In the Summer issue of the APSF Newsletter, I defended the use of single dose hyperbaric 5% lidocaine. Part of this defense rested on our very safe record of utilization of single dose 5% hyperbaric lidocaine over a period of almost 10 years without problems. Recently, the manufacturer (Astra) made some important changes in the dosage, administration and precaution section of the package insert for 5% lidocaine with 7.5% glucose used for spinal anesthesia during surgery. This new prescribing information states that “the safety of hyperbaric Xylocaine for single injection for spinal anesthesia was demonstrated using 22 or 25 gauge spinal needles. “It also states that in these studies free flow of CSF was visible before injection of the local anesthetic. The neurologic deficits reported have been seen only with the use of small bore needles and microcatheters.

The new prescribing information reinforces our position that single dose hyperbaric lidocaine administered through either a 22 or 25 gauge spinal needle is a safe and effective anesthetic. We have not used hyperbaric subarachnoid lidocaine with needles of a smaller than 25 gauge, nor with microcatheters. It is our belief that there is some relationship to the needle gauge or the microcatheter regarding subarachnoid lidocaine-induced neurotoxicity.

We will continue to utilize hyperbaric lidocaine (single dose) via either 25 or 22 gauge spinal needles when such an anesthetic is indicated. It is our hope that other practitioners will continue to utilize the drug in a similar fashion since it is clearly of benefit to a substantial number of patients.

Casey D. Blitt, M.D. Old Pueblo Anesthesia Tucson, AZ