Toxicity of intra-arterial barbiturates and tranquilizing drugs.

Abstract

Radiologists frequently utilize intravascular sedative and tranquilizing drugs during or prior to the performance of certain radiologic procedures. Since in many cases a needle or catheter may be within the arterial system, this site of injection may be chosen. The purpose of this paper is to emphasize the intra-arterial toxicity of some of these drugs. Interest in this subject was stimulated by the fact that several patients have been seen in this community following the accidental intra-arterial injection of barbiturates or hydroxyzine hydrochloride (Vistaril). In some of these patients, injection was into an artery of the upper extremity with resultant complete or partial loss of limb (Fig. 1). In one case, the injection was into the superficial temporal artery with subsequent necrosis of the scalp and face (Fig. 2). It was found possible to produce similar lesions in rabbits by the intra-arterial injection of 60 mg of pentobarbital sodium into the brachial artery in a 10- to 15-second period. Promazine (Sparine) and hydroxyzine hydrochloride (Vistaril) produced identical lesions. Various therapeutic regimens were utilized and will be reported elsewhere. It was then decided to test the organ toxicity of certain of these drugs. The nephrotoxicity of intra-arterial pentobarbital sodium and Seconal sodium form the basis of this report. Procedure The rabbit was studied initially. Renal necrosis could be obtained by the injection of 60 mg of pentobarbital sodium into the renal artery. This required laparotomy and the insertion of a #25 needle into the renal artery (Fig. 3). The dog was utilized for the remainder of the studies since the renal artery could be selectively catheterized by way of the femoral artery. Six dogs were used for acute studies and six dogs for more chronic studies. The animals were lightly anesthetized with pentobarbital. Under fluoroscopic control, a #8-F selective Teflon catheter was inserted into the femoral artery and threaded into the renal artery. Due to the size of the catheter, partial occlusion of the vessel was achieved. Either 100 mg of 5 per cent secobarbital sodium or 120 mg of 6 per cent pentobarbital sodium was injected. In the acute study, the animals were sacrificed within three to four hours and the kidneys were removed for gross and microscopic study. In the chronic study, the animals were allowed to recover. Excretory urography was performed prior to the study and at weekly intervals. The animals were then sacrificed at intervals over the next eight weeks, and gross and microscopic study of the kidneys were performed. Results Acute: The gross and microscopic appearance are well depicted (Fig. 4). There was bluish discoloration and swelling of the kidney with patchy areas of hemorrhage, most marked in the renal cortex. On microscopic examination, there appeared to be swelling of the endothelial cells of the glomeruli with loss of protein into the glomerular spaces.