A System of Operative Surgery, Volume 4 (of 4)

by Unknown

At the moment when the trachea is opened there is a sudden rush of air out of the lungs. This is reassuring to the surgeon, and at this point the dilator should be introduced and the anæsthetic abandoned. Temporary cessation of breathing is common after the first inspiration, but the great improvement in colour shows that there is no cause for alarm; with the return of consciousness the child begins to cough, and this has two results, partly clearing the tubes of mucus, pus, or membrane, and partly promoting deeper inspiration and better expansion of the lungs. Cyanosis is thus speedily removed, unless membrane is abundant; and even where this is the case, it is advisable to encourage coughing in order to dislodge the membrane, which can be grasped with forceps or caught with a sponge as it appears in the wound. The use of a feather or a soft rubber catheter for irritation of the trachea to promote coughing should be abandoned, as such instruments often displace the membrane downwards. As soon as breathing is regular and the cough allayed, the vessels can be ligatured.

A tube of suitable size having next been selected, the opening in the trachea is widely dilated and the point of the canula quickly inserted into position, the outer tube alone being used, with tapes for tying attached. Unless the tube ‘sits’ well without tilting, different sizes should be tried until the breathing becomes easy, a sure sign that the lower opening of the canula is pointing in the right direction. The tapes are tied firmly on the right side of the neck, after which the inner tube is introduced and fixed in position.

The wound remains to be treated. Various methods have been recommended to guard against infection: the use of antiseptic watery solutions, such as perchloride of mercury, chloride of zinc, carbolic acid, and perchloride of iron, is dangerous; insufflation of powders, on the other hand, such as orthoform, aristol, and the like, is certainly effective in keeping the wound clean, and is better than the employment of an oil emulsion; suturing the wound is unnecessary and is not recommended. A dry antiseptic gauze is applied to the wound and kept in position by the pressure of the shield. Lastly, a thin covering of gauze is placed over the front of the neck, and the patient returned to bed.

Low tracheotomy. The incision should be rather longer than in the ‘high’ operation and should reach almost to the suprasternal notch. The fasciæ, anterior jugular veins, and infrahyoid muscles are treated as before, and there must be no ‘tailing’ of the wound. The landmark required is the isthmus of the thyreoid gland, and its lower border must be determined and dragged upwards by a blunt hook. It is important to remember that the lower part of the trachea lies deeper in the neck and is more difficult to expose owing to the blood-vessels that lie anterior to it; the thymus gland, also, may extend upwards and require to be retracted. Whereas in high tracheotomy practically the whole operation is best done by clean cutting, in the lower operation this is more dangerous, and the deep dissection must be performed partly with forceps or blunt director; if an artery be divided or venous bleeding occurs, it should be controlled immediately. No attempt should be made to perform this operation rapidly owing to the relations of the parts; nor should the trachea be opened before its rings are exposed thoroughly, as complications may arise after imperfect division of the pretracheal fascia. In the opening of the trachea and the further stages, the operation is similar to high tracheotomy.

Median tracheotomy. The child being placed in the required position as before, an incision is made, from the lower border of the thyreoid cartilage almost to the sternum, through the skin and superficial fascia. With a series of cuts, exactly in the line of the original incision, the fascia lying between the pretracheal muscles is divided; the bleeding points are seized with pressure forceps, and retractors are introduced to expose the isthmus. The isthmus itself is treated in one of two ways: in urgent cases it is boldly divided by one or two cuts of the knife; but if time can be spared, a threaded aneurysm needle may be passed under it, first on one side and then on the other, after which the needle is withdrawn, and the two ligatures can be tied so as to leave between them a space of one-third of an inch in which a cut can be made without hæmorrhage. The tracheal rings are thus exposed and can be divided as before.

Accidents. The accidents that occur are less numerous than might be expected when it is considered how often this operation is performed by those who are quite unpractised in surgery; many of them are the direct result of inexperience or arise because the operator becomes confused. If the patient be in a bad position, or if a wrong incision be made, the trachea is difficult to find, and it is better to expose the thyreoid cartilage and prolong the incision downwards until the windpipe has been discovered.

Hæmorrhage, however, is the chief difficulty, and is sometimes unavoidable; it may be arterial or venous. The arteries of this region are generally small, being branches of the superior or inferior thyreoids, and this accounts for the fact that severe arterial bleeding is rare. Nevertheless, the smaller vessels may at times be very troublesome: for instance, the crico-thyreoid artery or one of its branches may be divided, in which case the cut ends will retract and will be difficult to seize; and if the trachea has been opened, blood may continue to enter in sufficient quantity to cause troublesome coughing. Abnormal arteries, such as the thyreoidea ima, are not of great practical importance.

Venous hæmorrhage is far more common, and, taking into account the anatomical relations of the veins, and their great size (increased by cyanosis) in children, it seems remarkable that bleeding is so seldom fatal; in desperate cases a very small amount of blood is sufficient to cause suffocation. Venous bleeding will stop only when respiration becomes free, and this is not possible so long as blood is being sucked into the air-passages. Every effort should be made, therefore, to prevent blood from passing into the trachea, either by hanging the head over the end of the table as soon as the dilators have been introduced, or by introducing a canula against which the walls of the trachea can be compressed.

Failure to breathe, after an opening has been made, is due to either obstruction or collapse and requires rapid treatment. The trachea must be widely dilated, and forceps used to remove any membrane which presents itself in the wound; the assistant must then slowly compress the ribs two or three times to empty the chest and encourage respiration. If consciousness returns, the patient begins to cough and mucus or membrane is expelled from the air-passages. On the other hand, it is useless to continue artificial respiration if the obstruction is not relieved; aspiration must be employed if special instruments are at hand. The fact that a number of surgeons have lost their lives as the result of sucking through a catheter in the attempt to save the child is sufficient to condemn this practice; but good results have been obtained by passing a catheter low down into the trachea and blowing through it with a syringe or even with the mouth. As soon as the trachea has been emptied by one of these methods, artificial respiration should be continued, and collapse treated by injections of strychnine, brandy, or ether. No attempt should be made to introduce a canula until the breathing is restored. As Turner remarks: ‘Heart failure during operation generally recovers with artificial respiration, and twelve hours later the condition is indistinguishable from that of a case who has not so closely approached death. The real remedy against such an accident is never to postpone operation until the heart is exhausted.’