Does pregnancy protect against intrathecal lidocaine-induced transient neurologic symptoms?

We investigated the incidence of transient neurologic symptoms (TNS) after the use of hyperbaric lidocaine as compared with hyperbaric bupivacaine in patients undergoing cesarean delivery under spinal anesthesia. Two hundred women scheduled for cesarean delivery were randomly allocated to receive sp inal anesthesia with 75 mg hyperbaric lidocaine 5% (n = 100) or 12 mg hyper baric bupivacaine 0.75% (n = 100). Spinal anesthesia was administered to al l patients in the sitting position with a 25-gauge Whitacre needle. The lev el of sensory blockade, time to full recovery, and intraoperative hemodynam ic profile were noted in all patients. The patients were interviewed postop eratively for three consecutive days to detect the occurrence of TNS. The incidence of TNS was zero (95% confidence interval 0%-3%) in both the L idocaine and the Bupivacaine Groups. Our results indicate that the frequency of postoperative TNS does not excee d 3% in patients undergoing cesarean delivery at term using hyperbaric lido caine 5% or hyperbaric bupivacaine 0.75%.