Randomized equivalence trial of the King Vision aBlade videolaryngoscope with the Miller direct laryngoscope for routine tracheal intubation in children <2 yr of age

Background. We conducted a randomized equivalence trial to compare direct laryngoscopy using a Miller blade (DL) with the King Vision videolaryngoscope (KVL) for routine tracheal intubation. We hypothesized that tracheal intubation times with DL would be equivalent to the KVL in children <2 yr of age. Methods. Two hundred children were randomly assigned to tracheal intubation using DL or KVL. The primary outcome was the median difference in the total time for successful tracheal intubation. Secondary outcomes assessed were tracheal intubation attempts, time to best glottic view, time for tracheal tube entry, percentage of glottic opening score, airway manoeuvres needed, and complications. Results. The median difference between the groups was 5.7 s, with an upper 95% confidence interval of 7.5 s, which was less than our defined equivalence time difference of 10 s. There were no differences in the number of tracheal intubation attempts and the time to best glottic view [DL median 5.3 (4.1-7.6) s vs KVL 5.0 (4.0-6.3) s; P=0.19]. The percentage of glottic opening score was better when using the KVL [median 100 (100-100) vs DL median 100 (90-100); P<0.0001]. Use of DL was associated with greater need for airway manoeuvres during tracheal intubation (33 vs 7%; P<0.001). Complications did not differ between devices. Conclusions. In children <2 yr of age, the KVL was associated with equivalent times for routine tracheal intubation when compared with the Miller blade.