The Secrets of Specialists/Chapter 13
It was during the International Congress of Dermatologists, in 1908, that the use of liquid air was publicly announced as a valuable agent in the treatment of certain malignant and cutaneous affections; this created widespread interest with the medical profession. However, the general introduction of liquid air, for therapeutic purposes, is impracticable, because it has so many disadvantages connected with its use and manufacture. It is not a medium in great demand for commercial and industrial purposes, and it is, therefore, difficult to obtain the product without securing special apparatus for its manufacture. For this reason, carbon dioxide snow has superseded liquid air; although there is some difference in their physical properties, it belongs to the same therapeutic family, and their analogy was first fully demonstrated by Drs. Dade and Whitehouse. The process of manufacture and supply is so simple with carbon dioxide, compared with liquid air, that the latter product has been nearly abandoned in therapeutics.
The temperature of liquid air is, approximately, 310 degrees F. below zero, while carbon dioxide is only 110 degrees. F. below zero. With this great difference in degrees of temperature, one would naturally think their physical properties would be correspondingly changed, but such is not the case. Carbon dioxide seems to possess just a sufficient amount of cold to accomplish the results desired, and the process of freezing is sufficiently low to act as a positive destroyer of tissue, without being so rapid as to prevent an intelligent observation of the progress of freezing. In fact, it has been found that carbon dioxide, in loose crystals, produces a more rapid freezing action than the solidly compressed carbon dioxide ice; therefore, in most cases the solidified carbon dioxide, or carbon dioxide ice (as it is more frequently called) is often preferable to the snow or liquid air, as we have better control of its action. The two factors which determine the results to be achieved are the degree of pressure, and the duration of the application.
The method of preparing solidified carbon dioxide for therapeutic purposes is rather an easy matter. Carbon dioxide gas is supplied, for commercial purposes, to all soda water counters, and may be found at almost any drug store for the purpose of supplying carbonated beverages. These receptacles are furnished to the trade in 20 and 50-pound tanks, under a pressure of about 1,000 pounds to the square inch. On opening the tap of the cylinder the liquid carbonic gas escapes, and evaporates so rapidly that intense cold is produced which freezes the liquid into a soft snow. There have been several special apparatus devised for the purpose of accumulating this snow; of these, the Goosmann apparatus is perhaps the most popular and convenient, for all general use. This outfit consists of a specially constructed crayon, which will fit any gas cylinder. To fill the crayon with ice it is attached to the nipple of the cylinder, and as the gas escapes, the ice is formed and molded into suitable shapes for clinical use, (see accompanying illustration).
A very simple way of preparing a stick of carbonic acid ice, is to roll a huckaback towel around a cylindrical wooden stick, about one inch in diameter; remove the wooden stick so as to form a cone, into which the ice crayon may be formed. Close one end of the towel cone, with a loosely fitting cork; the gas cylinder is placed upon the table, as illustrated above, with the delivery pipe pointed downward, and the foot of the tank raised about six inches, so as to allow the liquid contents to flow toward the tap. The open end of the towel cone is placed over the tap and the cylinder valve is opened, gently; as the carbonic acid gas escapes and evaporates into the cone, it will pass through the escaping channel, and the snow will be formed in about thirty or forty seconds. The cylinder valve may be closed and the snow molded in shape for clinical use.
After securing the solidified carbon dioxide by the foregoing processes, its application to diseased surfaces is simplicity itself. The carbon dioxide is suitably shaped, at the point, in the form of a pointed or blunt crayon, to correspond with the size of the diseased surface. In small surfaces, as warts and moles, the contact surface would be smaller than it would be for treating an epithelioma, one inch or more in diameter. The solidified carbon dioxide is applied to the disease by firm pressure. This was formerly done in one operation, which lasted twenty or more seconds, but as we have become acquainted with the destructive influence of this element, most operators prefer shorter freezing periods, frequently repeated. To illustrate: If we had a surface, four inches in diameter, to be covered, this could be divided in areas of one inch in dimension and instead of attempting to treat the entire surface with one application, prolonged to thirty or forty seconds, we would treat each division of the areas about five seconds; after each section had been thoroughly covered, we would commence at the first and repeat the treatment, until the areas had been treated from six to eight times, or until the required destruction of tissue was completed.
This method always allows a better observation of the freezing process, and the gradual development of the inflammatory progress, and is always the method to pursue in treating large areas. Small surfaces, like warts and moles, may be treated with one or two applications as desired. It is always well to cover slightly more than the defective area, especially in warts, moles and cancerous growths.
In order that we may be sure of destroying every remnant of the disease when the solidified carbon dioxide ice is applied to living tissue it will be found that the treated area is, at first, more pliable, and in a few seconds, becomes firm and dense; when the crayon is removed, the area treated will be found depressed, white and hard, showing that the freezing process has been complete.
The physiological effects of the frozen area will depend upon the length of time of the exposure, which may result in a simple erythema from a short application, to necrosis from a prolonged treatment. Raw surfaces respond with free exudation. Upon removing the crayon, the surface rapidly thaws out, and returns to its normal state, and sets up an inflammatory reaction, which is accompanied by considerable swelling; a wheel and vesicle follow, usually within a short time. The vesicle may be opened to allow the escape of fluids; within a few days, the frozen surface will form into a ernst, which should be allowed to remain until it exfoliates spontaneously. Any simple dressing may be applied, but it is better to keep dry and exposed to the air. The crust will desquamate, in from ten days to two weeks, and the underlying surface will be found smooth, and of delicate pink color, which gradually, resumes nearly the normal color of the surrounding skin, in a short time, providing the destruction of tissue has not been too deep.
The cosmetic effect of this method, as a rule, is superior to any other manner of treatment, when used as a destructive agent, and by its careful use, the resultant scar tissue is so slight as to be almost unnoticeable. The treatment is nearly painless, and only the most nervous patients will complain of suffering any inconvenience at all. A slight tingling sensation will be felt for about ten minutes after the application; this rapidly disappears, and the little pain and discomfort is so slight from this treatment, compared to other destructive agents that the results are more than gratifyinng to both the patient and operator.
There has not been a therapeutic agent introduced in medicine, within the last ten years, which has a broader scope of usefulness than solidified carbon dioxide. As a destructive agent, it stands in a class alone, and has no equal competition, when its superior qualities are considered. Its rapidity and certainty in action with the minimum amount of pain are the three redeeming features, which place this agent at the highest pinnacle of merit, and when we survey the field in which this agent is applicable, we can better appreciate its value; there is hardly a cutaneous lesion in which this agent may not be used to a good advantage, while there are many neoplasms within the cavities of the body, which may be reached and removed by this therapeutic measure. It is one of the best means of treating skin cancers, and will accomplish, in a few seconds, the same results which require several hours of continuous suffering by plaster, and other means. It is the treatment, par excellence, for navi, lupus, rodent, and tuberculous ulcers, and may be successfully used in the treatment of superficial and deep-seated epithelioma, warts, moles, indurated eczema, X-ray burns, pigmentary and hypertrophic congenital deformities, papilloma, skin tumors, and tattoo marks. Many diseases and growths may be reached through the orifices of the body, which involve the uterus, rectum and nasal canal. In fact, there are many conditions, too numerous to mention, which will yield to this treatment. These conditions will be further discussed in the following pages.
Whenever we have well founded facts regarding any therapeutic agent, there is someone to present a substitute, and carbon dioxide snow has met with the same fate. Dr. G. Knauer has introduced Trichloracetic acid for superficial cauterization, as equally as efficient, and much less expensive, and simpler in technique than the carbon dioxide treatment, but great care should be exercised that none of the acid touches the healthy skin; it is, therefore, always best to paint a zone of collodion around the affected area. The acid should first be liquefied with one or more drops of water, then applied with a glass rod, of which various sizes are kept on hand.
The cauterization is always very superficial, unless the acid is actually rubbed into the tissues. A second application is rarely necessary, and should be postponed until the scab has fallen off. The cauterized tissue will appear white as snow, and the surrounding area will show only a moderate hypermia. Vesicles never form, and the cauterized area will turn brown after several hours. After eight or ten days, the scab can generally be loosened. The cosmetic results are excellent and the scars appear like those after the carbon dioxide snow treatment, and are much sightlier than those after cauterization, while there is hardly any pain during the application.
Trichloracetic acid is indicated wherever carbon dioxide snow may be used; except, that the latter is more convenient to use when large areas are to be cauterized. This is a most excellent means of removing warts, small birth-marks, etc., and its convenience in application should recommend it for a large class of conditions.