BLEEDING 



Synonyms: Venesection, phlebotomy. 



General. — Bleeding, a healing method of the old therapeutics, 

 has in the last several decades very correctly passed out of fashion. 

 A critical examination of its indications has shown that in most 

 cases in which it is employed early it is at least unnecessary, while 

 in a large number of cases it is even directly harmful. This is 

 especially true of its former conventional employment in all 

 febrile and inflammatory diseases. Still, it cannot be entirely 

 dispensed with even to-day, especially in veterinary medicine. 

 There are some very well-defined diseases, especially of horses and 

 cattle, in which bleeding under certain circumstances saves life. 



Action. — ^The most important effect upon the body of the 

 decrease in the total quantity of blood (5 to- 10 liters in horses and 

 cattle) which results from bleeding is the withdrawal of a large 

 amount of water. In this respect, the effect of bleeding agrees 

 entirely with the action of diaphoretic, sialagogue, diuretic, and 

 laxative drugs, especially arecoline. Following this withdrawal of 

 water, the blood seeks to regain at least its former volume as 

 quickly as possible by taking up any fluids in the body at its 

 disposal (lymph, fluid exudates), creating a temporary hydrsemia. 

 Upon this process rests one of the most important effects of bleed- 

 ing. Another important effect is the derivation of the blood from 

 the internal organs; the quicker the blood is withdrawn in bleeding 

 the more rapidly and promptly this action occurs. The other 

 effects of bleeding upon the body are of no special practical im- 

 portance. It may be mentioned that bleeding also corrects dis- 

 turbances of the circulation, removes poisons from the body with 

 the blood and increases proteid metabolism, while the fat and 

 carbohydrate metabolism is depressed (increased excretion of 

 urea, decreased elimination of carbon dioxide and decreased 

 absorption of oxygen, according to Bauer). 

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