Comparison of 1% chloroprocaine hydrochloride versus hyperbaric bupivacaine spinal in patients undergoing anorectal surgery in an ambulatory surgery center: a double-blind randomized clinical trial

BACKGROUND: Preservative-free chloroprocaine is a promising spinal anesthetic for ambulatory surgeries, offering a short duration of action and minimal side effects, which promote faster recovery and discharge. Thus, this study aimed to compare chloroprocaine hydrochloride to the widely used bupivacaine as a spinal anesthetic in ambulatory anorectal surgeries. We hypothesized that chloroprocaine will lead to quicker recovery and discharge, supporting its use in the ambulatory surgical setting. METHODS: In this double-blind randomized controlled trial, 110 patients were randomized to 1% chloroprocaine or 0.75% bupivacaine treatment groups. Due to the inability to place a spinal anesthetic, five patients were excluded (one in chloroprocaine and four in bupivacaine groups). The co-primary endpoints were recovery time (defined as the time of motor and sensory function return), and time discharge criteria were met. The secondary endpoint was the onset of transient neurological symptoms (TNS). RESULTS: The chloroprocaine group had a significantly shorter time to meet discharge criteria (191.4±6.6 min) than the bupivacaine group (230.9±9.4 min; p=<0.001). There were no significant differences between interventions for recovery time. No TNS were recorded within 24 hours after the procedure for both groups. CONCLUSION: Our study demonstrated a significantly reduced time to meeting discharge criteria with chloroprocaine compared with bupivacaine without an increased risk of TNS. Our results support the use of chloroprocaine for spinal anesthesia in ambulatory anorectal surgeries. TRIAL REGISTRATION NUMBER: NCT03324984.