Stridor and Sleep Apnoea

Question 1

What is stridor?

Answer 1

Predominantly inspiratory wheeze due to large airways obstruction

Question 2

What are the causes of stridor in children?

Answer 2

Infections
- Croup
- Epiglottitis
- Pseudomembranous croup
- Retropharyngeal abscess
- Diphtheria
- Infectious mononucleosis
Foreign Body
Anaphylaxis / angioneurotic oedema
Other (eg burns)

Question 3

What are the causes of stridor in adults?

Answer 3

Neoplasms
–Larynx
–Trachea
–Major bronchi
Anaphylaxis
Goitre (retrosternal)
Trauma(eg strangulation, burns, irritant gases)
Other (eg bilateral vocal cord palsy, Wegener’s granulomatosis; cricoarytenoid arthritis, tracheopathia)

Question 4

What are the investigations for stridor?

Answer 4

Laryngoscopy (beware in acute epiglottitis)
Bronchoscopy
Flow volume loop
Chest X ray
Other imaging (CT; thyroid scan)

Question 5

What is the treatment of stridor caused by laryngeal obstruction?

Answer 5

Treat underlying cause eg foreign body removal, anaphylaxis
Mask bag ventilation with high flow O2
Cricothyroidotomy
Tracheostomy

Question 6

Describe Acute Anaphylaxis?

Answer 6

Type 1 (immediate) hypersensitivity (IgE)
Flushing, pruritus, urticaria,
Angioneurotic oedema
Hypotension (vasodilatation and plasma exudation) -> circulatory collapse (shock)
Stridor, wheeze and respiratory failure

Question 7

What is the treatment for Acute Anaphylaxis?

Answer 7

IM Epinephrine (adrenaline)
IV antihistamine
IV corticosteroid
High flow O2
Nebulised bronchodilators
Endotracheal intubation if necessary
Allergen avoidance (where possible)
Desensitisation (immunotherapy) eg venom
Self-administered epinephrine

Question 8

What happens during snoring?

Answer 8

Relaxation of pharyngeal dilator muscles during sleep (esp. REM)
Upper airway narrowing, turbulent airflow and vibration of soft palate and tongue base

Question 9

What is a normal score for the Epiworth sleepiness score?

Answer 9

<10/24

Question 10

What is Obstructive sleep apnoea?

Answer 10

Intermittent upper airway collapse in sleep

• apnoeas or hypopnoeas ± hypoxaemia
• recurrent arousals/sleep fragmentation

Question 11

What are the risk factors for sleep apnoea?

Answer 11

Enlarged tonsils, adenoids
Obesity
Retrognathia
Acromegaly, hypothyroidism
Oropharyngeal deformity
Neurological: stroke, MS, myesthenia gravis, myotonic dystrophy
Drugs: benzodiazepines, opiates, alcohol,
Post-operative period after anaesthesia

Question 12

What are the consequences of sleep apnoea?

Answer 12

excessive daytime sleepiness
personality change
cognitive / functional impairment
major impact on daytime function 
independent risk factor for hypertension
activated sympathetic system
raised CRP
impaired endothelial function
impaired glucose tolerance
(probable increased risk of stroke and cardiovascular events)

Question 13

What is the treatment for sleep apnoea?

Answer 13

CPAP (continuous positive airway pressure)