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[bg_faq_end]


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.[bg_faq_end] [bg_faq_start]

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[bg_faq_end]

4. What are the predictors of difficult LMA insertion?


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

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[bg_faq_end]

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[bg_faq_end]

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[bg_faq_end]

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[bg_faq_end]

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.
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 (Innovative Sport Medicine Calgary). His interests are in paediatrics, 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 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.