[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.
There is no absolute contraindication to bronchoscopy for foreign bodies. Extreme exhaustion or reaction from previous efforts at removal may call for delay for recuperation, but pulmonary abscess and even the rarer complications, bronchopneumonia and gangrene of the lung, are improved by the early removal of the foreign body.
Choice of Time to do Bronchoscopy for Foreign Body.—The difficulties of removal usually increase from the time of aspiration of the object. It tends to work downward and outward, while the mucosa becomes edematous, partly closing over the foreign body, and even completely obliterating the lumen of smaller bronchi. Later, granulation tissue and the formation of stricture further hide the object. The patient's health deteriorates with the onset of pulmonary pathology, and renders him a less favorable subject for bronchoscopy. Organic foreign bodies, which produce early and intense inflammatory reaction and are liable to swell, call for prompt bronchoscopy. When a bronchus is completely obstructed by the bulk of the foreign body itself immediate removal is urgently demanded to prevent serious lung changes, resulting from atelectasis and want of drainage. In short, removal of the foreign body should be accomplished as soon as possible after its entrance. This, however, does not justify hasty, ill-planned, and poorly equipped bronchoscopy, which in most cases is doomed to failure in removal of the object. The bronchoscopist should not permit himself to be stampeded into a bronchoscopy late at night, when he is fatigued after a hard day's work.
Bronchoscopic finding of a foreign body is not especially difficult if the aspiration has been recent. If secondary processes have developed, or the object be small and in a bronchus too small to admit the tube-mouth, considerable experience may be necessary to discover it. There is usually inflammatory reaction around the orifice of the invaded bronchus, which in a measure serves to localize the intruder. We must not forget, however, that objects may have moved to another location, and also that the irritation may have been the result of previous efforts at removal. Care must be exercised not to mistake the sharp, shining, interbronchial spurs for bright thin objects like new pins just aspirated; after a few days pins become blackened. If these spurs be torn pneumothorax may ensue. If a number of small bronchi are to be searched, the bronchoscope must be brought into the line of the axis of the bronchus to be examined, and any intervening tissue gently pushed aside with the lip of the bronchoscope. Blind probing for exploration is very dangerous unless carefully done. The straight forceps, introduced closed, form the best probe and are ready for grasping if the object is felt. Once the bronchoscope has been introduced, it should not be withdrawn until the procedure is completed. The light carrier alone may be removed from its canal if the illumination be faulty.
COMPLICATIONS AND AFTER-EFFECTS OF BRONCHOSCOPY
All foreign body cases should be watched day and night by special nurses until all danger of complications is passed. Complications are rare after careful work, but if they do occur, they may require immediate attention. This applies especially to the subglottic edema associated with arachidic bronchitis in children under 2 years of age.
General Reaction.—There is usually no elevation in temperature following a short bronchoscopy for the removal of a recently lodged metallic foreign body. If, however, an inflammatory condition of the bronchi existed previous to the bronchoscopy, as for instance the intense diffuse, purulent laryngotracheobronchitis associated with the aspiration of nut kernels, or in the presence of pulmonary abscess from long retained foreign bodies, a moderate temporary rise of temperature may be expected. These cases almost always have had irregular fever before bronchoscopy. Disturbance of the epithelium in the presence of pus without abscess usually permits enough absorption to elevate the temperature slightly for a few days.
Surgical shock in its true form has never followed a carefully performed and time-limited bronchoscopy. Severe fatigue resulting in deep sleep may be seen in children after prolonged work.
Local reaction is ordinarily noted by slight laryngeal congestion causing some hoarseness and disappearing in a few days. If dyspnea occur it is usually due to (1) Drowning of the patient in his own secretions. (2) Subglottic edema. (3) Laryngeal edema.
Drowning of the Patient in His Own Secretions.—The accumulation of secretions in the bronchi due to faulty bechic powers and seen most frequently in children, is quickly relievable by bronchoscopic sponge-pumping or aspiration through the tracheotomic wound, in cases in which the tracheotomy may be deemed necessary. In other cases, the aspirating bronchoscope with side drainage canal (Fig. 1, E) may be used through the larynx. Frequent peroral passage of the bronchoscope for this purpose is contraindicated only in case of children under 3 years of age, because of the likelihood of provoking subglottic edema. In such cases instead of inserting a bronchoscope the aspirating tube (Fig. 9) should be inserted through the direct laryngoscope, or a low tracheotomy should be done.
Supraglottic edema is rarely responsible for dyspnea except when associated with advanced nephritis.
Subglottic edema is a complication rarely seen except in children under 3 years of age. They have a peculiar histologic structure in this region, as is shown by Logan Turner. Even at the predisposing age subglottic edema is a very unusual sequence to bronchoscopy if this region was previously normal. The passage of a bronchoscope through an already inflamed subglottic area is liable to be followed by a temporary increase in the swelling. If the foreign body be associated with but slight amount of secretion, the child can usually obtain sufficient air through the temporarily narrowed lumen. If, however, as in cases of arachidic bronchitis, large amounts of purulent secretion must be expelled, it will be found in certain cases that the decreased glottic lumen and impaired laryngeal motility will render tracheotomy necessary to drain the lungs and prevent drowning in the retained secretions. Subglottic edema occurring in a previously normal larynx may result from: 1. The use of over-sized tubes. 2. Prolonged bronchoscopy. 3. Faulty position of the patient, the axis of the tube not being in that of the trachea. 4. Trauma from undue force or improper direction in the insertion of the bronchoscope. 5. The manipulation of instruments. 6. Trauma inflicted in the extraction of the foreign body.
Diagnosis must be made without waiting for cyanosis which may never appear. Pallor, restlessness, startled awakening after a few minutes sleep, occurring in a child with croupy cough, indrawing around the clavicles, in the intercostal spaces, at the suprasternal notch and at the epigastrium, call for tracheotomy which should always be low. Such a case should not be left unwatched. The child will become exhausted in its fight for air and will give up and die. The respiratory rate naturally increases because of air hunger, accumulating secretions that cannot be expelled because of impaired glottic motility give signs wrongly interpreted as pneumonia. Many children whose lives could have been saved by tracheotomy have died under this erroneous diagnosis.
Treatment.—Intubation is not so safe because the secretions cannot easily be expelled through the tube and postintubational stenosis may be produced. Low tracheotomy, the tracheal incision always below the second ring, is the safest and best method of treatment.