CRACKCast E001 – Airway

In CRACKCast, Podcast by Adam Thomas1 Comment

As highlighted in Rosen’s, the airway really is “the cornerstone of resuscitation and is a defining skill for the specialty of emergency medicine.” One important piece of this skill set is knowing when we need to take the airway.

Shownotes – PDF Here

1. How do you make the decision to intubate?

  • Failure to maintain or protect the airway
    • Can’t handle gastric and oral secretions
  • Failure to ventilate or oxygenate
    • ABG rarely useful
  • Patient’s anticipated clinical course and likelihood of deterioration
    • Multiple trauma, open#, neck trauma, burns

2. What are predictors of difficult bag valve mask ventilation?


  • Mask seal
  • Obstruction or obesity
  • Age > 55
  • No teeth
  • Stiffness of chest
    • Asthma, COPD, pregnancy

This is a fundamental skill we must learn so continue to practice this whenever you can.

3. What are the predictors of difficult intubation?


  • Look for gestalt signs :
    • ***KEY sign is the presence of an underbite: if the patient CANNOT bite their upper lip with their lower teeth (buck teeth boy) they will be a very difficult tube!!***
  • Evaluate the 3-3-2 rule
    • Mouth opening, length of mandible, and thyromental distance
    • A high riding larynx and receding mandible = impossible tube
  • Mallampati score :
    • Mallampati I = easy; Mallampati IV = challenging
    • Use a Laryngoscope to visualize in obtunded pts.
  • Obstruction or obesity
    • Epiglottitis, ludwig’s angina, etc.
  • Neck mobility
    • Spondylosis, Rheumatoid Arthritis, etc.

Bonus: Cormack Lehane grading view

  • Classifies views obtained on direct laryngoscopy
  • Scale from 1-4 (see Rosen’s)
    • 4 = not even the epiglottis seen.
    • 2a = arytenoids and portion of vocal chords, 2b=arytenoids only
  • POGO system can also be used

4. What are the predictors of difficult LMA insertion?


  • Restricted mouth opening
  • Obstruction/obesity
  • Distorted anatomy
  • Stiffness to ventilate

5. What are the predictors of a difficult surgical airway?


  • Surgery (previous to area)
  • Mass (abscess, hematoma)
  • Access/anatomy problems (obesity, edema)
  • Radiation (previous to area)
  • Tumor

6. Differentiate depolarizing vs. non-depolarizing paralytic agents?

Depolarizing Agents

Work by mimicking the Ach molecule

  • Succinylcholine : Depolarizes the motor end plate
    1. 45 sec to effect.
    2. Respiration recover at 6-10 mins
    3. Many contraindications

Non-Depolarizing Agents

Nondepolarizing, competitive antagonism  (prevents access of Ach on the receptors)

  1. Onset 60 secs
  2. Lasts 50 mins
  3. NO contraindications

7. What are the contraindications to succinylcholine?


  • Neuromuscular diseases
    • ALS, Myotonic muscular dystrophy, MS, etc.

INJURED (> 5 days) (see table 1-2, chapter 1)

  • Burn (>10%)
  • Crush
  • Denervation (spinal cord injury, stroke)
  • Intra-abdominal sepsis

Bonus: Crash Airway vs. Failed Airway

Crash Airway

  • Agonal breathing, near death, circulatory collapse, not protecting airway, not mentating
  • Need intubation, do not need paralysis as LOC so low (airway reflexes not intact)
  • No drugs needed, except possible single large dose of succinylcholine (2mg/kg) if unable to tube

Failed Airway (can’t ventilate, can’t oxygenate)

  • Failure to intubate despite three attempts at RSI by experienced operator
  • Failure to oxygenate using BVM or EGD
  • Experienced clinician identifies a grade 4 view on their first attempt
(Visited 9,212 times, 1 visits today)
Adam Thomas

Adam Thomas

CRACKCast Co-founder and newly minted FRCPC emergency physician from the University of British Columbia. Currently spending his days between a fellowship in critical care and making sure his toddler survives past age 5.
Adam Thomas
- 1 day ago
Chris Lipp
Chris Lipp is one of the founding Fathers for CrackCast. He currently divides his time as an EM Physician in Calgary (SHC/FMC) and in Sports Medicine. His interests are in endurance sports, exercise as medicine, and wilderness medical education. When he isn’t outdoors with his family, he's brewing a coffee or dreaming up an adventure…..
Tristan Jones

Tristan Jones

Tristan Jones is a resident by day, early 90s style hacker by night. We had to give this Emergency Medicine Resident from UBC a job, or else he would shut down our website faster than Anonymous taking down Donald Trump.
Tristan Jones
- 3 weeks ago