Part 84 (1/2)

[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 a.s.sistants 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 haemorrhage, emphysema, or abscess. In rare instances a false pa.s.sage 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 dyspna 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 dyspna is relieved and the expectoration easy; with intubation, on the other hand, there is no stage of apna after introduction, which seems to indicate that the air does not pa.s.s 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.

CHAPTER V

TRACHEOSCOPY AND BRONCHOSCOPY

=Indications.= (i) _Foreign bodies._ Accidental inhalation of foreign bodies is more common in children than in adults in the proportion of about two to one. The character of the foreign body should be considered before treatment is advised, and for this purpose the inhaled bodies may be divided into three cla.s.ses:

(_a_) Pointed; such as bones, needles, teeth, nails, &c.

(_b_) Rounded; i. Hard, such as coins, stones, or b.u.t.tons.

ii. Soft (in some cases capable of swelling), such as meat, beans, peas.

(_c_) Fluid; such as blood, pus, or vomited food.

To these may be added pieces of necrosed cartilage from the larynx, trachea, or bronchi; and calcareous concretions from bronchial glands, which occasionally perforate the walls of the air-pa.s.sages.

Any of the above may become impacted in the trachea or fall into one of the bronchi: the right bronchus is affected nearly twice as often as the left owing to its larger size, its direction (which is more nearly that of the trachea), and the inclination of the septum to the left of the middle line.

(ii) _Tumours of the trachea_ (see p. 546).

(iii) _Stricture of the trachea_ resulting from previous inflammation or trauma. Tracheoscopy is useful both for accurate diagnosis and for treatment of such conditions. The following case may be quoted as an ill.u.s.tration: A boy of 17 was admitted to my hospital on account of dyspna, caused by obstruction in the lower air-pa.s.sages. The chest was examined and a skiagram taken, the latter showing a definite shadow in the position of the bifurcation of the trachea. This was possibly an enlarged gland which pressed upon the trachea. I decided to give the boy an anaesthetic and perform tracheoscopy. On pa.s.sing the tube a stricture was found in the trachea at the level of the suprasternal notch, which was so small that a large probe completely blocked its lumen, thus causing cessation of breathing. Under the condition it was impossible to dilate the stricture by endotracheal methods. The trachea was therefore exposed, but appeared to be normal. An opening was made into it above the stricture, and it was then seen that the latter was caused by a thickening of the anterior and lateral walls, involving two rings of the trachea and apparently of inflammatory nature. As no history of inflammation had been obtained the tissue was examined microscopically, and this confirmed the diagnosis. Division of the stricture completely relieved the dyspna, and after a few days the wound was allowed to heal. Three months later there was some return of the dyspna, and tracheoscopy was again performed. The stricture had to some extent returned, but was easily dilated through the tube, and two months later there had been no further dyspna. By the pa.s.sage of bougies through a bronchoscope a stricture of the bronchus has been relieved in a similar manner.

(iv) _For diagnostic purposes_ alone, to determine the cause of pressure upon the air-pa.s.sages; as in tumours of the mediastinum, aneurism, and the like.

The instruments required correspond in the main to those used for direct laryngoscopy (see p. 480). The special instruments include (_a_) bronchoscopes, which are long circular tubes of dimensions suitable to the patient:

LENGTH AND SIZE OF TUBE REQUIRED IN UPPER BRONCHOSCOPY (KILLIAN)

_Adults._ _Children._

Length 30-40 cm. 20-30 cm.

Diameter 9-14 mm. 5-7 mm.

These should be marked externally in centimetres, measured from the distal end of the tube, and should be provided with a lateral window to allow of free breathing through the opposite bronchus when the tube is introduced into the one which is obstructed; of the various forms in use, the sliding tube of Bruenings appears to me superior; (_b_) instruments for extraction, including forceps and hooks according to the nature of the body to be removed; (_c_) aspirator for removal of mucus, and sponge-holders, the length of the bronchoscope.