Predicting the difficult airway

Difficult to Bag Ventilate

Difficult BVM (MOANS)

• Mask seal
• Obesity
• Aged
• No teeth
• Stiffness (resistance to ventilation)

Difficult to Intubate (LEMON)

An airway assessment score based on criteria of the LEMON method is able to successfully stratify the risk of intubation difficulty in the emergency department.

LOOK

• Look at the patient externally for characteristics that are known to cause difficult laryngoscopy, intubation or ventilation

• Trauma
• Short neck
• Micrognathia
• Prior surgery
• May also be difficult to bag
  • Body mass index
  • Advanced age
  • Beard
  • No teeth
  • Snoring
  • Dentures

Evaluate 3-3-2-1

3-3-2 ruleDistance between patient's incisor teeth of 3 finger breadths and distance between the thyroid notch and the floor of the mouth should be at least 2 finger widths

• 3 - Ideally the distance between the patient's incisor teeth should be at least 3 finger breadths
• 3 - Distance between the hyoid bone and the chin should be at least 3 finger breadths
• 2 - Distance between the thyroid notch and the floor of the mouth should be at least 2 finger breadths
• 1 - Lower jaw should not sublux more than 1cm

Mallampati

Mallampati Score

• The patient sits upright, opens mouth and protrudes tongue
• Grades are based on visibility of the uvula, posterior pharynx, hard, and soft palate

Obstruction

• Assess for conditions leading to airway obstruction such as Peritonsillar Abscess (PTA), trauma, or Epiglottitis.

Neck Mobility

• Patient places chin down onto their chest and extend their neck.
• Remove the hard collar and provide manual stabilization in trauma patients.
• Poor neck mobility impacts ability to have airway access alignment.

See Also

Airway Pages

• Pre-intubation
  • Predicting the difficult airway
  • Bag valve mask ventilation
    • Oropharyngeal airway
    • Supraglottic airway
  • Apneic oxygenation
    • EBQ:ED Preoxygenation
• Induction
  • Critical care quick reference
  • Rapid sequence intubation
  • Delayed sequence intubation
• Intubation
  • Intubation (peds)
  • Direct laryngoscopy
  • Video Laryngoscopy
  • Bougie
  • The difficult airway
  • Advanced airway adjuncts
    • Supraglottic airway
  • Non-traditional intubation
    • Awake intubation
    • Nasal intubation
    • Blind digital intubation
• Surgical airways
  • Surgical cricothyrotomy
  • Needle cricothyrotomy
  • Pediatric jet ventilation
• Post-intubation
  • Mechanical ventilation (main)
  • Deterioration after intubation (DOPE)