Disposable C-MAC(®) videolaryngoscope blade - not the same as the re-usable blade.

Abstract

The disposable plastic C-MAC® videolaryngoscope blade (Karl Storz, Tuttlingen, Germany) has been developed as a substitute for the metal re-usable blade. The reduced tensile strength of plastic requires a thickened plastic version to avoid breakage during use 1. The re-usable metal version has an ‘English’ Macintosh-type laryngoscope blade design with a blade (or spatula), web and flange sections. The web projects vertically from the blade and the flange is perpendicular to the web. Both the web and flange deflect the tongue to the left, out of the line of vision. The disposable plastic version has a marked thickening of both the web and flange sections, making tongue displacement difficult. In certain difficult airway scenarios, such as a large tongue and narrow palate when there is secretions or blood in the airway, this additional bulk causes two problems. Firstly, the pharyngeal view is significantly reduced, creating a ‘blind spot’” (Fig. 2) from the point where the line of vision contacts the blade to the video camera 2-4. The second problem is the limited space, making manipulation of the tracheal tube or adjunct (e.g. bougie) difficult. The combination of the blind spot and limited space for manipulating the tracheal tube is likely to increase the risk of upper airway trauma during intubation. Figure 3 shows the cross-sectional areas of the upper airway as seen by the operator when using both blades in the same patient. A dotted line shows reduced tongue displacement with the disposable blade. Upper airway trauma has been reported with other videolaryngoscopes 2, 4. It is likely that the disposable C-MAC videolaryngoscope, in its present design, may join them.