Evaluation of new laryngoscope blade for tracheal intubation, Truview EVO2 (c): a manikin study

Background and objective: Difficult airways present a clinical challenge for anaesthetists. The Truphatek Truview EVO2 (c) (Truphatek International Ltd, Netanya, Israel) is a new laryngoscope blade used for endotracheal intubation that could be used where there is difficulty in visualizing the laryngeal inlet. Methods: Twenty anaesthetists (12 trainees and eight consultants) compared the Truphatek Truview EVO2 (c) with a conventional Macintosh size 3 blade. The Trucorp Airsim Bronchi (R) (Trucorp Ltd, Belfast, Northern Ireland, UK) manikin was intubated under normal conditions and under simulated difficult conditions such as tongue inflation and neck rigidity. In each scenario, the Cormack-Lehane grade, time needed for successful intubation, perceived difficulty of tracheal intubation and personal preference of blade were compared. The results were analysed with t-test (time of intubation), Wilcoxon signed-rank sum (Cormack-Lehane grade, ease of manoeuvre, preferred blade) and analysis of variance with Bonferroni correction (augmentation of difficulties in different scenarios). Results: The Truview EVO2 blade allowed the best laryngeal view as judged by the Cormack-Lehane grade (P < 0.05) in two separate situations: under simulated tongue inflation and under simulated neck rigidity. However, this blade did not reduce the intubation time or the ease of tracheal tube placement with respect to conventional Macintosh blade. Conclusion: Compared with the classical Macintosh blade, the Truview EVO2 blade allowed a better view of the larynx, but did not facilitate endotracheal intubation in any of the difficult scenarios created with the adjustable manikin and in most scenarios in fact prolonged the intubation time.