Macintosh's Laryngoscope

Abstract

We have read the paper of Burkle et al. regarding the history of the laryngoscope in anesthesia1with great interest. The authors give a very good historical perspective of the different types of laryngoscope. Nevertheless we would like to highlight the laryngoscope designed by Robert Macintosh in 1943 because of its importance and significance.2In our opinion, the Macintosh blade is much more than a variant of the models previously mentioned, as it allowed a better view of the vocal cords, making the tracheal intubation easier.Sir Robert Reynolds Macintosh was the first professor of Anesthesia at Oxford University, which was the first chair of anesthesia in Europe.3,4The laryngoscope designed by Macintosh is probably the most successful and lasting instrument in the history of anesthesia; it has survived plastic translation and the adoption of fiber light. The laryngoscope was designed to lessen the difficulty of exposing the larynx by direct elevation of the epiglottis, as the blades existing at that time did not allow correct visualization of the vocal cords.2This becomes evident in a letter that Sir Robert Macintosh wrote to Jephcott in which he also explained how he got the idea to design a new laryngoscope:5“The ability to pass the endotracheal tube under direct vision was the hallmark of the successful anesthetist. Magill was outstanding in this respect. I described a new approach in 1941 but it was not much of an improvement.6The difficulty was to expose the cords. Then, one morning during a tonsillectomy list, I had a bit of luck and the nous to take advantage of it. On opening a patient's mouth with a Boyle-Davis gag, I found the cord perfectly displayed. Richard Salt (a really excellent chap) was in the theater with me; before the morning had finished he has gone out and soldered a Davis blade on to the laryngoscope handle and this functioned quite adequately as a laryngoscope. The important pint being that the tip finishes up proximal to the epiglottis. The curve, although convenient when intubating with naturally curved tubes, is not of primary importance as I emphasized subsequently.”Although, as manifested in this letter, Sir Robert Macintosh did not consider the shape or curve of the blade of primary importance, the use of a curved blade may often avoid jeopardizing the patient's upper teeth, as it makes it unnecessary to pass the straight blade of the standard laryngoscope beyond the epiglottis.7We consider that in an historical review about laryngoscope, the one designed by Sir Robert Macintosh in 1943, which is still nowadays the most common currently used blade, deserves a bit more mention, as it not only lessens the chance of damage of the patient's upper teeth but also allows a correct visualization of the vocal cords, which was sometimes more difficult with the previously existing models.* Hospital de Sant Pau, Barcelona, Spain. mcunzueta@telefonica.net