Anatomy of the Larynx and Trachea and the Position of Incisions for the Operations in this RegionFig. 268. Anatomy of the Larynx and Trachea and the Position of Incisions for the Operations in this Region.A, Subhyoid pharyngotomy;B, Thyrotomy;C, Infrathyreoid laryngotomy;D, ‘High’ tracheotomy;E, ‘Median’ tracheotomy;F, ‘Low’ tracheotomy; 1, Platysma; 2, Crico-thyreoid muscle; 3, Sterno-hyoid muscle; 4, Isthmus of thyreoid gland; 5, Sterno-thyreoid muscle; 6, Sterno-mastoid muscle; 7, Crico-thyreoid artery; 8, Anterior jugular vein; 9, Inferior thyreoid vein; 10, Innominate artery; 11, Right innominate vein; 12, Left innominate vein.
(a)The isthmus of the thyreoid gland, which varies greatly in size. It may be either a thin band with few vessels of importance, covering the second, third, and fourth tracheal ring; or hypertrophied and vascular, extending higher in the neck even to the front of the cricoidor thyreoid cartilage. This condition also results when a pyramidal lobe is present.
(b)The pretracheal fascia, which encloses the isthmus of the thyreoid gland and, when traced upwards, finds attachment to the anterior aspect of the cricoid cartilage, thus forming the suspensory ligament of the isthmus. Passing downwards it covers the anterior surface of the trachea, and, though somewhat indefinite, can easily be traced behind the sternum as far as the pericardium, with which it blends. This is a point of great practical importance in determining the extension of inflammation into the mediastinum.
(c)Veins.Small transverse branches of the superior thyreoid veins run upon the upper border of the isthmus between the layers of the fascia which surround this structure. The inferior thyreoid veins, larger in size, run from the lower border of the isthmus vertically downwards in front of the trachea to communicate with the left innominate; in their upper part they may consist of several small veins which join together to form two main branches, of which the left may lie directly in the middle line; small communicating branches of these veins run transversely across the lower border of the isthmus. The left innominate vein crosses the front of the trachea somewhat obliquely, and may lie at least half an inch above the suprasternal notch.
(d)Arteries.The crico-thyreoid artery runs transversely across the crico-thyreoid space, being placed in front of the suspensory ligament, and gives off numerous branches, which enter and supply the interior of the larynx, as well as small descending branches which run to the isthmus of the thyreoid gland. A small branch of the inferior thyreoid artery is also constantly found behind the isthmus, and in rare instances a thyreoidea ima branch of the innominate, varying greatly in size, may pass upwards in front of the trachea.
In young children the same relations are found, but with certain differences. Owing to the larynx being relatively high in the early years of life, the length of the cervical portion of the trachea is almost 2 inches when the head is extended, and the bifurcation is considerably higher than in the adult; further, the trachea is more movable and is smaller in diameter. The laryngeal cartilages are difficult to distinguish, but a mass composed of the thyreoid and cricoid cartilages can always be felt, and its position determined by careful inspection. It is very important to remember that, even when the head is extended, the cricoid cartilage lies rather less than 2 inches above the upper margin of the sternum. In very young children it is common to find two transverse creases in the skin, of which the upper usually lies over the upper border of the thyreoid and the lower over the cricoid cartilage.The lower crease thus assists in determining the upper limit of the trachea.
The anterior jugular veins in young children are comparatively large; the infrahyoid muscles are less defined and more difficult to recognize; and the isthmus of the thyreoid gland is very broad, appears to be part of the lateral lobes, and occupies a higher position in the neck, often passing in front of the crico-tracheal membrane as well as the first and second tracheal rings. The inferior thyreoid veins are larger, more numerous, and more difficult to separate; the left innominate vein is somewhat higher in the neck; the thymus gland, which gradually decreases in size with the increase of age, may extend into the neck, in front of the trachea, and may even reach as high as the isthmus of the thyreoid; the fasciæ are softer and less definite, and the fascia which covers the trachea is easily stripped from its surface.
Operation.As local anæsthetics are of little practical value in the case of children, the surgeon must decide whether a general anæsthetic shall be used; for any nervousness on his part increases the danger of death upon the table. A general anæsthetic is not necessary, but undoubtedly has certain advantages: the operation is easier and can be performed more rapidly; the patient is more likely to fall asleep; and any vomiting that occurs is beneficial rather than harmful. On the other hand, children suffering from diphtheria are apt to die suddenly under chloroform; and it should never be administered when there is any sign of heart failure, when obstruction is very marked, when cyanosis is present, or when the patient is prostrate. The danger has probably been exaggerated, and depends more upon the experience of the anæsthetist than upon the actual disease; in my opinion it is as a rule safer to employ a small quantity of chloroform, which should be given on the operating table after everything has been prepared. The child should be allowed to choose its own position, generally curled up on one side, and the administration must be slow. By observing these precautions it usually happens that the child becomes quiet, and that with the loss of consciousness the breathing improves; the child can then be placed in the proper position, and the more difficult part of the operation can be completed before restlessness returns.
The instruments required are: a small scalpel, scissors, two dissecting forceps, three or more fine-pointed pressure forceps, two double hook retractors, one blunt hook, an aneurysm needle, and a suitable dilator for the wound; some form of aspiration apparatus may also, in rareinstances, be necessary (Fig. 278). Three or four tracheotomy tubes such as described by Parker, and a small tube containing sterilized catgut, which is eminently suitable for the tying of vessels, and for that purpose preferable to silk, should also be in readiness. All the instruments should be kept together in a metal case, as well for private as for hospital practice, so as to be ready in case of emergency. They should be boiled for at least twenty minutes both before and after each operation, and should be laid out separately upon a dry sterilized towel in the position selected by the surgeon.
Tubes for TracheotomyFig. 269. Tubes for Tracheotomy.A, Parker’s;B, Durham’s;C, Baker’s rubber tube.
Tracheotomy tubes may be made of silver, rubber, vulcanite, celluloid, or a gum-elastic material, but most surgeons prefer a silver tube in the early stages of treatment. An angular form should be used, for ‘with the ordinary quarter circle tube, the lower extremity tends to impinge on the anterior wall of the trachea, and this is attended with many inconveniences and even with grave risks’ (Parker27). A movable shield is equally important, and this should be flush with the neck in order to avoid the possibility of its being removed by the patient. Further, the tube should consist of two parts—an outer tube to which the shield is attached, and an inner tube which projects slightly beyond the outer and can be removed for purposes of cleaning. To encourage breathing through the larynx, a window may be added in the upper part of the tubes. Parker’s tube, which meets all the above requirements, is the one most commonly used in England. When longer tubes are necessary, either Durham’s or Stewart’s is recommended: in these, the position of the shield can be altered, and the length of the tube arranged, to suit the patient. In cases of long duration the use of rubber tubes such as Morrant Baker’s is indicated. An introducer is rarely necessary except for rubber or long tubes. As taper and bivalve tubes are liable to injure the trachea, their use is not advised. The tube chosen should fit loosely,and should project far enough into the trachea to be secure from slipping out during coughing or struggling. Short tubes are preferable, and the wider the tube the easier the breathing and the better the drainage. The approximate diameter of the trachea varies at different ages, and the size of tube suitable in each case varies chiefly according to the trachea, but partly also according to the fatness of the neck. The accompanying table indicates the appropriate dimensions.
Table showing Size of Trachea and of Tube required at Different Ages
Age.Approximatediameter of trachea.Approximatediameter of tube.Number of tube.Parker’sDurham’s6 months4 mm.04 mm.16—1½–2 years6–8 mm.07 mm.2012–4 years8–10 mm.08 mm.2424–10 years10–12 mm.09 mm.28310–20 years12–19 mm.10 mm.304
Tracheotomy, even under favourable circumstances, is attended bymany difficulties; the urgency of the case, the restlessness of the patient, the movements of the larynx, the frequent absence of a proper operating table and equipment, the importance of a good light, of sensible assistants, of a trained nurse, and, above all, of a calm disposition, make this one of the most anxious and difficult operations in surgery, yet there is no medical man who may not be called upon to perform it.
It is important to make the best possible preparations. A table of suitable height can usually be improvised and placed in a good light. If the operation be at night, gas lamps or candles can be used, and the illuminant should be placed in a definite position rather than held by the parents. The child should be wrapped in a large towel in order to control the movements of the arms, body, and legs, and should then be placed upon the table; it is advisable to leave him in ignorance of the operation, whatever his age, until the last moment. The skin of the neck should be rapidly washed or sponged with ether, and the head extended over a small pillow or rolled towel. The operation must never be commenced until the proper position is obtained; on the other hand, extension of the head should not be too great for fear of increasing the dyspnœa. Three assistants are preferred—one to hold the head firmly in the middle line so that the point of the chin is exactly in line with the suprasternal notch (this is probably the anæsthetist), a second to hold the body at the opposite end of the table, and a third to assist the surgeon with sponges or retractors. It should be the duty of the last named to prevent any membrane or pus from being coughed over the principals after the trachea has been opened.
There are four varieties of the operation, viz.:
1.Crico-tracheotomy(with division of the cricoid cartilage).
2.High tracheotomy(involving section of the trachea above the isthmus of the thyreoid gland).
3.Low tracheotomy(section of trachea below the isthmus of the thyreoid gland).
4.Median tracheotomy(section of trachea through the isthmus of the thyreoid gland).
Crico-tracheotomyis an easy operation owing to the superficial position of this portion of the air-passage, but is inadvisable for the following reasons:—
(1) The larynx being narrower than the trachea, a smaller tube is required; (2) the swelling of the mucosa often extends downwards and causes constriction of this region; (3) the tube is not well tolerated; (4) pressure ulcers, necrosis of the cricoid, and granulations are frequent complications; and (5) retained tube is more common than with other operations, this really being the most important consideration. The comparative value of the remaining operations is largely a matter of opinion.
It is not uncommonly stated that tracheotomy is better done by touch than by sight: the object to be achieved is to find the trachea, and there are two methods of doing this. The first is thedeliberate method, suitable for patients in good condition when there is no urgent dyspnœa; it can be performed entirely by sight, and the greater the experience of the surgeon the fewer his difficulties. In such cases skilful technique is of far greater value than haste. The high operation is preferred, because the trachea is more superficial, less movable, and easier to find; it has less complicated relations, the blood-vessels are less numerous, the fasciæ are not so loose, the tube is easier to fit and unlikely to slip out, healing of the wound is more rapid, and complications seldom occur. In cases where the isthmus is very broad or highly placed, so that the upper parts of the trachea and cricoid are covered, a median operation is recommended. Low tracheotomy is rarely necessary.
The second is therapid method, to be applied in cases of emergency. Turner, of the South Eastern Hospital, strongly advocates such an operation without an anæsthetic. The incision made is from ½-5/8 of an inch in length, this being repeated without attention to the bleeding until the trachea is reached. The latter is opened in the usual manner. The tip of the finger is placed in the wound in order to control the hæmorrhage, and as a guide to the dilators. When these have been introduced, the child is at once drawn beyond the end of the table so that the head hangs downwards. The bleeding usually ceases in a few moments, though insome cases the tube is inserted to control it. The advantages claimed for this method are that the operation is quicker, and that no distinction between ‘high’ and ‘low’ is required. The wound is smaller, there is less danger of sepsis, and the eventual scar is hardly visible; no hooks or retractors are used, so that the trachea cannot be displaced. If the wound be in the middle line it is impossible to miss the trachea. This operation is performed entirely by touch, and the bleeding is not considered. Its adoption may be necessary to save the patient’s life, but in the hands of an inexperienced surgeon the operation is attended with great difficulties.
High tracheotomy.The incision must be exactly in the middle line; this can be accomplished easily if the surgeon keeps in mind two important landmarks, namely, the point of the chin, and the suprasternal notch. To determine the upper end of the incision, a point is chosen midway between the anterior borders of the sterno-mastoid muscles at the level of the cricoid cartilage. The thyreoid cartilages being steadied between the fingers and thumb of the left hand, a bold incision is made from the upper point, 1½ inches in length, extending in a young child almost to the suprasternal notch. A long incision is generally preferable, and, when the neck is fat, should commence over the middle of the thyreoid cartilage. The skin and superficial fascia are divided between the two anterior jugular veins, and any bleeding is controlled. The incision is repeated so as to divide the deep fascia lying between the sterno-hyoid muscles, close to one another in the upper part of the incision, and these are separated with the knife. It is now advisable to pause and to seize the bleeding points, allowing the pressure forceps to fall on both sides of the wound to act as retractors. The infrahyoid muscles are separated by at least an inch, and, if retractors are necessary, care must be taken that the muscles alone are included and that the retraction is equal on the two sides. If there has been no ‘tailing’ of the wound the following structures are then exposed from above downwards: the lower border of the thyreoid cartilage, and the front of the cricoid, both easily seen or felt; and a vascular mass, namely, the isthmus of the thyreoid gland, covered by fascia and completely concealing the trachea. The landmark that is required at this stage is the cricoid arch; this should be found, and a small transverse incision should be made along its lower border to divide the suspensory ligament; the handle of the scalpel or a blunt hook is introduced beneath the pretracheal fascia, and the isthmus dragged downwards into the lower portion of the wound, an operation which can be accomplished easily if done without hesitation. The upper rings of the trachea are now exposed; and, unless the superficial veins have been divided, there should be no bleeding. The tracheashould not be opened until it has been exposed completely and all bleeding has been arrested. It is unnecessary to ligature the vessels at this stage unless the forceps have been so placed as to interfere with the part of the trachea chosen for section, or an artery of considerable size is encountered; in the latter instance there is a danger of subsequent hæmorrhage if the ligature is applied close to the tube. While the trachea is being opened, it is necessary to overcome the movements of the larynx by grasping the cricoid with the finger and thumb of the left hand. The scalpel should be gently stabbed into the middle of the trachea to ensure puncturing the mucous membrane as well as the outer wall, and the opening should be quickly enlarged in an upward direction until three rings have been divided, preferably the first, second, and third. It is imperative that this incision should be in the middle line, should not be too small, and should only pass through the anterior tracheal wall; if force be used there is danger of puncturing the œsophagus, or even of striking the bodies of the vertebræ.
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 waterysolutions, 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 blowingthrough 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.’
After-treatment.Although this is a subject which has produced a great deal of discussion, there is a widespread impression among the younger members of the profession that it is of little importance. Much has been said about the dangers of interference, and any suggestion put forward has been criticized by those who have had large experience, with the result that confusion is prevalent. As a matter of fact, the subject is one of the greatest importance, for there is no operation in surgery in which the after-treatment can be neglected. Care should be exercised in choosing a nurse who has special knowledge of children and of the after-treatment of tracheotomy. Great discretion is required in the management of such cases, and there is little doubt that harm may result where too much attention is shown. At many of the hospitals a special nurse is appointed for attendance on the more desperate cases only. The main duty of the nurse is to watch the child, for any difficulty in breathing requires immediate attention. It is necessary that she should understand the proper management of the tube; she must see that the inner tube never becomes clogged, and if the tube slips out of the trachea it must be reintroduced or a dilator inserted; she must also be responsible for the feeding of the child. The difficulties that arise during the first few days after operation call for much tact and experience.
It is unnecessary to enter here into the discussion about food, stimulants, or general treatment, except to point out that swallowing may be very difficult. The food must be nourishing, fluid being in most cases preferred; occasional sips of water should be administered to find out whether coughing is produced, in which case nasal feeding can be advised without hesitation. A short rubber catheter should be passed through the nose at regular intervals according to the nature of the case. As a general rule a small quantity of nourishment should be given every two hours, studying, as far as possible, the likes and dislikes of the patient. By the observance of these principles the child soon becomes tolerant, and proper nourishment can be administered, thus removing one of the great difficulties of after-treatment.
The atmosphere of the room.The value of steam for producingwarmth and moisture is undoubted; the amount required depends on the case. The main object to be kept in view is to encourage secretion from the mucous membranes, and so to prevent the formation of crusts. When secretion is scanty a large amount of moisture is required, andvice versa; also, when much pus is present, extra moisture is of value to prevent it from becoming dried and to allow it to be expectorated. The value of disinfectants is doubtful, but on general principles it may be said that the more septic the secretion the greater the indication for their use: tincture of benzoin, oil of eucalyptus, and thymol act as sedatives; carbolic acid, creosote, and numerous other drugs are useful disinfectants; soda and potash, recommended by R. W. Parker, tend to liquefy the exudations. Steam, however, is more important than all these, and should be advised as being likely to encourage the quicker healing of the wound: even in catarrhal conditions improvement is more rapid when this practice is adhered to.
The most important point in the after-treatment, however, as far as the surgeon is concerned, is to prevent recurrence of the obstruction. Obstruction is most often due to the blocking of the inner tube by secretions, a condition easy to recognize from the symptoms which are produced. The inner tube should be removed, thoroughly cleaned, and reintroduced. This usually suffices to allow the child a period of quiet breathing, and sleep may be obtained. To keep the tube free it is very necessary to repeat the removal at regular intervals. In those cases where the secretion is tenacious, the tube constantly becomes blocked, but it is better to remove it again than to allow a feather to be passed. Nothing is gained by attempting to hurry the separation of crusts, and the passage of a feather tends to force downward far more than can be extracted, and so to increase the danger of broncho-pneumonia. If dyspnœa continues after removal of the inner tube, a spray should be used, or a small amount of fluid should be dropped into the trachea to moisten the secretions.
Changing the outer tube rarely presents any difficulty because the tissues of the neck soon become matted together, a funnel being thus produced along which the canula is introduced with ease. A new tube should be prepared before removal of the old, and dilators should be at hand for use if the child is frightened, struggles, or coughs: the canula should be introduced quickly and without hesitation, sufficient force being employed to overcome any obstruction. Unless the original opening in the trachea was too small, it should be possible to introduce a tube equal in size to that which was removed. Frequent changing of the outer tube should be avoided.
The time for removing the outer tube.In every case of diphtheriathere is a certain amount of catarrh, with swelling of the mucosa, increased secretion, and some difficulty of breathing. In addition, the habit of breathing through a canula is difficult to alter; the child shows an aversion to breathing through the natural air-passages, and is often frightened or bad-tempered. As soon as the secretion becomes small in amount and serous rather than purulent in consistence, an attempt should be made to discard the tube: the canula should not be retained a day longer than is necessary, the usual period varying from five to fifteen days. Various methods may be adopted:—
1. If the outer tube be provided with a window, the tip of the finger can be placed on the opening to compel the child to breathe through the larynx; breathing may be difficult, but by this means an indication can be obtained as to whether it is advisable to persist.
2. If the above method be successful, the tube may be removed. A small pad of gauze is placed over the wound and the child further encouraged to breathe through the larynx. Expiration is generally easier than inspiration, and older children should be encouraged to blow out a candle or to sound a whistle, this process being continued so long as the child can endure it, but not to the stage of exhaustion. It is often possible to remove the tube at the first attempt.
3. The canula may be plugged with a cork which the nurse removes when necessary: it is often possible to replace the plug while the child is asleep without his becoming conscious of the fact, thus showing that the dyspnœa is largely mental.
4. In some children breathing is easy so long as the tube is simply plugged and is not removed; in such cases the canula can be replaced by a shield and a plug which does not pass into the trachea. This may completely deceive the child.
5. The silver tube can be changed for one of rubber, and this can be shortened daily until nothing remains but the shield.
If these various methods have been tried with no success it is probable that the case is abnormal, but before this can be conceded it is necessary to repeat that, in the large majority of cases, the difficulty of removing the tube is due not so much to definite stenosis of the larynx as to the bad habit acquired by the patient.
Complicationsarising after tracheotomy and preventing removal of the tube:—
Trachea showing Ulceration caused by a Badly Fitting TubeFig. 270. Trachea showing Ulceration caused by a Badly Fitting Tube.A, Tracheotomy opening;B, Ulcer caused by the end of the tube. (From Specimen No. 1659a in the Museum of St. Bartholomew’s Hospital.)
1.Wound infection.This rarely occurs at the present time, and diphtheritic wounds are seldom seen. Some inflammation of the wound is natural under the conditions, and may be associated with œdema of the surrounding tissues; this generally yields to antiseptic treatment in a few days. In very weakly children suffering from a virulent formof disease the healing of the wound may be slow, and septic conditions are apt to arise ending in cellulitis of the neck or even typical erysipelas. Owing to the disposition of the fasciæ there is a tendency for the infection to spread in a downward direction, and for mediastinal inflammation or suppuration to occur: this appears to be more common after low tracheotomy. The prognosis in such cases is not good, and every endeavour should be made to prevent the possibility of their occurrence by absolute cleanliness at the operation and by suitable after-treatment of the wounds.
2.Septic conditionsof the trachea are less common since the introduction of antitoxin, but occur in cases where false membrane is abundant. There may be swelling of the mucosa, or copious discharge which persists for long periods.
3.Ulcerationmay be due to sepsis or to pressure from a badly fitting tube, especially when the latter has been worn for a protracted period (Fig. 270). It may cause perforation and localized abscess either in front of the trachea or in the neighbourhood of the œsophagus, and may result in a communication with the latter. In the region of the cricoid, ulcers are liable to cause necrosis. The signs of such ulceration are: continuance of purulent discharge, discoloration of the tube, bleeding from the wound, and, above all, difficulty in removing the tube.
At the first indication of ulceration the cause of irritation should be removed. It is advisable to discard a metal in favour of a rubber tube, or, if possible, to remove the tube altogether. Strenuous efforts must then be made to disinfect the trachea by the insufflation of antiseptics, either as powders or in solution. The healing of such ulcers is very slow, and granulations are apt to form resulting in obstruction and preventing removal of the tube. In later stages contraction of fibrous tissue causes stenosis; this is more common in the neighbourhood of the cricoid, especially when the latter has been divided at the time of the operation.
4.Granulations.The possible presence of granulations must always be borne in mind. I believe this condition is far less common than is generally supposed, and that in many cases the granulations are entirely limited to the neighbourhood of the wound, where they can be seen. It is doubtful whether they are responsible for the dyspnœa which occurs. Great ingenuity and patience are required for the treatment of this condition. The wound must be kept scrupulously clean and all source of irritation removed. A rubber canula should be substituted in place of a metal one; if it were possible it would be advisable to discard the tube altogether, but as yet no form of dilator has been devised which will take the place of the canula. If the granulations be large they should be removed either with a sharp spoon or with suitable forceps, the area having been anæsthetized previously by a small quantity of the novocaine and adrenalin mixture. When small, the use of silver nitrate is preferable. It may be necessary to repeat this after a few days, and as soon as seems advisable a further attempt should be made to dispense with the tube. At this stage time must be allowed for the various tissues to regain their normal condition. Should this treatment prove unsuccessful, a thorough investigation must be made under chloroform. The wound is enlarged as far upwards as the cricoid, bleeding being arrested with the mixture just described. By throwing a strong light into the wound, the condition of the mucous membrane can be inspected and granulations removed. If there be no granulations in the trachea, a tube speculum can be passed through the mouth to ascertain the condition of the larynx (seep. 480). Such a method of procedure is preferable to the passage of probes, forceps, sponges, and other articles through the larynx, in the hope that any obstruction may be removed. If ulceration or necrosis of cartilage be discovered, it is impossible to relieve the condition by surgical means without prolonged treatment with tubes and the constant use of antiseptics. Under these conditions it is advisable to consider the removal of the tracheotomy tube in favour of intubation. In the hands of many foreign authorities the use of intubation tubes covered with gelatine, in which antiseptic is introduced, has been attended with such conspicuous success that further attempts should be made in this country; there is little doubt that, as our knowledge of the treatment of such wounds improves, better results are daily attained. Whatever treatment is considered it is important first of all that the actual cause should be distinguished. This is now possible owing to the great advances made in methods of examining the larynx.
Stenosis following TracheotomyFig. 271. Stenosis following Tracheotomy.(From Specimen No. 1659d in the Museum of St. Bartholomew’s Hospital.)
5.Stenosisof the larynx or trachea occurs in old-standing cases, as the result of ulceration, after some cases of crico-tracheotomy, and especially where a tube has been worn for a very protracted period.Breathing through a tube, if continued for a long time, interferes with the natural growth of the air-passage above it. The child grows, but the larynx remains stationary. This condition is aggravated by the fact that some inflammation is constantly present, especially in the neighbourhood of the wound, so that the tissue become fibrous and hard. The fibrous tissue contracts and stenosis is caused. According to von Bruns, Kohl,28and others, constrictions of the trachea may in rare instances result from some kinking of its wall. Such conditions as a bulging of the posterior wall due to the approximation of the posterior ends of the cartilage secondary to the spreading of the anterior portions, inversion of the tracheal margins from too small an incision, overlapping of the tracheal wound, and cicatricial union between the thyreoid and cricoid, must be exceedingly rare. Here, again, a definite diagnosis can always be made by proper investigation, but treatment is more difficult. Dilatation must be attempted by either continuous or intermittent methods. If preferred, a short piece of rubber tubing can be passed upwards from the tracheotomy wound into the larynx and kept in place for several hours by two silk sutures, one passing out of the tracheal wound, the other out of the mouth; or a stenosis canula can be inserted with some form of hollow plug which passes upwards into the larynx (Fig. 272). The question whether the tracheotomy wound should be kept patent is difficult to answer. When stenosis is extreme there is no alternative, and the open wound allows of the constant passage of graduated bougies, which is more easily accomplished from below than from above. If treatment be persistent the prospect of a good result is not unfavourable, and there is every reason to believe that in the future the number of cases which require a permanent tracheotomy tube will be reduced to a minimum.
Tubes used in the Treatment of Stenosis of the LarynxFig. 272. Tubes used in the Treatment of Stenosis of the Larynx.A, Lack’s;B, Störk’s;C, Schimmelbusch’s.
6.Paralysis.In the larynx there may be paralysis of the sensory or of the motor nerves. In the former case food may enter into the trachea and cause troublesome coughing and possibly ‘Schluck-pneumonie’. When the motor nerves are affected, the paralysis is commonly abductor and may be unilateral or bilateral, the latter associated with inspiratory dyspnœa. ‘Complete paralysis of the recurrent laryngeal nerve may also occur, but is nearly always confined to one side’ (C. A. Parker29). Such paralyses may last from a few days to several months, and are very troublesome when associated with the passage of food into the trachea; when severe, nourishment should consist of fluids which can be administered by a nasal tube.
Further complications arising during the after-treatment of tracheotomy:
7.Broncho-pneumonia.This occurs in the worst forms, and is accompanied by high temperature with definite signs in the lungs. The absence of septic discharge, the restlessness of the patient, and the rapidity of the breathing (in many instances accompanied by ‘recession’ not caused by obstruction in the tube) make the condition easy to recognize. There is no satisfactory treatment for septic broncho-pneumonia which has already developed, but it may be prevented. Within recent years it has become less common. This is due to better technique in the operation, and to careful attention during the after-treatment. The habit of passing feathers into the trachea has been abandoned with advantage to the patient. When possible the child should be removed from septic influences which are liable to infect the throat, for theoccurrence of tonsil[l]itis as a sequel to tracheotomy is always to be feared in wards containing septic cases.
8.Emphysemamay occur in the neighbourhood of the wound, or in rare cases may be extensive and involve the whole of the face, neck, and chest. Champneys30was 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.Hæmorrhagemay 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. Kocher31states 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 Bruns32also 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.
Trachea showing Ulceration into the Innominate Artery after Tracheotomy
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.
Aneurism of the Aorta perforating the Trachea
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 paralysismay 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 causedby 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 (Goodall33). 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