ICM - Airway

Question 1

Describe your approach to the difficult airtway?

Answer 1

Will I be able to mask ventilate?

Will I be able to perform laryngoscopy, directly or indirectly?

Will I be able to intubate this patient?

Is there a significant aspiration risk?

If I predict difficulty, should I secure the airway awake?

Can I access the cricothyroid membrane if needed?

How will the airway behave at extubation?

Question 2

What is a difficult airway?

Answer 2

here are various definitions of “the difficult airway”, with no definition universally accepted

In general terms, an airway is considered difficult when oxygenation and ventilation cannot be achieved in the desired manner
‘The difficult airway’ represents a complex interaction between patient factors, the clinical setting, and the skills and preferences of the practitioner

Question 3

What are some the risk factors for a difficult airway?

Answer 3

Infections of oropharynx and neck
Previous surgery or radiotherapy to neck
Problems with mouth opening – e.g. trauma, soft tissue disorders, arthridities
Problems with neck mobility – e.g. cervical spine disruption, rheumatoid arthritis, cervical fusion (e.g. operative, ankylosing spondylitis, scleroderma)
obesity, OSA
oropharyneal or neck masses
difficult dentition
pregnancy
recent intubation (swelling, trauma)
angioedema
craniofacial syndromes
Burns
Airway trauma – blunt or penetrating
Airway obstruction

Question 4

What from the examination can you help you diagnose a difficult airway?

Answer 4

Face

Beard
craniofacial deformity
Mouth

Mallampati grade I to IV
Mouth opening — Inter-incisor distance (> 3cm = good, < 3cm = bad)
Shape of palate
Jaw protrusion
Teeth

Edentuous
Teeth prominence (upper incisors) and condition
Relation of maxillary to mandibular incisors during normal jaw closure
dentures/ caps/ crowns/ loose teeth
Neck

Range of motion of head and neck
thyro-mental distance <6cm
Neck length and circumference/ thickness
Compliance of mandibular space
Sternomental distance

Question 5

What is the CORMACK-LEHANE CLASSIFICATION

Answer 5

Grade 1: Full view of glottis
Grade 2a: Partial view of glottis
Grade 2b: Only posterior extremity of glottis seen or only arytenoid cartilages
Grade 3: Only epiglottis seen, none of glottis seen
Grade 4: Neither glottis nor epiglottis seen

Question 6

Describe the how you would manage a un anticipated difficult airway?

Answer 6

Plan A
Optimise head and neck position
Preoxygenate
Adequate neuromuscular blockade
Direct / Video Laryngoscopy (maximum 3+1 attempts)
External laryngeal manipulation
Bougie
Remove cricoid pressure
Maintain oxygenation and anaesthesia

Plan B:
Maintain oxygenation and SAD insertion
2nd generation device recommended
Change device or size (maximum 3 attempts)
Oxygenate and ventilate

Plan C: Final attempt to ventilate
If facemask ventilation impossible, paralyse
Final attempt at facemask ventilation
Use 2 person technique and adjuncts

Plan D: eFONA
Scalpel cricothyroidotomy

Question 7

Describe how you would approach emergency FONA

Answer 7

Declare CICO
Fi02 1.0
Ensure NMB, extend neck
Assemble - scapal, bougie size 6 blade
Laryngeal handshake to identify cricothyroid membrane

If cricothyroid membrane is palpable
- Transverse stab incision through membrane
- turn blade 90
- Bougie along blade into trachea
- railroad ETT
- Cuff up, ventilate, confirm C02

If not palpable
- make 8-10cm vertical skin incision caudad to cephalad
- blunt dissect
- Identify and stablise larynx
- then as above