Comparison of king vision video laryngoscope with macintosh laryngoscope for nasotracheal intubation: Randomized control study

Nasotracheal intubation is essential in oro-maxillofacial surgeries to provide a good operational field along with a secured airway. In this study, we aim to compare king vision video laryngoscope with conventional Macintosh laryngoscope for nasotracheal intubation in ear, nose throat and oro-maxillofacial surgeries under general anaesthesia. A total of 102 patients were posted for elective oro-maxillofacial surgeries under general anaesthesia with nasal intubation. Patients were randomized to two different groups. In group K nasotracheal intubation was done with king vision video laryngoscope (KVVL) and in group M with Macintosh laryngoscope. Primary objective was to compare total intubation time and each time intervals (time A: placement of the nasal tube from selected nostril to oropharynx; time B: use of devices to view the glottis, and time C: for nasal tube to be advanced from oropharynx into trachea and removal of the laryngoscope from oral cavity). Secondary objectives were to compare scores of Modified Naso Intubation Difficulty Scale (MNIDS) and haemodynamic responses. The mean total intubation time, and time C interval were noted in King Vision Video Laryngoscope group (37.29±7.83 s and 15.99±8.9 s) and Macintosh laryngoscope group (46.11±10.05 s and 19.86±9.96 s) respectively. There was significant difference between these two groups in terms of mean total intubation time, and time C interval (total time, p=0.001 and time C, p=0.041). The level of difficulty in intubation noted using MNIDS score which is zero in 52.9% patients in King Vision group and 23.5% in Macintosh group (p=0.011). As compared to Macintosh laryngoscope, the king vision laryngoscope requires lesser time for nasotracheal intubation. In addition, Intubation is easier with the king vision laryngoscope than with the Macintosh laryngoscope.