Mnemonics for difficult airway predictors

Can you list the predictors of a difficult airway?





1. Difficult Bag-Mask Ventilation
    Mnemonic = MOANS


Mask sealBushy beards, crusted blood on the face, or disruption of lower facial continuity
Obesity / ObstructionObesity, pregnancy, angioedema, Ludwig’s angina, upper airway abscess, epiglottitis
AgeAge > 55
No teethMay leave denture in edentulous patients.
Sleep apnea / Stiff lungsCOPD, asthma, ARDS, others





Mallampati classification

2. Difficult Laryngoscopy and Intubation
    Mnemonic = LEMON


Look externallyUse your clinical gestalt, evidence of lower facial disruption, bleeding, small mouth, agitated patient
EvaluateUse the 3-3-2 rule: mouth open, mandible, glottis
Mallampati scoreIn order of increasing difficulty Class I-IV
Obstruction / ObesityFour cardinal signs of upper airway obstruction: stridor, muffled voice, difficulty swallowing secretions, sensation of dyspnea. Obese patients frequently have poor glottic views.
Neck mobilityMay not be able to optimally move the head and neck due to trauma, arthritis, ankylosing spondylitis. Immobilize the neck and consider using video laryngoscopy.



3. Difficult Extraglottic Device 
    Mnemonic = RODS


Restricted mouth opening
Obstruction
Disrupted or Distorted airway
Stiff lung or cervical Spine




Difficult Cricothyrotomy
Mnemonic = SHORT


Surgery or other airway obstruction
Hematoma (includes infection/abscess)
Obesity
Radiation distortion (and other deformity)
Tumor

There are no absolute contraindications to performing an emergency cricothyrotomy.

References
Walls  R, Murphy M. Chapter 7: Identification of the Difficult Airway. Manual of Emergency Airway Management. Third Edition. Lippincott Williams & Wilkins
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