Gemma Malpas1, George Kovacs2, Sean P Mackinnon3, Orlando Hung4, Sarah Phipps5, J Adam Law4. 1. Department of Adult and Emergency Anesthesia, Level 8, Auckland City Hospital, Auckland District Health Board, 2 Park Road, Grafton, Auckland, 1023, New Zealand. gmalpas@icloud.com. 2. Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada. 3. Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada. 4. Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada. 5. Department of Anesthesia, Hawke's Bay Hospital, Camberley, Hastings, New Zealand.
Abstract
PURPOSE: Videolaryngoscopy is widely believed to give a superior view to that obtained by direct laryngoscopy. Published literature suggests this benefit extends to both hyper-angulated and Macintosh-style videolaryngoscopes. Notwithstanding, our clinical experience shows that the videoscopic view with a Macintosh-style videolaryngoscope is often no different or only marginally better than the directly sighted peroral view. METHODS: A human cadaver equivalence study was performed in which four experienced laryngoscopists obtained pre-assigned laryngeal views by direct sighting using the single-use Macintosh blades of the GlideScope® Spectrum™ (GS) DirectView Macintosh (DVM) and C-MAC®S videolaryngoscopes. Blinded to the laryngoscopist's view, two independent observers rated the videoscopic view presented on the proximal video monitor at the same time. Directly sighted and videoscopic views obtained by the laryngoscopist and video scorers were recorded on a visual analogue scale (VAS) for each device as the primary outcome measures and compared. RESULTS: On the VAS, the C-MAC®S videoscopic view revealed only approximately 0.9% more (99% confidence interval [CI], -2.5% to 4.3%) of the laryngeal inlet than the directly sighted view. Using GS DVM, the videoscopic view revealed 6.7% (99% CI, 2.3% to 11.0%) more of the laryngeal inlet than the directly sighted view. Although results for the GS DVM achieved statistical significance, neither device gave a clinically significantly improved videoscopic view compared with the directly sighted peroral view. CONCLUSION: This study failed to corroborate previously published findings of a clinically significantly improved videoscopic view compared with direct peroral sighting using Macintosh-style videolaryngoscopes. Further study of this class of device is warranted in human subjects.
PURPOSE: Videolaryngoscopy is widely believed to give a superior view to that obtained by direct laryngoscopy. Published literature suggests this benefit extends to both hyper-angulated and Macintosh-style videolaryngoscopes. Notwithstanding, our clinical experience shows that the videoscopic view with a Macintosh-style videolaryngoscope is often no different or only marginally better than the directly sighted peroral view. METHODS: A human cadaver equivalence study was performed in which four experienced laryngoscopists obtained pre-assigned laryngeal views by direct sighting using the single-use Macintosh blades of the GlideScope® Spectrum™ (GS) DirectView Macintosh (DVM) and C-MAC®S videolaryngoscopes. Blinded to the laryngoscopist's view, two independent observers rated the videoscopic view presented on the proximal video monitor at the same time. Directly sighted and videoscopic views obtained by the laryngoscopist and video scorers were recorded on a visual analogue scale (VAS) for each device as the primary outcome measures and compared. RESULTS: On the VAS, the C-MAC®S videoscopic view revealed only approximately 0.9% more (99% confidence interval [CI], -2.5% to 4.3%) of the laryngeal inlet than the directly sighted view. Using GS DVM, the videoscopic view revealed 6.7% (99% CI, 2.3% to 11.0%) more of the laryngeal inlet than the directly sighted view. Although results for the GS DVM achieved statistical significance, neither device gave a clinically significantly improved videoscopic view compared with the directly sighted peroral view. CONCLUSION: This study failed to corroborate previously published findings of a clinically significantly improved videoscopic view compared with direct peroral sighting using Macintosh-style videolaryngoscopes. Further study of this class of device is warranted in human subjects.
Authors: Florian J Raimann; Daniel M Tepperis; Dirk Meininger; Kai Zacharowski; Richard Schalk; Christian Byhahn; Christian F Weber; Haitham Mutlak Journal: Emerg Med Int Date: 2019-10-01 Impact factor: 1.112
Authors: J Adam Law; Laura V Duggan; Mathieu Asselin; Paul Baker; Edward Crosby; Andrew Downey; Orlando R Hung; Philip M Jones; François Lemay; Rudiger Noppens; Matteo Parotto; Roanne Preston; Nick Sowers; Kathryn Sparrow; Timothy P Turkstra; David T Wong; George Kovacs Journal: Can J Anaesth Date: 2021-06-18 Impact factor: 5.063