He was known for his studies on the uptake and distribution of inhalational anesthetics, as well for defining the various stages of general anesthesia.
During his time, he worked at the American Expeditionary Forces hospitals in Chaumont and Vittels, France.
Guedel taught various medical personnel, from nurses to orderlies, how to manage anesthesia.
He corresponded greatly with his colleague and friend, Dr Ralph M. Waters about inventing a cuffed endotracheal tube.
To show how well the cuffed airway worked, the dog was dunked underwater for one hour.