CHAPTER IV

INTUBATION OF THE LARYNX

Intubation, or ‘tubage’, was first recommended by Loiseau and Bouchut in France; in 1880 attention was drawn to the subject by Sir W. Macewen in England, and soon afterwards O’Dwyer[37] of New York published articles which resulted in its being extensively tried in America; since that time it has continued to be popular in that country for the treatment of laryngeal diphtheria. ‘The good results which American physicians have secured by intubation may be explained, perhaps, by the circumstance that according to their reports diphtheria takes a milder form in America’ (Tillmanns).[38] Intubation has been extensively used in Europe, especially in Germany, but never to the same extent as tracheotomy, and in England it has been practised at only a small number of hospitals; thus, of the nine M. A. B. fever hospitals in London only three used it regularly during 1906-7, and none of them so often as tracheotomy.

[37] _New York Med. Journ._, 1885, vol. xlii, p. 145.

[38] _Text Book of Surgery_, 1900, vol. ii, p. 625.

=Intubation versus Tracheotomy in Diphtheria.= Since the introduction of the newer method of treatment in 1880 the subject has been widely discussed in America, on the continent of Europe, and in England. There is no evidence to show that treatment with antitoxin has been beneficial to one operation more than to the other.

The _advantages_ claimed for intubation are:

1. No anæsthetic is required.

2. Consent of friends is easily obtained.

3. No cutting: great rapidity.

4. No wound to heal.

5. Tube worn more easily than the tracheotomy tube.

6. Breathing through natural passages, so that warmth and moisture are added to the air.

7. Its earlier performance.

8. Its better results in children under five.

9. Recovery is quicker.

The practical _disadvantages_ are:

1. Quite unsuitable except at special hospitals, as great dexterity and constant practice are necessary.

2. Respiration is interfered with during introduction, so that celerity is indispensable, accidents are frequent, and failure is common.

3. Tube may be coughed up (28%, Goodall[39]), blocked (12%, Goodall), and does not provide good drainage for secretions.

4. Swallowing difficult.

5. Complications common: Broncho-pneumonia, ulceration, cicatrization.

6. After-treatment difficult and constant watching required.

7. Necessity for secondary tracheotomy (32.6%), which has a greater mortality (death in 46.1%, see table below).

8. Retained tube.

[39] _Edin. Med. Journ._, 1902, p. 235, ‘Observations on Intubation of the Larynx.’

In considering the above it is the obvious duty of the surgeon to advise what he considers the better operation for the case, and this must depend largely upon the amount of his experience; the argument that the operation is superior because it can be previously practised on the cadaver is a bad one, and implies a failure to realize the many difficulties which will be encountered in the selection of cases, the operation itself, and its after-management.

I am strongly of opinion that the operation ought not to be tried indiscriminately by those who have no knowledge of these difficulties. In the hands of an expert it is a justifiable method of treatment which is suitable for selected cases, and it is one which can be used early; tracheotomy, on the other hand, is naturally delayed, or used for serious cases and those which have not derived relief from intubation.

Although intubation has received extensive trial, the published results show great variations and do not prove that intubation is superior to tracheotomy, but rather the reverse.

TABLE SHOWING DETAILS OF CASES DURING 1906 AND 1907 AT THE M. A. B. HOSPITALS WHERE INTUBATION IS FAVOURED

+-------+------------+------------+------------+------------+ | |_Intubation | _Both |_Tracheotomy| _Total | | | only._ |operations._| only._ |operations._| +-------+---+---+----+---+---+----+---+---+----+---+---+----+ | |_C |_D | |_C |_D | |_C |_D | |_C |_D | | | | a | e | | a | e | | a | e | | a | e | | | | s | a | | s | a | | s | a | | s | a | | | | e | t | %. | e | t | %. | e | t | %. | e | t | %. | | | s | h | | s | h | | s | h | | s | h | | | | ._| s | | ._| s | | ._| s | | ._| s | | | | | ._| | | ._| | | ._| | | ._| | +-------+---+---+----+---+---+----+---+---+----+---+---+----+ |Eastern| 78| 4| 5.1| 44| 19|43.1| 30| 13|43.3|152| 36|23.6| |Western| 25| 7|28.0| 10| 4|40.0|126| 41|32.5|161| 52|32.2| |Park | 31| 3| 9.7| 11| 7|63.6| 16| 11|68.7| 58| 21|36.2| +-------+---+---+----+---+---+----+---+---+----+---+---+----+ |Total |134| 14|10.4| 65| 30|46.1|172| 65|37.7|371|109|29.3| +-------+---+---+----+---+---+----+---+---+----+---+---+----+

Certain points in the table deserve attention:

1. In cases treated by intubation only, the results are excellent, namely, death in 10.4%.

2. In cases where tracheotomy was afterwards performed the mortality is high, _i.e._ 46.1%.

3. Where tracheotomy was the original operation the mortality is also high, _i.e._ 37.7%.

4. The total operations at these hospitals taken together show a rather higher mortality than appears in the table below.

As regards the first three points, the facts are the same as in any published statistics dealing with the relative advantages of the two operations. I wish to emphasize that the results obtained by intubation depend very largely upon the selection of the cases and I agree with Turner and Cuff that, in order to arrive at any conclusion in the matter, it is necessary to compare the total results of those hospitals where intubation is favoured with those of the hospitals where tracheotomy is chiefly employed.

TABLE SHOWING COMPARATIVE RESULTS AT ‘INTUBATION’ AND ‘TRACHEOTOMY’ HOSPITALS

+-------+------------------+--------------------+-----------------+ | | _Three | _Six | _Total | | | ‘Intubation’ | ‘Tracheotomy’ | Cases._ | | | Hospitals._ | Hospitals._ | | +-------+------+-----+-----+--------+-----+-----+-----+-----+-----+ | | _C | _D |_M p | _C | _D |_M p | _C | _D |_M p | | | a | e | o e | a | e | o e | a | e | o e | | | s | a | r r | s | a | r r | s | a | r r | | | e | t | t | e | t | t | e | t | t | | | s | h | a c | s | h | a c | s | h | a c | | | ._ | s | l e | ._ | s | l e | ._ | s | l e | | | | ._ | i n | | ._ | i n | | ._ | i n | | | | | t t | | | t t | | | t t | | | | | y ._| | | y ._| | | y ._| +-------+------+-----+-----+--------+-----+-----+-----+-----+-----+ | 1902| 76 | 23 | 30.2| 222 | 71 | 32.0| 298| 94 | 31.5| |[1]1903| | | | | | | | | | | 1904|156 | 47 | 30.1| 173 | 47 | 27.1| 329| 94 | 28.5| | 1905|157 | 46 | 29.3| 184 | 40 | 21.7| 341| 86 | 25.2| | 1906|166 | 58 | 34.9| 188 | 51 | 27.1| 354| 109 | 31.5| | 1907|205 | 51 | 24.8| 289 | 86 | 29.7| 494| 137 | 27.8| +-------+------+-----+-----+--------+-----+-----+-----+-----+-----+ | Total |760[2]| 225 | 29.6|1,056[3]| 295 | 27.9|1,816| 520 | 28.7| +-------+------+-----+-----+--------+-----+-----+-----+-----+-----+ [1] No return. [2] Of these more than 400 were intubations. [3] Of these 23 or more were intubations.

From these figures it will be seen that the total result for five years is a mortality of 27.9% as against 29.6%, in favour of tracheotomy. This serves, in my opinion, to strengthen the position of those hospitals which rely upon tracheotomy. Upon a comparison of this sort it would certainly appear that the results of intubation, at any rate in England, are not so good as has been stated. I am aware that this opinion is not shared by many authorities and that Stack[40] writes, ‘taking everything into consideration, my impression is that under the most favourable conditions of operating, nursing, &c., the mortality is almost halved by doing intubation as a routine instead of tracheotomy.’

[40] Allbutt and Rolleston, _Sys. of Med._, 1905, vol. i, p. 1025.

It has been claimed that intubation gives better results in children under five. This question has been worked out by H. W. L. Barlow,[41] who concludes that ‘the younger the child, the longer will it require the tube, and the more frequently, therefore, has the latter to be inserted’, and ‘from the mortality alone, there is no indication that one operation is better suited for certain age periods than another, but since secondary tracheotomy appears to be rarest at three years old and the intubation fatality is least between four and six years, it follows that children from three to six are best adapted for intubation’.

[41] _Metropol. Asylums Board’s Ann. Rep., Med. Supplem._, 1904, p. 319.

_Conclusions._ Intubation is justifiable for diphtheria of a mild type if sufficient experience can be obtained and if the after-treatment can be personally carried out. The success of the operation depends largely upon a proper selection of the cases; in other words, it is not suitable for the worst types of this disease. It should never be performed upon a patient in whose case the question of tracheotomy does not arise.

In my opinion it is not a good operation for those general hospitals where there is constant change among the resident officers; it seems probable that it will remain the treatment of a small number of physicians who have frequent opportunities of practising their art.

=Indications.= (i) _In diphtheria_, intubation is justifiable when the disease is of a mild type without great toxæmia, where early diagnosis has been made, and antitoxin has been administered. It is not recommended when there is great pharyngeal inflammation, or in cases with bronchitis or pneumonia, or when the patient is prostrate, nor for severe obstruction caused by excessive swelling or false membrane in the larynx or trachea. In the last-mentioned condition intubation is difficult to perform, and the patient may be choked by false membrane which has been pushed down: intubation should be abandoned in favour of tracheotomy when immediate relief is not obtained.

(ii) _In other forms of septic laryngitis_, there is evidence to show that with intubation the mortality is higher than with tracheotomy; in œdematous laryngitis, such as follows the inhalation of steam, every effort should be made to prevent laryngeal obstruction by other forms of treatment, for intubation is difficult to perform owing to the swollen condition of the tissues; moreover, injuries are common, and there is a danger that the upper opening of the tube will become obstructed. Again, the tube may be expelled by coughing, and the child suffocated without relief.

(iii) _In chronic stenosis_, intubation is now extensively employed. Fibrous contraction such as follows some cases of thyrotomy, or syphilis and other inflammatory diseases, can be treated successfully by this method. Short light tubes, of vulcanite or similar material, are inserted and retained in position for long periods, three months or longer; with the pressure so exerted the amount of fibrous tissue appears to be diminished, and the lumen of the larynx is dilated.

=Operation= (in diphtheria). The apparatus required consists of a gag for opening the mouth, a set of tubes with a gauge showing the size for each age, an instrument for intubation and extubation, and equipment for tracheotomy.

The tubes recommended by O’Dwyer are of gilded bronze, but other materials such as vulcanite or hard rubber are sometimes used. The tubes have undergone frequent modifications and those designed by Bayeux are shorter, lighter, and a great improvement (Goodall). In Thorner’s type (Fig. 276) the lower end has been cut off at an angle, so that it may pass more easily between the vocal cords; the intubator and extubator have been replaced by a single pair of beaked forceps with a ratchet attached to the handles, so that, when the beaks are separated, the tube is gripped firmly and cannot be disengaged until the trigger of the ratchet has been pulled; with these forceps the tube is not obstructed while it is being taken in and out of the larynx, and there is less need for hurry; further, the top of the tube has a funnel-shaped opening ‘which greatly facilitates the introduction of the beaks when the tube is in the larynx, inasmuch as it allows the beak to glide from any point of the rim almost automatically into the opening, and what this means can be appreciated by those who have had experience with the old extractor’ (Kyle).[42]

[42] _Diseases of the Nose and Throat_, 1907, p. 726.

No preparation of the patient is required, but a blanket must be wrapped round the arms, body, and legs to control the struggling. Two assistants are required, one to hold the patient, the other to steady his head and manipulate a gag. The upright position is preferred by many surgeons because the patient is less frightened, and the breathing is easier; but the child may be laid upon a table, with the head slightly extended and exactly in the middle line of the body, or the head may be allowed to hang over the end of the table and the tube passed from behind, in a manner similar to that used for direct laryngoscopy. No anæsthetic is necessary. The first assistant or nurse should sit on a low chair with the child on his knee, holding him so that he directly faces the surgeon; a second assistant stands behind with a gag in his hand. A tube of suitable size, with a thread attached, and mounted on the introducer, is taken in the right hand; the assistant introduces the gag, opens the mouth to the fullest extent, and steadies the head with his two hands; the surgeon now passes the left index-finger over the back of the tongue, so that the tip of it passes behind and below the epiglottis until the cricoid is felt; this is the most important landmark, and as soon as it is located the finger is drawn upwards and forwards in order to hook up the epiglottis, and the introducer and tube are rapidly passed over it; the method of introduction being that used for all laryngeal instruments. As soon as the end of the tube is level with the end of the finger, the handle of the introducer is raised so as to throw the point as far forward as possible; the instrument is then bodily lowered, so as to drive the tube downwards through the larynx until it rests firmly and securely against the ventricular bands, which prevent further passage of the collar; the tube is now held in place with the left index-finger until the introducer is removed. The whole operation in experienced hands should take from three to five seconds only, and must be performed without force.

If the tube has been properly introduced, it is usual for the child to begin coughing, and this may continue for a short time, accompanied by noisy and rattling inspiration; the cough gradually disappears and breathing becomes easy. The tube causes temporary aphonia, which may persist for a few days after its removal, but is otherwise well tolerated; the patient is not conscious of the presence of the canula unless it becomes blocked.

The operation is simple in the hands of those who are accustomed to the use of laryngeal instruments; in a normal larynx there is no difficulty in introducing a tube, but in diphtheria the parts are inflamed and obstruction is present. Children are often intolerant or frightened; they are liable to retch or choke during introduction, but the latter can sometimes be accomplished by waiting for an inspiratory effort; if the struggling is very troublesome a small quantity of chloroform (cocaine in adults) may be given with safety.

=Difficulties= of the operation. The difficulty of passing the tube over the base of the tongue can be avoided by pulling the tongue downwards and forwards and passing the introducer through the mouth with the hand to the left of the patient’s face and rotating downwards when the point is in the pharynx. Failure to find the opening of the larynx is often due to not keeping the instrument exactly in the middle line. The tube may be too large (even when it corresponds to the age of the child) owing to swelling either in the larynx or in the subglottic region; in such a case a smaller tube must be tried, and it is essential that no force should be used to drive the tube into place, or dangerous complications may arise. Even a smaller tube may not be passed on the first occasion, and the surgeon has to decide whether he will try the same tube again or one that is smaller; the latter may not be suitable for the age. The tube may be too small, and this may be recognized by the ease with which it passes; as a result, the first strong cough expels it out of the larynx, and another must be introduced. A tube of correct size may be in the larynx without relieving the dyspnœa; this may be due to one of the following causes: (_a_) some membrane may have been pushed in front of the tube, an event which is evidenced by the noisy and difficult respiration, and which requires that the tube shall be withdrawn with the thread and again introduced, after an interval; (_b_) the tube itself may become blocked with membrane, with the result that it is at once coughed out; or (_c_) the child may be asphyxiated so that tracheotomy becomes a necessity. This last is a point that must always be remembered: intubation should never be performed unless everything has been prepared for opening the trachea. The tube may pass into the œsophagus in spite of all care, and this may increase the dyspnœa by pressing upon the posterior part of the larynx, in which case it must be withdrawn by the thread and a further attempt made. It has frequently happened that the tube with its thread has passed down the œsophagus into the stomach, an accident which ought to be avoided. No serious consequences are likely to occur, as the tube will be passed per rectum, or in rare instances vomited.

The question arises as to how many attempts should be made before intubation is abandoned. This varies in each case and depends upon the amount of distress caused by the previous attempts. With each further trial the child becomes more and more restless, and if the third attempt fails, it is better to desist, or to allow at least an interval of half an hour. When the dyspnœa becomes urgent there must be no hesitation, and either the tube must be reintroduced or tracheotomy performed; both operations are difficult under these circumstances, and the surgeon should choose the method of which he has the greater experience.

It is very important to remember that tracheotomy is required in nearly a third of the cases at one stage or another; at the M. A. B. fever hospitals of London during 1902-6 there were 429 cases of intubation for diphtheria, and of these 117 required tracheotomy later, _i.e._ 27.2%. As Goodall says: ‘Every case that was intubated four or more times came to tracheotomy. I therefore lay down the rule that if three insertions, each of several hours’ duration, fail to cure the laryngeal obstruction, tracheotomy should be performed. Frequent expulsion of the tube by coughing a few minutes after its insertion is also an indication for tracheotomy.’

=After-treatment.= A case of intubation requires more personal attention than one of tracheotomy. It is essential that the doctor should remain within easy call, as the tube may be blocked or coughed out at any moment. This danger is not so great as it appears; when the tube is coughed out there is no immediate asphyxia, and a fatal result is uncommon; an interval of at least twenty minutes usually occurs before the dyspnœa becomes urgent, in which time the doctor can be called; it may even happen that the tube is not required again, and that the obstruction has disappeared. When the tube becomes blocked, the state is more serious; in most cases it will be coughed out of the larynx, but if the child is very weak or the tube very firmly fixed, the obstruction must be at once relieved. It is for this reason that some surgeons prefer to leave a thread attached so that the nurse can extract the tube, but the latter has a disadvantage, namely, that the child may pull the tube out. This can be prevented by tying up the hands of the child while the tube is being worn, but even then the child may bite the string; the general practice therefore is to remove the thread, and the tube is then expressed by lateral pressure on the sides of the trachea, or by passing the finger below and behind the larynx and so pushing out the tube. The method is termed ‘enucleation’,[43] and where it fails the extubator must be used. A nurse must be chosen who has had previous experience of intubation; she must understand the symptoms which necessitate interference with the tube, and the feeding of the child. Swallowing is often difficult, and liquids tend to pass through the canula into the trachea; the patient chokes and may cough up the tube. The danger of pneumonia is also increased. To overcome the dysphagia the patient should be made to suck uphill through a tube, or semi-solids may be tried: in other cases nasal or rectal feeding can be ordered: temporary removal of the tube has also been recommended for purposes of feeding, but vomiting often occurs with reintroduction immediately after a meal. In very troublesome cases there is distinct danger in repeated intubation; tracheotomy should be performed if the child is becoming exhausted from want of nourishment.

[43] For a description of this method see _Metropol. Asylums Board’s Ann. Rep., Med. Supplem._, 1898, p. 187.

_Changing the tube._ O’Dwyer recommends that the tube should be retained for forty-eight hours without change, after which it should be removed once a day: it must, however, be remembered that while the tube is retained coughing is greatly impeded, so that septic material collects in the trachea and is liable to cause pneumonia.

Extubation by the thread and by enucleation has already been mentioned, but these methods are not applicable in every case. Extubation is difficult to perform, especially if respiration is obstructed and the patient struggling; whenever necessary, chloroform should be given. The preparation required is similar to that for intubation; a table and tracheotomy instruments are made ready; the upright position is preferred, and two assistants are required to hold the child and the gag; expanding forceps are introduced as if intubation were being done, and the tube is grasped securely and rapidly extracted, the whole operation being carried out as quickly as possible and without any suggestion of force. In experienced hands no danger is to be feared, but if two or three attempts are unsuccessful, tracheotomy should be performed. The time for removal of the tube varies from a few hours to four or five days in favourable cases. The main object is to dispense with the tube as soon as possible, and to err on the side of too early removal even in spite of the fact that reintroduction may be necessary.

=Complications= may occur, but there is no evidence that they are more numerous than with tracheotomy. Injury to the larynx is liable to result, especially from inexperience of the method, and this may be followed by hæmorrhage, emphysema, or abscess. In rare instances a false passage has been made, generally through the ventricle of the larynx: pressure ulcers may form, there may be necrosis of the cartilage, peritracheal abscess, or cicatricial contraction; or, as with tracheotomy, subglottic swelling may persist and granulations may be formed. When urgent dyspnœa follows the removal of the tube, one of these conditions must be suspected. O’Dwyer maintains that ‘the cause of persistent stenosis following intubation in laryngeal diphtheria can be summed up in a single word--traumatism,’ but ‘paralysis of the vocal cords may possibly furnish an occasional exception to this rule’ (Jacobson).[44]

[44] _Operations of Surgery_, 5th ed., vol. i, p. 640.

‘_Retained tube_,’ which is the term applied to cases of more than five days’ duration, is certainly more common after injury, but does not occur more frequently than with tracheotomy; many cases have been reported where intubation tubes were used for long periods with ultimate recovery, but the method is uncertain unless the exact condition of the larynx can be determined (see p. 480).

_Pneumonia._ It has been shown that large numbers of bacilli are present in the lungs, where they may cause inflammation quite apart from any operation; in laryngeal cases the danger is increased owing to the obstruction which causes deficient aeration of, and improper expectoration from, the lung. Where tracheotomy is performed the dyspnœa is relieved and the expectoration easy; with intubation, on the other hand, there is no stage of apnœa after introduction, which seems to indicate that the air does not pass so easily through the smaller tube; coughing is more difficult and the amount of expectoration less; mucus, pus, or membrane in small pieces, can all be expelled through the tube, but not so freely as through the larger canula, and are more likely to be swallowed. For these reasons it would appear that pneumonia is less to be feared after tracheotomy; there is, however, considerable difference of opinion on this point, and statistics have not proved of great value.