Both have had an eruptive fever as their starting point, and a disability of the same organ for their consequence.

The concrete formula of both reads thus:

In the one measles, retropharyngeal abscess, pyothorax, heart disease.

In the other: scarlet fever, pulsating empyema, and again heart disease.

Measles and scarlet fever, entrance-door of the coccus of suppuration (streptococcus or pneumococcus); valvular lesions, effect of the microbic toxins.

PULSATING EMPYEMA

This case of Pulsating Pleuritis began, as I have just said, with scarlet fever. Along with two brothers and a sister, Frederic D., aged 6 years, was taken sick with scarlet fever in April, 1893. On account of the poverty of the family and because he was the last on the sick list, he had not the advantage of a physician's care except during two or three days. Yet, from the mother's account, one may judge that the boy had not been seriously sick, that the eruption had presented a good appearance, that the throat was most complained of, and that a cough, which appeared in the last stage of the fever, had continued until the time when the little patient was brought to the office because this cough had of late steadily grown worse. This was the 24th of August, that is, four months after the initial trouble which had given admission to the infection; and this infection had apparently at once attacked the respiratory apparatus. The first inference now would be that as the affection had lasted four months, it was essentially chronic; this is moreover in accordance with the general rule that all cases of this kind are chronic. However, as will be seen later on, and judging the case from its results, the disease appears rather to have pursued an active acute course.

Before proceeding any further, a few general observations may be made on account of the rare occurrence of this disease and the lack of any fairly elaborate description in classical treatises and text books. Thus, former writers, even those that were much read, are either entirely silent, such as Watson, Grisolle, Gregory, Nyemeyer, Béhier and Cornil,

Reynolds (System of Medicine), or give it but a passing notice, as Flint does. Tyson and Pepper, among more recent writers, devote hardly a few lines to the subject; Pepper calls it a curious variety of pleurisy, of which he had the opportunity of studying but three cases. Finally, in the Twentieth Century Practice, there is just one page devoted thereto. As proof of the extreme infrequency of this condition, it may be mentioned that Osler, in 1889, collected but forty-two cases in the whole medical literature on this subject. The most complete study known to me is due to Comby, who published it in 1891 in the "Archives de Médecine." In this study, he had availed himself, as he states, of other researches which were published about that time, and of which his essay was but a careful synthesis. In taking up the subject, I cannot do better than follow his descriptions, although my case does not support some of his conclusions.

Notwithstanding its infrequency, Pulsating Pleurisy has a clear and precise symptomatology and in most cases its diagnosis is easy.

Pleurisy is called pulsating when the thoracic wall on the affected side is seen to move with rhythmic pulsations synchronous with the pulse and the heart beats.

Under this term, two conditions, widely different in appearance, are included: In the first, the pulsations cover a wide area of the thorax; in the second, they are confined to a fluctuating tumor, which communicates with the effusion.

This pulsating tumor is not always single, there may be

two.

Light reports two such cases. Its most frequent location is between the second and sixth ribs in front, outside the mammary gland, but the pulsating area may be in the lower axillary region, as in our case; it may also be distant from the thorax. Miller reports a case where it was found in the lumbar region.

These pulsating pleurisies are nearly always left pleurisies; most generally, they are suppurative pleurisies; hence the term Pulsating Empyema is perfectly justified.

The verifying of the thoracic pulsation has, moreover, an important semeiotic meaning; for, prior to any other exploration, it authorizes the inference that the effusion is purulent.

When you meet with a case of pulsating pleuritis for the first time, you quite naturally suspect an "aneurism of the aorta." Such an error has occurred many a time; a sad occurrence, as it causes you to delay indefinitely an urgent intervention.

To clear away your doubts, it will be well to look at once for the coexistence of a copious effusion, which, however, pulsates in only a limited area of its surface. Then, you must also note that, while the thoracic pulsations are rhythmic and synchronous with the pulse, while they may sometimes be strong enough to raise the hand or head when you either palpate or auscultate, the location is generally different, and there is an absence of murmurs, of thrills, of aneurismatic expansion, of pressure symptoms. Not to speak of the anamnestics, these reasons are quite sufficient to set aside the existence of aneurism.

Another source of error to be guarded against is mistaking Pulsating Empyema for a "Pulsating Abscess of the Præcordia." In fact, there may exist in the præcordial region purulent collections offering phenomena of expansion and pulsation. A brief review of a case, which occurred in practice, will illustrate this condition and elucidate the differential diagnosis.

Marie D., aged four, is a member of a numerous family, all of habitual good health. March 19, 1889, we were called in, as the child had, during the past several months, frequently complained of pain in the chest, in the region of the heart. Three or four blisters had been applied. Later on, a tumor had made its appearance on the præcordia. Small at first, this had increased rapidly. Its situation was found to be a finger-breadth below the nipple, a little more than a finger-breadth above the ridge of the short ribs, extending inward to the median line of the sternum and outward to about two finger-breadths from the axillary line. It was pyriform with large base. It had pulsations synchronous with the arterial beatings and a very manifest expansion. It reduced slightly under pressure. It was almost absolutely indolent. On auscultation, the heart sounds were muffled but normal, there was no murmur; the vesicular murmur was clear and distinct above the tumor up to the apex (true

puerile respiration), and below in a zone extensive enough but very narrow; behind, the breathing was free over the entire back, no crepitation, perfect resonance. Hence, pleural sac was in a normal condition, and pleuritic effusion out of the question. Was an aneurism to be thought of? On the surface of the swelling, the skin was red, tense, thin and quite warm. It seemed suggestive of an abscess. Such was the opinion of my old and regretted friend, the late Dr. Boudrias, whose well tried and extensive experience was of much value to me in this instance as on many other occasions. "I admit an abscess," he argued, "for if it were an aneurism, it should be of the internal mammary artery, or of the intercostal. But those arteries are too small to furnish so voluminous a tumor. Moreover, it cannot be from the aorta, as then it would be located higher up. Neither can it be an aneurism of the apex; no observer has ever taught that such an aneurism had perforated the chest wall; as a conclusive sign, there is no murmur. In proof of abscess, there is the existence of previous pains." To assure the diagnosis, a capillary punction was then made at the base of the tumor, selecting a point where the skin was sound; a considerable amount of pus escaped. The pocket was now freely open so that a possible subcostal collection and diseased condition of the ribs might be looked for. After a little search, there was found a perforation located at the union of the intercostal cartilage with the sixth rib and which had afforded communication between the anterior purulent collection and another one located beneath the thoracic wall. The pus was inodorous and carried flocculent particles and pseudo-membranous shreds; there was denudation of the edge of the rib and of its posterior face, but to an extent which remained undetermined. Thus, it had become clear that it was a case of costal periostitis with "shirt-stud" abscess. One may infer that the posterior pocket of this abscess was in contact with some point of the ventricular part of the pericardium As Le Dentu remarks, "the heart impulse does not belong solely to the apex, every portion of the ventricle imparts the same sensation during the cardiac systole." The heart was pushing the liquid forward by compressing the retro-parietal pocket; by this compression, a certain amount of pus was

forced into the external abscess, and hence occurred expansion and impulses. After the operation, fistulous tracts persisted for about three months, but finally cicatrization took place without our having recourse to resection. On October 23, 1890, a little more than a year later, this child contracted diphtheria, which became laryngeal. I had to intubate, but in 28 hours the child was dead. Some time ago, I gave you a parallel between tracheotomy and intubation; I had this case in mind when I spoke of "an instance when I had to intubate with no other help than the father and a neighbor" (Medical Annals for May, 1898, page 252).

This digression has perhaps carried us a little too far from our subject, but no detail is insignificant which can guard against error.

Thus, the utmost care has been taken to make sure of your diagnosis. Yet, to clear up a last doubt, as in the case just referred to, you practice an exploring punction. It gives pus.

Should you now proceed to empty the pleural cavity by aspiration, you will cause the formation of a pneumothorax, which takes the place of the aspirated fluid. The atelectasis of the lung is such that this organ is incapable of dilating rapidly enough to fill the vacuum left by the punction. Hence the pneumothorax is almost inevitable; in very few cases has it failed to appear.

This pneumothorax is latent; for its detection, you can depend neither on the amphoric breathing nor on the metallic tinkling; the Hippocratic sound alone can reveal its presence.

The thoracic pulsations disappear after the evacuation of the pleura; they recur after aspiration as soon as the accumulating liquid is again abundant. Even in this case, they may finally disappear.

The heart is deviated and, so to say, transposed to the right; it is held by adhesions which prevent its return to the left after the punction. The cardiac impulses are regular; there is no enlargement, no dilatation, no valvular lesions.

Sometimes, a slight pericardial effusion has been detected, even adhesions extensive enough to produce cardiac symphysis.