INTRA-ARTERIAL BARBITURATES: A Study of some Factors leading to Intravascular Thrombosis

Abstract

A study was made of the effects of mixing thiopentone and mediohexitone with blood in the proportions likely to occur in accidental intra-arterial injection of die barbiturates. In addition to crystal formation, which had been previously reported, red blood cell haemolysis and platelet aggregation also occurred. Since these all lead to intravascular clotting the damaging effect of intra-arterial injection of barbiturates could be explained on this basis. On the basis of a further study of the crystal-forming properties of the commercially available barbiturates in aqueous solutions at differing dilutions, it was concluded that diis was less likely to occur with low concentrations. Thus the more potent the drug the safer it is with respect to the sequelae of intra-arterial injection because it can be used in a more dilute solution.