8. Emphysema may occur in the neighbourhood of the wound, or in rare cases may be extensive and involve the whole of the face, neck, and chest. Champneys[30] was the first writer to call attention to this complication of tracheotomy. After a large number of observations and experiments, he was of opinion that emphysema of the anterior mediastinum occurs in a certain proportion of tracheotomies and is of frequent occurrence in cases that are fatal; that it may be associated with pneumothorax; and that the conditions which favour its production are a low division of the deep cervical fasciæ in the neighbourhood of the sternum, combined with obstruction of the air-passages and strong inspiratory efforts; artificial respiration, especially if improperly performed; and want of skill on the part of the operator; further, that the dangerous period of the operation is between the division of the deep cervical fascia and the efficient introduction of the tube. To this may be added those cases in which the tube slips out of the trachea into the cellular tissue above the sternum and thus causes more or less obstruction to breathing. It seems probable that the air is sucked into the cellular tissues beneath the pretracheal fascia, rather from the outside than from the trachea, and that with forced expansion of the chest it finds its way beneath the fascia into the mediastinum.
9. Hæmorrhage may occur as the result of slipping of a ligature during an attack of vomiting or struggling after the operation; it is usually venous and requires nothing but passing notice. Secondary hæmorrhage may result from ulceration into one of the larger arteries or veins. Kocher[31] states that ‘the number of cases recorded is now about eighty-seven, of which fifty-six are associated with the innominate artery. Unfortunately it is not known how often in these cases inferior tracheotomy had been performed. Low tracheotomy was performed in my case because an excision of the larynx for cancer had been undertaken. Doubtless the danger of these fatal complications is much greater with inferior tracheotomy owing to the pressure of the canula.’ Von Bruns[32] also agrees that ‘the vast majority of fatal hæmorrhages were in cases of inferior tracheotomy. Of thirty-six cases in which the source of hæmorrhage was given, twenty-eight were traced to the innominate vein, two to the right carotid, and one each to the superior thyreoid, the left innominate, the right jugular and the left jugular.’ Bleeding is also recorded in cases of aneurism of the aorta, in which tracheotomy has been performed, as the result of erosion of the tracheal wall and the bursting of the sac. Further, troublesome oozing may take place from the mucous membrane of the trachea when this is inflamed, or when granulations are present, or when there is much sloughing of tissues, and especially after a metal tube has been worn for a considerable period. Hæmorrhage from an enlarged thyreoid isthmus is also described. When due consideration is given to the septic condition of the wounds and the close relation of large vessels, it is surprising to find that hæmorrhage proves so seldom fatal.
|
Fig. 273. Trachea showing Ulceration into the Innominate Artery after Tracheotomy. (From Specimen No. 1622a in the Museum of St. Bartholomew’s Hospital.) A, Aorta; B, Ulcer; C, Right subclavian; D, Right common carotid; E, Left common carotid; F, Left subclavian. | Fig. 274. Aneurism of the Aorta perforating the Trachea. (From Specimen No. 1500 in the Museum of St. Bartholomew’s Hospital.) A, Aorta; B, Left subclavian; C, Left common carotid; D, Ulcer in sac of the aneurism. |
10. Cardiac paralysis may also complicate tracheotomy. When supervening in the acute stages of the disease, the patient becomes prostrate and vomiting is persistent, while the heart gradually fails. In other cases death occurs suddenly and unexpectedly, in mild as well as in severe disease; this may happen at any period, during the first days or later, during convalescence. Heart failure is more common in diphtheria than in any other infectious disease which is met with in this country.
Prognosis. It may be said that all cases of laryngitis caused by diphtheria are of a serious nature, and especially those which require tracheotomy (see Table, [p. 517]). The mortality amongst tracheotomized patients during five years was 31.5%, and the variations in each separate year were slight. Such results are far from satisfactory, but it must be remembered that in pre-antitoxin days less than 30% recovered after tracheotomy (Goodall[33]). The use of antitoxin, first suggested by Behring, is undoubtedly responsible for this remarkable decrease in the mortality. The sooner the serum is injected the better the prognosis with tracheotomy. A large dose should be given, 8,000 to 18,000 units, irrespective of age, and the dose may be repeated on the second day if required. Improvement generally commences between twelve and twenty-four hours after injection; the swelling of the mucosa subsides, and secretion is diminished; false membrane is not so copious, and rarely extends to the trachea and bronchi; crusts become less adherent, and are expelled by the patient. In this manner the whole area of the disease becomes clean, and there is less absorption of toxins. It is now generally agreed that serum should be used in all suspicious cases, and some authorities inject at once not only the patient, but also other children living in the same house. It is hoped by early injection to avoid the necessity for tracheotomy.
The age of the patient is very important, as the following table shows:
Table showing Total Diphtheria Tracheotomies performed at the Fever Hospitals in London during 1902–6, including those in which Intubation was previously performed and those in which no Antitoxin was used
| Age. | Times. | Deaths. | Percentage of Deaths. |
|---|---|---|---|
| Under 1 | 0062 | 040 | 64.5 |
| 1–2 | 0256 | 123 | 48.0 |
| 2–3 | 0272 | 087 | 31.9 |
| 3–4 | 0231 | 054 | 23.3 |
| 4–5 | 0196 | 045 | 22.9 |
| 5–6 | 0119 | 019 | 16.0 |
| 6–7 | 0067 | 018 | 26.9 |
| 7–8 | 0022 | 005 | 22.7 |
| 8–9 | 0012 | 003 | 25.0 |
| 9–10 | 0009 | 003 | 33.3 |
| Over 10 | 0016 | 006 | 37.5 |
| Total | 1,262 | 403 | 31.9 |
From these figures it is apparent (1) that children less than one year of age rarely recover after tracheotomy; this is especially true of diphtheria, although in other forms of laryngeal obstruction cases of recovery have been reported in children of six months; (2) that in the early years of life tracheotomy is most commonly needed, especially between the ages of one and five years; (3) that the death-rate gradually decreases between the ages of one and six years, after which there is a rise.
In explanation of these facts it appears probable that after five years of age the larynx and trachea are increased in size, so that obstruction is only met with where there is a large amount of membrane, namely, in the worst cases; in patients over ten, the age which marks the change to the adult type of larynx, the air-passages become so large that obstruction seldom occurs even when much membrane is present; dyspnœa, in these cases, points to extension of the disease to the smaller tubes, and tracheotomy is unable to give the same relief.