Traumatic Shock. v. a Study of the Effect of Oxygen on Hemorrhagic Shock.

The accumulating evidence from our studies of the plasma volume in hemorrhagic shock agrees with that of Gregersen (1) and of Evans (2), to the effect that there is no further loss of plasma from the circulation after the initial loss caused by the bleeding. Radioactive plasma proteins in the tissues of the dog in hemorrhagic shock are not found in greater concentration than in the unshocked dog. The irreversibility of hemorrhagic shock therefore cannot be explained by the theory of increased capillary permeability. Venous anoxemia is one of the outspoken pathological phenomena in shock. It appears early, and the associated tissue anoxia, if prolonged sufficiently, might be considered responsible for the development of irreversibility because of irretrievable damage to vital structures. In that case, the prevention or amelioration of venous anoxemia might exert a beneficial therapeutic effect. Indeed, several recent reports (3, 4) claim such an effect from the administration of pure oxygen. The data given are not convincing, because the anoxemia was only partially corrected and the benefit derived consisted of temporary elevation of blood pressure or a prolofigation of survival time by a few hours. A more definitive judgment as to the value of oxygen and the importance of venous anoxemia would require the prevention or complete correction of venous anoxemia. Only if a resulting change from the usual trend of events in shock is observed, can a therapeutic benefit from oxygen be claimed. This communication presents experimental data showing that the usual trend of events in hemorrhagic shock is in no way influenced by oxygen so given as to prevent the occurrence of or restore to normal an already lowered venous oxygen.