A randomised, non-inferiority study of chloroprocaine 2% and ropivacaine 0.75% in ultrasound-guided axillary block

Sci Rep. 2021 May 11;11(1):10035. doi: 10.1038/s41598-021-89483-y.


Chloroprocaine is a short-acting local anaesthetic with a rapid onset of action and an anaesthesia duration up to 60 min. In this pivotal study success rates, onset and remission of motor and sensory block and safety of chloroprocaine 2% was compared to ropivacaine 0.75% for short-duration distal upper limb surgery with successful block rates as primary outcome. The study was designed as a prospective, randomised, multi-centre, active-controlled, double-blind, parallel-group, non-inferiority study, performed in 4 European hospitals with 211 patients scheduled for short duration distal upper limb surgery under axillary plexus block anaesthesia. Patients received either ultrasound guided axillary block with 20 ml chloroprocaine 2%, or with 20 ml ropivacaine 0.75%. Successful block was defined as block without any supplementation in the first 45 min calculated from the time of readiness for surgery. 90.8% patients achieved a successful block with chloroprocaine 2% and 92.9% patients with Ropivacaine 0.75%, thus non-inferiority was demonstrated (10% non inferiority margin; 95% CI - 0.097, 0.039; p = 0.02). Time to onset of block was not significantly different between the groups. Median time to motor and sensory block regression was significantly shorter as was time to home discharge (164 [155-170] min for chloroprocaine versus 380 [209-450] for the ropivacaine group, p < 0.001). For short-duration surgical procedures, the short-acting Chloroprocaine 2% may be used, with success rates non-inferior to ropivacaine and a favourable safety profile.Trial registration: The trial was registered at Clinicaltrials.gov with registration number NCT02385097 (March 11th, 2015) and European Clinical Trial Database with the EudraCT number 2014-002519-40 (July 7th, 2015, Austria-BASG).

Publication types

  • Equivalence Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anesthetics, Local / administration & dosage*
  • Axilla
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nerve Block*
  • Procaine / administration & dosage
  • Procaine / analogs & derivatives*
  • Prospective Studies
  • Ropivacaine / administration & dosage*
  • Ultrasonography, Interventional
  • Young Adult


  • Anesthetics, Local
  • Procaine
  • chloroprocaine
  • Ropivacaine

Associated data

  • ClinicalTrials.gov/NCT02385097