text source: Dental materia medica and therapeutics 1920
...Within recent years a new remedial measure has been introduced into therapeutics for the purpose of combating infectious diseases which is so surprisingly simple, and yet so very definite in its final result, that one can only wonder why it was not discovered a long time ago. The object of the treatment consists in the increased utilization of the natural resources which the body possesses in the fight against local infection, and is known at present as the hyperemic treatment of Bier. Bier founded his conception of this treatment on observations which he had made in the clinic of Rokitansky in Vienna. He had repeatedly pointed out that a lung with a chronic obstructive hyperemia resulting from some valvular insufficiency of the heart would not, in the great majority of cases, be attacked by tuberculosis. On logical reasoning Bier applied the same principle with surprisingly good results in the treatment of chronic infections of the joints. In due time the technic of this treatment, depending largely upon the construction of suitable apparatus, had to undergo many modifications; but, even with the remarkable increase of the scope of its utilization it is still employed by comparatively few practitioners...
...the aim of Bier's hyperemic treatment is to bring about "the increase of the beneficial inflammatory hyperemia resulting from the fight of the living body against invasion," and the most important principle underlying this treatment is that "the blood must continue to circulate—there must never be a stasis of the blood." ...
...At present it is generally conceded that inflammation is not a disease, but that it is the local defense of the tissues against an injury, manifesting itself by more or less pronounced symptoms— as redness, heat, swelling, pain, and impaired function. The most important changes occur in the blood vessels, which are distended by an increased influx of blood that is very quickly displaced by a retarded afflux. The white corpuscles conglomerate in bunches near the vessel wall, especially in the veins and capillaries, while the red blood corpuscles keep more to the center of the blood stream. The leucocytes and the lymphocytes now pass between the endothelial cells through the vessel walls of the veins and of the capillaries, but not of the arteries. This wandering of the white corpuscles—diapedesis—is accompanied by the transudation of blood serum, which fills the surrounding tissues, causing an edematous swelling. Later on the red blood corpuscles follow, but they migrate in very much smaller quantities...
Whenever living tissue is injured—whether by mechanical, thermal, or chemic means—the system at once tries to protect itself against the invading foe by an increased rush of blood into the injured area, resulting either in a victorious fight—complete resolution, or in a surrender to the enemy—necrosis.
According to the conception of the older practitioners, irritants were employed for the purpose of depleting the "malignant humors" from the diseased part into the immediate neighborhood. Such irritants were known as derivants, while revulsives were used to disseminate these humors into the farther situated parts. In many instances irritants are applied to the healthy tissue somewhat distant from the primary seat of disturbance, with the intention of diverting the deep-seated congestion into a new direction, or, as our forefathers expressed it, "to leave a way for the escape of the humors." Proof for this supposition has never been furnished. Medicaments applied for these purposes are known as counterirritants. If strong irritants are applied to a circumscribed area of tissue, an exudation of small globules of serum occurs; the latter soon coalesce and raise the epidermis of the true skin, thereby forming a blister...
...At present it is generally recognized that the milder irritants produce the preliminary stages of inflammation—hyperemia. An increased influx and a retarded afflux of blood in the irritated tissue is the sequence of the irritation, and not, as it has been generally supposed, a diversion of the blood stream. Depending on the nature of the irritant, the congestion may be superficial, or it may reach to quite a depth. Hyperemia, in the sense of Bier (see Artificial Hyperemia), is one of the most important functions which nature possesses in overcoming morbid processes. Tissues which are richly supplied with blood possess a very pronounced restorative power, and there is no doubt that artificial hyperemia exercises a distinct beneficial influence on the reparative processes. This is partially the reason why wounds in the oral cavity heal so much quicker than in other parts of the body. Pain in deepseated structures is often mitigated by applying an irritant. By counterirritation of a sensory surface located somewhat distant from the primary seat of irritation, we may be able to divert the pain to this newly excited focus. Such applications are usually employed in the many forms of ill-defined pericemental disturbances. Some of the substances employed as irritants act by reflex action—that is, after their primary action they produce socalled reflexes, which have a beneficial influence on pathologic disturbances.
It should be remembered that the same irritant produces different effects on tissues of different resistance. The more delicate mucous membrane of the mouth requires naturally less severe irritation to produce definite results than the thick and horny layers of the skin.
Counterirritation is sometimes referred to as depletion. Depletives (to empty) are means which were very frequently used in former years for the purpose of locally abstracting blood or serum from the tissues in general or from the point of disease. Dry and wet cupping, scarification, and leeching were the usual methods employed for such purposes. Local depiction by physical means is rarely practiced at present. General depletion of the system by artificially increased perspiration or by abstracting fluids from the body through the bowel by salines or hydragogues are referred to under Cathartics and Diaphoretics.
Iodin in aqueous or in alcoholic solution occupies an important place among the irritants. It possesses a powerful and penetrating action.
|iodine molecule- wiki images|
Average Dose.—1/10 grain (0.005 Gm.).
Medical Properties.—Antiseptic, caustic, and alterative.
Therapeutics.—Iodin, in concentrated solution, acts as a caustic; in diluted solution, applied locally, it produces only irritant effects. Iodin has a peculiar action on the vessel walls, as it increases their penetrability. It produces typical fibrinous inflammation of the serous membranes. After the destruction of their epithelial coat, these serous membranes show a pronounced tendency to stick together and to heal by first intention. For this reason iodin is successfully employed in the treatment of fistulous tracts, etc. Painted on the skin, iodin quickly penetrates into the structures, and produces sensible irritation, thereby relieving pain which may be present in the deep-seated tissues. Incidentally it enlarges the walls of the various vessels, promotes absorption, and by reflex action produces venous hyperemia, which involves all the tissues within the affected area. The favorable influence of this artificially produced hyperemia on the diseased tissues is more fully discussed under Physical Therapeutics. (See Artificial Hyperemia.) Iodin is very freely employed in an alcoholic solution (tincture of iodin), and as the milder acting Lugol's solution. In using the tincture of iodin the alcoholic component of the latter must be accredited with a certain share of its action.
To promote the more ready absorption of iodin, various solutions have been recently introduced. Iodipin, an iodized sesame oil, containing respectively 10 and 25 per cent of iodin, and iothion, a glycerinated solution, containing 77 per cent of iodin, are the more important representatives of this group. Both preparations are almost colorless and odorless, and are used as substitutes for the tincture for external and internal purposes.
Tincture of Iodin; Tinctura Iodi, II. S. P., B. P. It contains 7 per cent (2.5 per cent, B. P.) of iodin dissolved in alcohol. The U. S. P. tincture contains in addition 5 per cent of potassium iodin, which increases its therapeutic effect and stability.
Compound Solution of Iodin; Liquor Iodi Compositus, U. S. P.; Lugol's Solution. It contains 5 per cent of iodin dissolved in a 10 per cent aqueous solution of potassium iodid.
Iodin Liniment; Liquor Iodi Fords, B. P. It contains about 14 per cent of iodin.
Therapeutics.—Tincture of iodin is universally employed as a counterirritant in pericemental disturbances. Its beneficial influence is based on three principal functions of iodin—to act as a derivant by sensory irritation, to produce artificial hyperemia, and to promote absorption. Its antiseptic properties are of less importance in this connection. If a definite iodin action is desired in the mouth, the ordinary tincture is not well suited for this purpose. Its alcoholic component causes superficial coagulation of the delicate mucous membrane, and in reality very little iodin is absorbed from this weak solution. If the tincture is repeatedly applied at short intervals, the caustic effect of the alcohol destroys the mucous lining, and a painful excoriated surface is the result. The irritating effect of the alcohol is probably as much responsible for the apparent results attributed to the tincture as its iodin component. Liquid iodin preparation for dental purposes should be concentrated solutions in water, preferably in the form of Talbot's iodo-glycerol. (See page 206.) A colorless tincture of iodin is occasionally demanded; ammonia water added to the tincture will quickly destroy its color. If higher concentrated iodin solutions are wanted, Carson's or Churchill's iodin paint is serviceable, but these compounds should not be used indiscriminately on the mucous surfaces of the mouth...