Difficult Intubation

Question 1

How do you assess a difficult airway?

Answer 1

Hx: Known difficult intubation, prev Cx trauma or surgery, prev neck surgery or XRT, positional related airway obstruction, OSA, unable to lie flat, dysphagia

OE: Airway specific - look externally, overbite, buck teeth, retrognathia, micrognathia, TMD <6cm, Mallampatti, mouth opening (will a LMA fit!), evidence of foreign body, tracheal position, cervical AROM

General - Body habitus, neck circumference, palpable neck masses

Resp - Signs of obstruction (suprasternal or intercostal recession), stridor, secretions/drooling, tripoding, purse lip breathing, unable to lie flat, dysphagia, tachypnoea, silent chest on auscultation, very quiet patient, hypoxaemia

CVS - signs of sympathetic stimulation anxiety, elevated HR and BP

Question 2

Outline the immediate management in the event of an unanticipated difficult intubation

Answer 2

1. Call for help!
2. Request the difficult airway trolley
3. Monitor - time, SpO2, EtCO2
4. Confirm ability to BVM (if you can, then you have time, if not - see difficult BVM)
5. Maximise laryngeal view (position, BURP, adjust cricoid, different blade, CMAC)
6. x4 attempts at intubation if SpO2 permits and able to BVM between
7. Attempt x2 LMA insertions
8. Reverse NMB, postpone surgery or CICV

Question 3

In the DAS algorithm, how many intubation attempts are recommended for the unanticipated difficult intubation?

Answer 3

4

Question 4

In the DAS algorithm, what is the recommended number of attempts for LMA insertion?

Answer 4

2

Question 5

When should a CICV scenario be declared?

Answer 5

If after attempted ventilation and intubation:

1. SpO2 <90% with FiO2 1.0
2. No breath sounds or chest movement
3. Flat EtCO2

Question 6

Outline ongoing management once a CICV has been declared

Answer 6

Attempt cannula cricothyroidotomy or cannula tracheotomy:

1. Palpate cricothyroid membrane
2. Using a 14G cannula attached to a 5mL syringe of saline advance in midline until aspirate air into syringe
3. Stabilise the syringe and advance the cannula into the trachea
4. Remove the trochar, reattach the syringe and reassess air aspiration
5. Attach a jet ventilation system and deliver a 3 second insufflation
6. Once patient is stabilised, convert to a Melker cuffed tracheotomy tube using a Seldinger technique

Question 7

If cannula cricothyroidotomy attempts fail, what other options are available?

Answer 7

Can attempt either a scalpel bougie technique, or a scalpel finger cannula technique

Scalpel finger technique is an open technique that allows cannulation of the trachea under direct vision. It should be reserved for patient with no palpable neck anatomy

Question 8

What is the scalpel bougie technique for a CICV?

Answer 8

1. Identify the cricothyroid membrane
2. Make a horizontal stab incision through the skin and membrane
3. Rotate the scalpel 90’ and apply light sideways pressure towards you
4. Switch hands, so the ND hand is holding the scalpel
5. With a bougie pointing away and parallel to the floor, insert the tip into the trachea using the blade as a guide
6. Rotate and align the bougie to allow insertion along the line of the trachea
7. Reoxygenate via the bougie
8. Railroad a 6.0 ETT with continual rotation to facilitate passage
9. Remove the bougie
10. Ventilate
11. Secure