The existing situation in the fluid therapy of shock has been accurately summarized by Wiggers.1
It is generally suspected that the beneficial effects of sodium chloride do not depend solely or largely on its ability to restore plasma volume. It must be due to the action of the sodium or chloride ions or of the NaCl molecule.
Illustrative of the first sentence is the superiority of saline over plasma2-5 or dextran solution.6 The problem of the second sentence is explored in the present paper.
Tourniquet shock, which was first standardized in rats,2 was produced in dogs by tight constriction of both hindlegs as high as possible with heavy rubber bands or 6 mm. tubing. Anesthesia was induced with pentobarbital (Nembutal) intravenously or intraperitoneally. The animals were awake toward the end of the ligation period, when the limbs had lost sensation. Such constriction for five hours