Airway

Question 1

 Measurable predictors of difficult airway

Answer 1

Mouth opening less than 3 cm
Mallampati 3 or 4
Thyromental distance less than 6.5 cm
Sternomental distance less than 12.5 cm


Question 2

Talk through your assessment on airway

Answer 2

Move out to in.
Start with general physical features followed by airway specific measurements

Look for obesity large breasts beards obvious external signs of head and neck pathology
Mouth opening, mallampati, SMD, TMD
Jaw protrusion, upper lip bite test
Feel The submandibular space for softness (this is where the time has to be compressed during laryngoscopy)

Question 3

What investigations can help with airway assessment

Answer 3

1. Lateral C spine x-ray – less than 5 mm between C1 spinous process and occiputs equals difficulty

2. Ultrasound can be helpful in measurement of various parameters e.g. tongue fitness (not yet verified)
3. CT/MRI can be helpful in at normal hours (no specific measurements)
4. Nasoendoscopy

Question 4

List the factors that predict difficult mask ventilation

Answer 4

The most important factor is previous head and neck irradiation
The pneumonic for other factors is OBESE (obese, bearded, elderly (over 55 years), snorer, and edentulous

Question 5

Which nerves supply sensation to:

1. Nose
2. Oropharynx
3. Larynx

Answer 5

1. Anterior septum and nares by ANTERIOR ETHMOIDAL NERVE (V1)
   Rest of nose by GREATER/LESSER PALANTINE NERVE (V2)
2. GLOSSOPHARYNGEAL NERVE
3. VAGUS. Above VCs= SLN
   Below VCs= RLN