The Rusch ViewMax vs Macintosh laryngoscopy in human cadavers: impoved vocal cord visualization?

Abstract

Objectives: Adequate vocal cord visualization via laryngoscopy is a key component of successful endotracheal intubation. Several tools exist to facilitate laryngoscopy in difficult airways. We compared one such device, the Rusch "ViewMax" (Rusch, Duluth, Ga), to a standard Macintosh laryngoscope blade (Heine USA Ltd, Dover, NH) using human cadaver models. The purpose of this study was to determine if the ViewMax improved vocal cord visualization.

Methods: Emergency medicine residents and faculty (N = 26) attempted vocal cord visualization with both ViewMax and Macintosh laryngoscope blades for each of 6 cadaver airways at an airway laboratory training exercise. Percentage of glottic opening (POGO) score was estimated for each laryngoscopy attempt. Data were analyzed by nonparametric statistics.

Results: Of 6 cadaver airways, 4 had median POGO score estimates of 100% for both ViewMax and Macintosh laryngoscope blades. Two cadavers had median POGO estimates of less than 50% for both blades. No difference was found in POGO score estimates between the ViewMax and the Macintosh blades in any of the 6 cadavers including those with more difficult vocal cord visualization (P = .27, .35, .61, .40, .39, .31).

Conclusion: The Rusch "ViewMax" was not shown to improve vocal cord visualization over standard Macintosh blade laryngoscopy in these cadaver models. Further study with cadaver models known to have more difficult airways may improve power to detect a small difference in vocal cord visualization, though the clinical relevance of any slight difference remains uncertain.