Part 25

During the period of our work 639 patients were admitted to the hospital suffering from clinical influenza. The cases varied in type from the very mild to the extremely ill. The majority of the cases were of the type of “three-day fever.” Clinically 81 cases developed pneumonia, and of these, 35 died. It would, of course, be impossible to say how many other individuals had a pulmonary involvement which could not be recognized clinically. In fact, some of the cases which did come to autopsy were only recognized as having a pulmonary involvement when the lungs were examined outside of the body. The physicians freely admitted that the physical signs were quite unusual and unlike those of the ordinary forms of pneumonia. In fact, except for the fact that we were living in the midst of an epidemic of respiratory infections, there was nothing to make the clinician suspect that many of these cases had a pulmonary involvement. Obviously, when the recognized signs of different types of pneumonia made their appearance, the clinician did not fail to make proper interpretation of the lung involvement. This, as we shall discuss later, is an event superadded to a lung condition which pathologically must be recognized as pneumonia (inflammation) and which differs so decidedly from what we know of as croupous or lobar pneumonia, as well as ordinary broncho-pneumonia that it would be incorrect to include them under this heading, although the distribution of the lesion may have lobar, bronchial or lobular characters.

TABLE I

════════════════════════════════════════════════════════════════════ DATE 1918 PATIENTS PATIENTS CASES IN DEATHS ADMITTED DISCHARGED HOSPITAL ──────────────────────────────────────────────────────────────────── October 5 65 0 65 0 〃 6 23 0 88 0 〃 7 61 0 149 0 〃 8 77 0 225 1 〃 9 42 1 266 0 〃 10 35 1 300 0 〃 11 9 0 307 2 〃 12 2 16 290 3 〃 13 10 0 298 2 〃 14 1 18 278 3 〃 15 4 13 266 3 〃 16 9 23 248 4 〃 17 10 19 235 4 〃 18 16 34 217 0 〃 19 38 29 225 1 〃 20 27 0 252 0 〃 21 37 43 245 1 〃 22 33 7 270 0 〃 23 14 20 263 2 〃 24 20 17 266 0 〃 25 27 21 272 0 〃 26 10 29 250 0 〃 27 18 3 265 1 〃 28 10 31 243 3 〃 29 6 16 231 0 〃 30 11 27 215 1 〃 31 2 15 202 2 November 1 2 18 185 0 〃 2 4 18 170 1 〃 3 5 1 174 0 〃 4 2 19 156 1 〃 5 5 0 161 0 〃 6 4 16 149 0 ——— —— Admissions. 639 35 ────────────────────────────────────────────────────────────────────

The individuals admitted to this hospital were obtained from the two military camps at the University of Pittsburgh and the Carnegie School of Technology. All of them were enrolled in the army service and ranged from the ages of 18 to 30. They were vigorous individuals, who had passed their physical examinations for the army. The epidemic made its appearance in these camps on October 2, rapidly ascending from a report of two ill on October 2, four on October 3, eight on October 4, to 65 on October 5. On October 11 there were 307 cases in the hospital.

Of these cases 35 died, the day of death being indicated in the following table.

TABLE II

═══════════════════════════════════════════════╤═══════════════════════ DAY OF DISEASE ON WHICH DEATH OCCURRED │ NUMBER OF CASES ───────────────────────────────────────────────┼─────────────────────── Third │ 1 Fourth │ 3 Fifth │ 4 Sixth │ 4 Seventh │ 4 Eighth │ 5 Ninth │ 3 Tenth │ 4 Eleventh │ 3 Thirteenth │ 1 Fourteenth │ 1 Twentieth │ 1 Twenty-third │ 1 ───────────────────────────────────────────────┴───────────────────────

The time as indicated in the above table has no relation to the length of time that the patients were ill of pneumonia, but refer to the period of illness from the beginning of the influenza. The duration of the pneumonia is indicated in another table.

Of the 35 fatal cases 32 came to autopsy. Facilities were available to do the work very satisfactorily, in that the hospital was well provided with a modern post-mortem room and its accessories. The notes on the autopsies were taken immediately and fully, and the materials for subsequent study were collected in different types of preserving fluid. Portions of tissue were collected from all of the organs for microscopical study, while fluids from the chest, lungs, bronchi and heart were obtained for bacteriological investigations and for some chemical analyses.

Added to the above material we also had the opportunity of reviewing and studying the lesions of 18 autopsies performed by Dr. J. W. McMeans. These cases were very similar to our own series, in that they were cases of epidemic influenza amongst soldiers who were being cared for at the St. Francis Hospital. The disease processes were quite alike in the two series, and the analyses made by Dr. McMeans are comparable in our own and serve as a means of checking our results obtained in another institution. The similarity of the lesions in the lungs and other organs serve to indicate that what is reported in this paper is an index of the nature of the lesions of epidemic influenza as it occurred in the Pittsburgh district. In a few instances the autopsies performed by Dr. McMeans revealed more advanced pulmonary lesions with abscess and gangrene than were noted in the cases autopsied at the Military Hospital. The process, however, in the two series of autopsies was identical.

_General External Features_

There were no external characteristics of the bodies which were autopsied by us which were constant. Some features were more commonly present than others. Of these the cyanosis of the face, head, neck and shoulders, and in a few instances of the upper extremities, attracted our attention more than any other. This cyanosis was present in over one-half of the number of cases, and it was confined almost always to the upper part of the body. The face, ears and neck were always more affected than other parts. This cyanosis bore no relation to the length of time after death when the body was viewed, as we found that when it was present during life it maintained its prominent appearance for a long time after death.

The cyanosis differed from the bright hue or flush as it is at times observed in ordinary pneumonia, the color in these instances being of a dark purple, or better a purplish blue. The lips and ears showed the most intense color. The cyanosis was not associated with any evidence of œdema. The capillaries of the tissues were filled with blood which was of a very dark character. Cyanosis could also be seen in the finger tips about the nails. This was more marked in the upper extremities than in the lower. The skin of the body rarely showed any cyanosis, these tissues being quite pale, or at times showing a slightly yellowish tinge. In one instance the cyanosis of the head and neck was accompanied by a slight purplish rash upon the upper portion of the chest. This rash was of a petechial kind, there being slight hemorrhage into the tissues. The lesion, however, was not of the blotchy purpuric type which has been observed by others during this and past epidemics (Cole). This single case is the only one where we had evidence of superficial hemorrhages into the skin.

TABLE III

│CYANOSIS│ │ NO │ │ │CYANOSIS ═════╪════════╪═══════════════════════════════════════════════╪════════ NO.│DEGREE │DISTRIBUTION │ ─────┼────────┼───────────────────────────────────────────────┼──────── 741│+ │Chest and upper extremities │ 747 743│+ + │Face, neck and ears │ 748 744│+ + + │Head and neck (upper portion of chest and │ │ │ thighs mottled and purple) │ 749 745│+ + │Head and neck and upper extremities │ 751 746│+ + │Ears, neck and shoulders │ 752 750│+ + │Face, ears and neck │ 764 756│+ + │Neck, jaw, shoulders and upper extremities │ 765 757│+ │Face, neck, shoulders, arms and chest │ 778 758│+ + + │Face, ears, neck and upper chest │ 782 761│+ │Face, ears, neck and upper chest │ 784 762│+ │Ears, neck and chest │ 786 763│+ │Head and neck │ 793 767│+ │Face, ears and neck │ 773│+ + │Neck, ears and cheeks, extending moderately to │ │ │ upper chest. Hemorrhage into conjunctiva │ 781│+ + │Eyes, lips, ears and neck │ 783│+ + │Face, lips, neck and fingers │ 787│+ + + │Ears, neck and shoulders │ 791│+ + │Ears, neck and upper chest │ 792│+ + │Ears and back of neck │ ─────┼────────┼───────────────────────────────────────────────┼──────── 19│ │+ Blotchy or slight │ │ │ 6 │ 12 or or│ │++ Moderate │ │ │ 10 │ 38.6% 61.4%│ │+++ Well marked │ │ │ 3 │ ─────┼────────┼───────────────────────────────────────────────┼──────── 770│ │Fine petechial rash over upper chest. │ ─────┴────────┴───────────────────────────────────────────────┴────────

Occasionally we met with small hemorrhages lying in the upper layers of the subcutaneous tissue. These lesions were small and could not be seen from the external surface. Nevertheless, some of them seemed to have occurred in direct contact with the deep cutis and surrounded portions of the deep skin appendages. From an examination of our cases there was no reason at the time of autopsy to lay any particular stress upon the occurrence of these hemorrhages. Subsequently, it has come to mind, and since learning of the unusual frequency of boils and deep pustules making their appearance as post-influenzal sequelæ, that these minute lesions may have a bearing upon the localization of infection in the skin tissues. We must appreciate, of course, that other factors of a constitutional nature probably render the individual more susceptible to the invasion of the staphylococcus, and that such factors are all-important in allowing this organism to gain a foothold. Whether the decreased sugar-tolerance with hyperglycemia, which has been observed in the late stages of influenza, bears a relation to the increased susceptibility, as appears to be the case in diabetes mellitus, is an interesting point for further investigation. Other constitutional states are also undoubtedly involved in the increased susceptibility to the infection which the patient suffers. Elsewhere (Dr. Holman) it is shown that the natural complement content is considerably depressed during the height of the influenza. With such factors present and with the available infecting micro-organisms, it is possible that the minute deep skin hemorrhages bear a relation to the immediate localization of the infection.

In two instances slight hemorrhages were observed into the conjunctival tissues. In each case they were unilateral and occupied the tissues contiguous to the inner canthus. In one case there was well-marked icterus with yellow coloration of the scleræ and skin. In this case the icterus was associated with degenerative changes in the liver, there being no recognizable obstruction to the bile passages. The icterus had come on quite acutely and without any special clinical manifestations. In the epidemic of 1890 jaundice was present in a considerable number of cases (Medical Record, 1890, xxxvii, 473). Cole made similar observations in the epidemic of influenza amongst the Canadian soldiers. Œdema of the skin was not met with in any of our cases. This point is worthy of comment, inasmuch as some authors have been impressed with the serious damage taking place in the kidney and the resulting incapacity of these organs. Although, as we shall point out later, the kidney tissues in these cases showed a decided toxic degeneration, there was no evidence that a glomerular damage of serious degree ever occurred. The urinary excretion, as is pointed out in a report by Dr. Zeedick, varies considerably with the intensity of the disease. It is unusual to find derangement of kidney function to a degree to reflect seriously upon the general bodily state. At least this has been our experience in the present epidemic. Even where subsequently we were able to demonstrate a considerable tubular degeneration in the cortex of the kidney the change in the kidney function was not of sufficient magnitude to lead to a water-retention to be recognized in an anasarca. I wish to distinguish clearly at this point the difference in finding an œdema in certain involved tissue structures in various parts of the body and arising through an inflammatory reaction due to the presence of peculiar focal irritation, as compared with the accumulation of fluid in many and irregular situations as it occurs through retention and faulty excretion by the kidneys. Various organs as we have found—as, for instance, the lung, heart and liver—showed a condition of œdema which was not to be reconciled with an inadequate circulation because of a cardiac or renal incompetency. These œdemas, which we will discuss later, are local and are the result of damaging influences inducted in and upon the tissues where they are found.

_Muscle_

In all of our cases we have been struck with the excellent physique of the individuals succumbing to this epidemic. All were youths in the best of health, of good muscular build and strong bony frame-work. Post-mortem rigidity set in fairly rapidly after death. Where this rigidity had “set” for six or more hours it required much force to change the position of the muscles. The voluntary muscles of the thorax and abdomen were always carefully observed, and in a number of instances the muscles of the thigh were also examined. It was not possible routinely to dissect the muscles of the extremities, so that we are unable to give an accurate account of the occurrence of degenerations in these structures. We have, however, observed the reactions taking place in the pectorals, psoas and muscles of the abdominal parietes. Changes were observed with greatest frequency in the recti of the abdomen. Degeneration occurred in these muscles in 14 instances, while the same tissues suffered rupture, in part or completely with hemorrhage, in six instances. It was not uncommon to find marked degeneration in the lower segment of the rectus muscle on one side, while degeneration and hemorrhage had occurred in its fellow on the opposite side. In four cases rupture of the entire belly of the muscle had taken place, so that a considerable space had occurred between the broken ends and a large clot of blood filled the intervening space. This degeneration, which was seen only in the voluntary muscles, was quite interesting and in its milder degrees was rather difficult to detect. All gradations of loss of muscle color were seen. In some instances the muscle simply seemed to have lost its meaty lustre, while again in the more severe instances the muscle color had changed from the bright red to an insipid yellow or clay color. The most marked degeneration occurred in the midportions, while the ends of the muscle masses at the points of attachment were less involved. Complete rupture of the rectus always occurred in the lowermost segment, a short distance above the insertion into the pubic bone. At times the distribution of the degeneration within the muscle was quite patchy, and irregular islands of yellow about 2 cm. in diameter were splashed through the muscle masses, which in themselves were paler than normal. Where the muscle degeneration was advanced the tissue was soft and at times even buttery. It resembled the character of the degeneration observed in typhoid fever, although I have no recollection amongst many enteric cases of having seen the degeneration of the muscle occur so acutely. Recklinghausen claimed that these hemorrhages were most unusual in influenza. This is contrary to our findings.

Degenerations of a similar kind as those of the abdominal recti were found in both pectorals. In the chest region, however, the degeneration was less frequent and less severe. We observed it only twice, and in neither instance had the degeneration led to a rupture and hemorrhage of the muscle bundles. Kuskow observed a single case of degeneration and hemorrhage of the pectoral muscles. In the psoas muscle we observed degeneration on two occasions, in one of which the lesion was associated with a partial separation of the muscle fibers and hemorrhages into its substance. In one case clinically, but not coming to autopsy, a lesion, which from its character we presume to have been a degeneration, occurred in the sterno-mastoid, being accompanied by hemorrhage and the development of a firm clot the size of a hazel nut. In the subsequent history of this case the lesion passed through an aseptic process of organization with contracture so that the patient has recently been developing a “wryneck.” Kohts in 1890 reported the finding of muscle degeneration and abscesses in the arm. The condition arose as a late complication of influenza.

From our experience at the autopsy table in observing the relative frequency with which muscle degeneration occurs in the severe cases of epidemic influenza, we feel convinced that numerous cases which recover pass undiagnosed of this condition. Furthermore we have evidence, as illustrated in a case observed by Dr. McMeans, wherein a lesion which occurred in the gluteal muscles was followed by a localizing infection at this site that these muscle degenerations and hemorrhages may have serious consequences. There are a number of instances in which post-influenzal complications of the nature of deep-seated abscesses of the extremities, thorax, and abdomen may have their explanation for the localization in a primary muscle damage accompanied by hemorrhage and followed by an infection of variable type. Cole also comments upon the development of abscess in the deep muscles where degeneration had taken place. In illustrating some of our findings to Dr. J. Anderson he immediately recognized such a condition in the pectoral muscles of a patient in which he was unable to arrive at a conclusion of the pathological events which had taken place. It is one of the noteworthy features in this disease that the voluntary muscles of certain regions are apt to suffer severe damage, while the heart and the various unstriped muscular tissues are little if at all affected by a similar process. It would be interesting to know whether the lack of response and the delayed functional recovery on the part of the muscles of the extremities in so many patients who have suffered influenza is the result of the damaging influence of a peculiar intoxication present in this disease. One of the features in influenza is the prostration of the patient, and with it there is definite muscular weakness. We have been prone to lay the responsibility of this state entirely at the door of the nervous tissues. Here, however, we are able to offer evidence that quite aside from the lesions arising in the nervous tissue, there is definite muscle damage which, as we shall again discuss when describing the microscopic features, incapacitates even to the point of complete destruction the muscle elements in various fields of the body. Before, however, being able to state that the muscular weakness of the extremities is the result of such damage by toxins it is necessary to obtain more definite information regarding the frequency with which these degenerations occur in the limbs. In our own material we are unable to discuss the matter with adequate figures. We are, however, impressed with the changes observed in the muscles which were available to us. Naturally, too, a certain number of muscle degenerations have escaped our detection because of our unfamiliarity with the mildest grades. In fact, we have already discovered in our microscopic studies that certain cases, which in the macroscopic had escaped us, showed well-marked lesions under the microscope.

TABLE IV

MUSCLE DEGENERATION