Fearful of complications, most surgeons delayed the potentially life-saving tracheotomy until a patient was moribund, despite the knowledge that irreversible organ damage would have already occurred by that time. This began to change in the early 19th century, when the tracheotomy finally began to be recognized as a legitimate means of treating severe airway obstruction. In 1832, French physician Pierre Bretonneau (1778–1862) employed tracheotomy as a last resort to treat a case of diphtheria.[29] In 1852, Bretonneau's student Armand Trousseau (1801–1867) presented a series of 169 tracheotomies (158 of which were for croup and 11 for "chronic maladies of the larynx").[30] In 1871, the German surgeon Friedrich Trendelenburg (1844–1924) published a paper describing the first successful elective human tracheotomy performed to administer general anesthesia.[31][32][33][34] After the death of German Emperor Frederick III from laryngeal cancer in 1888, Sir Morell Mackenzie (1837–1892) and the other treating physicians collectively wrote a book discussing the then-current indications for tracheotomy and when the operation is absolutely necessary.[35]