Stridor and sleep apnoea

Question 1

What is stridor?

Answer 1

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

Question 2

What structures can cause stridor when they become smaller?

Answer 2

Extrathoracic

Supraglottis/larynx: laryngomalacia, supraglottic mass, glottic lesions, vocal chord paralysis

Question 3

What can infections can cause stridor in children?

Answer 3

Croup - RSV
Epiglottitis
Pseudomembranous croup
Retropharyngeal abscess
Diptheria 
Infections mononucleosis (glandular fever)

Question 4

What things other than infection can cause stridor in children?

Answer 4

Foreign body
Anaphylaxis
Other (burns)

Question 5

What can cause stridor in adults?

Answer 5

Neoplasms - larynx, trachea, major bronchi
Anaphylaxis
Goitre (retrosternal)
Trauma (strangulation, burns, irritant gases)
Other (bilateral vocal chord collapse, wegener’s granulomatosis, cricoarytenoid arthritis (RA)
Most common cause of stridor in adults is a tumour around the carina

Question 6

What is trachemalacia?

Answer 6

Any inflammatory condition that affects the cartilage rings in the trachea

Question 7

What can cause changes to the voice?

Answer 7

Benign upper airway inflammatory polyp’s

Question 8

How is stridor investigated?

Answer 8

Laryngoscopy 
Bronchoscopy 
Flow volume loop
CXR
CT, thyroid scan

Question 9

How is laryngeal obstruction treated?

Answer 9

Underlying cause e.g. foreign body removal, anaphylaxis
Mask bag ventilation with high flow ocygen
Cricothyoidotomy
Tracheostomy - needs surgeon

Question 10

When is the heimlich manoeuvre used and what is the mechanism?

Answer 10

Foreign body inhalation

Rapid upward thrust in epigastrium forces upward movement of diaphragm and forced expiration

Question 11

How is a malignant airway obstruction treated?

Answer 11

Tumour removal: laser, photodynamic therpy, cryotherapy, diathermy, surgical resection
Tumour compression: intraluminal stent
Radiotherapy: external beam, brachytherapy
Chemotherapy
Corticosteroids

Question 12

What type of reaction is acute anaphylaxis?

Answer 12

Type 1 (intermediate) hypersensitivity (IgE)

Question 13

What are the symptoms of acute anaphylaxis?

Answer 13

Flushing, pruritus, uticaria, angioneurotic oedema (lips, tongue, face, larynx, bronchi)
Abdominal pain, vomiting
Hypotension (vasodilation and plasma exudation), circulation collapse (shock)
Stridor, wheeze and resp failure

Question 14

What can cause anaphylaxis?

Answer 14

Foods - nuts, shellfish
Insect venom (bee, wasp)
Drugs (penicillin, asprin, anaesthetics)
Latex

Question 15

How can anaphylaxis be treated?

Answer 15

IM adrenaline - NEVER IV
IV antihistamine 
IV corticosteroid - immunosuppresion 
High flow O2
Nebulised bronchodilator
Endotracheal intubation 
Allergen avoidance 
Densisitation (immunotherapy) 
Self-administered epi

Question 16

What can happen if adrenaline is given IV not IM?

Answer 16

Induce ventricular tachycardia

Question 17

What is the epworth sleepiness scale?

Answer 17

The changes of dozing in certain situations

Question 18

What are some situations measured in the epworth sleepiness scale?

Answer 18

Sitting and reading 
Watching TV
Sitting inactive in pubilc 
Car passenger for 1hr 
Lying down to rest in the afternoon
Sitting talking
Sitting after lunch without alcohol
In car, stopped for few minutes in traffic

Question 19

What are the different scales on the epworth sleepiness scale?

Answer 19

0 = would never dose
1 = slight change of dozing 
2 = moderate chance 
3 = high change

Question 20

What is the normal number on the epworth sleepiness scale?

Answer 20

10-24

Question 21

What is snoring?

Answer 21

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

Question 22

What happens during the hypotonic state in sleep?

Answer 22

All the muscles relax. The throat can flop in the way which is fine for most people but in some people it will cause snoring

Question 23

What is obstructive sleep apnoea?

Answer 23

Intermittent upper airway collapse in sleep
Apnoeas or hypopnoeas cause hypoxaemia
This causes recurrent arousals/ sleep fragmentation

Question 24

What are the risk factors for sleep apnoea?

Answer 24

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

Question 25

What are the cosequences of sleep apnoea?

Answer 25

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

Question 26

What can improve sleep apnoea?

Answer 26

CPAP

Question 27

How is sleep apnoea diagnosed?

Answer 27

Snoring and EDS (raised Epworth score)
Overnight sleep study: Oximetry, domicillary recording (airflow, oximetry, thoracic/abdominal movement)
Full polysomnography

Question 28

How is obstructive sleep apnoea treated?

Answer 28

Remove underlying cause

CPAP (continous positive airway pressure) - this is the most effective therapy