First-pass Success Rate and Number of Attempts Required for Intubation in Anticipated Difficult Airway: Comparison between Macintosh and Channeled King Vision Video Laryngoscopes

BACKGROUND AND AIMS: Video laryngoscopy has been shown to improvise Cormack–Lehane grading and rate of successful tracheal intubation and is now incorporated in most of the difficult airway guidelines. Since there is scarce literature regarding the use of channeled blade of King Vision video laryngoscope (KVVL) in anticipated difficult intubation, we planned to undertake this randomized control trial to assess the performance of channeled blade of KVVL and Macintosh laryngoscope in patients with anticipated difficult intubation. DESIGN AND SETTING: This prospective randomized study was conducted in a tertiary care hospital. MATERIALS AND METHODS: Patients fulfilling the inclusion criteria were randomly assigned equally to the KVVL group or Macintosh group. The primary outcome of the study was intubation success in the first attempt and number of attempts required for intubation, and the secondary outcomes were Cormack–Lehane grading and time required to intubate in both the groups. RESULTS: The first-pass success of intubation was 88.6% in the KVVL group and 76.5% in the Macintosh group (P = 0.035). The second attempt of intubation was required in 11.4% and 20.6% of patients in the KVVL and Macintosh groups, respectively. Cormack Lehane Grade I was achieved in 100% of patients of the KVVL group as compared to 29.4% of patients in the Macintosh group. Moreover, the difference was statistically significant (P = 0.035). The mean duration of intubation was prolonged in the KVVL group as compared to the Macintosh group, and the difference was statistically significant (P = 0.04). CONCLUSION: The channeled blade of KVVL had a higher first-pass success rate and required fewer attempts to intubate when used in patients with anticipated difficult intubation. Further, the KVVL was found to be significantly better than the Macintosh laryngoscope in terms of Cormack–Lehane grading, but the time taken to intubate the trachea was more in the KVVL group.