Stridor and sleep apnoea

Question 1

What is stridor?

Answer 1

Predominantly inspiratory wheeze due to large airways (larynx/trachea/major bronchi) obstruction

Question 2

What are the causes of stridor in children?

Answer 2

INfection
forgeign body
anaphylaxis

Question 3

What infections can cause stridor in children

Answer 3

Croup
Epiglottitis
Pseudomembranous croup
Retropharyngeal abscess
Diphtheria
Infectious mononucleosis

Question 4

What are the causes of stridor in adults?

Answer 4

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

Question 5

What is tracheomalacia?

Answer 5

is a condition characterized by flaccidity of the tracheal support cartilage which leads to tracheal collapse

Question 6

How is stridor investigated?

Answer 6

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

Question 7

How can stridor be treated?

Answer 7

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

Question 8

How can a malignant airway obstruction be treated?

Answer 8

Tumour removal:
laser; photodynamic therapy; cryotherapy; diathermy; surgical resection

Tumour compression: intraluminal stent

Radiotherapy (external beam; brachytherapy)

(Chemotherapy; Corticosteroids)

Question 9

What type of hypersensitivity is associated with acute anaphylaxis

Answer 9

type one (IgE)

Question 10

What are the clinical features of acute anaphylaxis?

Answer 10

flushing
prutitus
urticaria
angionecrotic oedema
abdominal pain
hypotension- shock
stridor
wheeze
resp failure

Question 11

What can cause anaphylaxis?

Answer 11

Foods eg nuts; shellfish
Insect venom (bee, wasp)
Drugs (eg penicillin, aspirin, anaesthetics)
Other eg latex

Question 12

HOw is anaphylaxis treated?

Answer 12

IM Epinephrine (adrenaline)
IV antihistamine
IV corticosteroid
High flow O2
Nebulised bronchodilators
Endotracheal intubation if necessary

Question 13

What is the epworh sleepiness scale?

Answer 13

Measure how likely you are to fall asleep doing certain activites

Question 14

What is obstructive sleep anoea syndrome?

Answer 14

Intermittent closure/collapse of the pharyngeal airway causing apnoeic episodes during sleep which are terminated by partial arousal

Question 15

What is snoring?

Answer 15

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

Question 16

What are the risk factors for sleep apnoea

Answer 16

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 17

WHat are the consequences of sleep apnoea?

Answer 17

excessive daytime sleepiness
personality change
cognitive / functional impairment
Major impact on daytime function 
Road traffic accidents

Question 18

What are the pathological consequences of sleep apnoea?

Answer 18

Independent risk factor for hypertension
Activated sympathetic system
Raised CRP
Impaired endothelial function
Impaired glucose tolerance
(probable increased risk of stroke and cardiovascular events)
All improved by CPAP

Question 19

How is a diagnosis of sleep apnoea made?

Answer 19

Snoring & EDS (raised Epworth score)
Overnight sleep study
		- oximetry
		- domicillary recording (airflow, oximetry, thoracic/abdominal movement)
		- full polysomnography

Question 20

How is sleep apnoea treated?

Answer 20

Remove underlying cause
CPAP (continuous positive airway pressure)
- most effective therapy

Question 21

What other treatments are there for sleep apnoea?

Answer 21

Mandibular Advancement Device
	- improves snoring
	- moderate reduction in AHI
	- use in mild OSA (AHI 5-15/hr)
	Surgery (UPPP, laser Rx)
	- avoid if sleep apnoea (future CPAP less effective)
	- may be used in simple snoring