;`BLEEDING (hemorrhage) is one of the most serious accidents which can happen to an animal, and constitutes the most anxious complication in surgical operations. As there is but a limited quantity of blood in the body, and as the sudden escape of a large por tion of it is sufficient to cause death, every one should be instructed as to the measures which experience has shown to be the most efficient for preventing a dangerous loss of blood.
B. may be either from a wounded artery or vein, or from a raw surface; and it may be in the form of a general oozing from the surface of a sore or a •mucous membrane. We shall consider these varieties separately.
Arterial B. is recognized by the florid redness of the blood, and by its issuing from the cut vessel per sattum or by jerks. There are exceptions to this, however. When an artery has been tied, and bleeding occurs from below the ligature, the flow of blood is continuous, and of a dark color.
If a large artery be wounded, the first gush of blood may prove fatal, but in general the patient faints, and nature takes advantage of the respite to place the cut artery in circumstances as favorable as possible to the preservation of life; viz., the artery draws up within its sheath (see ARTERY); the blood, no longer impelled vigorously by the heart, clots between the cut end and the cellular tissue surrounding it; the inner and middle coats not only retract but contract, and another clot forms within the arterial tube. These clots—which, with the faintness and the contraction and retraction of the artery, are termed natural heemostaties (blood-stoppers)—are sufficient in many cases to prevent a recurrence of the B.; but such a happy concurrence is not be depended on, and we must be prepared to adopt some of the many surgical or artificial means for restraining the flow of blood till adhesion (q.v.) canoceur between the cut surfaces of the coats of the artery. The principal surgical means are: Immediate pressure, which may be applied by pressing the finger-tip on the place whence the blood is seen to flow, and may be kept up by pads of lint, or a coin of con venient size wrapped in cloth, and secured with a bandage to the part.
Pressure on the artery above, or as it comes to the cut part. This requires some
knowledge of anatomy, but not more than any intelligent person may easily acquire. Thus, pressure on the inside of the arm, about midway between its front and back, will press the brachial artery (q.v.) against the bone, and arrest any bleeding from wounds of the forearm and hand. Pressure on the middle of the groin with a thumb placed crosswise will control the stream of blood in the fetnoml artery, so that none can escape from any wound below where the pressure is made.
Pressure on the course of the vessel may be very efficiently effected by tying a hand kerchief round the limb above where it is injured, and then inserting a stick and twist ing it sufficiently tight. This is the principle of the original tourniquet, which was invented by Morel, a French surgeon, at the siege of Besancon, in 1674. Ile got the idea from seeing how carriers tightened the ropes which secured bales of goods on their carts. It has been modified from time to time. At present it consists of a strap and buckle. a pad which may be adjusted over the course of theartery wounded, or likely to be cut in an operation, and a screw by.which the strap may be tightened as the sur geon may deem necessary. See TOURNIQUET. The objections to pressure as a means of arresting hemorrhage, are. that it is very painful, that it includes the vein, and thereby engorges the limb with blood, and may cause mortification, if continued for any length of time.
"Actual" cautery, or hot iron, is occasionally useful in bleeding from a bone, or at some points where pressure cannot he efficiently applied. It is the oldest method of stopping bleeding, and until the 18th c., was much in use; but its abuse and the natural horror felt for it by both patient and surgeon, have almost banished it from the list of surgical Inemostaties. If used, the iron should be at a white heat, the wound pressed for•an instant, and then the iron should be held in contact with the bleeding vessel. It causes an eschar or slough, with shriveling of the artery; and if the latter be small, it effectually stops the bleeding, until the eschar drops off, when the vessel may be found still pervious at the wounded part, and the danger of bleeding, be as great as at first.