Surgery, with Special Reference to Podiatry Part 3

+Creolin+ is mildly germicidal and is used a great deal in from 2 to 4 per cent. solutions.

Both lysol and creolin act very much like carbolic acid, but neither possess its irritating qualities.

+Formaldehyde Gas+ is an active germicide and very valuable as a disinfectant. It is used in the shape of formalin which is a 4 per cent. solution of the gas in water. This agent is very irritating to the normal tissues in the stronger solution, but a 2 per cent.

solution of formalin may be used for the sterilization of the hands, instruments, etc.

The formaldehyde fumes are employed for the disinfection of clothing, rooms, bedding, and also for the sterilization of catheters. The fumes of the gas are very irritating to the mucous membrane and when this agent is used for the disinfection of rooms, every crevice and crack must be tightly sealed to prevent the escape of the gas.

+Iodoform.+ The action of iodoform is not due directly to its ability to destroy germs but to its undergoing decomposition in the presence of moisture, liberating iodin and thus rendering inert ptomains that have resulted from the growth.

+Iodoform Powder+ is rapidly absorbed by the skin and fatal cases of iodoform poisoning have occurred from treating burns with it.

Iodoform is also used in ointment form and in suppositories. As it is insoluble in water it is commonly used in a 10 per cent. emulsion. The gauze is also greatly used.

The symptoms of iodoform poisoning are: delirium; odor of iodoform on the breath; presence of iodoform in the urine; eruption over the skin, and finally, coma. Iodoform is also capable of producing a localized dermat.i.tis, with great irritation, and must therefore be used with care on all delicate skins.

+Aristol+, a subst.i.tute for iodoform, is a compound of iodin and thymol, producing no toxic effects and having no disagreeable odor; it does not, however, possess the germicidal qualities of iodoform. Nosophen, iodol, and airol are among the more recent subst.i.tutes.

+Iodin.+ This drug no doubt possesses more germicidal properties than was at one time supposed. It is probably the most powerful antipyogenic known. The 7 per cent. tincture is the one most frequently used.

+Acetate of Aluminum+, or more properly, aluminium, is prepared by adding five parts of sugar of lead to a solution of five parts of alum in 500 parts of distilled water. Burow's solution, see page 35, is chiefly employed as a wet dressing.

+Chloride of Zinc+ in a solution of 15 to 30 grains to the ounce, has marked antiseptic properties, but it blanches the tissues when applied to infected wounds.

+Sulphocarbonate of Zinc+ is less irritating than the chloride of zinc and is of the same value as a germicide.

+Peroxide of Hydrogen+ when used as a 15 volume mixture or diluted, seems to have a direct action upon pus generation by destroying microorganisms of the pus. It is frequently employed for sterilizing abscess cavities, and for hastening the separation of necrotic tissue.

This agent has also a marked hemostatic power and is used to some extent on this account in nose and throat work. Its hemostatic power is also observed in bone cavities. Care should be taken never to use it unless there is a free exit, as it increases rapidly in volume after coming in contact with dead tissue or pus, and serious accidents have happened from its improper use; for instance, if it is injected into an abdominal sinus where free escape is not provided for, the distention will result in ruptures of the sinus and infiltration of the surrounding tissues; possibly of the peritoneal cavity. The distention produced by it is also quite painful and therefore only a small quant.i.ty, or a much diluted solution should be introduced into cavities.

+Boric Acid+ is not very actively antiseptic, but even in a saturated solution it is not irritating. Where bichloride or carbolic dressings have produced irritation of the skin, or burns, a boric acid ointment is a very satisfactory subst.i.tute.

+Salicylic Acid+ is an antiseptic of value. It is generally used in the form of an ointment. It is but slightly soluble in water.

+Pota.s.sium Permanganate+ by its rapid liberation of oxygen, acts as an antiseptic of proven merit for the disinfection of foul wounds and ulcers. It is also used satisfactorily for disinfecting the hands in preparation for operations, in the form of a 5 per cent. solution, any stain being removed later by a saturated solution of oxalic acid.

+Alcohol+ possesses marked antiseptic properties and is one of the best agents for the sterilization of the hands of the surgeon, and for the skin of the patient. A 60 or 75 per cent. solution of alcohol is much more efficacious as a skin disinfectant than a 95 per cent. solution.

This is because the purer alcohol is much less penetrating than the dilute. It is also used when diluted with water, one part to four, as a dressing for granulating wounds. It is efficacious in limiting the action of carbolic acid, when this agent has been applied in full strength.

It is a useful agent in which to store certain materials such as ligatures, sutures, etc.

+Silver Nitrate+ possesses undoubted antiseptic properties, and solutions of varying strengths are decidedly antiseptic. These solutions are from 5 grains to the ounce, to 60 grains to the ounce.

The solid stick of nitrate of silver is used for destroying exuberant granulations. Among the different silver preparations on the market, protargol and argyrol are the best known. Both of these are extensively used in the treatment of inflammations of the mucous membranes.

The unguentum of Crede, is an ointment of silver which is used in cases of septic infection and also in localized inflammations. From 15 to 45 grains of silver can, in this form be rubbed into the skin. It is absorbed and undoubtedly exercises an antiseptic influence on the infecting microorganisms.

+Saline Solution+, or normal, or isotonic salt solution, as it is called because of its close approximation to the blood serum, consists of a solution of 7 per cent. of sodium chloride in plain sterilized water.

Roughly speaking and for ordinary purposes, this solution can be made by adding an even teaspoonful of ordinary table salt to one pint of boiled water and then reboiling the mixture.

It can be stored for a limited time in sterile gla.s.s jars, which are sealed with sterile cotton. The jars can be heated to whatever temperature is required for use. This solution is the one which is generally used for irrigating wounds and cavities; it is non-irritating and possesses no antiseptic quality. When a moist dressing is desired there is no solution comparable to it, largely because of its non-irritating quality. It has at times a slight irritating effect upon the kidneys and when large quant.i.ties of it are used it is better to dilute it.

+Pure Oxygen and Ozone+ have been used, and the latter is more effectual. It has been found that oxygen but slightly r.e.t.a.r.ds the growth of bacteria, but both ozone and oxygen produce a hyperemia, and r.e.t.a.r.d the growth, especially of anaerobic organisms. Pure oxygen in the abdominal cavity produces a marked hyperemia and a leukocytosis.

Ozone has been put to some practical use in this country but the results have not been sufficiently studied.

+Sunlight+ has a marked r.e.t.a.r.ding effect on some bacteria and actually destroys them. The anthrax spore is said to be killed very promptly by exposure to strong sunlight and it is claimed that the tubercule bacillus is slowly destroyed by it.

+Electricity and the X-rays+ also produce a marked r.e.t.a.r.ding effect on the propagation of certain microorganisms.

CHAPTER IV

+INFLAMMATION+

+Definition.+ Inflammation may be defined as the local reaction against injurious influences. An aseptic wound heals without any of the clinical signs of inflammation and without reaction. It is only by a study of the minute changes about such a wound that the resemblance, between the processes of wound repair and those of slight inflammation, become evident.

+Etiology.+ The cause of inflammation is any injury to the tissues by mechanical, thermal, or chemical means; by the effect of electricity, or by the growth of bacteria.

+Pathology.+ Inflammation occurs through changes in the circulation.

When one of the causes mentioned above acts upon the tissues, the first alteration seen is an increasing blood supply to the part, the arterial circulation being increased both by the greater rapidity and force of the current through the vessels, and by the dilatation of all the small branches and capillaries.

When the inflammation grows more intense, the circulation in the capillaries becomes slower and the corpuscles collect, until they clog the vessels. The normal current of blood in small vessels, as seen under the microscope, shows a thick central stream of corpuscles with a transparent border of lymph (containing only a few white corpuscles) between it and the vessel wall.

As the stream diminishes in rapidity, the number of white cells in the clear s.p.a.ce increases, the blood plaques appear also, and finally, when the current is reduced to stagnation, the clear s.p.a.ce disappears, being filled entirely with cells, chiefly leucocytes, although red cells find their way into it.

This tendency of the white cells to separate from the others, even when the current is rapid, is partly due to their viscosity and power of ameboid movement, but in the main is a purely mechanical effect of the slower current.

It has been proven that when particles of different density are suspended in a liquid which is circulating through a system of narrow tubes with a very rapid current, there is a clear s.p.a.ce next to the wall of the tube where the friction necessarily reduces the speed of the fluid which is free from particles, and, as the current is slowed down, some of the particles of least density, begin to appear in this clear s.p.a.ce, their number increasing as the current becomes slower, until even the heavy particles also collect here when it is very slow.

It is known that among the cellular elements of the blood, the leucocytes have the least specific gravity or density, and the blood plaques rank next, while the red blood disks are the heaviest, and these bodies appear in the clear serum near the vessel wall in that order, according to the law just cited. The slow current is a.s.sociated with an increased intravascular blood pressure, which, in part, is the cause of the phenomena of exudation, emigration and diapedesis.

+Exudation.+ Serum of the blood pa.s.ses out of the vessels, and collects in the lymphatic s.p.a.ces in the cellular tissue, and elsewhere, and also exudes from the surface of the mucous membranes or forms vesicles or blisters in the skin by detaching the superficial epithelial layers. Complete stasis, or stoppage of the circulation is seen only when the inflammation is exceedingly intense, and would cause the death of the part if continued long.

Usually the current merely becomes slower than normal. This r.e.t.a.r.ded circulation is followed by the phenomena of emigration.

+Emigration.+ Emigration of the white blood corpuscles consists in the pa.s.sage of the cells directly through the vessel walls. It is most frequently seen in the capillaries, although it also takes place in the small veins. The white corpuscles, or leucocytes, have the property of ameboid movement, stretching out at will in any direction, long, narrow processes of their protoplasm, called pseudopodia, which may be attached to any object, and having secured such an anchorage, the rest of the protoplasmic body is drawn towards it.

In this way, the leucocytes are able to pa.s.s through the interstices between cells, or along narrow channels in the tissues. When the blood current becomes sufficiently slow to enable them to cling to the walls of the vessels, it is then that ameboid movement begins. Sometimes the cells loose their hold and are swept on again, but in other cases a minute bud of protoplasm will appear on the other side of the wall of the vessel, opposite to the spot where the leucocyte is clinging, and as this grows larger, a narrow neck of protoplasm can be traced through the wall directly to the leucocyte, and presently the ma.s.s of the leucocyte becomes proportionately smaller as the external bud of protoplasm grows larger. The conditions are gradually reversed, the nuclei of the cells appear outside and only a small ma.s.s of protoplasm remains within the vessel until finally the entire leucocyte is in the tissue outside of the vessel and is free to wander in any direction.

The mechanical part of this process is not yet understood. It is claimed by some that small openings exist in the walls of the vessels, between the endothelial cells which line them, to which is given the name of _stomata_. These openings ordinarily are invisible, but they are said to enlarge under the effect of the dilation of the vessels, and of the alterations in their walls, produced by the inflammatory reaction, and that the leucocytes escape through those openings.

There can be no doubt that the emigration is due to the ameboid motion of the cell, and the discovery of the phenomenon, to which is given the name chemotaxis, affords a sufficient explanation.

This is the influence possessed by certain substances to attract or repulse ameboid cells. In some cases this attraction appears purely to be mechanical, but it is probably a chemical effect of some kind in most, if not in all, instances.