Intubation with channeled versus non-channeled video laryngoscopes in simulated difficult airway by junior doctors in an out-of-hospital setting: A crossover manikin study

Failure to secure the airway is an important cause of morbidity and mortality during resuscitations. We compared the rate of successful intubation of the King Vision(™) aBlade(™) channeled and non-channeled video laryngoscopes, and McGRATH(™) MAC video laryngoscope when used by junior doctors to intubate a simulated difficult airway in an out-of-hospital setting. 105 junior doctors were recruited in a crossover study to perform tracheal intubation with the three video laryngoscopes on a simulated difficult airway using the SimMan(®) 3G manikin. Primary outcome was the rate of successful intubations. Secondary outcomes were time-to-visualization, time-to-intubation and ease of use. Rates of successful intubations were higher for King Vision channeled and McGrath compared to the King Vision non-channeled (85.7% and 82.9% respectively versus 24.8%; p<0.001). Amongst the participants who had successful intubations, King Vision channeled and McGrath had shorter mean time-to-intubation compared to the King Vision non-channeled (41.3±20.3s and 38.5±18.7s respectively versus 53.8±23.8s, p<0.004;). There was no significant difference in the rate of successful intubation and mean time-to-intubation between King Vision channeled and McGrath. The King Vision channeled and McGrath video laryngoscopes demonstrated superior intubation success rates compared to King Vision non-channeled laryngoscope when used by junior doctors for intubating simulated difficult airway in an out-of-hospital setting. We postulated that the presence of a guidance channel in the King Vision channeled laryngoscope and the familiarity of the blade curvature and handling of the McGrath could have accounted for their improved intubation success rates.