Procaine Spinal Neurotoxicity

Abstract

THE rare but devastating complication of cauda equina syndrome (CES) after spinal anesthesia has been reported with several local anesthetics, most frequently lidocaine. 1 A separate complication of spinal anesthesia, transient neurologic syndrome (TNS), consisting of potentially severe but transient lumbosacral pain, has also been reported and is also most frequent with lidocaine. 2 The mechanism of CES from local anesthesia is most likely necrotic or apoptotic neuronal death, depending on the intensity of the local anesthetic exposure. 3 The mechanism of TNS is unknown but seems to be distinct from that of CES. 4,5 Lidocaine's pharmacokinetics are ideal for spinal anesthesia for short-duration, ambulatory surgery. The increased frequency of CES and TNS with lidocaine has encouraged the study of other local anesthetics to substitute for lidocaine, without complete success. 6-8 Procaine has been reported to be less likely to produce TNS than lidocaine, with a kinetic profile also suitable for short-duration surgery. 9,10 However, there has been no modem study of procaine and CES. We now report a case of permanent CES after procaine spinal anesthesia.