Intrathecal 1% 2-chloroprocaine vs. 0.5% bupivacaine in ambulatory surgery: a prospective, observer-blinded, randomised, controlled trial

Background This prospective, observer-blinded, randomised, multicentre study aimed at determining the non-inferiority of 50 mg of plain 1% 2-chloroprocaine vs. 10 mg of 0.5% plain bupivacaine in terms of sensory block onset time at T10 after spinal injection. The study hypothesis was that the difference in onset times of sensory block to T10 between the two drugs is ≤ 4 min. Methods One hundred and thirty patients undergoing lower abdominal or lower limb procedures (≤ 40 min) were randomised to receive one of two treatments: 50 mg of plain 1% 2-chloroprocaine (Group C, n = 66) or 10 mg of plain 0.5% bupivacaine (Group B, n = 64). Times to sensory and motor block onsets, maximum sensory block level, readiness for surgery, regression of sensory and motor blocks, first analgesic requirements, unassisted ambulation, home discharge, and side effects after 24 h and 7 days were registered blindly. Results Chloroprocaine was comparable with plain 0.5% bupivacaine in terms of time to sensory block at T10 level. Group C showed faster onsets of motor block (5 vs. 6 min), maximum sensory block level (8.5 vs. 14 min), resolution of sensory (105 vs. 225 min) and motor (100 vs. 210 min) blocks, unassisted ambulation (142.5 vs. 290.5 min), first analgesic requirement (120 vs. 293.5 min), and home discharge (150 vs. 325 min) (all comparisons, P