Difficult airway

Question 1

Criteria for difficult intubation

Answer 1

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

Question 2

Overall incidence of difficult intubation

Answer 2

5.8%

Question 3

Incidence of difficult intubation for normal patients

Answer 3

6.2%

Question 4

Incidence of difficult intubation for obstetric patients

Answer 4

3.1%

Question 5

Incidence of difficult intubation for obese patients

Answer 5

15.8%

Question 6

Difficult airway is generally defined as

Answer 6

3 or more basic DL attempts from an experienced practitioner

Question 7

How does video laryngoscopy work

Answer 7

the laryngoscope handle has a video camera attached to the tip in which you look at a remote screen to indirectly visualized the laryngeal aperture

Question 8

Video laryngoscopy pros

Answer 8

• tend to get a great view
• short learning curve, user friendly
• up to 40% less traumatic than DL
  (potential become std of care)

Question 9

Video laryngoscopy cons

Answer 9

• limited mouth opening may make introduction of blade impossible
• passing tube can be difficult
• usually requires specific equipment (rigid stilettos, variable attachments, etc)

Question 10

Safest method for difficult intubation

Answer 10

awake fiberoptic

Question 11

Methods of anesthetizing the airway for an awake fiberoptic

Answer 11

• transtracheal block
• SLN block (superior laryngeal nerve)
• topic anesthesia in mouth/tonsils
• nebulizer with LA

Question 12

What should you use during awake fiberoptic intubation

Answer 12

• antisialagogue (like glycopyrolate to recuse salivation)

- possibly need sedation (conscious sedation) with versed, fentanyl, little propofol or ketamine, precedex

Question 13

Dexmedetomidine (precedex) allows for

Answer 13

spontaneous ventilation and some airway protection (safety and efficacy similar to versed)

Question 14

Loading dose dexmedetomidine (precedex)

Answer 14

1 mcg/kg over 10 minutes

Question 15

Maintenance infusion for dexmedetomidine (precedex)

Answer 15

0.2-1 mcg/kg/hr

Question 16

How is dexmedetomidine (precedex) prepared

Answer 16

100 mcg/cc diluted to 4 mcg/cc

Question 17

Side effects dexmedetomidine (precedex)

Answer 17

• hypotension
• bradycardia/sinus arrest
• respiratory depression with high doses
• nausea

Question 18

dexmedetomidine (precedex) contraindications

Answer 18

• cautious in patients with heart block or ventricular dysfunction

Question 19

dexmedetomidine (precedex) MOA

Answer 19

A2 agonist

Question 20

dexmedetomidine (precedex) onset and elimination

Answer 20

10-15 minutes (slow loading dose)

2 hours

Question 21

dexmedetomidine (precedex) metabolism and excretion

Answer 21

hepatic (2A4 and 2A6) metabolism

Urine/feces excretion

Question 22

Awake fiberoptic intubation pros

Answer 22

SAFEST (pt remains in complete control of airway assuming sedation is kept to minimum)

• good views early to obtain with experience
• atraumatic

Question 23

Awake fiberoptic intubation cons

Answer 23

• most time consuming
• sharp learning curve (due to prep, not physic use of scope)
• least tolerated by patients )explanation, pt participation, localization necessary)

Question 24

Intubating LMA pros

Answer 24

• Easy to place (potential for airway control)

- If placed correctly, may easily/blindy pass ETT (even if fail, LMA used for airway control)

Question 25

Intubating LMA cons

Answer 25

- time consuming | - not guaranteed to be placed correctly nor ventilate the patient

Question 26

Light wand pros

Answer 26

Minimal set up Quick Short learning curve

Question 27

Light wand cons

Answer 27

- no direct or indirect visualization of vocal cords is utilized - can be traumatic to the airway - may require significant OR darkness

Question 28

Only difficult intubation technique used for tube exchange

Answer 28

Bougie

Question 29

Bougie pros

Answer 29

- no set up - more accessible (esp with unanticipated difficult airways) - only device that feasibly allows tube exchange - user friendly - flexibility make it atraumatic

Question 30

Bougie cons

Answer 30

- blind approach often (not considered a blind approach) - no view of laryngeal aperture if poor grade DL - Lack of rigidity

Question 31

Combitude pros

Answer 31

- User friendly - potential more secure than LMA but less than ETT (pushes air and hopes it goes through) - quicker to prepare than some other difficult airway equipment

Question 32

Combitude cons

Answer 32

- less secure than ETT - potential for leaks around the cuffs (difficult ventilation or aspiration risk) - traumatic

Question 33

Last resort effort when you are on the verge of respiratory collapse

Answer 33

criciothyroidotomy

Question 34

criciothyroidotomy pros

Answer 34

- most direct access to trachea - may be only route of access (facial trauma) - quick with experience - can be converted for long term vent

Question 35

criciothyroidotomy cons

Answer 35

- rare to use (few people have significant experience, MD only) - invasive (not for normal surgery, emergency only)

Question 36

Post Difficult airway considerations

Answer 36

- check teeth/lips for trauma (suction blood) - ensure ETT cuff still intact - decadron to decrease swelling - OG suction air from stomach (likely after aggressive BMV) - strict emergence criteria to protect airway

Question 37

Decadron dose to decrease swelling post difficult intubation

Answer 37

8-10 mg

Question 38

What drug should you use post difficult intubation to decrease swelling

Answer 38

decadron

Question 39

Strict emergence criteria post difficult airway intubation

Answer 39

Des vs sevo Tight narcotic control (don't collapse their airway more) Adequate NMBD reversal

Question 40

Post difficult intubation identification of vocal cord damage

Answer 40

- hoarseness - loss of vocal ability - difficulties breathing - granulomas long term