The Clarus Video System (Trachway) intubating stylet for awake intubation

The Clarus Video System (Trachway®) intubating stylet (Biotronic Instrument Enterprise Ltd., Tai-Chung, Taiwan, R.O.C.) is a new video intubating stylet for tracheal intubation [1, 2]. Views of the laryngeal inlet and vocal cords are presented on the colour monitor via the distal camera. This airway equipment has been used for difficult intubation in simulated scenarios [3], but its clinical application for recognised difficult intubation has not been investigated. A 49-year-old man with a history of odontoid fracture was admitted with six months’ progressive bilateral upper limb weakness and sensory loss. Cervical spine radiographs demonstrated a C1-C2 subluxation. A halo vest frame (Halo Cervical Traction System 1223, PMT® Corporation, Chanhassen, MN, USA) was applied before surgical intervention. He was scheduled for C1 and C2 decompression and fusion. Pre-operative airway assessment revealed limited mouth opening (3 cm) and intact upper and lower dentition without overbite. His thyromental distance was ∼6 cm and his modified Mallampati score was grade 4. His neck was fixed due to the halo vest. As general anesthesia with tracheal intubation was required for the surgery, we elected to proceed with an awake intubation. Following informed consent, we placed the patient supine and slightly head-up. After establishing noninvasive monitoring and pre-oxygenation by facemask, we performed a transtracheal injection of 100 mg lidocaine 2% and administered 50 μg fentanyl intravenously for light sedation. We used 10% lidocaine spray to anaesthetise the oropharynx. After placing an oral mouthpiece as a bite guard (E-Z-EM Inc, NY, USA), we performed tracheal intubation using the Trachway, over which a standard 7.5-mm tracheal tube (Unomedical Inc., McAllen, TX, USA) was fitted (Fig. 1). Trachway, preloaded with tracheal tube, inserted into mouth. We observed the anatomical structures on the monitor attached to the handle, as we advanced the tube and stylet along the dorsum of the tongue. We easily identified the epiglottis and vocal cords on the first attempt. We then slid the tube off the stylet and advanced it into the trachea under direct vision. After removing the Trachway, we immediately inflated the cuff. The patient exhibited no reflex coughing or retching during the procedure, and we did not need to move the neck or employ jaw thrust or external laryngeal manipulation. This case report is the first describing the use of the Trachway intubating stylet for awake tracheal intubation in a patient wearing a halo vest. The Pentax Airway Scope (AWS; Pentax Corporation, Tokyo, Japan) has been used to aid tracheal intubation in a patient wearing a halo vest [5]. The Trachway intubating stylet has the advantage of providing direct observation during intubation and can therefore avoid blind and potentially traumatic airway manipulation. Also, in patients with limited mouth opening, insertion of laryngoscope blades into patient’s mouth can be difficult or even impossible, but the Trachway intubating stylet faces no such problem and can be selected as an alternative intubating device.