TECHNIC OF TRACHEOTOMY A tracheotomy set contains: one scalpel for the skin-incision, one surgical and one anatomical forceps for separating the connective tissue, One grooved director for raising the fascia, two blunt hooks with several teeth for holding apart the layers of tissue, two sharp tenacula for hold ing up the trachea, one sharp-pointed knife for opening the trachea, one blunt-pointed knife for enlarging the tracheal opening, two or three eannulas with movable shields, as suggested by Luer or Ilagedorn, or two plain cannulas, as suggested by Bruns, artery forceps, scissors.
The patient should be wrap ped in a blanket (as for intuba tion) and then laid on a table with the neck put gently on the stretch, which may be conven iently accomplished by wrap ping a bottle or other article in a towel and placing it under the nape of the neck. An assistant should have charge of the amesthetization—which is super fluous with a high degree of carbon dioxide poisoning—and he should also watch carefully to prevent any lateral displacement of the neck. The preliminary steps of cleansing are the same as for every cutting operation. The incision, as with all subsequent separa tion of tissues, should be in the median line; extending for at least five centimetres, in superior tracheotomy to the thyroid isthmus, in inferior tracheotomy to the sternum. The subcutaneous connective tissue is to be torn apart with blunt instruments, such as closed hemo static forceps, the next step being, with the help of a grooved director, to divide the superficial cervical fascia and the linen. alba of the sterno hyoid muscles, visible through it. The next steps depend on whether the tracheotomy is high or low. In high tracheotomy, the deep cervical fascia lying directly under the muscles must be separated by a trans verse incision from the lower edge of a tracheal cartilage and then bluntly dissected from the trachea and drawn downwards with the thyroid gland enclosed in it, thus laying bare the trachea.
If the low tracheotomy is being done, the separate layers of the cer vical fascia arc to be divided longitudinally on a grooved director until the thyroid gland is exposed. After division of the lowest layer, the partly exposed trachea is to be drawn up by two tenacula and freed from any remaining areolar tissue. A pointed scalpel is now introduced into the trachea until a whistling sound tells that the lumen is opened, when the incision is to be enlarged sufficiently (1 to 1.5 cm.) to admit
the cannula. (In a low tracheotomy the opening is to be placed as high as possible.) As soon as respiration is easy, the cannula is to be intro duced and held in place by tapes around the neck. The wound should be carefully dusted with iodoform and protected by lint or rubber pro tective from the tracheal mucus.
Difficulties may arise during the operation from a large or adherent thyroid gland, a large thymus, numerous distended veins and rarely also from arterial anomalies.
After forty-eight hours the cannula should be changed for a clean one. To prevent collapse of the soft. parts they should be held up with tenacula, and an elastic catheter (with lateral holes) should be intro duced through the cannula into the trachea, to serve as a guide for the removal of the old and the introduction of a fresh one. After a day or two a speaking cannula may be introduced and by closing the external aperture a test may be made of the degree of patulousness of the larynx. When the child has slept quietly at night with a closed speaking cannula, then it may be entirely dispensed with and the wound allowed to heal under an occlusive dressing.
Following a secondary tracheotomy after a long intubation, it is wise to hasten removal of the cannula as much as possible, in order that the breathing in the natural way with the air-pressure which this exerts in the larynx may hinder the formation of a stricture (v. Ranke).
When extreme peril exists, Fischl's instantaneous method may be followed by which after the deep cervical fascia is reached, the trachea is drawn forward by two tenacula, and opened by one cut passing through all the soft parts including the isthmus of the thyroid. The eannula, held ready, is immediately thrust into the gaping opening, only the cannula ending in a closed point being suitable. Pressure controls the bleeding which starts as respiration is established. Even quicker is the procedure of L. G. Simon and Schinzinger which consists of fixing the trachea against the vertebral column and opening it with one single inci sion through skin and soft parts. The index finger of the left hand is immediately pressed into the wound to check the bleeding while the cannula is guided along the nail as the finger is withdrawn.
Less dangerous than this mode of tracheotomy is cricotomy, which, however, has the disadvantage that it always causes speech-defect, an interference with the formation of the voice.