The Early History of Epidural Anesthesia

Abstract

Leonard Corning first conceived the concept of injecting an anesthetic solution into the epidural space in the mid-1880s. In his classic paper, Spinal Anesthesia and Local Medication of the Cord, published in 188 5 in the New York Medical Journal, he described a new and way to pro ­ duce an artificial, temporary, and local­ ized anesthesia of the lower limbs.l He theorized that the mode of action was ab­ sorption of an anesthetic drug (cocaine) into the venous system of the epidural space and then into the spinal cord where it would have its action. Corning's initial experiments favored deposition of an an­ esthetic agent into the epidural space, rather than into the subarachnoid space, because of previous problems with the sys­ temic toxicity of strychnine when it was placed into the subarachnoid space. He reasoned that direct deposition of a local anesthetic into the subarachnoid space would result in similar systemic toxicity. He also recognized the possibility of physi­ cally damaging the spinal cord if he at­ tempted to inject a medication into the subarachnoid space, with a needle, with­ out direct visualization. After injection of cocaine between the dorsal spinous processes in two subjects, first a dog and then a man, he tested for anesthesia with use of an electric current on the lower extremities. He described the lack of sensibility, which developed over 5-16 minutes, and the subsequent regres­ sion of this anesthesia over a period oHour to eight hours. Corning performed these injections without knowing the exact ana­ tomic position of his needle. Because he didn't mention cerebrospinal fluid aspira­ tion, and because the time course of the block was consistent with an epidural an­ esthetic, people have speculated that he performed an epidural rather than a spi­ nal anesthetic. Corning's work was successful at produc­ ing a novel means of regional anesthesia. He hypothesized that it would be useful in sur­ gery of the abdomen and pelvis. Interestingly, after his momentous initial start in epidural anesthesia, Corning abandoned further stud­ ies.