Difficult Airway

Difficult Airway

"The difficult airway is something one anticipates, the failed airway is something one experiences" - Ron Walls

Difficult airway can be due to:

1.  Difficult Bag Valve Mask (BVM); mnemonic = MOANS

2.  Difficult laryngoscopy and dificult intubation; mnemonics = LEMON

3.  Difficult cricothyrotomy; mnemonic = SHORT

4.  Difficult extraglottic devices; mnemonic = RODS

1. Difficult BVM = MOAN!

M = Mask seal not good, e.g. beard, facial deformity, etc

O = Obesity (difficult ventilate), 3rd trimester pregnancy, or obstruction e.g. neck swelling, angioedema, hematomas, cancer, etc

A = Age, elderly, loss of muscle tone to support the upper airway

N = No teeth (no teach causing caved in face)

S = Stiff lungs - upper airway obstruction - exacerbation of asthma, COPD, etc

2. Difficult laryngoscopy: use LEMON

L = Look externally, e.g. short neck, large tongue, large teeth, etc

E = Evaluate 3-3-2

        3 = adequacy of oral access

        3 = to assess capacity of mandibular space to accommodate tongue

        2 = distance of larynx to level of base of tongue

M = Mallampati scoring

O = Obstruction

        Any signs of upper airway obstruction?

        Three cardinal signs of upper airway obstruction:

        - muffled voice (hot potato voice),

        - difficult swallowing secretions,

        - stridor; when stridor happens, consider that circumference of airway reduced to
           roughly 10% of normal caliber!!!!

N = Neck mobility

3. Difficult cricothyrotomy

S = previous surgery

H = Hematoma/swelling around neck

O = Obesity

R = Radiation distortion

T = Tumor

4. Difficult Extraglottic devices

R = Restrictied mouth opening

O = obstruction upper airway

D = Disrupted or distorted upper airway

S = stiff lungs, spine of cervical

(Source: C K Sheng, 2009. Lecturer/Emergency Medicine Specialist, School of Medical Sciences, Universiti Sains Malaysia from http://emergencymedic.blogspot.ae/p/my-list-of-publications.html)