• Airway assessment
• History
• General examination
• Obesity
• Pregnancy
• Large breasts
• Short thick neck
• Goitre, haematoma or neck mass
• Micro or macrognathia
• Prominent upper incisors
• High arched palate
• Large tongue
• Limited mouth opening
• Investigations
• CT
• X-rays
• Flexible nasendoscopy
• Thyroid notch to mentum in full extension
• < 7cm = difficult
• Sternomental distance <12.5cm = difficult
• Malampatti Score
• MP 3/4 & thyromental distance < 7cm is sensitive and specific for grade IV C&L
• 'Difficult airway'
• 3 or more attempts
• Longer than 10 mins to acheive
• None of the cord anatomy seen at laryngoscopy
• May be due to:
  Upper airway issues (beard, face, nose, mouth abnormalities)
  Middle airway (tumour, infection)
  Lower airway (tracheal stenosis, mediastinal compression)
  
• Atlanto-occipital joint
• > 35 degrees is normal
• Jaw protrusion (Wilson)
• a = lower in front of upper
  b = equal
  c = upper in front of lower
• Wilson Risk Score
• Weight
  Head and neck movements
  Mouth and jaw movements
  Receding jaw
  Prominent incisors
• Each marked from 0-2
  Score of > 3 predicts 75% of difficult intubations
• Mouth opening
• < 3cm = difficult
• CEACCP
  Link:ceaccp.oxfordjournals.org/content/1/2/44.full.pdf