Airway management

Question 1

Need for intubation (7)

Answer 1

1) Respiratory rate >35 breaths/min
2) Vital capacity <5 ml/kg in adults and 10 ml/kg in children
3) Inability to generate a negative inspiratory force of 20 mm Hg
4) Arterial partial pressure of oxygen (PaO2) <70 mm Hg on 40% oxygen
5) Alveolar-arterial (A-a) gradient >350 mm Hg on 100% O2
6) Arterial partial pressure of carbon dioxide (PaCO2)>55mmHg (except in chronic retainers)
7) Dead space (VD/VT) >0.6

Question 2

Mallampati class: Pharyngeal pillars and soft palate are visible, with visualization of the uvula
obstructed by the tongue.

Answer 2

Class II

Question 3

Mallampati class: Soft palate is visible, but pharyngeal pillars and uvula are not visualized.

Answer 3

Class III

Question 4

Mallampati class: Only the hard palate is visible; the soft palate, pillars, and uvula are not visualized.

Answer 4

Class IV

Question 5

Mallampati class: Pharyngeal pillars, entire palate, and uvula are visible.

Answer 5

Class I

Question 6

Areas to assess TMD

Answer 6

mental process to the prominence of the thyroid cartilage (thyromental distance)

Question 7

This structure is shaped like a signet ring, faces posteriorly, and is the only complete cartilaginous ring of the laryngotracheal tree.

Answer 7

Cricoid

Question 8

These cartilages articulate on the posterior aspect of the larynx and are the posterior attachments of the vocal ligaments (or vocal cords).

Answer 8

Arytenoid

Question 9

In a patient with an anterior airway what structure may be the only visible structures.

Answer 9

Arytenoids

Question 10

The recurrent laryngeal nerves provide sensory innervation below the level of the cords and motor innervation of what muscle?

Answer 10

Posterior cricoarytenoid muscles

Question 11

The only abductors of the vocal cords

Answer 11

Posterior cricoarytenoid muscles

Question 12

This nerve provides sensory innervation to the vallecula (the space anterior to the epiglottis)

Answer 12

Glossopharyngeal or ninth cranial nerve

Question 13

What is the most frequent cause of airway obstruction.

Answer 13

Obstructed tongue

Question 14

What structures must be aligned to accomplish visualization of the larynx?(3)

Answer 14

1) Oral
2) Pharyngeal
3) Laryngeal

Question 15

What is the hole in the bevel of an an endotracheal tube?

Answer 15

Murphy eye

Question 16

How much elevation of the head must be positioned to align the axis for intubation?

Answer 16

10 cm

Question 17

What nerve blocks are useful when awake intubation is planned?

Answer 17

1) glossopharyngeal nerve
2) superior laryngeal nerve

The glossopharyngeal nerve, which provides sensory innervation to the base of the tongue and the vallecula, may be blocked by transmucosal local anesthetic injection at the base of the tonsillar pillars. The superior laryngeal nerve provides sensory innervation of the larynx above the vocal cords and may be blocked by injection just below the greater cornu of the hyoid.

Question 18

Inspired room air contains approximately how much oxygen?

Answer 18

21%