ANEMIA.
In acute anxmia the result of loss of blood through injury of veins or arteries caused by wounds or by diseased processes (as in duodenal ulceration) the diminished bulk of blood must be made up before the blood pressure falls to a degree incompatible with life. Often the urgency of the case can be met by the hypodermic, intraperitoneal, rectal or intra venous injection of Normal Saline in large doses; oz. Sodium Chloride dissolved in 6o oz. sterilised water may be injected by means of a fine canula to which is attached a rubber tube ending in a funnel. The canula may be inserted into an opened vein or into the loose areolar tissue, or made to penetrate the peritoneal cavity, the degree of pressure being secured by the elevation of the funnel and the temperature being kept at about 104° F. Isotonic Glucose Solution 5 per cent, or Trunecek's Serum—sodium chloride 492, sodium carbonate 21, potassium sul phate 40, and water io,000 parts—may be used, and 20-30 mins. adrenal solution may be added to the normal saline or injected hypodermically.
Hurwitz adds 5 per cent. Gum Acacia to Locke's Solution, which increases the viscosity of the blood and prevents its escape from the vascular walls.
In grave cases of injury causing extensive loss of blood the operation of blood transfusion must be performed. This procedure, hitherto rarely resorted to, has been employed many thousands of times during the late war, and is becoming a common agent in the treatment of pernicious and other forms of chronic anaemia.
When time permits, the dangers of any incompatibility between the blood of the donor and the patient must be eliminated by the tests for agglutination and htemolysis. Whether the direct or indirect methods be employed, the danger of clotting, air, sepsis, &c., must be scrupulously guarded against. The indirect method possesses the great advantage of the certainty of the exact dose administered, whilst the direct plan reduces to a minimum the exposure of the blood to air and the foreign materials constituting the walls of the tubes, cantffie, &c., and these should always
be coated over with a layer of paraffin wax. The technique is most varied, and is constantly changing as improvements in detail suggest themselves, so that the simple operation is being encumbered with apparently endless minutia. In emergency the blood may be recevied into a sterilised glass vessel from a vein in the donor's forearm at the front of the elbow. The addition of z per cent. sodium citrate in such amount that the entire bulk of the blood shall contain 0•2 per cent. of the salt (blood ifio c.c., sodium citrate solution, 2 per cent., zo c.c.) will prevent clotting. Some operators dispense with the citrate by defibrinating the blood, or by adding a small amount of leech extract, or by using the Kimpton-Brown tube.
The blood so treated is slowly injected by a syringe, or by a canula attached to rubber tubing with funnel; 500-1,000 c.c. may be given as a moderate dose, but in acute hamorrliages an attempt should be made to approximately replace the lost blood.
Many appliances are employed in the direct method; the simplest of these is the one introduced by Col. Fullerton, Major Dreyer and Capt.
Bazett. It consists simply of two silver canuhe connected by transparent rubber tubing; the ends of the canulm, being bulbous, require no ligatures to retain them in the vessels. One is inserted into the incised artery of the donor and the other into the vein of the patient, the flow being controlled by clips placed on the vessels. Before use the appliance is coated over externally and internally with a layer of paraffin congealing at a temperature of r r3° F. The sterilisation and the application of the paraffin coating is effected by heating on a bath. The dose may be guessed at by the first symptoms of faintness, pallor, and thirst in the donor, which usually occur after the loss of about r,000 c.c. The employ ment of syringe appliances in direct transfusion does away with the necessity of opening an artery. The chills which supervene (especially after the use of the citrate method) pass off in a few hours.