Obstructive Sleep Apnoea

Question 1

What is Obstructive Sleep Apnoea (OSA)?

Answer 1

A sleep‑disordered breathing condition characterised by recurrent episodes of partial or complete upper airway obstruction during sleep.

Question 2

What physiological consequences occur during OSA episodes?

Answer 2

Intermittent hypoxia, hypercapnia, and sleep fragmentation.

Question 3

What systemic complications can OSA contribute to?

Answer 3

Cardiovascular disease, hypertension, impaired cognition, mood disorders, and metabolic dysfunction.

Question 4

Which anatomical regions must airflow pass through during inspiration?

Answer 4

Nasal/oral cavities → nasopharynx → oropharynx → laryngopharynx → larynx → trachea.

Question 5

What causes airway obstruction in OSA?

Answer 5

Critical narrowing or collapse of the upper airway during sleep.

Question 6

How does allergic rhinitis contribute to OSA?

Answer 6

Mucosal swelling narrows the nasopharyngeal airway.

Question 7

How do enlarged tonsils/adenoids contribute to OSA?

Answer 7

They obstruct the airway, especially in children and young adults.

Question 8

How does a retrognathic jaw contribute to OSA?

Answer 8

Posterior displacement of the tongue and soft palate reduces airway patency

Question 9

How does a narrow or high‑arched palate affect airflow?

Answer 9

It restricts upper airway space, increasing obstruction risk.

Question 10

How does obesity increase OSA risk?

Answer 10

Excess neck/airway adipose tissue narrows the pharynx and worsens collapse when supine

Question 11

Why does airway collapse occur more during sleep?

Answer 11

Reduced neuromuscular tone in upper airway muscles (e.g., genioglossus, tensor palatini).

Question 12

How do hormonal changes contribute?

Answer 12

Reduced catecholamines during sleep → further muscle relaxation → increased obstruction.

Question 13

What are key risk factors for OSA?

Answer 13

Obesity

Older age

Family history

Smoking/alcohol

Large tonsils/adenoids

Sleeping supine

COPD (Chronic Obstructive Pulmonary Disease)

Question 14

Why does OSA cause daytime fatigue?

Answer 14

Repeated arousals fragment sleep architecture.

Question 15

Why does OSA increase cardiovascular risk?

Answer 15

Heightened sympathetic drive prevents normal nocturnal BP drop → sustained hypertension.

Question 16

How does OSA affect cognition?

Answer 16

Causes concentration difficulties, memory impairment, and reduced academic/work performance.

Question 17

How is OSA linked to type 2 diabetes?

Answer 17

Shared risk factors + reduced insulin sensitivity in OSA patients.

Question 18

What liver condition is associated with OSA?

Answer 18

MASLD (Metabolic Dysfunction‑Associated Steatotic Liver Disease), formerly NAFLD.

Question 19

What symptoms suggest OSA?

Answer 19

-Snoring

-Witnessed apnoeas

-Waking unrefreshed

-Morning headaches

-Excessive daytime sleepiness

-Nocturia

-Choking episodes

-Insomnia

-Cognitive dysfunction

Question 20

What is the first step in diagnosing OSA?

Answer 20

Detailed history taking, including sleep symptoms and risk factors.

Question 21

What is the ESS?

Answer 21

Epworth Sleepiness Scale — assesses daytime sleepiness severity.

Question 22

Who should be prioritised for urgent assessment?

Answer 22

-Professional drivers (lorry drivers, pilots, heavy machinery operators)

-Patients with comorbidities (COPD, angina, HF, pulmonary hypertension)

Question 23

What is polysomnography?

Answer 23

A comprehensive overnight sleep study measuring airflow, oxygen saturation, EEG, respiratory effort, and more.

Question 24

What is the Oxygen Desaturation Index (ODI)?

Answer 24

Overnight pulse oximetry measuring frequency of oxygen drops → indicates hypoxia severity.

Question 25

What is CPAP?

Answer 25

Continuous Positive Airway Pressure — first‑line treatment for moderate–severe OSA.

Question 26

How does CPAP work?

Answer 26

Provides constant positive pressure to keep the upper airway open during sleep.

Question 27

What benefits does CPAP provide?

Answer 27

-Reduces daytime sleepiness -Improves quality of life -May lower blood pressure -Prevents airway collapse

Question 28

Does CPAP reduce cardiovascular events?

Answer 28

Evidence is mixed; lifestyle modification remains essential.

Question 29

When are MADs used?

Answer 29

Mild OSA or CPAP intolerance.

Question 30

How do MADs work?

Answer 30

Move the mandible and tongue forward to maintain airway patency.

Question 31

When is tonsillectomy considered?

Answer 31

Large obstructive tonsils + BMI <35 kg/m².

Question 32

When is oropharyngeal surgery considered?

Answer 32

Severe OSA with CPAP/MAD intolerance.

Question 33

What lifestyle changes help manage OSA?

Answer 33

-Weight loss -Smoking cessation -Reducing alcohol (especially before bed) -Good sleep hygiene -Managing comorbidities (BP, diabetes risk)

Question 34

Why is weight loss important?

Answer 34

Reduces pharyngeal fat deposition → improves airway patency.

Question 35

Why avoid alcohol before bed?

Answer 35

Alcohol relaxes throat muscles → worsens apnoea events.

Question 36

What is the hallmark of OSA?

Answer 36

Recurrent upper airway collapse during sleep causing intermittent hypoxia.

Question 37

What is the gold‑standard diagnostic test?

Answer 37

Polysomnography.

Question 38

What is first‑line therapy for moderate–severe OSA?

Answer 38

CPAP.