Expected difficult tracheal intubation: a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients

The Berci-Kaplan video laryngoscope was developed to improve the visualization of the glottis and ease tracheal intubation. Whether this technique is also effective in patients with an expected difficult intubation is unclear. We have prospectively evaluated the conditions and success rate of tracheal intubation in patients with a Mallampati score of III or IV. Two hundred patients, undergoing general anaesthesia, were randomized to be intubated using direct laryngoscopy (n=100) or video laryngoscopy (n=100). Visualization of the vocal cords, success rate, time for intubation, and the need for additional manoeuvres (laryngeal manipulations, head positioning, and Eschmann stylet) were evaluated. Video laryngoscopy produced better results for the visualization of the glottis using Cormack and Lehane criteria (P < 0.001), success rate (n=92 vs 99, P=0.017), and the time for intubation [60 (77) vs 40 (31) s, P=0.0173]. In addition, the number of optimizing manoeuvres was also significantly decreased [1.2 (1.3) vs 0.5 (0.7), P < 0.001]. Video laryngoscopy, when compared with direct laryngoscopy for difficult intubations, provides a significantly better view of the cords, a higher success rate, faster intubations, and less need for optimizing manoeuvres. Therefore, we feel that the video laryngoscopy leads to a clinically relevant improvement of intubation conditions and can be recommended for difficult airway management.