24 Vide Phthisis, in a Series of Clinical Studies, for abstracts of the histories of these cases. Absence of all pulmonary symptoms was known to have existed in the different cases for periods between six months and twenty-seven years. Throwing out two cases in which the period was six months, and one case in which it was eight months, the average period was six years.
Next to recovery, the course of the disease is favorable when it ceases to be progressive and life with fair health is continued for a long period. Out of the cases which I have analyzed, there were 28 in which the disease was known to have existed for periods ranging from one year and three months to twenty-five years. The duration was reckoned up to the time of the analysis or of the last information obtained. The number of years noted does not express the duration of life. The average period during which the disease was known to have been non-progressive is a fraction over eight years. The histories in these cases exemplify the fact that phthisis, when it ceases to be progressive, although recovery does not take place, is not incompatible with fair and even good general health and long life. That recovery does not take place is owing to the persistence of pulmonary lesions, such as cavities which do not cicatrize or an interstitial pneumonia with dilatation of bronchial tubes. The tuberculous disease no longer continues, but the local effects of the disease remain. Slowness of progress and prolonged tolerance are to be hoped for when the disease neither ends in recovery nor becomes non-progressive. In some cases the disease ends fatally, having existed for many years where at no time could it be said that its progress had ceased. The prolongation of life under these circumstances depends on the slowness with which the disease progresses and the ability of the system to tolerate it.
The extremes of the duration of the disease in a large collection of fatal cases are so far apart that the average period is of little practical value as bearing on the prognosis in individual cases. In the collection of recorded cases which I have studied analytically, there were 112 the duration of which from the commencement of the disease to its fatal termination was ascertained. The mean duration was about twenty-three months. Laennec found the average duration twenty-four months; Louis and Bayle, twenty-three months; Andral, twenty-four months; Sir James Clark, thirty-six months; and Williams of London, forty-eight months.
TREATMENT.—The author premises the consideration of the treatment by stating that this article was written before sufficient time had elapsed after the publication of the researches by Koch for their confirmation by other competent observers. At the present time (May, 1885) the doctrine that phthisis depends on the presence of a special micro-organism is to be considered as probably established. The grounds for this statement have been presented under the head of the Etiology, and reference to the practical bearings of the doctrine have been introduced in connection with the Diagnosis and Prognosis. It is evident that the doctrine is likely to have important bearings on the treatment. If it be true that the origin, the extension, and the diffusion of the disease within the body require the presence and the multiplication of a particular parasite, it is evidently a rational object of treatment to effect its destruction. For this object an efficient parasiticide is to be sought after, to be administered either by inhalation or by its introduction into the blood-vessels. Already, within the short time which has elapsed since Koch's discovery, extended observations have been made with various substances which are destructive to bacteria outside of the body, but thus far without success. A difficulty as regards inhalation is in the way of a destructive agent in the form of either an impalpable powder or a vapor or a gas reaching the colonies of bacilli in sufficient quantity to effect the object, without doing injury to the tissues or inducing toxæmia. As regards the introduction of parasiticides into the blood, it seems hardly probable that a toxic agent can be safely introduced in sufficient quantity to effect the object. It remains to be determined by clinical observation whether or not these difficulties are insuperable.
Efforts to destroy the parasite in another direction promise to be more effectual—namely, by the removal of the co-operating conditions on which their multiplication depends. It is to be borne in mind that the development and continuance of phthisis involves two factors, one which is the presence of the parasite, and the other the existence of those unknown conditions constituting the tuberculous predisposition or cachexia. The removal of the latter may effect the destruction of the parasite indirectly, but not less certainly than by bringing into direct contact with it a destructive agent. It is in this indirect way that the measures of treatment which experience has shown to be more or less effective may be supposed to operate. And it is to be added that those measures of treatment the usefulness of which rests on clinical observation are in no wise disproved or modified by the parasitic doctrine. At the present time the treatment of the disease is to be governed by principles which, based on reason and experience, are independent of that doctrine.
The intrinsic tendency of phthisis to be either progressive or non-progressive underlies the treatment. In a certain proportion of cases the disease tends to advance steadily and actively, as shown by the symptoms and the physical signs. In these cases treatment cannot be expected to do more than to palliate symptoms, and perhaps prolong the duration of life. These are cases of so-called galloping consumption. In a larger proportion of cases the disease does not steadily or actively advance. Remissions occur. The pulmonary affection increases, and extends by successive tuberculous invasions or eruptions after intervals variable in duration. These cases offer more encouragement for treatment. There is room to hope after each invasion that another will not take place, and that the affection which exists may be tolerated indefinitely if the cases do not end in recovery. In a minority of cases when a certain amount of pulmonary affection has taken place there is no further increase or extension. In this respect the disease ceases to progress. In some of these cases after the lapse of weeks or months all pulmonary symptoms disappear, and the patient may be said to have recovered. The probabilities of the recovery and the time required therefor vary, other things being equal, according to the amount of the pulmonary affection. In other cases recovery does not take place. More or less of pulmonary symptoms remain. The existing lesions which these symptoms represent, however, may be well tolerated, and their existence may not interfere with fair or even good general health and long life.
Whenever the disease ceases to be progressive, with or without recovery, an intrinsic tendency has more or less agency in the cessation of progress. In some instances it is certain that this result is wholly due to self-limitation. Expressing the fact in other language than that of personification, the disease may become non-progressive because the unknown, special, constitutional morbid conditions which it is customary to embrace under the name tuberculous cachexia no longer exist; or, assuming that a particular parasite is essential to the progress of the disease, this organism may cease to multiply in consequence of the non-continuance of conditions which are necessary for its multiplication. Whatever be the explanation of the tendency of the disease—to be, on the one hand, progressive, or, on the other hand, non-progressive—it must be taken into account in estimating the influence of measures of treatment. How largely an intrinsic tendency to be non-progressive is accountable for apparent success in treatment cannot be determined with precision. The evidence of its agency can only be derived from the accumulation of cases of non-progressive phthisis in which no active measures of treatment were pursued. Reference has been made to a few such cases among those which I recorded during a period of thirty-four years. Some cases in addition have come under my observation since the analysis of my cases recorded up to 1875. It is evident that a large collection of such cases cannot be made by a single observer.
From what has been stated, it follows that the treatment in case of phthisis has reference especially to the constitutional conditions which stand in a proximate causative relation to the pulmonary affection. The chief objects are to arrest the disease and to keep the cachexia in abeyance. In the present state of our knowledge measures of treatment addressed directly to the pulmonary affection, albeit important, are of secondary importance when compared with those which either co-operate with or oppose the underlying intrinsic tendency of the disease as manifested in individual cases.
Proceeding to consider the treatment in cases of phthisis, a convenient division of topics is into those relating to the climatic treatment, the dietetic and regiminal treatment, and the medicinal treatment.
Climatic Treatment.—It would be impossible within the limits of this article to enter into a discussion of the various questions connected with climatic influences or to consider the relative advantages of different climates. Nor, were it possible, would this be desirable as regarded from a practical standpoint. I shall confine myself to the general considerations which bear upon the climatic treatment.25