opaque and more easily dislodged by coughing, all the more important
{172} symptoms begin slightly to improve, and by the end of the second
week convalescence is fairly established. Many cases, however, are less
acute, slower in progress, and do not reach convalescence in less than
two or four weeks; and many of this class manifest a strong tendency to
continue indefinitely in a chronic form, more especially in persons
past the middle period of life. In some of the cases that do not
continue in a chronic form, the bronchial membrane is left in a
condition of such susceptibility that the attack is renewed on the
slightest exposure to the exciting causes.
Rheumatic Bronchitis.
Although many systematic writers on practical medicine make no mention
of this form of bronchitis except as a complication of general
rheumatic fever, yet cases both of acute and chronic inflammation of
the bronchi, of unmistakable rheumatic character, have so often come
under my observation that I am constrained to recognize it as a
distinct form of disease. In regard to the relative frequency of the
occurrence of this class of cases, I find in a brief report concerning
965 cases of chronic pulmonary disease, read in the medical section of
the American Medical Association by F. H. Davis in 1877,[5] the
following classification of the cases:
Chronic catarrhal bronchitis . . . . . . . . . . . . . . . . . . 403
Chronic rheumatic bronchitis . . . . . . . . . . . . . . . . . . 283
Chronic bronchitis accompanied by gastric derangement and
spasmodic dyspnoea . . . . . . . . . . . . . . . . . . . . . . 119
Chronic bronchitis, modified by syphilitic disease . . . . . . . 37
Hereditary pulmonary tuberculosis . . . . . . . . . . . . . . . 56
Inflammatory pulmonary phthisis . . . . . . . . . . . . . . . . 67
---
Total . . . . . . . . . . . . . . . . . . . . . . . . . . . 965
It will be seen that, of the 842 cases of chronic bronchitis included
in the table, the writer classes 283, or a trifle more than 33 per
cent., as of rheumatic character. That the relative proportion of acute
cases of a distinct rheumatic character is less than those of a chronic
grade I have no doubt, and yet their number is not so small as to be
insignificant or unworthy of careful attention.
[Footnote 5: See _Transactions of American Medical Association_, vol.
xxviii. p. 269, 1877.]
They differ in clinical history from ordinary acute bronchitis chiefly
in the following particulars: Etiologically, a large proportion of them
occur in persons of a rheumatic diathesis, either hereditary or
acquired, and at those seasons of the year characterized by a
predominance of cold and damp air with frequent changes of temperature.
Symptomatically, they are characterized from the beginning by more
continuous dull pain in the chest, often extending to the attachments
of the diaphragm, the shoulders, and the dorsal portion of the spine;
by more persistent dry, harsh cough, often exhibiting a marked
spasmodic character and accompanied by a great aggravation of the pains
in different parts of the chest. When the smaller bronchi are involved
the stage of dry râles is much more protracted, the dyspnoea and
suffocative paroxysms of coughing more uniformly aggravated at night;
and when mucous exudation does take place it remains scanty and viscid,
rarely presenting a distinct muco-purulent character unless the case is
protracted into a chronic form, and sometimes not then. During the
active stage the urine is less in quantity and more decidedly acid in
reaction than natural, and the bowels generally costive.
When not interfered with by appropriate treatment, these cases run a
much more protracted course, and more frequently degenerate into a
chronic form, {173} than those of an ordinary catarrhal character. When
they are thus allowed to run a protracted course or to continue in a
chronic form, they manifest another tendency of great
importance--namely, to have the inflammation extend by continuity from
the fibrous and muscular structures of the small bronchi into the
connective tissue of the pulmonary lobules, inducing sclerosis of the
latter tissue and consequent compression or obliteration of the alveoli
or air-cells, and permanent contraction of the chest. Much and careful
clinical observation has satisfied me that many of the cases now
classed by writers as fibrous and inflammatory phthisis began as simple
acute or subacute rheumatic bronchitis, which, being renewed at every
return of the cold, damp, and changeable part of the year, not only
ultimately caused permanent thickening of the bronchial structures, but
gradually invaded portions of the connective tissue of the lungs, and
induced similar pathological changes in it, constituting the sclerosis
just mentioned.
Pseudo-membranous Bronchitis.
This affection has been described by different writers under the
additional names of plastic, croupous or croupal, and diphtheritic
bronchitis. The extension of the inflammation and membranous exudation
to the bronchial tubes in cases of diphtheria and pseudo-membranous
tracheitis and laryngitis or croup, is of frequent occurrence. But as a
distinct disease limited to the bronchial membrane it is of
comparatively rare occurrence.
In 1854, T. B. Peacock noticed in the _Transactions of the London
Pathological Society_ 34 cases collected from European sources; Biermer
in 1867 increased the number to 58; Kretschy in 1874 added 10, and
Chevstok 4 more cases--making in all 72 cases in Europe. In 1879, W. C.
Glasgow of St. Louis read to the medical section of the American
Medical Association an interesting report on the subject of plastic
bronchitis, in which he notices 23 cases which had occurred in this
country, accounts of which were obtained from an extensive
correspondence with leading physicians in all parts of the United
States, as well as from reference to our periodical medical
literature.[6] These statistics are certainly sufficient to justify the
statement that the disease is of rare occurrence both in this country
and in Europe.
[Footnote 6: See _Transactions of the American Medical Association_,
vol. xxx. p. 177, 1879.]
The statistics thus far collected show a much greater prevalence of the
disease in males than in females, and that the larger number of cases
occur between the ages of fifteen and fifty years, although one case is
reported by T. G. Simons of Charleston, S. C., as quoted by Glasgow, at
four years of age, and Goumoens one at seventy-two. In a large
proportion of the cases reported the disease existed in a chronic form.
When acute, and affecting a large portion of the bronchial membrane, it
is liable to lead to an early fatal termination from obstruction to the
ingress of air to the air-cells of the lungs. But in many cases the
disease has extended to only a limited number of the bronchi, and
recovery has generally taken place in from two to three weeks.
The symptoms differ from those of ordinary bronchitis in only two
important particulars--namely, the more violent and suffocative
character of the cough, and the actual appearance of shreds, patches,
or casts of pseudo-membrane in the matters raised and ejected by
coughing. The latter is the only reliable diagnostic symptom by which
it can be certainly differentiated from all other forms of bronchial
inflammation. When the membranous exudation is discharged in shreds or
small pieces, it may readily escape the attention of the physician, and
even considerable casts when expectorated are in some cases so
surrounded with mucus and collapsed into a slightly yellowish mass in
the central part of the mouthful expectorated, that they might be
regarded as only {174} a more muco-purulent part of the mucous
secretion. If the whole is thrown into water, however, and agitated a
little, the membranous patches and casts will be quickly unfolded in
such a manner as to be easily recognized. It is distinguished from
mucus by placing it in a solution of acetic acid, which causes it to
swell, while mucus contracts in a similar solution. It has the
appearance of having been formed in concentric layers, and is sometimes
cast-off so complete as to present a continuous representation of one
or both primary and several of the secondary bronchial tubes. Under the
microscope it has the same fibrillated appearance as other
pseudo-membranous formations.
Chronic Bronchitis.
Cases of acute and subacute bronchitis belonging to either of the five
varieties just described may be protracted until they assume a chronic
form, and other cases of each variety are met with which have been
chronic from the beginning. This form of the disease is met with in
aged persons more frequently than at an earlier period of life. In
children it sometimes follows as a sequel of measles and whooping
cough, and in adults is often associated with tuberculosis, emphysema,
and cardiac diseases.
ETIOLOGY.--Chronic bronchitis is capable of originating from any and
all the causes that have been enumerated as capable of producing the
more acute forms of the disease, and consequently prevails most under
the same conditions of topography, climate, and social relations.
SYMPTOMATOLOGY.--The symptoms of ordinary chronic catarrhal bronchitis
differ from those accompanying the acute form of the disease, chiefly
in the absence of general fever and the existence of much less pain or
feeling of soreness and oppression in the chest. The patient generally
complains of a rather harsh, full cough, usually more severe on first
retiring to bed at night and on rising in the morning, but occurring at
intervals through the day, and accompanied by a mucous or muco-purulent
expectoration varying much in its amount and tenacity. In the great
majority of cases occurring in young persons and in the first part of
adult life, the expectoration is simply a whitish or slightly opaque
mucus, more or less frothy from the intermixture of minute bubbles of
air, and easily dislodged, especially in the mornings. In old persons
and in cases which have continued a long time, the expectoration often
becomes more copious and more decidedly purulent, with slight
feverishness at night and some loss of flesh.
In all the cases except those last mentioned the general health of the
patient is but little impaired, the appetite and secretions usually
remaining nearly natural. Those who pursue indoor occupations or are
sedentary in their habits will be prone to constipation and imperfect
digestion--more, however, from the circumstances just mentioned than
from the effects of the bronchial disease. All cases of chronic
bronchitis are subject to temporary aggravation by exposure to a cold
and damp atmosphere, whether indoors or out, and are also very
susceptible to increase from the inhalation of air containing dust or
floating particles of solid matter or of irritating gases.
Cases of ordinary chronic bronchitis rarely prove fatal without the
intercurrence of some other disease, and yet there is no natural limit
to their duration. In many cases the symptoms almost disappear during
the warm months of summer, but return with the first period of cold and
wet weather of autumn. Such patients usually find permanent relief by
changing their residence to a mild and dry climate.
The symptoms of the rheumatic grade of chronic bronchitis differ from
those just described mostly in the more severe paroxysmal character of
the {175} cough, with either no expectoration or only a scanty quantity
of a glairy, tenacious mucus; in the more soreness or dull pain in the
intercostal muscles and attachments of the diaphragm; and in the more
marked influence of sudden and severe meteorological changes. Perhaps
the most marked and distressing cases of this variety of bronchitis are
those we occasionally meet with in old persons whose joints, especially
those of the extremities, have long been stiffened and sometimes
enlarged from chronic rheumatism, and who are harassed and worn from a
harsh, suffocative cough, the worst paroxysms of which are almost
always during the latter part of the night and the early morning,
accompanied by the expectoration of considerable quantities of a thick,
viscid, and very tenacious mucus, which is dislodged with so much
difficulty that in the midst of the more violent paroxysms of coughing
the action of the stomach is reversed and its contents ejected by
vomiting. This is very liable to happen just after breakfast, and to
occasion the loss of the morning meal. The condition of these patients
is very generally ameliorated during the warm months of summer, but on
the whole they emaciate and grow more helpless from year to year, until
they die either from exhaustion or the supervention of pulmonary
sclerosis (fibroid phthisis), endocarditis, or chronic diarrhoea. There
is one grade of rheumatic irritation which is liable to attack the
fibrous texture of the smaller bronchi and to give rise to a very
persistent form of asthma, which increases with every returning cold
season of the year; but as asthma in all of its forms is treated in
other parts of this work, I only allude to it in this connection.
PATHOLOGY AND MORBID ANATOMY OF BRONCHITIS.--The special pathology of
inflammation involving the mucous membrane and other structures of the
bronchi does not differ from that of similar grades of inflammation in
any other structures of the body. It consists essentially of an
increase or disturbance of those properties of living organized matter
which regulate the molecular movements constituting nutrition,
disintegration, secretion, and cell-evolution to such a degree as to
cause accumulation of blood in the capillaries, followed by exudation
and increased cell-proliferation, which may organize into plastic
material or pseudo-membrane or degenerate into pus, according to the
coincident circumstances and condition of the patient.
Consequently, the anatomical changes resulting from acute catarrhal
bronchitis are, in the early stage, more or less intense congestion of
blood in the vessels, causing redness and tumefaction of the membrane,
soon followed by an increased flow of mucus, with increase or
proliferation of mucous corpuscles and epithelium-cells, while
leucocytes or white corpuscles are seen permeating the capillary walls
and penetrating the submucous tissue or mingling with the increased
epithelium upon the surface. These several inflammatory products are
seen adhering to the surface of the inflamed membrane and in the
smaller tubes, often so filling their calibre as to greatly interfere
with the ingress and egress of air through them, and of course adding
to the dyspnoea that characterizes the capillary form of bronchitis.
During the latter stage of the disease pus-corpuscles are seen freely
intermingled with the mucus, and, owing to the exfoliation of much of
the epithelium, the surface of the mucous membrane often appears
irregular, abraded, or ulcerated.
When the inflammation has been protracted into a chronic form, the
vessels appear less congested, but the cell-proliferations continue
both in the mucous and submucous structures, causing thickening and
increased density, with a still more purulent quality of secretion. The
bronchial glands are also {176} sometimes found enlarged, and either
softened, colored with pigment, or, more rarely, calcified.
In addition to the foregoing changes, in many cases of the capillary
form of bronchitis some lobules of the lungs are found collapsed from
the complete occlusion of the bronchi leading to them by the
accumulation of tenacious mucus with other inflammatory products. And
in the same cases the air-cells in other parts of the lungs, more
frequently the upper and anterior parts, are enlarged from
over-distension, constituting a degree of emphysema.
In very chronic cases, especially of the rheumatic variety,
considerable hypertrophy of the connective tissue of the bronchi has
been found, and in other cases atrophy of the same tissue, the latter
generally accompanied by more or less dilatation of the tubes.
In pseudo-membranous or croupous bronchitis the bronchial tubes are
found lined, and in some cases filled, with a plastic exudate. Usually,
only a limited number of the bronchi are affected. The tube-casts that
may be expelled are generally in the form of balls, which may be
unrolled, and which will then be found to be fragments or complete
cylindrical casts of the tubes. They are, when expelled, usually
yellowish and often sanious. When washed they are white. There are
frequently points of enlargement along the casts which are caused
either by the presence of air-bubbles within them, or by a more rapid
exudation from that point on the bronchus. The largest casts are
usually solid and laminated in structure; the smaller ones more
frequently are hollow, containing a greater or less number of
air-bubbles; the smallest consist of a single solid thread. Under the
microscope the casts seem to be composed of a structureless or
fibrinous substance holding numerous mucus and pus-cells, more or less
numerous globules of fat, and occasional epithelial cells; seldom red
blood-corpuscles, although these may be numerous on the surface. The
casts are usually moderately compact, firm, and elastic. Toward the end
of the disease, however, they may be less firm. In some cases toward
the close of life epithelial cells are abundant in them, but in other
cases on post-mortem examination the epithelial lining of the bronchi
is found nearly or quite entire. The mucous membrane may be much
reddened, or, on the other hand paler than normal. The submucous
tissues are also sometimes involved in the swelling, and occasionally
infiltrated with serum.[7]
[Footnote 7: For a representation of one of the most complete specimens
of pseudo-membranous casts from the bronchi the reader is referred to
the paper of Glasgow in the _Transactions of the American Medical
Association_, already referred to.]
DIAGNOSIS.--The principal diseases from which acute inflammation of any
part of the bronchial mucous membrane needs to be differentiated are
pneumonia, pleurisy, laryngitis, tracheitis, and asthma, while it is
still more important to keep a clear line of diagnosis between the
chronic grades of bronchial inflammation and the earlier stages of
pulmonary phthisis and of emphysema. From nearly all the diseases named
it is separated by negative evidence or the absence of symptoms and
physical signs characteristic of those affections. It neither presents
the rusty expectoration or high temperature or fine crepitant râle of
pneumonia, nor the acute pains or short stifled cough or
friction-sounds of pleurisy in the early stage, and still less is there
in the middle and later stages any of the dulness on percussion that
characterizes the corresponding stages of the other two diseases. In
true asthma the active symptoms are distinctly paroxysmal, without
fever or increase of temperature, and the respiration during the
paroxysms is slow, with marked prolongation of the expiratory act;
while in bronchitis, both catarrhal and capillary, the symptoms are
continuous, the temperature increased, and the respirations more
frequent than natural. All grades of bronchitis are easily
distinguished from laryngitis and tracheitis by auscultation, which
enables us {177} to trace all the morbid sounds to the chest in the
former, and to the front part of the neck in the two latter.
The great advantage of recognizing pulmonary tuberculosis and other
forms of phthisis in the early stage of the disease makes the diagnosis
between it and chronic bronchitis a matter of primary importance. This
can be readily done by all practitioners who have acquired a reasonable
degree of skill in the practice of auscultation and percussion. In all
forms and stages of pulmonary phthisis, whether from primary tubercular
deposits, pneumonic exudation followed by caseous degeneration, or from
interstitial fibroid sclerosis, there is increased vocal fremitus and
diminished resonance on percussion; neither of which is present in any
grade of uncomplicated bronchitis. It is true that in the advanced
stage of some very severe cases of capillary bronchitis there occurs
sufficient pulmonary oedema to increase the vocal fremitus and diminish
the resonance over some parts of the chest; but the accompanying
symptoms and immediately preceding history of such cases are sufficient
to separate them from any stage of phthisis. The same remark is
applicable to those rare cases in which an attack of pseudo-membranous
bronchitis results in the complete occlusion of one or more of the
bronchi and the permanent collapse of the pulmonary lobules to which
the occluded tubes lead. If in addition to the plain difference in the
physical signs already mentioned we remember that in all the forms of
phthisis there is progressive loss of flesh, some increase of
temperature and acceleration of pulse, with a contraction of the upper
and anterior part of the chest, while none of these changes result from
bronchitis alone, there should be no difficulty in keeping the line of
diagnosis clear between these two diseases. And yet there is probably
no more frequent or important error committed in diagnosis than that of
mistaking the early stage of pulmonary phthisis for bronchitis. This
may arise in part from the fact that bronchitis often supervenes and
continues coincidently with phthisis. But the practitioner should
remember that whenever there is increased vocal fremitus and diminished
resonance in any given case there is some altered condition of the
lung-structure, and consequently some form of disease besides
bronchitis, however plain the ordinary symptoms of the latter may be at
the same time.
From pulmonary emphysema, chronic bronchitis is distinguished chiefly
by the abnormally-increased resonance on percussion in the former,
especially over the upper and anterior parts of the chest, and the
peculiar depression of the spaces above the clavicles and between the
ribs at the beginning of the inspiratory act, and their return to
over-fulness near its close; while none of these changes accompany any
grade of simple bronchial inflammation.
PROGNOSIS.--In the ordinary form of acute and chronic bronchitis there
is very little tendency to terminate fatally except when it attacks
infants or persons infirm from age. And even when it occurs at these
extremes of life the fatal terminations are usually caused by the
supervention of lobular pneumonia as a complication, and not from the
bronchial inflammation alone. Severe cases of capillary bronchitis are
more dangerous, and in young children and aged or debilitated persons
often prove fatal before the end of the first week of their progress by
the direct obstruction to the entrance of air into the air-cells of the
lungs. The pseudo-membranous or plastic bronchitis is still more
dangerous. It has been estimated that one out of every five dies. But
the statistics concerning the number and character of cases are not
sufficient to furnish a reliable deduction of the ratio of mortality.
The duration of acute attacks of bronchitis of all varieties from which
recovery takes place is from one to three weeks. Uncomplicated cases of
chronic bronchitis seldom prove fatal, neither is there any self-limit
to their duration. Many cases undergo marked improvement during the
warm {178} months of summer, but suffer a renewal of all the more
severe symptoms on the return of the cold and wet weather of autumn. In
other cases the symptoms continue nearly the same through all the
seasons of the year and until an advanced period of life.