Spinal 2-chloroprocaine: a comparison with lidocaine in volunteers.

UNLABELLED: Subarachnoid lidocaine has been the anesthetic of choice for outpatient spinal anesthesia. However, its use is associated with transient neurologic symptoms (TNS). Preservative-free formulations of 2-chloroprocaine are now available and may compare favorably with lidocaine for spinal anesthesia. In this double-blinded, randomized, crossover study, we compared spinal chloroprocaine and lidocaine in 8 volunteers, each receiving 2 spinal anesthetics: 1 with 40 mg 2% lidocaine and the other with 40 mg 2% preservative-free 2-chloroprocaine. Pinprick anesthesia, tolerance to transcutaneous electrical stimulation and thigh tourniquet, motor strength, and a simulated discharge pathway were assessed. Chloroprocaine produced anesthetic efficacy similar to lidocaine, including peak block height (T8 [T5-11] versus T8 [T6-12], P = 0.8183) and tourniquet tolerance (46 +/- 6 min versus 38 +/- 24 min, P = 0.4897). Chloroprocaine anesthesia resulted in faster resolution of sensory (103 +/- 13 min versus 126 +/- 16 min, P = 0.0045) and more rapid attainment of simulated discharge criteria (104 +/- 12 min versus 134 +/- 14 min, P = 0.0007). Lidocaine was associated with mild to moderate TNS in 7 of 8 subjects; no subject complained of TNS with chloroprocaine (P = 0.0004). We conclude that the anesthetic profile of chloroprocaine compares favorably with lidocaine. Reliable sensory and motor blockade with predictable duration and minimal side effects make chloroprocaine an attractive choice for outpatient spinal anesthesia. IMPLICATIONS: The spinal anesthetic profile of chloroprocaine (40 mg) compares favorably with the same dose of spinal lidocaine. Reliable sensory and motor blockade with predictable duration and minimal side effects and without signs of transient neurological symptoms make chloroprocaine an attractive choice for outpatient spinal anesthesia.