Improvement of the Airway Scope® orotracheal intubation blade to nasotracheal intubation blade and its usefulness

The Airway Scope® (PENTAX : AWS-S 100, AWS) is a novel intubation device which made possible to perform endotracheal intubation easily. The AWS is paired with an Intlock® blade (ITL-S) for orotracheal intubation. We improved the ITL-S to nasotracheal intubation blade (ITL-N), and evaluated its usefulness by a manikin study. There are two main parts in the ITL-S. One is the laryngoscopy part, and the other is the endotracheal tube guide part. We removed the endotracheal tube guide part in the ITL-S (Fig. 1), and used the laryngoscopy part as the nasotracheal intubation blade (ITL-N) (Fig. 2). We compared the ITL-N with the ITL-S in simulated right and left nasotracheal intubations. Twenty-four dental anesthetists and oral surgeons who have anesthesia training consented to participate in this study. The design of the study was randomized. Twelve participants used the ITL-N, and other twelve used the ITL-S. At first, each participant exercised to use AWS on the Laerdal Airway Management Trainer®. All nasotracheal intubation were performed with a 7.5 mm internal diameter endotracheal tube (Kendall, Curity®) using Magill forceps. Each participant first performed a right nasotracheal intubation, and then performed a left nasotracheal intubation. The right nasotracheal intubation time was 20.0±7.0 sec (mean±SD) by ITL-N, and 20.6±7.9 sec by ITL-S. There was no significant difference between ITL-N and ITL-S. The left nasotracheal intubation time was 19.1± 5.0 sec by ITL-N, and 29.2±14.9 sec by ITL-S. There was significant difference (p = 0.037) between ITL-N and ITL-S. These results indicated that ITL-N was useful for a left nasotracheal intubation on a manikin study. The AWS with ITL-S is possible to use for the orotracheal intubation in trismus patients. However, we experienced that ITL-S was not proper for the nasotracheal intubation in trismus patients. We also experienced that ITL-N was beneficial for nasotracheal intubations in such a kind of patients. The results of this study and our clinical experience indicated that ITL-N may be beneficial for nasotracheal intubation.