hyperemia. Excessive amount of blood.

Hyperemia  as a therapeutic agent was described by Bier and is of two kinds, active  and passive. The former is the same as the arterial, while the latter is the venous. Between the blood of active and passive hyperemia there are important physical and chemical differences, the one containing much free oxygen with but little carbonic acid and alkali, while the other presents the exactly opposite character.

In active hyperemia normal elements of the blood are kept in active motion, while in the passive form they are allowed to escape, more or less, into the tissues.

Hyperemia possesses a great many properties:

1. Power to diminish pain.
2. Bactericidal action.
3. Absorptive property.
4. Solvent action.
5. Nutritive power.
6. Suppression of the infection.

Hyperemia may be produced in three ways; first, by means of the elastic bandage or band; second, by cupping glasses, and third, by hot air. The first two produce venous or passive hyperemia, and the third, arterial or active hyperemia.

Passive Hyperemia. This obstructive hyperemia is produced by means of a thin, soft rubber elastic bandage, two or three inches in width, better known as the Esmarch, or Martin bandage. When this is applied moderately tight around a limb about six or eight turns, one layer overlapping the other, pressure is evenly distributed over a comparatively wide area, causing the subcutaneous veins below the constriction to swell; the extremity becomes somewhat bluish red in color, also larger and edematous, giving a feeling of warmth to the touch.

The rubber bandage, properly applied, should not cause any uncomfortable feeling and there should be absolutely no pain present. At all times one must be able to feel the pulse below the site of the bandage. If the bandage is applied too tight, the skin of the limb looks grayish-blue and there appear whitish, or vermilion colored spots, which grow larger and larger, as long as the too tightly drawn bandage is on. Paresthesia and pain, with disappearance of the pulse, can also be noted.

The two cardinal rules to be observed in the application of the bandage are: (1) absolutely no pain with the application of the bandage; (2) the pulse at all times must be felt below the bandage.

In cases which require the bandage to remain in place from sixteen to twenty hours each day, it will be necessary to first apply a soft flannel bandage underneath the rubber one in order to prevent pressure necrosis.

Frequently changing the location of the bandage up and down the extremity, and treating the skin with alcohol rubs, will also be helpful to patients with a tender skin. The elastic bandage must always be placed upon a healthy area, proximal to the diseased part. All dressings should be removed while the compressing bandage is on, in order that the part may become hyperemic.

Wounds or sinuses are covered with sterile gauze and kept in place with a towel, fastened with a few safety pins.

In acute inflammation, septic wounds and phlegmons, the increased inflammation is apt to frighten the beginner, but this is a desired phase of the treatment.

As a prophylatic against infection, it cleanses the wound, produces a local immunization and reaction before the infection has a chance to work; the earlier the bandage is applied the more remarkable is the effect.

For incised wounds of the foot with division of the muscles and tendons, if the tissues are not too seriously injured, the muscles and tendons should be united and the skin closed with interrupted sutures sufficiently far apart to allow free excretion. No drainage is employed and a slight compressing dressing is applied. The elastic bandage is applied very lightly, producing only a slight venous engorgement and the bandage should remain on from ten to eighteen hours a day.

As soon us the symptoms of acute inflammation subside, the time of application of the bandage is reduced. If signs of suppuration are present, the wound should be promptly opened and the pus evacuated. The knife takes care of the pus; hyperemic treatment fights the infection.

In gonorrhoeal arthritis of acute or chronic nature, and in cases of tuberculosis of the bones and joints, the passive form of hyperemia is especially indicated.

The use of cupping glasses is limited to abscesses, furuncles and sinuses.

Active Hyperemia , or arterial hyperemia, is produced by means of hot-air boxes such as the Tyrnauer electric apparatus, or the gas apparatus of Betz.

Active hyperemia increases the arterial blood to any part of the body, thus favoring the absorption of chronic exudates, infiltrates, adhesions, etc. Dry, hot air permits the use of a high degree of temperature without injury or pain to the respective part.

For neuritis of the foot, ulcers, especially diabetic, perforating and varicose, and for the stiffness following a chronic inflammation, or after a fracture, the arterial form of hyperemia gives good results.