Parker Flex-Tip Tube® facilitates intubation when the Pentax-AWS® fails to reach the larynx

Abstract

To the Editor: Pentax-AWS Airway Scope (AWS: Hoya, Tokyo), a new rigid, indirect videolaryngoscope with integrated tube guidance, has been successfully used in patients with both normal and difficult airways. In some case, however, the blade tip cannot be advanced beneath the epiglottis, even after multiple attempts [1], and the intubation frequently fails due to blade configuration [2]. Several authors proposed the use of tube introducer (elastic bougie) to solve the problem [3]. We propose the use of the Parker Flex-Tip Tube to facilitate intubation under this situation. Preoperative airway assessment of a 61-year-old man scheduled for general anesthesia indicated a risk of difficult intubation because of relatively small mandible, his thyromental distance being 4 cm. Since the patient did not have risk factors of difficult mask ventilation, he was anesthetized with propofol and rocuronium. After complete paralysis was confirmed with the peripheral nerve stimulator, laryngoscopy was performed with a Macintosh no. 4 blade, but only the epiglottis was visualized, and it was graded as Cormack‐Lehane grade 3b. We next used the AWS for the second intubation attempt. However, the tip was not able to be advanced beneath the epiglottis but inserted into the vallecula. The epiglottis was indirectly elevated, and the laryngeal exposure was approximately 80% of the glottic opening. We tried to insert the standard bevel tube (Phycon Tube, Fuji System, 7.5 mm ID, 10 mm OD) set in the channel, but the tube tip impinged onto the epiglottis, and intubation failed. Next, we used the Parker Flex-Tip Tube (Kobayashi Medical, 7.5 mm ID, 10 mm OD), and the tube was inserted smoothly into the glottis without trapping on the arytenoids. The Parker Flex-Tip Tube has a tapered, curved tip and has been shown to facilitate intubation with the Bullard laryngoscope [4] and fiberoptic bronchoscope [5]. The advantage of using the Parker tube in combination with the AWS has not been well evaluated. Figure 1 shows the two tubes, with the same outer diameter as those used in this case, protruding from the channel. We can see more space from the blade tip to the Parker tube than with the standard tube. It seems that this space allows the Parker tube to be advanced without impinging upon the epiglottis, and the tapered, curved tip glides on the posterior surface of the epiglottis to lead the