Bronchial Obstruction

1) Bronchial obstruction, temporary or prolonged, is a universal pathologic occurrence; it is common among the newborn; it affects everyone many times later in life, and it is commonly the terminal phase in slow deaths from any cause. Only the cough reflex prevents us all from drowning in our own secretions. Only the cough reflex prevents extermination of the human race by bronchial obstruction.

2) The power of bronchial obstruction to cause bronchial and pulmonary disease is threefold. It acts as a primary, a predisposing and a perpetuating factor.

3) An effort is made to clarify the confusion in the literature due to theory and inference regarding valvular obstruction. Complete obstruction of a bronchus, as shown at necropsy, has been well known since the days of Hippocrates and Galen. The bronchoscope, 26 years ago, revealed the clinical fact that in the living bronchi, normal rhythmic respiratory movements produced valvular types of obstruction that caused emphysema and atelectasis in the respective tributary areas. The mechanism of two of the types was similar to the stop valves and check valves common in mechanical engineering, but the most frequently encountered type of mechanism was unknown to mechanical engineers. This newly discovered mechanism was named the "expansile check-valve." It converts the rhythmic respiratory to-and-fro flow of the gaseous contents of the bronchi into a one-way flow. The inspiratory diametric luminal enlargement opens a chink past an obstruction, but the expiratory diametric luminal diminution closes the chink at the beginning of expiration, trapping the air before it can escape. Though the quantity trapped at each expiration is small, repetition 18 or more times a minute soon results in emphysema of the tributary lung, lobe or segment. This expansile type of one-way valve is irreversible. The two types of one-way valvular mechanism known to mechanical engineers, the ball valve and the flapper valve, are reversible; and when they occur in reversed position in a bronchus, they cause atelectasis rapidly. They are often seen to produce atelectasis in a few minutes, whereas absorption of air by the circulation after a stop-valve obstruction usually takes 24 hours or more to cause atelectasis. A flapper valve may cause atelectasis in one lobe and at the same time an emphysema in another lobe.

4) The expansile check-valve mechanism is seen at some stage in practically every disease of the lung. It occurs not only in endobronchial conditions, but also in neoplastic, adenopathic and other compression stenoses.

5) Various causes of bronchial obstruction are discussed. The most frequent are pathologic secretions and exudates that the cough reflex cannot expel because of their greatly increased adhesiveness and cohesiveness. Difficulty of expulsion is also greatly increased by accumulation. Opportunity for accumulation occurs when the cough reflex is fatigued, feeble, inefficient from lack of glottic cooperation, or suppressed by toxemia, or alcohol, or drugs, especially opiates and other sedatives. Opiates are the most frequently prescribed frustraters of the vital defense of the lungs. Their routine use as antitussives is one of the most deplorable and widely spread therapeutic errors in the history of medicine.

6) It was discovered bronchoscopically many years ago that opiates and atropine act powerfully in four different ways in promoting bronchial obstruction. (a) The dessicating effect of these drugs greatly increases the adhesiveness and cohesiveness of pathologic secretions and exudates, and this change enormously increases the difficulty of expulsion by nature's defensive mechanism, ciliary wafting, tussive squeeze and bechic blast. (b) The dessication also favors coagulation into firm plugs. (c) By suppression of the cough reflex opiates give time for accumulation, coagulation and plug formation. (d) By suppressing cough, opiates directly cripple the natural machinery of defense of the lungs. They drug the watchdog to sleep. It is hard to conceive of a drug better adapted to the promotion of bronchial obstruction.

7) Peroral synergetic aspiration of the bronchial tree is an important means of prophylaxis. It is easily done with a silk-woven aspirating tube inserted through the laryngoscope, or with a bronchoscope inserted without the laryngoscope. Deep insertion of an aspirating tube is unnecessary; the tussive squeeze will force exudates up into the large bronchi. Chronic bronchitis and bronchiectasis are largely preventable diseases. Prompt arrest of beginning stagnation of pathologic secretions and exudates, when subacute bronchitis lingers after acute infections of the respiratory tract, will prevent chronic bronchitis and bronchiectasis which are so often the sequelae of such acute infections.

8) By diagnostic bronchoscopy the treatment of bronchial obstruction has been removed from the domain of theory and inference and placed upon a plane with other departments of medicine and surgery in which therapy is based on direct inspection of pathologic tissue changes, laboratory examination of exudates and histologic examination of pathologic tissue specimens. As a means of treatment its close to 100 per cent of successful removals of exogenous foreign bodies gives bronchoscopy a unique position; but exogenous foreign body as a cause of bronchial obstruction is relatively rare. In all other forms of bronchial obstruction the relations of the bronchoscope to treatment are those of a speculum through which treatment may or may not be indicated, according to the pathologic conditions found in the particular case. Two important duties of the bronchoscope in all kinds of cases, are to maintain constantly a clear and adequate airway to the alveoli, and to reestablish normal physiologic peroral drainage by ciliary wafting, tussive squeeze and bechic blast. No matter what else is done in the way of operative or non-operative treatment, the patient will never have healthy lungs as long as stagnation persists. Prevention of stagnation by a series of systematic peroral aspirations of the tracheobronchial tree, as soon as convalescence is established will greatly aid in restoration of normal peroral drainage, by taking the load off the clogged cilia. After operations such as pulmonary resections, or external drainage of empyema, bronchoscopic removal of obstructive bronchial exudates and a series of peroral aspirations are usually of great aid in reestablishment of normal physiologic drainage of the lungs. Such aspirations are easily done by the anesthesiologist, on whom maintenance of a clear airway so largely depends.

9) In case of a patient with impending drownage in his own secretions, resuscitation by bronchoscopic aspiration is dramatic.