Updating the Cormack and Lehane classification

Abstract

Difficult intubation was classified into four grades according to the view obtained at laryngoscopy by Cormack and Lehane in 1984 [1]. The development of new laryngoscopes such as McCoy's levering laryngoscope and, more recently, video laryngoscopes such as the Glidescope and the McGrath has allowed improved laryngeal views at intubation. The Glidescope has been shown to improve laryngoscopic views by one or two grades [2]. The McCoy laryngoscope has been shown to improve the grade obtained by a standard Macintosh laryngoscope by at least one when fully activated [3, 4]. However, many anaesthetists still document the laryngeal views using the Cormack and Lehane classification when they perform tracheal intubation with any of the above mentioned devices. Confusion may arise if the type of the laryngoscope used is not documented on the anaesthetic sheet. It is important to know the type of the laryngoscope or blade used to achieve a certain laryngeal view. We propose a modified grading system in which the usual Cormack and Lehane grade is preceded by a suffix indicating the type of the scope used for each individual intubation. For example, “Mac-3” could indicate a grade 3 view with a Macintosh laryngoscope and “McG 1” can represent the view obtained by a McGrath laryngoscope, and so forth. This modification of the Cormack and Lehane classification would stop confusion, improve documentation and facilitate communication between clinicians.