McGrath(®) series 5 videolaryngoscope evaluation for double-lumen tube intubation.

Abstract

Several studies 1-4 have demonstrated that videolaryngoscopy is superior to Macintosh laryngoscopy for double-lumen tube (DLT) intubation. However, Russell et al. 5 recently found that DLT intubation was more difficult for 30 anaesthetists in 70 patients with anticipated normal airways using the GlideScope® (Verathon Inc., Bothell, WA, USA) compared with Macintosh laryngoscopy, particularly for novices, suggesting that sufficient training is required before preferring videolaryngoscopy for DLT intubation. The McGrath® Series 5 videolaryngoscope (Teleflex Incorporated, Limerick, PA, USA) has been successfully used in patients with anticipated and unanticipated difficult airways 6, 7, but there is limited information about its use in DLT intubation. We hypothesised that a McGrath Series 5 videolaryngoscope could be used for DLT intubation, using a stylet and similar maneuvres to those previously reported for successful GlideScope left DLT intubation. With Local Institutional Ethics Committee approval and patients' written consent, we enrolled 43 adult patients without predictors for difficult ventilation and/or intubation, who were scheduled for thoracic surgery requiring DLT intubation. Following standard monitoring, pre-oxygenation and induction, McGrath Series 5 videolaryngoscope-assisted left 35F-41F DLT intubation was performed by two experienced operators. According to previous studies 1, 8, the DLT was curved by a malleable stylet, which was removed when the DLT's distal tip passed through the vocal cords. Sequential rotation or a ‘left to right’ rotation was performed to facilitate passage of the bronchial cuff and tracheal lumen through vocal cords 1, 2, 9. The tube was further rotated to align the bronchial tip of DLT with the left main bronchus. A Cormack and Lehane grade-1 view was obtained in 38 (88%) patients and a grade 2a view in 5 (12%) patients. The mean (SD) intubation time (from when the videolaryngoscope passed between the patient's lips until three complete cycles of end-tidal carbon dioxide were displayed) was 54 (23) s. The cumulative success rate of intubation was 95% at the first attempt and 100% by the second attempt. Tracheal intubation was rated as ‘easy’ in 34 (79%) patients, ‘moderately difficult’ in seven (16%) and ‘very difficult’ in two (5%). Fibreoptic bronchoscopy confirmed correct tube position in 35 (81%) patients. None of the subjects experienced serious complications associated with intubation. The main difficulty in DLT intubation was found to be advancing the DLT further once its tip had passed through the vocal cords, similar to reports using the Glidescope 1, 9 and CEL-100™ videolaryngoscope (Connell Energy Technology Co. Ltd., Shanghai, China) 2. We conclude that the McGrath series 5 videolaryngoscope is a suitable tool for DLT intubation, providing a high rate of grade-1 laryngeal views, acceptable intubation time and a high rate of successful intubation at the first attempt.