Using the Cormack-Lehane score is unhelpful to describe tracheal intubation using videolaryngoscopy since it describes the glottic view achieved by aligning the oral, pharyngeal and laryngeal axes. Direct laryngoscopy aims to obtain the best view possible since this should allow the most straightforward passage of the tracheal tube. Whilst not a perfect score to describe direct laryngoscopy, the Cormack-Lehane score has been widely accepted probably because increasing Cormack Lehane grades correlate well with increasing difficulty with tracheal intubation. Videolaryngoscopes have a camera positioned in the distal third of the blade which means that obtaining the glottic view is usually straightforward since the view point is already beyond most of the anatomy (if not all!) that would have obstructed the view with a direct laryngoscopy technique. Furthermore, videolaryngoscopy techniques do not require the three axes to be aligned. For these reasons, unlike with direct laryngoscopy, the ease at which the glottis can be viewed may not necessarily correlate with the ease of tracheal intubation.
