oral devices: mandibular advancement
Inform DVLA if excess daytime sleepiness

Question 19

What intervention is first line in moderate-severe OSAS?

Answer 19

Continuous positive airway pressure (CPAP)

Question 20

What surgical management may be appropriate for OSAS?

Answer 20

Adenotonsillectomy if evidence of obstruction/ children with adenotonsillar hypertrophy