Bronchial Asthma.
Synonyms:—Spasmodic asthma; asthma.
Definition:—A condition of dyspnea depending upon contraction of the bronchial tubes and bronchioles. The term is applied to any chronic difficulty of breathing if accompanied with a wheezing respiration. Correctly speaking it does not include any form of difficult breathing, which does not have its cause in irritation and consequent contraction or constriction of the bronchial tubes.
Etiology:—Underlying all immediate causes is nervous hyperesthesia, inducing a predisposition to the disease. Most commonly the disease follows bronchitis in some one of its various manifestations. There is often present in asthma many of the pathologic factors of this disease. It is also due to chronic disease of the post-nasal mucous membrane, and is commonly induced by all those conditions named as the cause of chronic bronchitis, which may induce considerable irritability of the terminal filaments of the nerves distributed to the mucous membrane of the bronchial tubes. There is but little doubt that lithemia and rheumatic conditions in general are the cause of many cases. General nervous irritability, with or without evidences of neurasthenia, is present in a proportion of the cases.
It is estimated that nearly one-half of the cases of asthma, pure and simple, have a history of heredity. Some cases are dependent entirely upon the presence of chronic heart disease, with which the symptoms are intimately associated. Other cases arise evidently from irritation of the stomach, induced by the ingestion of certain kinds of food. At other times indigestion of any kind will induce an asthmatic paroxysm. The inhalation of dust and irritating vapors is a common inducing cause; certain individuals have an idiosyncrasy to irritation from certain substances only. This is so marked in some cases that while asthma is never present at any other time, it will be induced by the presence of an exceedingly small quantity of the irritating substance in the atmosphere.
Symptomatology:—Spasmodic asthma occurs in abrupt paroxysms; usually there are no prodromal symptoms. The patient is awakened in the latter part of the night with suddenly obstructed breathing, so great as to cause the most intense alarm. The face assumes a characteristic expression; he is apt to spring from the bed and rush to an open window for air, believing that he is suffocating. All the respiratory and abdominal muscles are exercised in the effort to get breath; the skin is cool and is soon covered with a profuse cool perspiration; the countenance becomes livid or cyanosed, and the extremities cold. The inspiration, made with much effort, is comparatively short, while the expiration is greatly prolonged. If sitting up in the bed, the patient supports the thorax with the arms, the palms of the hands pressing upon the bed. The temperature falls, becoming sub-normal, and the pulse, at first slow, but large and soft, soon becomes feeble and quite rapid. The appearance is as if immediate dissolution threatened, but death never occurs in simple, uncomplicated cases.
When there is chronic heart disease, or dropsy, or protracted exhaustion from Bright's disease, the paroxysms may be serious. Unless artificial relaxation is induced, the spasm may continue for two or three hours. Toward the end of the paroxysm there is a short, harsh, irritating cough, with an effort as if to expel a tenacious mucus. Expectoration occurs finally, when all the symptoms abate. Soon the difficult breathing has disappeared entirely, but the patient will remain weak and exhausted for some hours.
In other cases there is at first the appearance of a very mild wheezing respiration, which may exist for perhaps twenty-four hours, but not sufficient to produce any great discomfort or to prevent sleep. Upon retiring the patient falls into a natural slumber, not at first disturbed by the impaired respiration, which to an observer may be seen to be increasing in difficulty. The patient is finally awakened and while not complaining of extreme difficulty in breathing, will sit up in bed and remain awake the rest of the night. During the latter hours of the night the breathing will become greatly obstructed. Daylight will bring much relief, but there may be no entire absence of the difficult breathing for several days. Or successive nights may bring an increasing difficulty of breathing until the total symptoms are relieved by remedial measures. In extremely nervous cases the disease may occur as a pure neurosis, occurring usually after a day of unusual effort, exhaustion or anxiety, or perhaps after a violent fit of anger.
While there is no apparent organic disease, persistently recurring attacks, after a longer or shorter period, will induce chronic disease of the bronchial tubes, of the lungs or of the kidneys, or more commonly of the heart, which, in this case, may assume the form of hypertrophy, with more or less dilatation and valvular incompetency. The author attended a young lady in a paroxysm of asthma of an exceedingly exaggerated type, where the heart was so feeble that it seemed impossible that it should continue its action through the attack. The friends expressed no anxiety whatever, but insisted upon the immediate administration, hypodermically, of one-fourth grain of morphin. This was not given, but relief was obtained by other means. The friends claimed that there was absolutely no danger in giving morphin, as they had given it hundreds of times in previous attacks with best results. In a subsequent paroxysm the friends administered morphin themselves hypodermically. Relief from the difficult breathing was immediately obtained, the patient fell into a quiet slumber and was left alone for a few minutes, when death occurred during the short absence of the attendant. Upon post-mortem examination the heart was found greatly dilated, had ceased in diastole and contained an enormous clot of black blood.
Diagnosis:—Usually the history of previous attacks is sufficient to determine positively the identity of the disease.
The physical signs present are usually characteristic. There are peculiar musical rales, with greatly exaggerated bronchial breathing; these are apparent both upon inspiration and expiration, or to and fro rales are present, which are diffused throughout the structure of both lungs uniformly and are apt to change their position quite constantly. The disease may be differentiated from hay fever by the absence of the nasal symptoms, and by the appearance of that disease at a given time each year, although asthma, in one form, is an accompaniment of hay fever. It may be distinguished from inflammation of the larynx by the changes of the voice that are apt to be present in that disease, and while spasmodic laryngitis involves difficult breathing there is an absence of the characteristic wheezing of asthma. In spasmodic croup the difficulty is in the inspiration, while in asthma it is in the expiration.
Prognosis:—Uncomplicated cases do not prove fatal and are usually amenable to treatment, while complicated cases, however complicated, are serious in proportion to the character of the cause upon which they depend. It is sometimes exceedingly difficult to prevent the recurrence of paroxysms, but the paroxysm may be postponed by treatment and rendered mild and comparatively unimportant.
Treatment:—Relief of the excessive paroxysms, is the immediate demand for treatment. This being accomplished, attention is paid to the prevention of future attacks. Cases depending upon an acute attack of indigestion are relieved by the use of a thorough emetic for the purpose of evacuating the stomach and relieving both the local and reflex irritation. Cases depending upon intestinal irritation may be relieved by a thorough cleansing of the intestinal canal by a non-irritating physic. It may be found advisable also to administer, subsequently, santonin in grain doses every two hours. This has recently been found to be an efficient remedy with which to relieve reflex irritation, which remains after the cause has been removed, or where the cause is difficult to determine. Antispasmodics are of service in cutting short the paroxysms. A single dose of specific lobelia will sometimes accomplish this result so immediately as to occasion surprise or alarm lest an overdose of a poisonous medicine had been given. The remedy should not be given often enough to produce violent emesis or depression, and must be avoided where serious disease of the heart complicates the case.
Sometimes the administration of a very small quantity of chloroform will temporarily relieve. It is better, however, to produce general relaxation. A full dose of the compound mixture of lobelia and capsicum is excellent in most cases; where there is simple nervous irritation, without prostration, gelsemium is a serviceable remedy.
In cases somewhat protracted in character, where the asthmatic breathing continues between the paroxysms, the author has obtained good results from the use of grindelia robusta. A single large dose of the syrup of ipecac will benefit those cases, complicated with bronchial irritation from acute or sub-acute inflammation of the bronchial tubes. Glonoin has been found of service in the violent paroxysm, and minute doses of apomorphin may be given where there is no danger of depressing the heart. In cases where the asthmatic breathing is uniform for a number of days, five drops of veratrum, three or four times a day, will be of much service. This remedy in smaller doses, of one minim every three or four hours, may be sometimes continued for a number of days with only good results. The inhalation of the fumes of potassium nitrate and stramonium leaves burned together gives relief so universally that their use has become common. A combination is prepared at drug stores for indiscriminate use. The inhalation of tobacco smoke to those not accustomed to it, and the fumes from lobelia, belladonna and hyoscyamus are also beneficial.
