CHAPTER II
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SURGICAL PATHOLOGY OF THE BLOOD.
The part played by the constituent elements of the blood in inflammation, suppuration, and other still more disastrous conditions is so great and so important that, before proceeding to discussion of these lesions, it seems necessary to set forth a _resume_ of facts illustrating the importance of accurate knowledge concerning this most important fluid.
The total amount of blood in the human body has been variously estimated at from one-eleventh to one-twenty-fifth of the body weight, the average being about one-sixteenth. The amount which the body may lose and still retain vitality is very vague and differs not only with individuals, but very greatly under various conditions. Severe loss of blood is one to be atoned for as quickly as possible, and is to be prevented as far as it can be after accidents or during operation. For this reason the so-called bloodless method of operating upon limbs, by the use of the rubber bandage, constituted a great advance in surgery. For the same reason the use of hemostatic forceps is of equal value in operating upon other parts of the body; other things being equal the quickest and most satisfactory recoveries follow the bloodless operations, and it is an advantage to conserve this vital fluid as far as possible.
It has been roughly estimated that the blood is divided about as follows, between the different parts of the body: the heart, lungs, and large vessels holding one-fourth, the skeletal muscles one-fourth, the liver one-fourth, the remaining quarter being distributed over the balance of the body.
The blood varies within wide limits in its coagulability, and this variation occurs apparently even within conditions of health. In some patients the blood may be seen to coagulate almost as rapidly as it collects upon the surface, while in others the exposed parts continue to ooze, and the checking of hemorrhage is a difficult, sometimes almost impossible, matter. There are certain diseases in which the blood is known to have reduced power in this direction; for example, in the toxemias, especially those connected with biliary obstruction and jaundice. There were not a few of these cases of slow bleeding to death in days gone by, simply because the capillary hemorrhage could not be controlled. Recently, it has been shown that calcium chloride administered internally has a marked effect in favoring coagulation, and when opportunity is afforded it should be given for several days previous to operating and as part of the necessary preparation. It may be administered in doses of from 1 to 2 Gm., and should be given three or four times, at least, in twenty-four hours.
A test of the coagulation time, normally three to five minutes, but lengthened under circumstances like those mentioned above, even to an hour, will often prove of great value.
There are certain albumoses whose effect on coagulation of the blood is very suggestive and very mysterious. A very minute dose of cobra poison, for instance, will make the blood of an experimental animal remain fluid for days, unless this animal has been previously immunized against it, in which case coagulation takes place even more rapidly than normally. A trace of serum from an immunized rabbit is enough to prevent the fluidifying effect of the cobra poison, but quite insufficient to neutralize its toxic effects. The surgeon practically never desires to reduce coagulability of the blood, but frequently to increase it. When it is increased by natural conditions or those not easily controlled, then it may lead to thrombosis and produce trouble in that way.
=Fibrin.=--Increase of fibrin, _hyperinosis_, accompanies the leukocytosis of inflammation and suppuration. It may be approximately estimated on the cover-glass by noting the closeness of the network resulting after fifteen minutes’ exposure. The inflammatory indication of leukocytosis may, therefore, be inferred from its determination, while the leukocytosis of malignant disease will not be so accompanied. Hyperinosis is most marked in pyogenic processes, pneumonia and rheumatism. Its opposite, _hypinosis_, is met with in pernicious anemia. There is no change in the percentage of fibrin in the ordinary anemias or chlorosis. In hemophilia and purpura hemorrhagica the coagulation time is greatly increased.
=The Formed Elements of the Blood.=--The specialized elements of the blood which are of particular interest to the surgeon are the red and the white corpuscles. These may both vary in relative size within certain physiological limits. The red cells especially are not of uniform size and vary from 6 to 9 microns in diameter. There are also present in normal blood a small number of red cells having a diameter of only 6 microns, which are known as microcytes. In infancy there are present also so-called giant corpuscles, or megalocytes, with a diameter of 10 microns or more. Considerable variation occurs in disease, especially in the severe anemias. Red corpuscles ordinarily stain with acid dyes, which facilitate their examination and a computation of the number present. When present in unusually large number the condition is spoken of as a _polycythemia_; when in reduced number as _oligocythemia_. In several of the anemias variations in size, shape, and color occur, and in certain of them many of the red corpuscles are found to be nucleated. Red cells which are nucleated are known as _erythroblasts_, and according to their size are spoken of as _microblasts_, _normoblasts_, and _megaloblasts_. Again, under certain diseased conditions the ordinary discoid form of the cells becomes irregular and crenated, and to those which are thus altered is given the name of _poikilocytes_.
There is another form of degeneration which consists in death or necrobiosis of the cell, whereby it loses its capacity for staining, or, at all events, stains irregularly and abnormally. This is seen also in cases of severe anemia and in conditions where the blood has been altered by the addition of toxic material, such as chloroform, etc. Occasionally also the red cells show a tendency to a granular change, which is probably entirely degenerative.
The red corpuscles have a certain degree of elasticity which helps them to pass through capillaries which are smaller even than their own diameter; after escaping from these the corpuscles regain their original form. In the presence of carbon dioxide they lose this elasticity and become distorted or crenate. The influence of high altitudes in increasing the number of corpuscles is known, but unexplained. For instance, a residence of less than a month in the mountains will cause an increase of from 2,000,000 to 3,000,000 corpuscles per cubic millimeter. It has been surmised that under the influence of oxygen red corpuscle formation is stimulated to greater
## activity; in other words, that the red marrow becomes more active in
the production of the hematoblasts.
In general terms it may be said that the blood of a normal adult male contains 5,000,000 red corpuscles per cubic millimeter, and that of an adult female 4,500,000. These figures are, of course, approximate and variable. When the number is reduced to 3,000,000 by common consent the case will be regarded as oligocythemia, and when increased to 6,000,000 as one of polycythemia.
The latter condition is most evident in cases of newly born infants. The excess rapidly diminishes during the first week of extrauterine life. It is to be explained by the loss of fluid suffered by the infant upon the establishment of respiration. The proportion of red cells also varies according to the nutrition of the individual, the season of the year, the altitude (as above), and climate, and varies during menstruation, pregnancy, lactation, and at the climacteric. With the loss of red cells the number is reduced in proportion to the hemoglobin, although the change in one respect is not exactly proportionate to that in the other.
That the _colorless corpuscles_, or leukocytes, are not all of one kind has been recognized for nearly sixty years, and long ago they were divided into granular and nucleated cells. A vast impetus to the study of hemocytology was given by Ehrlich, in 1878, when he introduced the use of aniline dyes. The reader must be reminded that some of these, like eosin, are acid in reaction, and others, like methyl blue, are basic; while a third group has been supposed to be neutral in reaction, like a mixture of methyl blue and acid fuchsin; but it has been found that the so-called neutral dyes have really a slightly acid reaction. We may, therefore, divide the cells according to the reaction of the dyes with which they usually are distinguished into the acid and basic, or, more technically, into oxyphile, which includes neutrophile, and basophile.
This is not the place in which to go into any minute discussion of this subject nor further than should be of practical interest to the surgeon; nevertheless an examination of the blood by some common and routine procedure is so necessary in many surgical conditions that it is impossible to entirely avoid the subject in a work like this. I have accordingly condensed it and put the salient facts about leukocytes into the following table:
_Classification of Leukocytes._
_Granular._ _Non-granular._
{ A. With fine granules C. Hyaline. Transiti- {Oxyphile. (polynuclear) 60- onal (large mono- { 70 per cent. nuclear) 4-8 per {Neutrophile. cent. Normal. {The so-called B. With coarse {neutral stain granules (eosino- D. Lymphocytes (small {being slight- philes) 2-5 per mononuclear) 20-30 {ly acid. cent. per cent. {
{ E. Fine and coarse G. Atypical hyaline { granules (baso- (myelocytes). Patho- {Basophile. philes, mast- logical. { cells, etc.). { {Oxyphile. F. Atypical (myelo- { cytes).
In normal blood by far the greater part of the leukocytes consists of A and D. _Lymphocytosis_ means a relatively high percentage of C and D. _Eosinophilia_ means an increase in the proportion of B. Basophile cells are not absolutely pathological, for they may be present in very small numbers in normal blood.
The number of leukocytes in normal blood will average about 7000 to 10,000 per cubic millimeter, the percentage of each variety being given in the above table. Leukocytes are sometimes diminished in number; under diseased conditions they are often increased, and these are then included under the term leukocytosis. Variations occur daily and almost hourly under normal conditions. Increase naturally occurs after digestion, when the number of leukocytes may be almost doubled, the same being due principally to lymphocytes which are washed into the blood system from the lymph nodes by the flow of lymph or chyle. In starvation, however, the number may be remarkably reduced and in the case of the fasting man, Succi, the leukocytes were reduced at the end of the first week to 860 per cubic millimeter. The rather unusual condition of reduction of the number of corpuscles is called _leukopenia_.
Leukocytosis is usually the rule in carcinoma, with increase in A and F; the more rapid the growth, the greater this increase. In sarcoma this is even more pronounced; when occurring without hyperinosis the probability of malignancy is greater. Non-malignant tumors produce no such changes.
The blood _platelets_ or _plaques_ first described by Bizzozero, in 1882, have no small interest for physiologists and pathologists, but little for the practising surgeon. They number perhaps 5,000,000 per cubic millimeter and sustain a fairly constant ratio to the red cells. Their surgical interest is limited to the role which they may play in the formation of thrombus.
The term _phagocytosis_ has to do in a general way with those leukocytes which act as scavengers by removing from the blood its noxious elements, presumably by a process of ingestion and digestion (see