| (a) | Pointed; such as bones, needles, teeth, nails, &c. | ||
| (b) | Rounded; | i. | Hard, such as coins, stones, or buttons. |
| 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-passages.
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 illustration: A boy of 17 was admitted to my hospital on account of dyspnœa, caused by obstruction in the lower air-passages. 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 anæsthetic and perform tracheoscopy. On passing 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 dyspnœa, and after a few days the wound was allowed to heal. Three months later there was some return of the dyspnœa, 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 dyspnœa. By the passage 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-passages; 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.