Risk factors in the oropharynx:
(1) large tongue
(2) small mouth
(3) overbite
(4) dental trauma
(5) clenched jaw or trismus
(6) intact gag reflex
Risk factors affecting the neck and muscles:
(1) inadequate muscular relaxation
(2) poor neck flexibility
(3) short and/or fat neck
Risk factors associated with the vocal cords and/or larynx:
(1) inability to pass an endotracheal tube through the vocal cords
(2) inability to visualize the vocal cords
(3) anterior vocal cords
(4) laryngospasm
Problems occupying or obscurring the airway
(1) epistaxis
(2) vomiting
(3) foreign body or trauma to the airway
Problems during the intubation attempt:
(1) hypoxemia or desaturation (< 90%) during the intubation attempt
(2) bradycardia during the intubation attempt
(3) equipment failure
(4) combative behavior by the patient
