Fig. 1

Percentage of a difficult airway view (Cormack-Lehane grade III or IV) in the presence or absence of each of the HEAVEN criteria for both direct and video laryngoscopy. Each of the HEAVEN criteria was associated with a statistically significant increase (*p < 0.01) in the likelihood of a difficult airway view. In addition, direct laryngoscopy had a higher incidence of difficult airway view for each of the HEAVEN criteria except “Exsanguination”