This procedure may be modified in accordance with any local indications, and may be made according to the needs of the case. When the opening is made into the trachea below the isthmus it is called a low tracheotomy. Here the anterior part of the trachea lies free from the skin, but may be covered with a plexus of veins connecting with the inferior thyroid. Farther down the arteria thyroidea ima may be encountered. There is always reason for operating as high as the case will permit. The trachea may itself be displaced by the growth which compresses it and necessitates the operation. Thus it may be crowded to one side, other anatomical relations being disturbed, or it may be compressed into scabbard shape, and thus be difficult to find or to open.
The moment the trachea is open more or less marked expulsive efforts will drive blood and foam in all directions, and may for a moment obscure the field of vision. Every precaution should be taken to prevent the entrance of blood into the trachea. Pressure of the tracheal walls against the tube to be inserted may check hemorrhage from its margins. The operator should be ready to suspend all other procedures and make artificial respiration, and he should also be prepared to open the trachea suddenly, should impending suffocation require it.
In a general way, then, the indications for tracheotomy are symptoms of rapidly or slowly threatening obstruction to respiration from causes either within the larynx—e. g., diphtheria, foreign bodies, tumors, and the like—or causes external to it, such as tumors, phlegmons, cicatrices, etc. Any cause which interferes with the free play of air through the respiratory tube, which can be either relieved or atoned for by the operation, will always justify it.
Tracheotomy tubes are mechanical devices for not only keeping the tracheal wound open but permitting the unobstructed passage of air. They are made of various materials, of which silver is the most satisfactory, as aluminum is too easily acted upon by the fluids of the body, and rubber occupies too much space. The tracheotomy tube is a double tube, the inner one slipping easily into and out of the outer, and being necessitated by the ease and abundance with which secretions may collect and dry, and thus obstruct. Were it necessary to remove the entire tube for each cleansing, difficulty might be met in re-introducing it, whereas the inner tube is easily removed, quickly cleansed, and restored to place within the outer without disturbance or pain to the patient.
Aside from the tracheal tubes ordinarily used there are others made exceptionally long, and with flexible lower ends, which may be used in case of tumor low in the neck or high in the mediastinum—for instance, in cases of enlarged thymus, where it is necessary to go beyond an obstruction.
In the after-care of these cases it should be remembered that air passes directly into the lung without being warmed, or moistened, by passage over the mucous membrane of the upper respiratory tract. The patient, therefore, should be kept in a warm room, and the air should be kept moist by the use of a croup kettle or a spray machine. The inner tube should be kept unobstructed, the length of time during which it should remain depending on the nature of the case. So soon as its usefulness is passed it should be removed. A tracheotomy wound kept open but for a day or two will quickly close, but one which has remained open for weeks may close with difficulty, and then there may be trouble from granulation stenosis or cicatricial contraction. (See above under [Stricture].) In instances where a permanent opening is to be maintained it is desirable to remove the tube as early as circumstances may permit.
INTUBATION.
The perfection by Joseph O’Dwyer of a method, at which others had worked, of substituting intubation of the larynx for the old tracheotomy, not only shed the greatest luster upon his own name, but has afforded a speedy and bloodless method of accomplishing much more than had been previously possible by the older procedure. The method comprises the emplacement of a suitably sized and shaped tube within the larynx, by a manipulation guided almost entirely by the sense of touch, for the relief of suffocative symptoms due to disease at this level, and leaving the tube in situ for a sufficient time to permit morbid activity to subside and justify its removal.
It is advisable to have a half-dozen tubes, varying in size from 1¹⁄₂ inches to 2¹⁄₂ inches in length, and of corresponding increase in other dimensions, each of which affords a passage-way for respiratory purposes, and is also provided at its upper end with a flange, which shall rest upon the false vocal cords and prevent the descent of the tube into the trachea below. The complete set of instruments as now furnished by all the manufacturers provides an assortment of these tubes, with a scale indicating which one to use upon a patient of a given age, and includes a mouth-gag, which may be used for many purposes, and two handled instruments—one intended for the introduction, the other for the extraction of the metal tubes.
Fig. 483