Should intrathecal lidocaine be used in the 21st century?

Hyperbaric 5% lidocaine has been available for intrathecal use since 1954. The initial studies concluded that it was a safe drug for short procedures. Recently, the use of this drug for spinal anesthesia has been questioned. There were cases of cauda equina syndrome following its use for continuous spinal anesthesia. Following these occurrences, it was felt that lidocaine should not be used for continuous spinal anesthesia, rather for single-shot spinal anesthesia only. Intense follow-up of patients receiving intrathecal lidocaine for single-shot spinal anesthesia revealed a higher incidence of back pain radiating to the thighs and legs as compared to other drugs or general anesthesia. Although these symptoms have been linked to the drug, there were other factors affecting the incidence. Lithotomy position was a more significant predictor for developing these symptoms. Furthermore, there are seven cases of cauda equina syndrome following single-shot hyperbaric lidocaine. Cauda equina syndrome is a permanent disability. It occurred in patients of varying ages and with doses ranging from 60 mg to 120 mg. There are safe alternatives to lidocaine for outpatient spinal anesthesia, such as bupivacaine, prilocaine, or mepivacaine. These drugs have a lower incidence of transient neurologic symptoms and do not delay discharge. Given the possibility of permanent neurologic injury and given that safe alternatives exist, one has to question whether intrathecal lidocaine should still be used in the 21st century.