Background and aims In ambulatory lower limb surgery, spinal anaesthesia with rapid onset and a short duration of block is preferable. We hypothesized that the use of 2-chloroprocaine would be associated with a faster full recovery from motor block compared to prilocaine. a difference of 15 minutes was considered as clinically relevant.
Methods 150 patients were randomly allocated to receive either spinal 40 mg 2-chloroprocaine or 40 mg prilocaine. Primary outcome was the time to complete recovery from motor blockade. Secondary outcome parameters included time to full regression of sensory block, peak sensory block level, urine retention needing catheterisation, time until hospital discharge, TNS and patient satisfaction.
Results Time to complete recovery from motor blockade was 15 minutes shorter for 2-chloroprocaine (median: 60 min; interquartile range (IQR) 60–82.5) than for prilocaine (median: 75 min; IQR 60–90; p = 0.004). 2-Chloroprocaine also resulted in faster full regression of sensory block (median: 120 min; IQR: 90–135 compared to 165 min; IQR: 135–190, p < 0.001) and faster time to hospital discharge (mean difference: 57 minutes; 95% confidence interval: 38–77, p<0.001). Peak sensory block was higher in the 2-chloroprocaine group (median: T9; IQR: T6-T12: compared to median: T10; IQR: T8-T12, p<0.008). Patient satisfaction and urine retention needing catheterisation were equal in both groups. No TNS were reported.
Conclusions In knee arthroscopy, spinal anaesthesia with 2-chloroprocaine results in sufficient anaesthesia with a faster recovery of motor and sensory block, leading to quicker hospital discharge compared to prilocaine.