Local anesthesia is an essential part of surgical dermatology. A proper understanding of the selection and administration of anesthesia, including indications, contraindications, potential side effects, and toxicities, is necessary to maximize patient safety and comfort.
The biologic effects of local anesthestics were first described in the ninteenth century, when Albert Niemann, a graduate student in pharmacology in Gottingen, Germany, extracted cocaine from the leaves of the coca plant (Erythroxylum coca) and noted numbness after application to his tongue.1 Niemann, however, did not consider cocaine’s utility as an anesthetic during surgery. Approximately 25 years later, Sigmund Freud, then a graduate student in Vienna who had read Niemann’s work, began experimenting with cocaine. In the 1880s, he published a famous paper “Uber Coca,” in which he advocated this agent as a means of treating patients with morphine addiction, dyspepsia, fatigue, hysteria, and headaches, as well as a number of mental disorders.1 In 1884, Karl Koller, a resident in ophthalmology and a colleague of Freud, introduced cocaine into the clinical arena by publishing a paper on its use in ophthalmologic surgery.1 Although the medical establishment was slow to accept this new anesthetic and its vast potential, most practitioners eventually began to adopt the use of cocaine as an aid in preventing pain during a variety of operations. As its use for local anesthesia expanded, however, reports of potential toxicities and addictive effects also began to emerge.
In the twentieth century, a number of safer anesthetics were identified. In 1904, Alfred Einhorn synthesized procaine hydrochloride, an ester of para-aminobenzoic acid (PABA).2 In 1905, Heinrich Braun became the first to use this new anesthetic in surgery.1 Soon, Höechst and Company marketed procaine under the trade name Novocain. However, it was soon learned that procaine, a vasodilator, caused a profound drop in blood pressure, by allowing the anesthetic to travel widely from the site of injection. In fact, a number of deaths were reported after infiltration of procaine. Fortunately, this was overcome by combining procaine with epinephrine, initially at a ratio of 1 to 20,000, which shortly became 1 to 200,000. In 1930, tetracaine, a more potent PABA ester, was introduced. Additional side effects such as allergic reactions were noted in some patients. In 1943, Lofgren and Lundqvist synthesized lidocaine, an amide derivative of diethylaminoacetic acid.1,2 This new anesthetic displayed superior safety and efficacy, which has since led to its widespread use in cutaneous surgery, as well as its claim as the prototype of local anesthetics. Following the introduction of lidocaine, additional amide derivatives were developed.
Currently, there are multiple local anesthetics and modes of delivery available for cutaneous surgery. A comprehensive understanding of the pharmacological properties, as well as techniques for administration of local anesthesia, is necessary in order to maximize patient safety, minimize pain and discomfort, and improve the ease with which ...