The Difficult Airway

Question 1

What will you routinely examine during your airway interview?

Answer 1

Malampati score, thyromental distance, mouth opening, neck flexibility and extension

Question 2

Predicting difficult airway anagram

Answer 2

O (BMI >26)
B (Bearded)
E (Elderly) 
S (Snorers) 
E (Edentulous)

Question 3

Mallampati score is based on

Answer 3

how much of the oral anatomy can be visualized (class III or IV can help predict a difficult intubation)

Question 4

Mallampati score estimates

Answer 4

size of tongue relative to the oral cavity and assesses head and neck mobility

Question 5

Mouth opening is related to

Answer 5

craniocervical extension

Question 6

In a Class I Mallampati, you can see

Answer 6

Soft palate
Fauces (arch)
Uvula
tonsillar pillars

Question 7

In a Class II Mallampati, you can see

Answer 7

soft palate
fauces
uvula

Question 8

In a Class III Mallampati, you can see

Answer 8

Soft palate

base of uvula

Question 9

In a Class IV Mallampati, you can see

Answer 9

Hard palate only

Question 10

Thyromental (TM) distance is an indicator of

Answer 10

mandibular space and can also predict an “anterior airway” (narrow, receded mandibles)

Question 11

A normal thyromental distance is considered to be

Answer 11

3 finger breadths (>6cm)

Question 12

Normal value for sternomental distance

Answer 12

~13 cm

Question 13

Sternomental distance is an indicator of

Answer 13

head and neck mobility (potential single most important factor but rarely studied)

Question 14

Mouth opening indicates

Answer 14

movement of the temporomandibular joint (TMJ) (some patients will have lock jaw)

Question 15

Normal mouth opening is considered

Answer 15

3 finger widths

Question 16

Significantly limited mouth opening is very predictive of

Answer 16

poor VC visualization

Question 17

What Wilson risk score is considered high risk for difficult intubation

Answer 17

> 8

Question 18

Parameters involved in Wilson Risk Score

Answer 18

Weight 
Head/neck movement 
Jaw movement 
Receding mandible 
Prominent incisors

Question 19

Series of grade views during direct laryngoscopy

Answer 19

Cormack-Lehane

Question 20

How is the Cormack-Lehane grade determined

Answer 20

by how much of the laryngeal aperture can be visualized

Question 21

In a Cormack-Lehane grade 1, you can visualize

Answer 21

entire laryngeal aperature

Question 22

In a Cormack-Lehane grade 2, you can visualize

Answer 22

Only the posterior portion of the glottis is visualized
2A: partial view of vocal cords
2B: only arytenoids/epiglottis visualized

Question 23

In a Cormack-Lehane grade 3, you can visualize

Answer 23

The epiglottis, but no part of the glottis is visualized

Question 24

In a Cormack-Lehane grade 4, you can visualize

Answer 24

soft palate visualized only

Question 25

What grades for Cormack-Lehane predict a difficult intubation

Answer 25

3 and 4

Question 26

Criteria for difficult intubation

Answer 26

• MP score III or IV
• Cormack-Lehane grade view III or IV
• TMD < 3 finger breadths
• Small mouth opening
• minimal head/neck ROM

Question 27

Overall incidence of difficult intubation

Answer 27

5.8%

Question 28

Incidence of difficult intubation for normal patients

Answer 28

6.2% (excluding obstetric and obese)

Question 29

Incidence of difficult intubation for obstetric patients

Answer 29

3.1%

Question 30

Incidence of difficult intubation for obese patients

Answer 30

15.8%

Question 31

Difficult airway is generally defined as

Answer 31

3 or more basic DL attempts from an experienced practitioner