HEMOCONCENTRATION AS A DIAGNOSTIC SIGN OF SHOCK

Observations on shock during the World War seemed to show that substances absorbed from injured tissues were responsible for the circulatory failure which followed. The British Medical Research Council organized an investigation on the nature and appropriate treatment of shock. Eminent surgeons, physiologists and pharmacologists of England, France and the United States cooperated in this endeavor. The accumulated experience and experimental evidence, summarized by Cannon, indicated that secondary shock is due to a toxic factor absorbed from injured tissues which causes an increase in permeability of the capillary walls and a consequent reduction in blood volume through the escape of plasma into the tissues. In a large series of cases of hemorrhage and of shock in which hemorrhage was insignificant, Cannon, Fraser and Hooper¹ found that the blood showed dilution in the former proportional to the amount of blood lost, while in the latter there was concentration of the