15. Laryngospasm

Question 1

What is laryngospasm?

Answer 1

Laryngospasm is the reflex

adduction of the vocal cords

and

occurs most commonly during
lighter planes of anaesthesia.

Direct or indirect stimulation
of the larynx may precipitate laryngospasm:

Question 2

Precipitated by

Answer 2

> Direct stimulation, 
e.g. blood, 
mucus, 
laryngoscope or 
endotracheal tube.

> Indirect stimulation via another site,
e.g. pain,
cervical or
anal stimulation.

Laryngospasm may present as intra-operative stridor or sudden difficulty in ventilating the un-intubated patient.

Left unchecked laryngospasm may result in:

> Complete upper airway obstruction

> Desaturation and hypoxaemia

> Negative-pressure pulmonary oedema

Question 3

What are the risk factors for laryngospasm?

Answer 3

> Pre-existing upper respiratory tract infection
(‘irritable airway’).

> Smoking.

> Children are more susceptible than adults
especially if asthmatic,
chest infection within last 6 weeks,
exposed to passive smoking.

> Inadequate depth of anaesthesia for either airway manipulation or for surgical stimulus.

> Soiling of the vocal cords, e.g. blood.

> Upper airway surgery, e.g. tonsilectomy.

Question 4

How would you manage a case of laryngospasm?

Answer 4

State that this is an anaesthetic emergency
and that you would call for senior
anaesthetic assistance.

> Remove the stimulus.

> Apply 100% O2.

> Apply positive pressure to the airway
to assist inspiration.

> If the above measures fail,
deepen anaesthesia rapidly, e.g. administer a
bolus of propofol at a dose appropriate to the patient.

> If deepening of anaesthesia fails, 
administer 1–2 mg/kg of
suxamethonium to relax the vocal cords. 
If IV access is impossible, 
give 4 mg/kg i.m.

> Reintubation may be necessary.
This will depend on the situation,
patient and operation.

Remember that laryngospasm may recur on
re-
extubation.

> Ensure documentation of the event and completion of a critical incident form.