The A.P. Advance video laryngoscope as a rescue airway device in an unpredicted difficult airway.

Sir,

Direct laryngoscopy using Macintosh (MAC) blades remains the standard technique for securing airways during anesthetic practice. However, performing a direct laryngoscopy may be difficult or impossible in a percentage of cases that depends on the definition given, ranging from 0.3% to 13%.[1] Difficulty in airway management often leads to serious harm.[2] The Venner AP Advance video laryngoscope (APA) (Venner Medical Ltd., Singapore) [Figure 1] is a video laryngoscope functionally similar to standard MAC laryngoscopes. It is a hand held portable device provided with a rechargeable, high resolution 86 mm (3.5”) LCD color display that can be attached to the top of the handle of the laryngoscope. The blades are mounted onto the camera module and three types of single use cover-blades are available: MAC 3, MAC 4 for routine laryngoscopy and a difficult airway blade (DAB) for difficult laryngoscopy. The DAB blade is more acutely curved in shape than the MAC blades, obeying the “look around the corner” philosophy and is designed with a guiding channel in its distal one third, to facilitate passage of the tracheal tube into the glottis. We describe the case of a 44-year-old man (body mass index: 25 kg/m2) scheduled for uvulopalatopharyngoplasty. He had no significant medical history and the preoperative airway evaluation did not foresee difficulties in airway management, the preoperative El-Ganzouri Risk Index score being 3 (Thyromental distance: 62 mm, Mallampati score 2, negative upper lip bite test). After preoxygenation, the induction of anesthesia was performed with propofol 160 mg intravenous (IV), fentanyl 100 mcg and atracurium 40 mg IV. Direct laryngoscopy using a MAC blade showed a Cormack-Lehane Grade 3e view[3] despite external laryngeal manipulation and correct sniffing position. After confirmation of easy ventilation by face mask, we decided to perform a second laryngoscopy using the APA mounted with the DAB. Once the epiglottis was visualized (Cormack-Lehane: 2) on the video viewer of the laryngoscope, the APA was advanced further to obtain an optimal view of the larynx. Next, a sized seven cuffed reinforced tracheal tube was directed into the glottic aperture via the DAB guide channel. The endotracheal intubation was then confirmed by capnography and auscultation of the chest. The surgery proceeded uneventfully and the patient underwent a protected extubation using an airway exchange catheter (Cook Critical Care, Bloomington, IN). Several types of video laryngoscopes[4] have been reported to have been used for airway rescue after a direct laryngoscopy failure, but to our knowledge, this is the first report about the APA. In our opinion, the APA has several advantages. First, it can be used as a standard MAC laryngoscope, making video laryngoscopy more familiar and encouraging its diffusion among experienced anesthetists. The DAB offers the opportunity, with the same device, to use a blade for the management of difficult airway in case of failure of the MAC blades. In our experience, the DAB immediately offered a good view of the glottis, and safely allowed the insertion of the tracheal tube sliding in the channel guide. To conclude, in our opinion, the Venner APA video laryngoscope has a potential role in managing difficult airway,[56] however further studies and clinical experience are necessary to establish its role in difficult airway management.

Figure 1

Venner AP Advance: (a) note single parts, (b) Macintosh (MAC) 3 assembly, (c) blades configuration and MAC blades comparison, (d) Venner MAC 3 and difficult airway blade (DAB) comparison, (e) simulation of tube passage via DAB channel