The Airway Scope, a new video laryngoscope: its use in three patients with cervical spine problems

Abstract

Editor—The Airway Scope AWS-S100 (Pentax, Tokyo, Japan) is a new video laryngoscope that enables laryngoscopy without alignment of the oral, pharyngeal, and laryngeal axes.1Koyama J Aoyama T Kusano Y et al.Description and first clinical application of AirWay Scope for tracheal intubation.J Neurosurg Anesthesiol. 2006; 18: 247-250Crossref PubMed Scopus (120) Google Scholar The handle has a 6 cm LCD monitor screen, and a flexible image tube with a camera and LED light source mounted at the tip. The disposable polycarbonate blade, the Pblade, has a channel that completely encloses and protects the image tube, a groove to hold and guide the insertion of the tracheal tube, and a separate channel for a suction catheter (Fig. 1a). The Pblade tip is positioned posterior to the epiglottis, to lift it during laryngoscopy. The target symbol on the LCD display helps alignment of the Pblade with the larynx for tracheal intubation (Fig. 1b). We report our use of the Airway Scope in three patients with cervical spine pathology and difficult conventional laryngoscopy. Patient 1 was a 58-yr-old man who sustained subluxation at the C2/C3 level with cord oedema after a fall. The surgeon planned posterior decompression and stabilization surgery, and requested that the patient remain conscious during tracheal intubation and positioning. We maintained cervical immobilization with a rigid collar and manual inline stabilization, and oxygenated the patient in between all airway procedures. We sedated the patient with remifentanil and midazolam, sprayed lidocaine on his oropharynx, and injected lidocaine through his cricothyroid membrane. During gentle laryngoscopy with a Macintosh laryngoscope, we were unable to see even the epiglottis. We were able to see the larynx fully with the Airway Scope. We inserted a suction catheter through the Pblade suction channel to spray lidocaine to the epiglottis and larynx under vision. We then intubated the trachea easily at the first attempt, without the patient gagging. The patient was able to move his hands and feet upon instruction immediately after intubation and again after being positioned prone. Patient 2 was a 73-yr-old man with severe cervical myelopathy for whom posterior laminectomy and decompression at C7/T1 level were planned. As a result of previous cervical spine surgery, he had very limited neck movement, and awkward gaps in his front teeth. Patient 3 was a 54-yr-old man with subluxation of C5/C6 and cervical myelopathy for whom anterior cervical decompression and fusion of C4/C6 were planned. He too had limited neck movement and several missing teeth. In these two patients, we applied manual inline stabilization, induced anaesthesia, and induced muscle relaxation after checking that ‘bag mask ventilation’ was possible. In both patients, we were able to see only the tip of the epiglottis with the Macintosh laryngoscope. With the Airway Scope, we were able to see their larynxes fully and intubate their tracheas easily. With the Airway Scope, we found the ability to easily guide the tracheal tube under vision advantageous compared with other devices. With the GlideScope®, it can be difficult to direct the tracheal tube into the trachea, despite the ability to view the larynx.2Lai HY Chen IH Chen A Hwang FY Lee Y The use of the GlideScope for tracheal intubation in patients with ankylosing spondylitis.Br J Anaesth. 2006; 97: 419-422Crossref PubMed Scopus (111) Google Scholar With a fibreoptic laryngoscope, railroading of the tracheal tube over the scope into the trachea is blind and often difficult.3Asai T Shingu K Difficulty in advancing a tracheal tube over a fibreoptic bronchoscope: incidence, causes and solutions.Br J Anaesth. 2004; 92: 870-881Crossref PubMed Scopus (184) Google Scholar The Airway Scope's LCD image could be viewed by two or more staff simultaneously and this helped in confirming tracheal intubation.4Asai T Enomoto Y Okuda Y Air way scope, a portable video-laryngoscope, for confirmation of tracheal intubation.Resuscitation. 2007; 72: 335-336Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar A potential limitation is the Airway Scope's length of 325 mm, which may make insertion difficult in patients with fixed neck flexion or barrel chests. Secondly, a minimum mouth opening of 2.5 cm is required. Early work in patients with normal airways showed that the Airway Scope views are not affected by the grade of Macintosh laryngoscopy views.5Suzuki A Toyama Y Katsumi N et al.Pentax-AWS improves laryngeal view compared with Macintosh blade during laryngoscopy and facilitates easier intubation.Masui. 2007; 56: 464-468PubMed Google Scholar We suggest that the Airway Scope is a promising device for difficult airway management, including patients with cervical spine pathology.