Relation of Anesthetics to Experimental Shock Syndrome Produced by Venous Occlusion

Abstract

A major difficulty encountered in studies of the factors affecting the onset and course of experimental traumatic or circulatory shock has been that of failure to bring about a fairly constant and readily reproducible syndrome. A partial solution, at least, seems to be offered by the technic reported by Perlow et al. 1 who modified the method of regional venous occlusion (Mann) 2 for this purpose. This approach to the problem has been utilized in our laboratory in a considerable number of animals with gratifying results, and certain experimental variables have been studied. The present report deals with the influence on the experimental picture of certain anesthetic agents.

Methods. The technic of venous occlusion as outlined by Perlow et al. consisted of ligation, under anesthesia, of the common and the internal iliac veins, followed by injection of a suspension of animal charcoal either into the external iliac or the femoral vein; the latter, in our hands, has seemed preferable in view of easier access. Anesthetics were given at dose levels biologically standardized for each animal (Wiggers); 3 these usually approximated the calculated doses, which were: (1) morphine sulfate, 2%, 1 cc sub-cutaneously followed by 1.5 g/kg urethane, 50% intravenously; (2) barbital sodium, lo%, 225 mg/kg intravenously; (3) pentobarbital sodium, 376, 30 mg/kg intravenously; (4) ether, by mask.

Complete surgical anesthesia was induced in all cases. Jloreover, it was maintained throughout the observational periods in the urethane, barbital sodium, and in one series of pentobarbital sodium experiments. Anesthesia during the surgical procedure only (aseptic technic) was employed in one pentobarbital series and in the animals in which ether was used.