The principles and practice of modern surgery

by Roswell Park

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.