publication of the results in March, 1882. Moreover, his ability as a
skilled experimental observer in the study of micro-organisms, and his
sincerity as a truth-seeker, are universally admitted. Naturally, the
publication of the results of his researches excited at once great
interest in all countries. At the present moment (April, 1885)
questions connected with the bacillus tuberculosis are more considered
than any others relating to medical pathology and etiology. Thus far,
the observations of competent medical mycologists are confirmatory of
the results of the researches by Koch. It seems to be established that
the so-called bacillus tuberculosis is uniformly present in tuberculous
products, and as uniformly absent in other morbid products; that it is
generally present in the sputa of phthisical patients, and never
present in the sputa of non-phthisical patients; and that tuberculous
disease in animals may be produced by inoculation with this organism
after cultivation has been sufficiently continued to eliminate all else
pertaining to the tuberculous product. On these data are based the
conclusions that phthisis is an infectious disease--in other words,
that it involves in its causation a specific agent capable of
self-multiplication; that it is a communicable disease, and that the
agent of the communication is the bacillus tuberculosis--that is, this
agent is the contagium. The supposition that the presence of the
bacillus is secondary to the tuberculous affection is not tenable in
view of the fact that the affection is produced by the introduction of
this organism after it has passed through several generations by
culture out of the body.
As has been already seen, clinical experience fails to furnish positive
proof of the communicability of phthisis. There are many striking
instances which, taken by themselves, render it probable that the
disease was communicated; but, on the other hand, there are so many
cases of its development under circumstances not pointing to contagion,
and of the number of persons in close proximity to tuberculous patients
the proportion of those who become affected is so small, that it has
seemed impossible to establish the doctrine of contagion by clinical
evidence.
The insufficiency of clinical proof, however, cannot invalidate the
demonstration by inoculation. Assuming it to be demonstrated that the
disease involves a specific agent, and that this agent is proven to be
a contagium by its capability of producing the disease when introduced
into a healthy body, the conclusion as to communicability is not to be
shaken by the lack of corroborative clinical evidence or by inability
to explain certain facts which seem to be inconsistent with that
conclusion. Having accepted a demonstrated truth, the endeavor should
be to reconcile therewith facts which do not sustain it and which may
appear to be opposed to it. It remains to inquire in what way the
communicability of phthisis by means of a contagium vivum is to be
reconciled with facts furnished by clinical experience.
If we accept the conclusion that a particular parasitical organism is
the primary and efficient causative agent in the production of
phthisis, the development and multiplication of this organism must
require certain local conditions. Without these the parasite is
innocuous. The conditions are to its development and multiplication
what the peculiarities of soil are to the production of different
vegetables. Of the nature of these conditions we are at present
ignorant. When they exist the bacillus develops and multiplies; when
they are wanting the parasite is incapable of development and
multiplication. This dependence of specific morbific agents upon
particular {400} conditions is exemplified in other infectious
diseases. For example, the contagium of the eruptive fevers, received
into the system ever so abundantly, is inoperative in some persons,
and, as a rule with rare exceptions, it is never operative after the
disease which it occasions has been once experienced. In these
instances it is not the contagium itself which has lost the capability
of producing the disease, but the conditions for its activity are
wanting. Of the nature of these conditions we know as little as of
those which are essential to the development and multiplication of the
bacillus tuberculosis. The inoculation of animals with tuberculous
matter shows that the disease is produced in some species of animals
much more readily than in other species, and some animals of the same
species much more than others are susceptible to this contagium. These
facts are to be explained by variations in different species of
animals, and in different animals of the same species, as regards the
conditions required for the efficiency of the morbific agent.
The facts in the clinical history of phthisis which denote a
constitutional predisposition thereto or a tuberculous cachexia are
explicable by reference to the conditions requisite for the development
and multiplication of the parasite. A predisposition which may be
innate, inherited, or acquired involves the existence of these
conditions. The latter may be greater or less in degree. The causative
agencies of confinement within doors, humidity of soil, pregnancy, etc.
operate by either giving rise to or increasing these conditions. If
this view be correct, it is evident that the curative influence of
climatic changes, alteration of the habits of life, and other hygienic
agencies must be by means of an effect exerted upon these conditions;
and probably it is in this way chiefly that remedies are useful. Of the
essential nature of these conditions we know neither more nor less than
of what consists the tuberculous cachexia. We are, of course, as
ignorant of the one as of the other if it be assumed that they are
identical--that, in other words, the different expressions have the
same meaning. The only difference is this: If phthisis be an infectious
and a communicable disease, a contagium enters into its etiology;
whereas if the existence of a contagium be denied, it follows that the
cachexia is itself sufficient for the causation of the disease.
In connection with the etiology of phthisis a theory which of late
years has found favor with many should be referred to. It is, that this
disease may be a result of the absorption of caseated non-tuberculous
morbid products in different parts of the body. This theory of
autochthonous infection derives but little support from clinical
observation. In much the larger proportion of the cases of phthisis it
is impossible to discover anywhere caseated morbid products which may
be supposed to have a causative connection with the disease. To assume
that, when not discovered, foci of infection nevertheless are concealed
somewhere within the organism is evidently begging the question. On the
other hand, how often do suppurations, necroses, and degenerated morbid
products occur in different situations without being followed by
phthisis!
SYMPTOMATOLOGY AND COMPLICATIONS.--Giving under this head a fuller
account of the symptomatology and complications than has been already
given in sketching the history of the disease, it will be a convenient
arrangement to consider these topics in their relations to the
different anatomical systems of the body--namely, the respiratory,
circulatory (including temperature), hæmatopoietic, digestive, nervous,
and genito-urinary systems.
Symptoms, etc. referable to the Respiratory System.--The dry cough
which is the earliest pulmonary symptom in typical cases is to be
regarded as an effect of the local irritation caused by the presence of
the tuberculous product. This product, increasing and extending, gives
rise to circumscribed bronchitis which causes increase of cough with
expectoration. The expectoration represents this secondary bronchitis
prior to the occurrence of {401} ulceration, the escape of liquefied
tuberculous product, and the existence of cavities. The quantity and
the characters of the matter expectorated depend on the degree and the
extent of the bronchial inflammation, the latter depending on the
extent of the phthisical affection. Different cases present wide
variations in these respects. The frequency and severity of the cough
depend in a great measure on the quantity of the matter of
expectoration and its adhesiveness. The matter expectorated, at first
semi-transparent mucus, becomes muco-purulent, the characters
pertaining to mucus and pus being combined in varying proportions, as
in cases of chronic bronchitis. Nummular sputa--so called from the
resemblance in form to a coin when lying on a flat surface, the edges
often serrated--are considered as casts of small cavities formed by
dilated bronchi. A microscopical examination of the sputa may show
elastic yellow fibres. The presence of these is almost pathognomonic of
phthisis, and denotes either the process of ulceration or exfoliation
of tissue from within cavities.[8] Liquefied tuberculous product
appears in the matter of expectoration as a puriform fluid. It
sometimes contains small semi-solid tuberculous masses. The lining
membrane of tuberculous cavities furnishes a veritable purulent matter
of expectoration. It is stated by Buhl that the presence of alveolar
epithelium in the sputa is distinctive of phthisis; hence the name
proposed by him, desquamative pneumonia. It is, however, stated by
Frischl that the alveolar epithelium is found in the matter
expectorated in cases of oedema and congestion of the lungs.[9] There
is sometimes notable fetor of the matter of expectoration, due to
putrescent decomposition of the purulent contents of cavities or to
small sloughing portions of pulmonary tissue. The varieties of sputa
which have been mentioned may be accompanied by a serous liquid in more
or less abundance. Calcareous masses varying in size from a pin's head
to a pea are expectorated in some cases. I have known several hundred
to be expectorated in a single case. In the instances which have fallen
under my observation these pulmonary calculi have been expectorated
when the symptoms have denoted arrest and regression of the disease;
and it is consistent with this fact to regard them as obsolete
tubercles. They are not to be confounded with the small solid bodies
sometimes formed in the follicles of the tonsils, the latter consisting
of a sebaceous-like product, which is crushed, without crumbling, by
pressure, and emits a fetid odor. Since the discovery of the bacillus
tuberculosis by Koch microscopical examinations of sputa in a large
number of cases by different observers have shown that this parasite is
generally, but not invariably, present. Its abundance in the sputa
appears to correspond to the rapidity with which the tuberculous
affection is progressing, and examinations with reference to its
presence and its abundance are of much practical utility in diagnosis
and prognosis.
[Footnote 8: In order to discover the elastic fibres readily, Fenwick
advises as follows: "Prepare a solution of caustic soda, about twenty
grains to an ounce of distilled water. Collect all the patient has
expectorated in twelve or twenty-four hours, from ten at night to ten
the next morning being the best period. Pour this, previously mixed and
well shaken with an equal quantity of the soda solution, into a glass
beaker, and boil it over a gas or spirit-lamp, stirring it occasionally
with a glass rod. A test-tube does not warm as well as a beaker. As
soon as it boils pour it into a conical glass, and add four or five
times the amount of cold distilled water. If the mucus is still
gelatinous after boiling, you have either added too little soda or not
boiled it sufficiently. The cold water carries down to the bottom of
the glass any lung-tissues that may be present, where they form a
slight deposit in about a quarter of an hour; if no deposit is visible,
put the glass aside for two or three hours. Remove the deposit with a
dipping-tube, place it in a glass cell, cover it with a piece of thin
glass, and examine with a one-inch object-glass. The lung-structures
will be often found clinging to hairs and other foreign bodies present
in the sputa" (_Guide to Medical Diagnosis_).]
[Footnote 9: Vide Niemeyer by Seitz, tenth ed.]
Hæmoptysis occurs in a large proportion of the cases of pulmonary
phthisis. {402} It occurs much oftener in the early than in a later
period of the disease. As regards the number of attacks, their
duration, the intervals between them, and the amount of hemorrhage,
there are wide variations. Prior to the formation of cavities the
hemorrhage is from the bronchial tubes (bronchorrhagia). After cavities
are formed the blood comes from the interior of these. As a rule,
bronchial hemorrhage is not followed by the evidence of any increase of
the phthisical affection. Not infrequently a sense of relief follows.
The analytical study of a large collection of cases shows that the
occurrence of bronchial hemorrhage does not diminish, but apparently
increases, the chances of arrest and of tolerance of the disease. This
statement holds true with regard to cases in which the hemorrhage is
often repeated and profuse, as well as to those in which it is slight
and infrequent.[10]
[Footnote 10: Vide _Phthisis, in a Series of Clinical Studies_, by the
author.]
Cavernous hemorrhage may be due to rupture or ulceration of
parenchymatous bands which traverse cavities, but often it is caused by
the bursting of small aneurisms in their walls. It may be so profuse as
to prove fatal. Cavities sometimes become filled with coagulated blood,
which, if life continue, becomes decomposed and gives rise to a
grumous, fetid matter of expectoration. Bronchial hemorrhage is
supposed to be caused by a circumscribed hyperæmia at the situation
where the blood escapes. In a case under my observation in which death
took place shortly after a profuse hæmoptysis, there was congestion
limited to the middle lobe of the right lung, and the bronchial tubes
in this situation contained bloody mucus, none being found elsewhere. A
circumscribed hyperæmia, however, must depend upon some local cause.
Probably in most instances this anterior local cause is the tuberculous
product. That the escape of blood involves a change in the coats of the
vessels from which it escapes is probable.
A rare event occurring in connection with hæmoptysis is the coagulation
within the bronchial tubes of fibrin which may be expectorated in the
form of casts of the tubes, analogous to those which characterize
fibrinous or plastic bronchitis. I have met with an instance, and also
with a case in which after death the bronchial tubes of an entire lobe
were found to be filled with solidified fibrin. The death in this
instance followed quickly a profuse hæmoptysis. There is not the danger
connected with the gradual disintegration and expectoration of the
coagulated fibrin which was surmised by Niemeyer.
The presence of the tuberculous product in the lungs and the processes
to which it gives rise, inclusive of the secondary bronchitis, occasion
no pain. Patients often strike the chest with violence, as affording to
them evidence that the organs are sound. But in most cases, from time
to time during the course of the disease, sharp stitch-like pains
occur. They are sometimes slight or moderately severe, but they may be
sufficiently intense to confine to the house or even to the bed. They
last, usually, but a few days, and recur at variable intervals. They
are referred generally to the upper part of the chest, often beneath
the scapula. Patients are apt to imagine that the pains are rheumatic.
They are symptomatic of successive, circumscribed, dry pleurisies,
which are very rarely wanting in cases of phthisis, leading to the
pleuritic adhesions constantly found after death. These pleurisies are
secondary to the phthisical affection, and recur at epochs when new
developments of the latter take place. There is no reason to suppose
that they contribute in any way to the increase of the phthisical
affection. On the other hand, they protect against one important event
at least--namely, perforation of lung, and, as consequent thereon,
pneumo-hydrothorax. In this point of view they are conservative. These
pleuritic pains are to be discriminated from those of intercostal
neuralgia. The neuralgic pains generally are situated lower, and the
diagnostic criterion of intercostal neuralgia is {403}
available--namely, the tenderness on pressure in the intercostal spaces
near the median line in front, the axillary line, and the spinal
column.
The respirations are more or less frequent in different cases and at
different periods in the same case according to the impairment of the
function of hæmatosis by the pulmonary affection and the increased
frequency of the heart's action. A sense of the want of breath as
implied in the term dyspnoea is, however, seldom sufficient to occasion
much suffering. Even when the respirations are considerably increased
in number it is rare for the patient to complain of the want of breath
when at rest. A degree of muscular weakness which prevents the patient
from freeing the bronchial tubes and cavities of morbid products may
give rise to distressing dyspnoea. A sudden increase in the frequency
of the respirations, with dyspnoea and cyanosis, when not attributable
to filling of the bronchial tubes nor to pneumothorax nor pleuritic
effusion, points to the development of miliary tubercles in
abundance--in other words, to the supervention of acute tuberculosis.
Important complications referable to the respiratory system are
laryngitis, non-tuberculous pneumonia, pleurisy with effusion,
perforation of lung with pneumo-hydrothorax, pneumorrhagia, and
pulmonary gangrene.
Dysphonia and aphonia, the voice being husky or hoarse and the whisper
stridulous, denote laryngitis. These diagnostic symptoms are never
wanting, and the laryngeal complication may be excluded if they be
absent; but the extent to which the larynx is affected is of course
determinable by means of the laryngoscope. The affection in some cases
extending to the epiglottis, paroxysms of cough and spasm of the
glottis are produced by the act of swallowing food and drinks. The
interference with deglutition may be so great as to restrict seriously
alimentation, and in this way may hasten a fatal termination of the
disease. In the majority of cases, however, deglutition is not
interfered with. There is very rarely laryngeal obstruction to
respiration. The affection involves little if any liability to the
supervention of acute laryngitis or oedema of the glottis.
In most cases the laryngitis occurs at a considerable period after the
commencement of the pulmonary affection, this period, in a proportion
of more than one-third, being from two to four years. In some instances
it seems to occur coincidently with, and in some to precede, the
pulmonary affection. In the latter instances it is probable that latent
tuberculous disease of the lungs preceded the laryngitis. The diversity
as regards the interval of time between the date of the pulmonary
affection and of the occurrence of the laryngitis, the apparent
coincidence in the occurrence of both in some instances, and the want
of any uniformity in different cases as regards the amount of pulmonary
disease and the stage of its progress when the laryngitis occurs,
render it a rational conclusion that laryngitis is not dependent on the
disease of the lungs, but that it proceeds from the same cause which
determines the latter.
Excluding the instances in which the laryngitis involves the epiglottis
and interferes with alimentation, clinical experience teaches that this
complication does not diminish the chances of arrest or recovery from
the pulmonary affection, and that it has no untoward influence on the
duration of the disease in the cases which sooner or later end
fatally.[11] As a rule, in cases which recover the voice remains
permanently more or less affected.
[Footnote 11: Vide _Phthisis, in a Series of Clinical Studies_, by the
author.]
Acute lobar pneumonia or pneumonic fever is sometimes an intercurrent
affection in cases of phthisis. The cases are so rare as to show
absence of any predisposition to that disease derived from the
phthisical affection. The pneumonia ends in recovery in a proportion of
cases sufficiently large to show that, as a rule, the prognosis is not
unfavorably influenced by phthisis, and, as a rule also, the course of
the latter is not influenced unfavorably by the {404} pneumonia. A
circumscribed pneumonia is an occasional complication of phthisis. Its
non-tuberculous character is shown by the rapidity and completeness of
the absorption of the intra-vesicular product. This circumscribed
pneumonia gives rise to physical signs which appear to denote a rapid
and considerable increase of the phthisical affection. The
disappearance within a short period of the added dulness on percussion,
bronchial respiration, and bronchophony, is the evidence that these
signs represent a circumscribed pneumonia occurring as a complication.
Pleurisy with serous effusion is not an infrequent complication at an
early period in the course of the disease. There is very little if any
liability to its occurrence at an advanced period, except as associated
with pneumothorax from perforation of lung. It is probably secondary in
certain of the cases in which the phthisical affection appears to
follow the pleurisy. The pleuritic effusion appears to retard the
progress of the phthisical affection. Clinical experience shows that
this complication, if it be unilateral, is not an untoward event. A
double pleurisy with effusion is evidence of the existence of phthisis.
Perforation of lung, giving rise to pleurisy with effusion and
pneumothorax, is an event which belongs, with some exceptions, to an
advanced period of the disease. The perforation is caused by rupture of
the wall of a cavity superficially situated where pleuritic adhesion
from circumscribed dry pleurisy had not taken place. In most instances
the occurrence of the perforation is quickly followed by acute pain and
orthopnoea, with notable disturbance of the circulation, fever, and
prostration, these symptoms being due to the sudden entrance of air
into the pleural sac, the development of acute inflammation, and rapid
serous effusion. The recognition of the pneumo-hydrothorax by means of
physical signs is easy. The suffering of the patient becomes less after
twenty-four or forty-eight hours. In the great majority of cases death
takes place within a short period; that is, within a few days or weeks.
The duration of life depends on the amount of phthisical disease,
together with the condition of the patient as regards strength, etc. In
some instances, the perforation taking place when the phthisical
affection is small and accompanied by favorable symptoms, the
pneumo-hydrothorax is tolerated for a long period. The accumulation of
liquid within the pleural sac sometimes causes the air to disappear,
and the pneumo-hydrothorax is converted into simple pleurisy with large
effusion.
Pneumorrhagia and pulmonary gangrene are very rare complications of
pulmonary phthisis. The analytical study of nearly 700 recorded cases
furnished but a single example of each of these complications.