Abstract
A large series of dogs, subjected to severe muscle trauma, has been studied. Eighty-four per cent died or would have died of shock within 24 hr. had they not been treated with a blood substitute. Of these about half developed severe shock in less than five hours. A few, 3.7% of the series, died between 24 and 80 hr., and 12.3% were considered indefinite survivors either being well when killed at 24 hr. or appearing well at the end of three days after trauma.Repeated observations made on the blood pressure and heart rate made it possible to predict death some time in advance in a great majority of cases. Haemoconcentration, as evidenced by an increase in the volume of packed red blood cells, occurred in the majority of the animals. This is ascribed partly to the fact that the fluid loss into the damaged tissues was principally plasma rather than whole blood, and partly to the fact that the animals were not deeply anaesthetized for a long time and consequently reflex splenic contraction added cells to the circulation. The blood sugar in dogs dying within three hours of trauma was normal or elevated. In dogs dying later it was often low. In those in which life was prolonged a few hours by a blood substitute the terminal value was very low. In many dogs in which life was prolonged beyond 24 hr. the blood sugar values slightly before death were within normal limits.The significance of these findings is discussed.