Chapter XIII: Part 13

Although removal to the city frequently affords relief, there are exceptions to the rule, and many cases are recorded where a change of residence to the country has effected a cure. Ozone, of which but little is as yet known, is supposed by some to be a cause of asthma, and it is not unlikely that the relief afforded by removal to a large city may be partly due to the relatively small proportion of this agent in the atmosphere of crowded localities.

Dust of various kinds, the pollen of plants, certain vapors, gases, smoke, and the emanations from many species of animals, have all been known to excite attacks of asthma. Some persons are so sensitive that the simple act of brushing their clothes is sufficient to bring on a paroxysm. Others are unable to inhale the perfume of roses, lilies, heliotropes, and many other flowers without suffering with an attack. The dust of hay will often cause paroxysms even in those who are not hay-fever subjects. Since Cullen first published the case of an apothecary's wife who had asthma whenever ipecac was powdered in her husband's shop numerous cases of a similar nature have {193} been recorded. Ramadge relates the case of an employé in the East India Company who was compelled to relinquish a lucrative appointment because the smell of tea always provoked a paroxysm of asthma. Many persons are unable to come into close proximity with horses, rabbits, cats, and other animals without suffering, and Austin Flint of New York experienced great inconvenience when absent from home from sleeping upon feather pillows. In his case the asthmatic attack was not brought on by all pillows, but what it was that made one kind more active than another he was unable to determine.

In persons predisposed to bronchial asthma the eating of any indigestible substance may of itself be sufficient to cause an attack, and even an ordinarily full meal, if partaken of late in the day, may have the same effect. Dyspepsia in its various forms and the presence of irritating substances in the intestinal canal are such frequent causes of asthma that they have led to the establishment of several special varieties of the disease--_e.g._ a. dyspepticum, a. verminosum.

Asthma is frequently due to uterine and ovarian disorders, the so-called a. uterinum.

Voltolini of Breslau has described cases which were evidently due to the presence of naso-pharyngeal polypi, the attacks disappearing with their removal and reappearing with their renewed growth. These statements have been confirmed by subsequent cases observed by Haenisch. Attention has lately been directed to a number of cases in which the asthmatic paroxysm was found to be associated with catarrh of the naso-pharyngeal and laryngo-tracheal mucous membrane. In such cases it is thought that the irritation caused by the pressure of the swollen mucous membrane upon the adjacent nerves is conveyed through them to the pneumogastric, and thus provokes the bronchial spasm. Daly, Roe, Harrison Allen, Hack, and others have traced the paroxysms of hay asthma to an hypertrophied condition of the mucous membrane over the turbinate bones and septum of the nose, which renders it peculiarly susceptible to the action of the irritants which cause that troublesome affection, and have succeeded in curing many cases by simply removing the diseased tissue.

Mental emotion, if sufficiently powerful, may sometimes prevent the occurrence of the asthmatic paroxysm; thus, Steavenson, referring to his own case, states that although subject to frequent attacks he never had one on going up for an examination; and the writer is acquainted with a patient whose attack of hay asthma could frequently be checked by an exciting game of cards.

Asthma, like other neuroses, is much more frequent among the educated and refined than among the coarser and more ignorant classes of society, and those leading luxurious lives are more liable to the disease than those of simple and frugal habits. Of the various professions, those which involve much exertion of the voice furnish the largest contingent; hence it is common among public speakers, clergymen, and lawyers.

In former days the retrocession of cutaneous eruptions was supposed to play an important rôle in the production of asthma, but of late years this theory of causation has found but few advocates among intelligent physicians, the only author of any prominence who still adheres to it being Waldenburg, who has proposed to designate such cases as a. herpeticum.

PATHOLOGY.--We have elsewhere alluded to the various theories with which the older writers endeavored to explain the phenomena of asthma, and need not here refer to them again.

The first step toward a truly scientific theory of the pathology of asthma was the discovery by Reisseisen of the smooth muscular fibres of the bronchial tubes. These fibres are found not only in the large and medium-sized bronchi, but even in those of the smallest calibre, Kölliker having {194} demonstrated them in bronchioles 0.18 millimeter in diameter. It was ascertained by Williams that by irritating the lung he could cause contraction of these fibres, and Longet subsequently proved that the same effect could be produced by galvanizing the pneumogastric nerve. Guided by these important discoveries, most modern pathologists have arrived at the conclusion that bronchial asthma is a spasmodic contraction of the middle and finer bronchi, dependent upon some derangement in the function of the pneumogastric nerve. This, the so-called spasmodic theory, is not entirely new, Willis, as we have before stated, having described as early as 1682 a variety of asthma which he believed to be the result of a "spasmodic action of the muscles and nerves of respiration," and to which he applied the term "asthma convulsivum." Although revived from time to time, it was not until some two hundred years later, and after Romberg had definitely settled the question of the essential character of the disease, that the spasmodic nature of asthma received general recognition. Bergson adopted it in his prize essay in 1840, and ten years later it found a warm supporter in the person of Hyde Salter, whose valuable contributions have added so much to our knowledge of bronchial asthma. The theory that asthma is due to spasm of the bronchial muscles met with but little opposition until 1854, when Wintrich, after a series of experiments, arrived at conclusions directly opposed to those of Williams and Longet in regard to the contractility of the muscular fibres of the bronchi, and refused to accept the spasm theory on the ground that it afforded no rational explanation of the phenomena of asthma. He believed that the various symptoms of that disease were due to tonic spasm either of the diaphragm alone or of the diaphragm and the other muscles of respiration. These experiments of Wintrich were so carefully conducted, and his standing as a specialist in respiratory diseases so high, that his theory found many supporters, and might perhaps have been generally accepted had it not been for the distinguished French physiologist, Paul Bert, who in 1870, with improved methods of scientific research, succeeded in demonstrating that Williams and Longet were after all correct in their statements as to the contractility of the bronchial muscles.

One of the most zealous advocates of the spasm theory of asthma, and at the same time its most learned expositor, is Biermer,[13] whose classical lecture on that disease, which appeared a short time after the publication of Bert's experiments, is perhaps the most satisfactory work ever published on the subject. He defines bronchial asthma as a "neurosis depending upon tonic spasm of the bronchial muscles and caused by faulty innervation of the pneumogastric nerve." He claims that this theory is confirmed by clinical experience--that the suddenness with which the attack comes and disappears, and the long and forced expiration with the sibilant râles and other evidences of stenosis which accompany it, admit of no other explanation. In support of this view he calls attention to the rapidity with which the paroxysm yields to chloral, all of its symptoms disappearing within from five to ten minutes after the administration of a moderate dose of that agent. Wintrich and his supporters, besides denying the contractility of the bronchial muscles, object to the spasm theory that the distension of the thorax and descent of the diaphragm, both constant symptoms, are incompatible with spasmodic closure of the bronchial tubes, and that constriction from such cause by impeding the entrance of air into the alveolæ would be more likely to cause diminution in the size of the thorax than its enlargement, and that the diaphragm, instead of descending, would be drawn upward. Biermer acknowledges that this to a certain extent is true, and concedes that constriction of the tubes would interfere with both acts of respiration, but claims that it does not do so {195} to the same extent in the two movements. The spasmodic constriction acts as a sphincter which is readily overcome during inspiration, but prevents the escape of air during expiration, the latter movement being slower and less complete than the former. Were the expiratory pressure exerted upon the contents of the alveolæ alone, it would readily overcome the spasmodic constriction of the bronchi, but it also compresses at the same time the bronchioles. "When the bronchi are spasmodically contracted, they are subjected during expiration to the general pressure of that movement plus the pressure of the spastic contraction of the bronchial muscles. The walls of the bronchioles being soft and compressible, the expiratory pressure, instead of overcoming the obstruction and opening them, would tend to close them all the more tightly." He calls attention to an analogous condition which obtains in capillary bronchitis, when, owing to swelling of the mucous membrane and to the accumulation of secretion in the tubes, the alveolæ are cut off. Here, too, the expiratory pressure is often sufficiently powerful to overcome the obstruction, but if under these circumstances it is too feeble, collapse of the lung ensues. When, on the other hand, the inspiration is strong enough to overcome this obstacle, air enters the alveolæ, and, being imprisoned there, causes inflation of the air-cells as in asthma. That collapse of the lung does not occur in the latter disease is due to the fact that the inspiratory act is always sufficiently powerful to overcome the spastic contraction of the bronchioles.

[Footnote 13: A. Biermer, "Ueber Bronchial Asthma," _Sammlung klinischer Vorträge_, No. 12, Leipzig, 1870.]

The air entering the lung during inspiration is pent up by the spastic constriction of the bronchi, which, acting as a valve, admits of its passage in one direction, but impedes its escape during expiration, and thus causes inflation of the air-cells and insufficient aëration. Owing to the distension of the alveolæ the thorax is expanded and the diaphragm forced downward. A tetanic spasm of the diaphragm lasting for hours, such as that which Wintrich describes, and with which he endeavors to explain the descent of that muscle as well as the other symptoms of asthma, is not only improbable, but is contrary to clinical experience. If the diaphragm were thus spasmodically contracted, it would remain fixed in one position, but Biermer has demonstrated that there is more or less rhythmic movement of that muscle even during the paroxysm; but if no movement of the diaphragm were observed, it would still be no proof of tonic spasm of that muscle, as its immobility might be due to other causes. According to Biermer, the inflation of the lungs and their insufficient ventilation afford a satisfactory explanation of the most important symptoms of asthma, as Breuer[14] has shown, in his paper on the automatic regulation of respiration through the pneumogastric nerve, that various embarrassments of respiration must be corrected by some suitable modification of the act itself; hence when, as in asthma, the lung is unable to empty itself, the expiratory act must be strengthened and prolonged to overcome the obstruction occasioned by the spasmodic constriction of the bronchial tubes; whereas incomplete filling of the lung would necessitate increased inspiratory effort. According to Biermer, "expiratory dyspnoea is as characteristic of obstruction of the finer tubes," be it from spasm, as in asthma, or from stoppage with viscid mucus or from swelling of their lining membrane, as in bronchitis, as the same condition during inspiration is of narrowing of the larger air-passages--an important point in differential diagnosis to which we shall again have occasion to refer. He is unable to explain the relationship between bronchial spasm and catarrhal hyperæmia of the air-passages, but believes that it may be accounted for as follows: "Either the bronchial fluxion causes the spasm--that is, that there exists between them a causal connection--or the hyperæmia and the spasm are the {196} joint effect of the exciting (centripetal) nerves; in other words, both are due to reflex action."[15]

[Footnote 14: "Die Selbsterneurung der Athmen durch den N. vagus," _Sitzungsbericht der K. K. Akademie der Wissenschaften zu Wien_, Bd. lviii. Abtheilung ii., Nov., 1868.]

[Footnote 15: In presenting Biermer's theory the writer has drawn freely upon that author's well-known lecture on "Bronchial Asthma," as published in _Volkmann's Sammlung klinischer Vorträge_, _loc. cit._]

Another explanation of the phenomena of asthma is that proposed by Lebert,[16] who, although he concedes that bronchial spasm is an all-important factor, denies that it of itself is sufficient to account for the sudden and enormous inflation of the lungs observed in that disease. He doubts the possibility of a valvular closure of the bronchi, as claimed by Biermer, but believes that the bronchial spasm, which he regards as primary, causes secondary spasmodic contractions of the diaphragm and of the inspiratory muscles of the neck and chest. The spasm of the diaphragm he believes to be tonic in its character, but not continuous, thus meeting Biermer's objection to the Wintrich theory, that tonic spasm of that muscle lasting longer than a few minutes would inevitably cause fatal asphyxia.

[Footnote 16: _Klinik der Brustkrankheiten_, 1ster Band, 2te Hälfte, p. 438.]

Theodor Weber,[17] rejecting the above theories on the ground that neither bronchial spasm nor tonic contraction of the diaphragm is capable of explaining why catarrhal secretion should come on at the close of an attack in which at the commencement there was no catarrh, attributes the phenomena of asthma to sudden swelling of the bronchial mucous membrane, the result of dilatation of its blood-vessels produced through the agency of the vaso-motor nerves; thus reviving the fluxionary theory of Traube. In support of this theory he cites the result of Von Loven's[18] experiments, which prove that irritation of the sensory nerves is followed by reflex engorgement of the territory to which they are distributed. Weber considers that this engorgement of the bronchial mucous membrane is somewhat similar to the acute swelling and stoppage of the nostrils to which many persons are subject--a closure which often does not last longer than a few moments, and which is attended with increased redness and swelling of the Schneiderian membrane. The mucous membrane of the nostril and that of the bronchi being both parts of the respiratory tract, and somewhat similar in structure, he concludes that the process in the nostrils is analogous to that which occurs in the bronchi during the asthmatic paroxysm. As additional proof of the correctness of his hypothesis he cites the fact that such occlusion of the nostrils is often the precursor of the asthmatic attack, and in some cases continues throughout the paroxysm. See investigations of Daly, Roe, Allen, and Hack, further on.

[Footnote 17: "Ueber Asthma Nervosum," _Tageblatt der 45 Versammlung deutscher Naturforscher u. Aertze in Leipzig, etc._, 1872, p. 159.]

[Footnote 18: _Naturforscher u. Aertze in Leipzig, etc._, 1872, p. 159.]

The idea that asthma is due to swelling and engorgement of the bronchial mucous membrane appears to have been confirmed by the tracheoscopic observations of Stoerk.[19] On examining the air-passages with the laryngoscope, he could see the mucous membrane of the trachea as far as visible (that is, to the bifurcation) grow red with the onset of the paroxysm, and resume its normal appearance after the termination of the attack. He opposes the spasm theory, denies the correctness of Biermer's conclusions, and adopts Weber's explanation of the asthmatic phenomena. He agrees with Wintrich that spasm of the diaphragm occurs, but claims that it results from the tension to which it is subjected by the inflated alveolæ: the diaphragm being forced downward by the distended lung, its fibres are stretched, and the result is a tonic spasm of that muscle. His objections, although well stated, are not sufficiently conclusive to cause us to accept his opinion in preference to that of Biermer and other supporters of the spasm theory.

[Footnote 19: _Mittheilungen über Asthma bronchiale, etc._, Stuttgart, 1875.]

{197} Max Schaeffer maintains that asthma is due to bronchial fluxion, as advocated by Weber, but claims that the hyperæmia is followed by spasm of the bronchial muscles, the former being primary and the latter secondary. He also, with many other recent writers, believes that asthmatic attacks are often associated with pathological conditions in and about the upper air-passages, such as naso-pharyngeal and laryngo-tracheal catarrh, polypi, hypertrophied tonsils, and enlarged cervical glands; all of which act as irritants, which, being transmitted through the neighboring nerves to the vagus, induce the bronchial spasm.

Among the older and discarded theories is that of Bree, who in a work published at the commencement of the present century expressed the opinion that the dyspnoea of asthma was simply an effort on the part of nature to rid the bronchial tubes of an irritating substance supposed to have accumulated in them previous to the attack. He believed that this materia peccans was thrown out with the expectoration which occurs toward the close of the attack. He regarded the violent efforts made by the respiratory organs to expel this offending substance from the bronchial tubes as similar to the tenesmus of dysentery or the painful contractions of the bladder when irritated by a rough calculus. Bree was unable to define more clearly the nature of this offending substance, but of late years another writer, Leyden,[20] has discovered in the sputa of asthmatics certain peculiar crystals to the irritating effects of which he attributes the various symptoms. These crystals had been observed previously by Charcot in the blood of leukæmic patients, and subsequently by Neumann in the medulla of the bones of patients who had died of that disease. Leyden describes the expectoration in asthma as tough, grayish-white, and very frothy. Imbedded in a transparent hyaline mass are a number of small bodies, some thread-like, others in the form of little plugs or flakes. Under the microscope these little bodies are found to consist of a mass of brownish cellular detritus containing large numbers of crystals. These are colorless, octahedral in form, with sharp points, and vary greatly in size, some of them visible at once, while others are seen only with the highest powers of the microscope. Their composition has not been determined, but is supposed to be a substance resembling mucin. Leyden's idea is that the sharp points of these octahedral crystals irritate the terminal ends of the pneumogastric nerve in the mucous membrane of the bronchi, and that this irritation, being transmitted to the nervous centre, is reflected back, and thus causes spasm of the bronchial muscles. It seems, however, that these crystals are not peculiar to bronchial asthma, having been also found in chronic catarrh and other affections of the bronchi.[21]

[Footnote 20: "Zur Kentniss des Bronchial Asthmas," _Virchow's Archiv_, Band liv., 1871.]

[Footnote 21: Not being able to obtain the original paper, the writer is indebted for the greater part of what he has written in regard to the Leyden theory to the treatises on asthma by Knauthe in _Eulenburg's Encyclopædie der gesammten Heilkunde_, and by Riegel in the work already quoted.]

Of the different theories of bronchial asthma which have just been presented, that of Biermer, although unsatisfactory in many respects, offers the best explanation of the pathology and symptoms of that disease.

PATHOLOGICAL ANATOMY.--Bronchial asthma being a purely functional neurosis, the organs involved present no anatomical changes specially characteristic of that affection. It is true that in cases of long standing, in which, owing to oft-repeated attacks, the air-cells have become distended and their walls attenuated, we find the lungs in the condition which will hereafter be described as emphysema, but these, as well as the evidences of chronic catarrh observed in these cases, are due to the secondary affections, and not to the primary disease.

As previously stated, a certain amount of hyperæmia of the mucous {198} membrane of the larynx, trachea, and bronchi may be observed during life with the aid of the laryngoscope; but whether this condition leads to permanent tissue-changes observable after death is exceedingly doubtful.

In the pneumogastric nerve pathologists have as yet been unable to discover, either at its origin or along its course to the lungs, any alteration in structure capable of explaining the phenomena of bronchial asthma.

DIAGNOSIS.--The suddenness of the attacks; the occurrence of the paroxysm usually in the latter half of the night; the slow, labored expiration, with the whistling, wheezing sounds which accompany it; the expectoration of catarrhal sputa toward the close of the attack; the normal respiration and absence of all signs of disease during the interval between the paroxysms,--are the features by which a case of simple uncomplicated asthma may be readily recognized. When these symptoms are present in their integrity in an otherwise healthy subject, there is no difficulty in arriving at the diagnosis; but, unfortunately, the picture is not always complete. The asthma may be complicated with organic disease of the heart or lungs, while primary disease of these organs, as well as certain affections of the nervous system, may produce symptoms closely resembling those of bronchial asthma, and from which it is very essential to distinguish them.

The following are some of the affections which may be mistaken for bronchial asthma:

1. Bronchial catarrh may be accompanied with more or less difficult respiration, but even in its worst forms it never causes the severe attacks of dyspnoea observed in bronchial asthma, and, as Riegel justly remarks, the severity of the symptoms in the latter disease are out of all proportion to the insignificance of the physical changes.

The dyspnoea of bronchitis comes on more gradually, the attacks being dependent upon a variety of accidental circumstances; whereas the asthmatic paroxysm usually occurs quite suddenly in the night without any apparent cause. The cough in bronchitis is severer and the expectoration more abundant than in asthma; the latter is also different in quality, becoming purulent as the disease advances, whereas in asthma it seldom loses its mucous character. These points of difference and the presence of the other symptoms of bronchitis are sufficient to differentiate that disease.

2. Emphysema is frequently associated with asthma, either as a cause, as is believed by many, or as an effect of that disease. It is often exceedingly difficult to determine whether the emphysema when present is the cause of the dyspnoea (symptomatic asthma), or whether the inflation of the air-cells and other symptoms are not the result of the bronchial spasm: a careful inquiry into the history of the case will often decide the question. The points of difference between the two diseases are very similar to those to which we have just called attention as the distinguishing features between the dyspnoea of bronchitis and the true asthmatic paroxysm. The suddenness with which the attack comes and goes, the severity of the symptoms compared with the insignificance of the local lesions, the absence of dyspnoea in the intervals between the attacks (in uncomplicated cases), are all the reverse of what is observed in emphysema. In that disease the attacks develop more gradually; there is always more or less shortness of breath, and the evidences of changes in the structure of the lung are quite marked.

3. Dyspnoea resulting from cardiac disease is often very severe, but may be distinguished from bronchial asthma by the presence of the various murmurs and other physical signs by means of which that class of diseases is recognized. The asthmatic paroxysm, as a rule, comes on when the patient is most quiet, usually during sleep. The attack of cardiac dyspnoea, on the contrary, is always brought on or aggravated by physical exertion, mental excitement, or some other apparent cause. In asthma the respiration during {199} the intervals between the paroxysms is quite natural; in cardiac dyspnoea there is always more or less embarrassment. Pain in the region of the heart, in many cases quite severe and extending down the left arm, may direct attention to that organ as the source of the dyspnoea.

4. Spasm of the glottis, croup, oedema of the glottis, tracheal stenosis, are all attended with more or less violent attacks of dyspnoea. We are indebted to Biermer for having directed attention to an important symptom by means of which all these affections may be distinguished from bronchial asthma. In the latter, and in all other diseases causing narrowing or obstruction of the finer bronchi, the dyspnoea is during the expiration, but if the impediment be in the larger air-passages the dyspnoea will be during the inspiration. "Dyspnoea during expiration is just as characteristic of narrowing of the finer bronchi as the same condition during inspiration is of croup and other forms of laryngeal stenosis." In croup the neck is extended and the head thrown back. Notwithstanding the violent inspiratory efforts of the patient, the lungs are but partially filled; the air in them becomes rarefied, causing a yielding of the less-resisting parts of the thorax--_e.g._ the supraclavicular space, the lower portion of the sternum, and adjacent costal cartilages--and a sinking in of the abdomen. During expiration, which is accomplished quickly and with comparative ease, the thorax resumes its natural form. In bronchial asthma, on the contrary, the head is thrown forward, and the shoulders fixed in such a position as to enable the muscles of expiration to work to the best advantage. The thorax, instead of sinking in, is expanded and abnormally round, giving on percussion the peculiar pasteboard-box sound (Schachtelton) which Biermer has described as characteristic of inflation of the alveolæ. In croup the sibilant râles are heard during inspiration, while in asthma they are more pronounced during expiration.

5. Spasm of the diaphragm is another affection from which it may be necessary to distinguish bronchial asthma. This rare disease, which is almost always associated with hysteria, is characterized by a short inspiratory movement, during which all the muscles of inspiration are brought into action, and we have the same sinking in of the more yielding portions of the thorax which has just been mentioned as one of the distinguishing features of laryngeal stenosis. After this the thorax remains fixed for a few seconds, the muscles of inspiration remaining in a state of contraction. There then ensues a quick and powerful expiratory effort, accompanied by a sound not unlike that of hiccough; then another inspiration, with a repetition of the above symptom; and so on until the attack is over. It will be seen from this description that this affection resembles singultus more than asthma, and that there is but little likelihood of its being mistaken for the latter disease.

6. Paralysis of the posterior crico-arytenoid muscles, like croup, spasm of the glottis, and all other affections which produce narrowing of the larger air-passages, is distinguished by the dyspnoea being inspiratory, and not expiratory. The function of the posterior crico-arytenoid muscles being to enlarge the glottis, the result of their being paralyzed would be to lessen the opening through which the air passes to reach the lung; and in viewing the cords in such a case with the laryngoscope it will be found that the opening is reduced to a narrow chink. Another distinguishing feature is that the dyspnoea is continuous, and, unlike bronchial asthma, does not come on in paroxysms.

7. An affection which, like asthma, comes on in the night during sleep is the condition known as nightmare, and, like the former disease, is characterized by labored breathing. To distinguish it, it is only necessary to awaken the patient, when the immediate cessation of all symptoms will at once remove all doubt as to the nature of the affection.

8. Through carelessness or ignorance intercostal neuralgia has been {200} sometimes mistaken for asthma. Pain along the course of the nerve and the presence of the points douloureux, which Valleix has described as characteristic of neuralgic affections, are sufficient to establish the diagnosis.

9. Embolism of one of the middle or larger branches of the pulmonary artery is also characterized by great embarrassment of respiration, but is not likely to be mistaken for asthma by any one at all familiar with the two affections. The cachectic appearance of the patient, the intense anxiety depicted on his countenance, the evidence of cardiac disease or of some affection of the vessels, the weakened cardiac impulse, the thready and at times irregular pulse, together with evidences of more or less pulmonary oedema, are sufficient to distinguish this form of dyspnoea from that of asthma.

PROGNOSIS.--As there is no well-authenticated case of death from uncomplicated asthma, the prognosis quoad vitam may be regarded as absolutely favorable. That death never occurs during the severe paroxysms of asthma may be due to the action of the deficiently aërated blood upon the respiratory centres, and bronchial spasm, causing relaxation when the symptoms have become most threatening. The asthmatic, if his case be incurable, may live for a number of years, and even attain to extreme old age, but his life will be one of intense suffering, which becomes more intolerable as he advances in years. Sooner or later, bronchitis, emphysema, or heart disease is developed, which in its turn may lead to renal disease and dropsy.

Such is the almost invariable result in middle-aged and elderly persons; in the young, however, the chances of recovery are much more favorable. Salter[22] states "that in youth the tendency is invariably toward recovery, whereas in one attacked with it after forty-five the tendency is generally toward a progressive severity of the disease and the production and aggravation of those complications by which asthma kills." The favorable result in childhood he attributes to the recuperative power of youth: growth and change, being more rapid than later in life, enable the system to repair during the intervals whatever damage may have been sustained during the paroxysms.

[Footnote 22: _On Asthma_, Am. ed., p. 168.]

There is another class of cases in which, owing to our being able to recognize and remove the cause, the prognosis is quite favorable: thus, if it has been discovered that the disease is due to some local influence, change will often effect a cure, and the patient will remain well as long as he remains in the locality which agrees with him, but generally relapses if he ventures to return to the place where he first contracted the disease. The same may be said of that form of asthma in which the disease is due to some trade or pursuit necessitating the inhalation of irritating dust or gases: the indications are obvious. Cases in which the paroxysms have been traced to the presence of nasal polypi or to a tumor pressing upon the course of the pneumogastric nerve have been promptly cured by the removal of these growths. In all these cases it is presupposed that there is no organic disease, for the presence of any one of the serious complications we have mentioned would dissipate all hope of cure.

In arriving at a prognosis it is all-important to inquire into the severity and frequency of the attacks, as violent paroxysms at short intervals soon lead to incurable complications. It is also essential to ascertain the condition of the patient during the intervals between the paroxysms: if at that time he feels well and does not suffer with shortness of breath, we may infer that as yet no organic change has occurred; if, however, he complains of more or less dyspnoea during the intervals, we may safely conclude that some organic disease has set in and that the case is incurable. Salter attaches great importance to the persistence of expectoration during the intermissions, regarding it as indicative of bronchitis, and therefore as an unfavorable indication: to use his own words, "Spitting is one of the worst signs in asthma."

{201} Briefly, those cases may be regarded as favorable in which the patient is young and has no inherited tendency to the disease, is free from the many complications of asthma, and in whom the attacks are light and occur at long intervals. On the other hand, all cases may be regarded as unfavorable in which the patient has reached or passed the middle period of life, has inherited a tendency to asthma, if the attacks are severe with short intervals, or if he has some one or more of the secondary affections of the disease.

TREATMENT.--The treatment of bronchial asthma consists of measures to mitigate and relieve the paroxysms and prevent their recurrence.

_A._ Of the Paroxysm.--A patient suffering with an attack of asthma will generally instinctively assume the position in which he can use the muscles of respiration to the greatest advantage, but if found in the recumbent posture he should be advised to sit up in bed and grasp the knees with his hands, so as to gain a position which admits of the more ready entrance of air into the lungs. In severe cases it is better to have him rise from the bed and support the head with the hands, the elbows resting on a table in front of him. An ingenious suspension-apparatus, intended to promote the comfort of persons suffering with severe dyspnoea, was extensively advertised several years ago, and may possibly still be furnished by the instrument-makers. It consists of a cross-piece suspended from the ceiling, to which straps are attached for supporting the shoulders without in any way pressing upon the chest; it is also provided with a band for the support of the head. In severe and protracted cases, when, notwithstanding the patient's exhaustion, he is unable to rest upon pillows, such an arrangement might afford great relief. If not undressed, the clothing should be so arranged as to interfere as little as possible with the respiratory movements. An abundant supply of fresh air is essential, and to secure this one or more windows should be thrown open.

Asthma being the most capricious of diseases, remedies often acting differently in each individual case, it is well before commencing treatment to follow Salter's advice and inquire of the patient what remedy has usually afforded the most prompt relief in previous attacks, and thus avoid the risk of prolonging suffering by using remedies which, although apparently indicated, may in his case, owing to peculiar idiosyncrasies, prove to be useless or even injurious.

We have seen that the disease is often due to some special cause, such as the inhalation of an atmosphere laden with the perfumes of certain flowers, with ipecac, dust, etc., the removal of which, if practicable, should of course precede all attempts at treatment. The condition of the stomach and bowels should be inquired into, and if found overloaded they should at once be relieved, the one by an emetic and the other by enema.

In the absence of any hint afforded by the previous experience of the patient the choice of the remedial agent will depend upon the severity of the attack. In the majority of cases, when severe, no remedy will afford such prompt relief as the subcutaneous injection of morphia. To be effective, the dose should be a full one, a fourth to a third of a grain, either alone or, if there is likelihood of this occasioning nausea, combined with one one-hundredth to one-eightieth of a grain of sulphate of atropia. The writer is aware that the use of opium and other hypnotics in bronchial asthma is discouraged by one of the most distinguished authorities on that disease, Salter, who claims that they are not only worthless, but often injurious. He believes that sleep tends to promote the paroxysm, reflex action being much more active then than during the waking hours, and that any agent which induces such a condition is necessarily contraindicated--that, in his opinion, in addition to exalting reflex action, it acts prejudicially, as "by lowering sensibility it prevents that acute and prompt perception of respiratory arrears which is the normal stimulus to those extraordinary breathing efforts which are necessary to restore the balance." These objections, although supported by {202} scientific evidence, are insufficient to cause the abandonment of an agent which in the hands of others has proved so prompt and efficacious in relieving the terrible sufferings of asthma, and Salter himself admits that since writing the above he has had cases in which it has been of signal service. A serious objection to its use is that the dose has to be increased as the patient becomes accustomed to its use. In confirmation of its marked beneficent effects, I give the following extract from Steavenson's treatise on asthma. Describing his own experience, he says:[23] "Sedatives and antispasmodics I should consider most serviceable drugs, but above all in value I should place the hypodermic injection of morphia. This has never failed to relieve an attack in myself, and I have never seen it fail in other patients. The objection to it is that if often used the dose must be increased; but it is better to increase the dose of morphia than suffer the agonies of asthma and allow those organic changes in the constitution to take place which I have described when speaking of the pathology of the disease. I have now used morphia for five years, but my attacks are so quickly relieved and so reduced in frequency that I have never yet had to increase the dose I commenced with--namely, one-sixth of a grain."

[Footnote 23: _Op. cit._, p. 29.]

Having administered the morphia, other measures for the relief of the patient should be resorted to. The feet and hands should be immersed in hot water to which a small quantity of mustard has been added. Dry cups between the shoulder-blades or sinapisms over the chest or epigastrium often afford marked relief.

If, on account of the existence of an idiosyncrasy on the part of the patient or from other causes, opium cannot be employed, we have in chloral hydrate a substitute which is almost as efficacious and perhaps even more prompt. Next to morphia, it is the most valuable remedy, and many esteem it superior to that drug, over which it possesses the advantage of not being followed by the disagreeable effects which so often succeed the administration of opiates. It should be given in doses of thirty or forty grains, and repeated if the paroxysm does not yield.

The inhalation of chloroform has long been esteemed as a potent agent in overcoming the bronchial spasm. One would naturally suppose that the use of such a powerful sedative as chloroform would be a dangerous proceeding in a disease which, like asthma, is attended with so much embarrassment of respiration and circulation; but experience does not justify this fear, and Salter, who has used it with good effect in 12 out of 13 cases, assures us that he has administered it "in the very agony of the worst attacks; that, so far from fearing it under such circumstances, it has been able to relieve the intensest asthma that nothing else would reach; that he has given it, and that he has never seen any bad effects from it." He goes on to state that as chloroform relaxes the bronchial spasm, and thus removes the cause of the "asphyxial stoppage, the intensity of the apnoea, so far from being a reason against the administration of chloroform, is the great reason for its immediate employment." He considers neither muscular weakness of the heart nor valvular disease as any contraindication to its administration, provided the circulation is not materially affected. According to Stokes, the paroxysm is not entirely suppressed by chloroform, but returns as soon as the patient passes from under its influence; hence it must be repeated as occasion may require. It should always, if possible, be given at the commencement of the paroxysm, and should never be allowed to produce complete insensibility, nor should so seductive a remedy be left in the hands of the patient. The danger of the self-administration of chloroform is only too well attested by the frequent accounts in the journals of persons found dead in their beds from the effects of that agent, death in such cases being usually due to the patient's {203} unconsciously leaving the handkerchief over the mouth and continuing to inhale the chloroform after having become insensible. When given sufficiently early, a few whiffs may be all that is necessary to overcome the paroxysm; and this repeated as soon as it threatens to return, will often enable us to control the symptoms without resorting to larger quantities.

An old and still very popular treatment--said to have been introduced by an American, Nicholas Frisi,[24] in 1843--consists of the inhalation of the fumes of burning saltpetre or in smoking cigarettes made of paper which has been soaked in a saturated solution of that substance. Inhaled into the bronchi, it is supposed to act as an anæsthetic, and produces relaxation of the constricted bronchial muscles. In point of efficiency these inhalations rank quite high, and are probably more generally used than any other remedy. Aside from the relief which they undoubtedly afford, this method derives much of its popularity from being within easy reach of the patient himself. The preparation of the papers is exceedingly simple: A sheet of bibulous paper is dipped into a saturated solution of the nitrate of potassa prepared with cold water; after drying it is divided into strips of the size required. These papers are burnt before the patient, the windows and doors of the apartment having been previously closed to prevent the escape of the fumes. Nitrate of potassa has been prepared in a variety of other ways for the use of asthmatic patients, one of the most convenient of which is the Kidder pastilles so extensively used in this country. Another method is to roll the paper prepared as above into cigarettes, the smoke of which is inhaled by the patient. The nitre is best used early in the attack, but is also beneficial when the paroxysm is at its height. The efficacy of this treatment is attributed by Germain Sée to the formation of protoxide of nitrogen and carbonic acid gas, which act as an anæsthetic, and perhaps also to the particles of carbon in the smoke floating in the air, a smoky atmosphere being beneficial to many asthmatics.

[Footnote 24: Germain Sée, _op. cit._, p. 709.]

The smoking of the Datura metel having been found efficacious in asthma in India, Anderson of Madras in 1802 sent some of the leaves to Gen. Gent, an English officer, by whom they were introduced into England. Simms of Edinburgh, believing that the Datura stramonium might prove equally good, tested it with such good results that it soon came into general use, not only in asthma, but in other forms of dyspnoea. This is the ordinary Jimson or Jamestown weed which is so widely distributed over the Southern, Middle, and Northern States, and, like nitrate of potassa, is much used, not only by the profession, but largely as a household remedy for asthma. The dried leaves are either smoked in a pipe or in the form of a cigarette. The effects, however, are quite uncertain, sometimes acting like a charm, while at others it affords no relief; its physiological action is that of a sedative. Of late years another species of Datura has been introduced--the Datura tatula. Its properties and uses are similar to those of stramonium, but it is supposed to be less narcotic.

Belladonna and its alkaloid, atropia, are often used in the treatment of asthma, but their action is uncertain and often unsatisfactory. The three last-mentioned remedies are also used in combination, as in the well-known Espic cigarettes, the formula for which, according to Trousseau, is as follows, viz.:

Rx. Fol. belladonnæ, gr. vj;
Fol. hyoscyami, gr. iij;
Fol. stramonii, gr. iij;
Fol. phillandrii aquatic. gr. j;
Ext. opii, gr. ¼;
Aq. lauroceras, q. s.

{204} The leaves, after being cut up, should be thoroughly mixed, after which they are moistened with the cherry-laurel water, in which the opium has been previously dissolved. The wrapper of the cigarette is also soaked in the same solution and dried. One or two of these cigarettes should be smoked during the attack. Abbott has been very successful with belladonna applied as a spray (drachm j of the extract to one ounce of water) when the spasm threatens.

Tobacco is a powerful depressant, and in those who are unaccustomed to its use is an invaluable remedy in asthma. In the uninitiated it excites nausea, vertigo, cold sweats, and other symptoms of relaxation which Salter not inaptly compares to those of sea-sickness. "The moment this condition can be induced the asthma ceases, as if stopped by a charm." It may, however, be asked whether the remedy is not worse than the disease. Those who retain a vivid recollection of the horrible consequences of their first smoke will hesitate before prescribing tobacco for one unaccustomed to its use. There are many who, not wishing to lose the beneficial effect of tobacco in asthma, never smoke unless a paroxysm threatens.

Lobelia, like the above also a depressant in its action, was formerly much employed in asthma. It is still used, but its effects are disagreeable and by no means certain.

The intimate nervous connection which exists between the lungs and stomach would naturally lead us to anticipate good results from emetics. In asthma, as in laryngismus stridulus, an emetic often affords prompt relief and arrests the paroxysm. The nausea which precedes the act of vomiting, acting as a depressant, causes relaxation of the spasm, while the emesis by unloading the stomach removes an important source of irritation. Like tobacco and lobelia, remedies of this class are only beneficial when pushed far enough to produce the symptoms of depression and collapse to which we have alluded; these once established the relief is usually complete. Tartar emetic and ipecacuanha are the representatives of this class most used in asthma. Tartar emetic, owing to the excessive and long-continued depression which it occasions, is now rarely employed, having been almost entirely superseded by ipecacuanha, which is equally efficacious and more prompt. Its effects also disappear more rapidly than those of antimony. Like other remedies intended to cut short the paroxysm, ipecacuanha should be given as early as possible. It should be taken in full doses of at least twenty grains.

Bromide of potassium, as is well known, acts upon the vaso-motor nerves, causing contraction of the arterioles of the brain and spinal cord, and thus inducing a state of partial anæmia which results in a lessening of the irritability of these organs, quieting muscular spasm and inducing sleep. These effects would naturally lead to its employment in spasmodic asthma. Although occasionally used with success in shortening the paroxysm, it is better adapted, as suggested by Riegel, for use during the intervals, when, if given continuously, it sometimes diminishes the severity of the paroxysms and causes them to recur less frequently.

Nitrite of amyl, a most valuable addition to our materia medica, has been extensively used in the treatment of asthma, but the reports of the results attained are too contradictory to admit of our forming any just estimate of its merits. The general opinion is that it relieves the dyspnoea and makes the patient for the time being more comfortable; and this accords with my own experience. The usual method of administration is to drop one or more minims upon a handkerchief and to inhale the vapor. It is also used internally, and, in the single case that has come under my observation, with benefit. The following case, reported by Pick and cited by Riegel,[25] is instructive as showing the favorable effects of nitrite of amyl: "The case was that of a medical student who from his youth onward had suffered with {205} asthmatic troubles, which increased as he grew older and had proved rebellious to all remedies. Nothing except expectorants and narcotics afforded him the slightest amelioration of his symptoms. On inhaling nitrite of amyl he experienced immediate relief, which lasted for some time after the inhalation. He was enabled to breathe deep and with comparative ease. The relief afforded was but transitory, but, on the other hand, was so sure that the patient resorted to it whenever the attack came on." The same writer reports two other cases in which he succeeded by means of nitrite of amyl in relieving the paroxysms and in increasing the interval between them.

[Footnote 25: _Op. cit._, p. 295.]

More agreeable to the taste and at the same time more effectual than the potassium iodide is hydriodic acid. It is best administered in the form of a syrup, preferably that prepared by Gardener of New York.

Salter, who appears to have had more experience with alcohol than any other writer, narrates the case of an elderly Scotch lady who, having exhausted all the known medicines and other agents used in asthma, was finally relieved by full doses of whiskey. This was invariably successful, but the dose, of course, had to be increased as the disease grew older. He also mentions another case in which nothing except chloroform afforded any relief. This he describes as the severest he has ever witnessed. "I have never seen or heard of spasms so violent or that seemed so nearly to put life in peril. His most intense spasms he calls 'screaming spasms,' from the strangling cries that the want of breath compels him to make. At the time of which I am speaking he lived on the same street with myself, and, although his house was half the length of the street from mine, his nurse has often assured me that if the doors had been open I could have heard his screams at my house at night. All remedies except the chloroform had failed, when one day his nurse advised him to try brandy. It afforded him almost instantaneous relief. He took enormous quantities of it, the first day a quart, and in the course of two months as much as twelve gallons. The spasm invariably stopped as soon as he took it, and for the last five months that he was under observation he had only what he called a 'thickness, a tight, constricted breathing,' several times during the night." Salter is particular in stating that the brandy should be given strong and hot.

Another stimulant highly recommended by Salter is coffee. In stating his objections to the use of opium it will be remembered that one of his reasons for not availing himself of that remedy was that it caused sleep, and that the exaltation of reflex action in that state favored the asthmatic paroxysm. Coffee, being a strong excitant of the nervous and vascular system, has the contrary effect and keeps the patient awake. It should be prepared as a strong infusion without the addition of either sugar or milk and given some time before the expected paroxysm. Administered in this manner, he claims that coffee will relieve two-thirds of all cases of asthma. The relief afforded is, however, very unequal, being in some cases complete, while in others it is only slight and transitory.

Quebracho in the form of an extract has been much used of late years in the treatment of asthma and other affections attended with dyspnoea. It has been found quite useful in mild cases.

The induced electrical current has been recommended by Schaeffer as a means of cutting short the paroxysm. His method is to place one pole on either side of the neck immediately below the angle of the jaw and in front of the sterno-cleido-mastoid, so as to cover the course of the pneumogastric and sympathetic nerves. The current should be sufficiently strong to enable the patient to feel the passage from one side of the throat to the other. It is applied for fifteen minutes twice a day for six days, twelve sittings being usually sufficient to afford relief. When the current is first applied it not {206} infrequently causes dilatation of the pupils, but this is succeeded by contraction when the treatment begins to manifest its beneficent effects.

_B._ During the Intervals between the Paroxysms.--The diet and daily regimen of the asthmatic should be most carefully regulated, the best and most skilfully directed treatment being of little avail if these important matters are neglected.