Diagnosis is by the roentgenray, first without, then, if necessary, with a capsule filled with an opaque mixture. Flat objects, like coins, always lie with their greatest diameter in the coronal plane of the body, when in the esophagus; in the sagittal plane, when in the trachea or larynx. Lateral, anteroposterior, and sometimes also quartering roentgenograms are necessary. One taken laterally, low down on the neck but clear of the shoulder, will often show a bone or other semiopaque object invisible in the anteroposterior exposure.
[149] CHAPTER XIII—FOREIGN BODIES IN THE LARYNX AND TRACHEOBRONCHIAL TREE
The protective reflexes preventing the entrance of foreign bodies into the lower air passages are: (1) The laryngeal closing reflex and (2) the bechic reflex. Laryngeal closing for normal swallowing consists chiefly in the tilting and the closure of the upper laryngeal orifice. The ventricular bands help but slightly; and the epiglottis and the vocal cords little, if at all. The gauntlet to be run by foreign bodies entering the tracheobronchial tree is composed of: 1. Epiglottis. 2. Upper laryngeal orifice. 3. Ventricular bands. 4. Vocal cords. 5. Bechic blast.
The epiglottis acts somewhat as a fender. The superior laryngeal aperture, composed of a pair of movable ridges of tissue, has almost a sphincteric action, in addition to a tilting movement. The ventricular bands can approximate under powerful stimuli. The vocal cords act similarly. The one defect in the efficiency of this barrier, is the tendency to take a deep inspiration preparatory to the cough excited by the contact of a foreign body.
Site of Lodgment.—The majority of foreign bodies in the air passages occur in children. The right bronchus is more frequently invaded than the left because of the following factors: I. Its greater diameter. 2. Its lesser angle of deviation from the tracheal axis. 3. The situation of the carina to the left of the mid-line of the trachea. 4. The action of the trachealis muscle. 5. The greater volume of air going into the right bronchus on inspiration.
The middle lobe bronchus is rarely invaded by foreign body, and, fortunately, in less than one per cent of the cases is the object in an upper lobe bronchus.
Spontaneous Expulsion of Foreign Bodies from the Air Passages. A large, light, foreign body in the larynx or trachea may occasionally be coughed out, but the frequent newspaper accounts of the sudden death of children known to have aspirated objects should teach us never to wait for this occurrence. The cause of death in these cases is usually the impaction of a large foreign body in the glottis producing sudden asphyxiation, and in a certain proportion of these cases the impaction has occurred on the reverse journey, when cough forced the intruder upward from below. The danger of subglottic impaction renders it imperative that attempts to aid spontaneous expulsion by inverting the patient should be discouraged. Sharp objects, such as pins, are rarely coughed out. The tendency of all foreign bodies is to migrate down and out to the periphery as their size and shape will allow. Most of the reported cases of bechic expulsion of bronchially lodged foreign bodies have occurred after a prolonged sojourn of the object, associated which much lung pathology; and in some cases the object has been carried out along with an accumulation of pus suddenly liberated from an abscess cavity, and expelled by cough. This is a rare sequence compared to the usual formation of fibrous stricture above the foreign body that prevents the possibility of bechic expulsion. To delay bronchoscopy with the hope of such a solution of the problem is comparable to the former dependence on nature for the cure of appendiceal abscess.
We do our full duty when we tell the patient or parents that while the foreign body may be coughed up, it is very dangerous to wait; and, further, that the difficulty of removal usually increases with the time the foreign body is allowed to remain in the air passages.
Mortality and morbidity of bronchoscopy vary directly with the degree of skill and experience of the operator, and the conditions for which the endoscopies are performed. The simple insertion of the bronchoscope is devoid of harm if carefully done. The danger lies in misdirected efforts at removal of the intruder and in repeating bronchoscopies in children at too frequent intervals, or in prolonging the procedure unduly. In children under one year endoscopy should be limited to twenty minutes, and should not be repeated sooner than one week after, unless urgently indicated. A child of 5 years will bear 40 to 60 minutes work, while the adult offers no unvarying time limit. More can be ultimately accomplished, and less reaction will follow short endoscopies repeated at proper intervals than in one long procedure.
Indications for bronchoscopy for suspected foreign body may be thus summarized: 1. The appearance of a suspicious shadow in the radiograph, in the line of a bronchus. 2. In any case in which lung symptoms followed a clear history of the patient having choked on a foreign body. 3. In any case showing signs of obstruction in the trachea or of a bronchus. 4. In suspected bronchiectasis. 5. Symptoms of pulmonary tuberculosis with sputum constantly negative for tubercle bacilli. If the physical signs are at the base, particularly the right base, the indication becomes very strong even in the absence of any foreign body circumstance in the history. 6. In all cases of doubt, bronchoscopy should be done anyway.