Liguori, Gregory A., et al., Anesthesiology 1998;  88:619-23

Reviewed by:  R. Coombs, M.D.

Introduction:  Reports of transient neurologic symptoms (TNS) following Lidocaine spinal anesthesia has led to interest in Mepivacaine as a replacement  for Lidocaine when a short duration spinal anesthetic is desired, as in ambulatory surgery.  This study tries to determine whether transient neurologic symptoms are as frequent with Mepivacaine as they are with Lidocaine.

Study:  Sixty ambulatory patients undergoing knee arthroscopy received spinal anesthesia with either 45 mg. 1.5% Mepivacaine or 60 mg. 2% Lidocaine.  A 27 gauge Whitacre needle was used via the L3-L4 midline approach.  The local was injected over 30 seconds with the aperture of the needle in the cephalad direction.  Two to four days after operation, each patient was questioned about the development of TNS.  In addition, the two groups were compared for time to regression of sensory and motor blockade and time to discharge.

Results:  Three patients receiving Lidocaine were lost to follow-up.  None of the 30 patients in the Mepivacaine group developed TNS, whereas 6 of 27 (22%) in the Lidocaine group did (P=0.008).  Time to regression to the L5 sensory level and to complete resolution of motor block were similar in both groups.  The times to discharge milestones were also comparable.

Conclusion:  The incidence of TNS is greater with 2% Lidocaine than with 1.5% Mepivacaine.  Mepivacaine seems to be a promising alternative to Lidocaine for short duration procedures because of a similar duration of action.