102 VASOCONSTRICTORS 



METHODS OF INCREASING THE VOLUME OF BLOOD IN THE 



ARTERIES 



The principal methods of increasing the volume of blood in the 

 arteries are : 



1. Transfusion of blood. 



2. Administration of saline solution by intravenous infusion, 

 hypodermoclysis or rectal injection. 



Transfusion of blood. This is usually accomplished by trans- 

 mitting the blood from an artery of one animal to the vein or artery 

 of another. It requires very careful technic and is comparatively 

 dangerous since clotting may take place, disease may be transmitted 

 and hemolysis may occur. It has, however, the advantage over nor- 

 mal saline infusion in that nourishment is supplied, oxyhemoglobin 

 furnished and, furthermore, the added fluid is not so easily transuded 

 out of the vessels or excreted so rapidly as salt solution and conse- 

 quently tends to maintain increased pressure for a longer time. 



Uses. 1. In collapse and shock from any cause, but especially 

 from bleeding. 



2. Poisoning by carbon monoxide (illuminating gas) after re- 

 moving a portion of the blood of the patient by venesection. 



3. Profound malnutrition. 



4. Profound anemia of secondary type or from hemorrhage. 



5. Protracted weakness or prostration. 



Saline Infusion. This means the injection of normal or phy- 

 siological saline solution, warmed to a temperature of 110°— 115° Y., 

 toward the heart. Normal saline solution is 0.85 per cent, of sodium 

 chloride, corresponding to about one full teaspoonful to a pint of 

 water. This is the most popular of all infusion fluids, but is not 

 generally considered as the best one on account of the absence of all 

 other salts, especially calcium and potassiimi, which are needed in 

 the tissues and, according to Jacques Loeb, prevent the poisoning by 

 sodium chloride, and furthermore, since its reaction is not alkaline, 

 it is not generally considered the best solution. In fact, it is now 

 believed that hard drinking water, which contains calcium, is better 

 than distilled water for making infusions. This is because pure 

 sodium chloride injected intravenously is poisonous and normal 

 saline solution in distilled water has a veratrine-like action upon 

 muscle, i.e., increased contraction with prolonged relaxation, but if 

 a slight amount of calcium is present this is prevented. Ordinary 

 table salt usually contains some calcium. 



Dawson's Solution. This contains 0.8 per cent, of sodium 

 chloride with 0.5 per cent, of sodium bicarbonate. 



Locke's Solution is probably the best of all according to most 

 authorities. It contains Sodium Chloride 0.9 gm.. Potassium Chlo- 

 ride 0.042 gm., Calcium Chloride 0.024 gm.. Sodium Bicarbonate 



