Complete anesthesia is often described using terminology that pertains to the pharmacodynamic effects of the medications administered. This vocabulary often includes akinesia, analgesia, amnesia and hypnosis. Local anesthesia is more specific and represents the administration of an amide or ester local anesthetic, to affect analgesia, at or around the site of administration. Anesthesiologists employ a breadth of different clinical techniques that utilize local anesthetic medications. These techniques include topical, mucosal, endotracheal, intravenous, peripheral nerve block, epidural, and intrathecal (spinal) administration. Unique to the fields of anesthesiology and pain medicine, however, is the administration of epidural and intrathecal local anesthetic. Together, these routes are jointly referred to as neuraxial anesthesia and are often utilized to facilitate surgical intervention, labor analgesia, or pain therapy. The history of neuraxial local anesthetic administration is rich and intriguing. The anatomy of the spinal cord and surrounding structures is complex and pertinent to the pharmacologic discussion of neuraxial local anesthetic administration. The pharmacodynamic and pharmacokinetic interactions of local anesthetics, when administered via the neuraxial route, are unique and worthy of continued investigation. Much has been studied, but there is still more to be discovered. These topics will be the focus of our discussion.
Part of the book: Topics in Local Anesthetics