CORRESPONDENCE Force and pressure distribution using Macintosh and GlideScope laryngoscopes

Force and pressure distribution using Macintosh and GlideScope laryngoscopes Editor—Carassiti and colleagues are to be commended for their work attempting to compare the forces applied to the airway during laryngoscopy with the Glidescope Cobalt and the Macintosh laryngoscope. However, one issue deserves comment, there is an important difference between the two blades that was not accounted for in the placement of the force transducers or addressed in their discussion. The angulated blade of the Glidescope is different from the curve of the Macintosh blade. As a consequence of this, one might anticipate that forces generated by the blades may be in different locations of the blades. The transducers were placed in relatively similar positions on both blades. Because of the acutely angulated tip of the GlideScope and based on our clinical experience with the device, we believe that most of the force applied to the airway occurs at the very tip of the blade. This area is embedded into the soft tissue and transmits the forces generated by the laryngoscopist. This area was not covered by the transducer in the authors’ images and therefore puts into question their conclusions regarding forces generated by the two blade types. The Macintosh blade, because of its less acute curvature, has most of its force applied along the blade surface rather than the very tip as demonstrated in their paper.