BLEEDING or BLOODLETTING.—Blood may be drawn from a vein (phlebotomy—we/1w sectio), or from an artery (arteriotomy).
The veins most commonly opened for this purpose are those at the bend of the elbow (see Amt), but those of the lower limbs are occasionally selected. The patient should be placed sitting up in bed, as he limy lose a dangerous amount of blood without show ing the usual premonitory symptoms, if his head be kept low.
The venous return should now be obstructed by a bandage, and when the veins swell, one should be selected, steadied with the left thumb, and slit obliquely with lancet; .the blood allowed to flow till the desired quantity has escaped, or till faintness comes on. The surgeon's thumb should now be replaced on the cut in the vein, and kept there till the bandage is removed, when a small pad of lint and figure of 8 bandage will sufficiently prevent the bleeding, and the wound will speedily heal.
Phlebotomy was at one time habitually resorted to in inflammatory diseases, or such as were thought so; and even when there was no positive disease, it was often applied periodically at particular seasons, as spring and autumn, as a hygienic precaution. A
great change in this respect has taken place in medical practice; as physiological knowledge advances, the opinion seems gaining ground that abstracting blood from a sick man gives him but temporary relief, and renders him less able to combat with the disease. When there is a wound of the cavities of the body with internal hemorrhage, venesectiou is very useful in lowering the heart's action, and perhaps, according to the old theory, in exercising a derivative influence on the wounded vessels. Local B. is effected by cupping and leeches. See articles on these.
Arteriotomy is generally performed on the temporal artery, by a transverse cut about half way through the vessel. When the required amount of blood has been abstracted, it ought to be completely cut across, to allow of its ends retracting and healing. if this precaution is neglected, an aneurism (q.v.) would form, A compress and bandage should be put on the head for a day or two.