Article Text

Download PDFPDF
Spinal 2-Chloroprocaine: Minimum Effective Dose
  1. Dan J. Kopacz, M.D.
  1. From the Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington.
  1. Reprint requests: Dan J. Kopacz, M.D., Department of Anesthesiology, Virginia Mason Clinic, 1100 Ninth Avenue, B2-AN, Seattle, WA 98111. E-mail: Dan.Kopacz{at}


Background and Objectives: Recent studies using preservative-free 2-chloroprocaine (2-CP) for spinal anesthesia have shown it to be a reliable short-acting agent in the 30-mg to 60-mg range. Investigations of doses below this range have not been performed.

Methods: To establish the minimum effective dose for spinal anesthesia, this randomized, double-blind, crossover study investigates the characteristics of spinal 2-CP 10 mg and 20 mg in 8 volunteers and compares the results with previous data obtained for 30 to 60 mg in the same human model.

Results: Peak block height, regression to L1, tolerance to tourniquet, and transcutaneous electrical stimulation all increased with increasing doses from 10 to 60 mg (P < .0001). Likewise, time to complete block regression, ambulation, and micturition also increased with increasing spinal 2-CP dosage (P < .0001). Degree of motor block generally increased with increasing doses from 10 to 60 mg; however, no differences existed between the 20-mg and 30-mg and between the 40-mg and 60-mg doses.

Conclusions: Spinal 2-CP 40 mg and 60 mg provide rapid and reliable sensory and motor block. Although the 20-mg and 30-mg doses can produce sensory anesthesia adequate for brief surgical procedures, less motor block and some sacral sparing should be anticipated. Because the 10-mg dose produces only brief and inconsistent sensory anesthesia, it can be considered a no-effect dose.

  • Anesthetic techniques
  • 2-Chloroprocaine
  • Local anesthetics
  • Outpatient anesthesia
  • Spinal anesthesia

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Reprints will not be available.

    Portions of this work have been submitted for presentation to the American Society of Anesthesiologists Annual Meeting, Las Vegas, Nevada, October, 2004.