Makers of Modern Medicine

by James J. Walsh

In 1880, Dr. O'Dwyer began to devise some method of providing a channel for the passage of air and secretions through the larynx. He knew that tracheotomy, as a serious, bloody operation, always is put off until the condition of the patient is quite alarming, if not hopeless, and that some device for holding the larynx open, if not too difficult of application, would surely prove life-saving in a great many cases. His first thought was that the introduction of a wire spring within the larynx might serve to hold the inflamed sides apart. He realized, however, that the edema and false membrane would force their way around the wires, and so gradually occlude the throat passage in spite of the presence of the spring.

His next thought was a small bivalve speculum, that is to say, two portions of tubes cut longitudinally and fastened together in such a way that the ends could be forced apart. Such instruments are used very commonly for the examination of various cavities in the human body. The laryngeal spring, or speculum, was more successful than the wire, but it had one of the faults of the wire spring. Into the slit between the two portions of the speculum the inflamed mucous membrane was apt to force itself, so that before long difficulty of breathing would recur. Besides, if the spring which kept the blades of the speculum apart were weak, the instrument would fail of its purpose in [{331}] keeping the mucous membrane apart, while, if it were strong, the pressure of the blades would cause ulceration.

Notwithstanding its faults, however, the bivalve laryngeal speculum accomplished somewhat of the purpose intended. In one case it kept a child alive until the dangerous period of the disease was passed, and thus was the means of saving the first little patient suffering from membranous croup in the thirteen years that the Foundling Asylum had been in existence. Dr. O'Dwyer continued to experiment with the speculum for some time, but finally gave it up and began to study the detailed anatomy of the human larynx. These studies included not only the normal larynx, but also its conditions under the influence of various pathological lesions. Finally (as one of Dr. O'Dwyer's assistants at that time says), he appeared one day in the autopsy-room with a tube. This tube was a little longer than the speculum that before had been in use. It was somewhat flattened laterally, and had a collar at its upper end. This tube was very soon to prove of practical value.

In the first case in which it was employed it was a failure, inasmuch as the patient died from the progress of the diphtheria, though the notes of the case show that after the introduction of the tube the dyspnoea was relieved and the child breathed with comparative ease for the sixteen hours that elapsed before death took place. To any one who knows the harrowing agony of death from asphyxiation, and who appreciates the fact that this form of death was now to be definitely done away with, the triumph of this first introduction of the tube will be at once clear. Dr. O'Dwyer himself was very much encouraged. The relief afforded the patient was for him a great personal satisfaction, since one of the severest trials to his sensitive nature in the midst of his professional work had always [{332}] been to have to stand helplessly by while these little patients suffered.

The fact that this tube had been retained for sixteen hours demonstrated definitely that the larynx would tolerate a foreign body of this kind without any of the severe spasmodic reflexes that might ordinarily be expected under such circumstances, while the fact that the tube had not been coughed up showed definitely that the inventor was working along the proper lines for the solution of his life-problem. The second case in which the tube was employed resulted in recovery, and Dr. O'Dwyer's more than a dozen years of labor and thought were rewarded by not only relief of symptoms, but the complete recovery of the patient without any serious complications and without any annoying sequelae.

As the first case (alluded to above) is now a landmark in the history of medicine, the details relating to it seem worth giving. The little patient was a girl of about four years of age, who on the fifth or sixth day of a severe laryngeal diphtheria developed symptoms of laryngeal stenosis, with great dyspnoea. Hitherto the only hope would have been tracheotomy, but Dr. O'Dwyer introduced one of his tubes. The little patient was very much frightened and, as might be expected, in an intensely irritable condition because of the difficulty of breathing. She absolutely refused to permit any manipulations, and it was only with great difficulty that he finally succeeded in introducing the tube. After its introduction the little one shut her teeth tightly upon the metallic shield which the doctor wore on his finger for his protection, and he was absolutely unable to withdraw it from her mouth. It was only after chloroform had been given to her to the extent of partial anesthesia, with consequent relaxation of muscles, that he succeeded in freeing himself.

This proved to Dr. O'Dwyer the need of another [{333}] instrument (to be employed in the introduction of tubes)--an apparatus by which the mouth could be kept widely open so as to allow of manipulation without undue interference by the patient. For this purpose he contrived the mouth-gag--a very useful little instrument that has been found of service in many other surgical procedures about the mouth besides intubation.

His first tubes, however, were not without serious defects. For instance, in order to permit of the extraction of the tube afterward, there was a small slit in the side of the tube, into which the extractor hooked. Into this slit the swollen and edematous mucous membrane was apt to force its way, and (as can readily be understood) in the removal of the tube considerable laceration in the tissues usually was inflicted. Accordingly the tubes subsequently made were without this slit. Moreover, the first tubes that were employed were not quite long enough, a defect which led to their being rather frequently coughed up. This inconvenience was not wholly obviated even by the lengthening of them.

O'Dwyer continued his studies, and finally hit upon the idea of putting a second shoulder on the tubes. This, it was hoped, would fit below the vocal cords, and with the cords in between the two shoulders the tubes would surely be retained. This improved tube was actually retained, but the drawback to its adoption (as shown in practice) proved to be that it was retained too tightly. When the time for its removal came it was almost impossible to get it out. It was evident then that some other model of tube would have to be constructed in order to make the process of intubation entirely practical, and thus do away with certain dangers.

One of O'Dwyer's assistants at this time at the Foundling Asylum tells of the amount of time the doctor gave to the [{334}] study of the problem involved in these difficulties and of his ultimate success therein. Putty was moulded in various ways on tubes, which were inserted in specimen larynxes, and plaster casts were taken, with the idea of determining just the form of tube which would so exactly fit the average normal larynx as to be retained without undue pressure, yet at the same time keep the false membrane from occluding the respiratory passages and furnish as much breathing space as possible. Finally Dr. O'Dwyer decided that the best form of tube for all purposes would be one with a collar, or sort of flaring lip at the top, which was to rest on the vocal cord, with, moreover, a spindle-shaped enlargement of the middle portion of the tube, which lay below the vocal cords, fitting more or less closely to the shape of the trachea. To avoid the pressure and ulceration at the base of the epiglottis--a very sensitive and tender portion of the laryngeal tissues--a backward curve was given to the upper portion of the tube. On the other hand, the lower end, which rests within the cricoid ring and which was likely to be forced against the mucous membrane of the trachea occasionally, was somewhat thickened to avoid the friction and leverage that might be exerted if there were any free-play allowed. At the same time the lower end of the tube was thoroughly rounded off.