Methods of raising a low arterial pressure

Abstract

In the course both of physiological experiments and of clinical practice a low arterial pressure may be due to two different causes, apart from failure of the heart. After hæmorrhage, the blood pressure is low on account of deficiency of blood in circulation, so that the output of the heart is decreased and is insufficient to keep up a due supply in the arteries to take the place of that flowing through the capillaries. Now, while it is obvious that constriction of the arterioles would raise the pressure in such cases, by diminishing the rate of outflow through the capillaries, the result would be to decrease the supply of blood to all organs whose arterioles are affected, so that no real gain would be obtained. In such cases, what is needed is to increase the volume of blood, without constricting arterioles.