Reducing the Dose of Local Anesthetic Reduces the Duration of Analgesia—Myth or Reality: A Double-Blind Randomized Study


Background: The aim of the study is to determine the effect of a reduction in dose of local anesthetic blockade on the development of the sciatic nerve. Methods: Forty blocks of sciatic nerve were used in a double-blind randomized research, under ultrasonic guidance, using an electric stimulator with the peripheral nerves. Forty patients were divided into 2 equal groups. In the first group, a sciatic nerve block was performed with 5 ml of 0.75% ropivacaine solution (37.5 mg); in the second group, 10 ml of 0.75% ropivacaine solution (75 mg) was used. The assessment of the time required for developing sensory and motor blocks was carried out from the beginning of local anesthetic solution injection in the fascial sheath of the sciatic nerve. Results: Demographic data of patients were identical in the two sample groups. The time required for achieving a complete sensory block in groups treated with 5 and 10 ml ropivacaine was 45 (40; 48) and 30 (28; 30) min, respectively, (р < 0.01). There was no difference in analgesic duration in the postoperative period among groups at p > 0.05. Conclusions: Complete blockade of the sciatic nerve is developed using 5 ml of 0.75% ropivacaine. Reducing the dose of ropivacaine prolongs the latent period of the LA during the blockade of the sciatic nerve. Time of postoperative analgesia was not significantly changed.

Share and Cite:

Valery, P. and Aliaksei, M. (2015) Reducing the Dose of Local Anesthetic Reduces the Duration of Analgesia—Myth or Reality: A Double-Blind Randomized Study. Open Journal of Anesthesiology, 5, 7-12. doi: 10.4236/ojanes.2015.51002.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Fanelli, G., Casati, A., Beccaria, P., Aldergheri, G., Berti, M., Tarantino, F., et al. (1998) A Double Blind Comparison of Ropivacaine, Bupivacaine, and Mepivacaine during Sciatic and Femoral Nerve Blockade. Anesthesia & Analgesia, 87, 597-600.
[2] Neuburger, M. and Büttner, J. (2011) Complications of Peripheral Regional Anesthesia. Anaesthesist, 60, 1014-1026.
[3] Kuthiala, G. and Chaudhary, G. (2011) Ropivacaine: A Review of Its Pharmacology and Clinical Use. Indian Journal of Anaesthesia, 55, 104-110.
[4] Valery, P. and Aliaksei, M. (2014) Features and Principles the Spread of Local Anesthetic Blockade of the Sciatic Nerve at Depends on the Amount of Anesthetic. Open Journal of Anesthesiology, 4, 31-35.
[5] Chelly, J.E. (2009) Peripherial Nerve Blocks: A Color Atlas. 3rd Edition, Wolters Kluwer/Lippincott Williams & Wilkins, Philadelphia, 1-474.
[6] Moayeri, N. and Groen, G.J. (2009) Differences in Quantitative Architecture of Sciatic Nerve May Explain Differences in Potential Vulnerability to Nerve Injury, Onset Time, and Minimum Effective Anesthetic Volume. Anesthesiology, 111, 1128-1134.
[7] Brull, R., Macfarlane, A.J., Parrington, S.J., Koshkin, A. and Chan, V.W. (2011) Is Circumferential Injection Advantageous for Ultra-Sound-Guided Popliteal Sciatic Nerve Block? A Proof-of-Concept Study. Regional Anesthesia and Pain Medicine, 36, 266-270.
[8] Perlas, A., Wong, P., Abdallah, F., Hazrati, L.N., Tse, C. and Chan, V. (2013) Ultrasound-Guided Popliteal Block through a Common Paraneural Sheath versus Conventional Injection: A Prospective, Randomized, Double-Blind Study. Regional Anesthesia and Pain Medicine, 38, 218-225.
[9] Hadzic, A., Karaca, P.E., Hobeika, P., Unis, G., Dermksian, J., Yufa, M., et al. (2005) Peripheral Nerve Blocks Result in Superior Recovery Profile Compared with General Anesthesia in Outpatient Knee Arthroscopy. Anesthesia & Analgesia, 100, 976-981.
[10] Taboada, M., Rodriguez, J., Valino, C., Carceveller, J., Bascuas, B., Oliveira, J., et al. (2006) What Is the Minimum Effective Volume of Local Anaesthetic Required for Sciatic Nerve Blockade? A Prospective, Randomized Comparison between a Popliteal and a Subgluteal Approach. Anesthesia & Analgesia, 102, 593-597.
[11] Latzke, D., Marhofer, P., Zeitlinger, M., Machata, A., Neumann, F., Lackner, E., et al. (2010) Minimal Local Anaesthetic Volumes for Sciatic Nerve Block: Evaluation of ED99 in Volunteers. British Journal of Anaesthesia, 104, 239-244.
[12] Ponrouch, M., Bouic, N., Bringuier, S., Biboulet, P., Choquet, O., Kassim, M., et al. (2010) Estimation and Pharmacodynamic Consequences of the Minimum Effective Anesthetic Volumes for Median and Ulnar Nerve Blocks: A Randomized, Double-Blind, Controlled Comparison between Ultrasound and Nerve Stimulation Guidance. Anesthesia & Analgesia, 111, 1059-1064.
[13] Janzen, P.R., Vipond, A.J., Bush, D.J. and Hopkins, P.M. (2001) A Comparison of 1% Prilocaine with 0.5% Ropivacaine for Outpatient-Based Surgery under Axillary Brachial Plexus Block. Anesthesia & Analgesia, 93, 187-191.
[14] Riazi, S., Carmichael, N., Awad, I., Holtby, R.M. and McCartney, C.J. (2008) Effect of Local Anaesthetic Volume (20 vs 5 ml) on the Efficacy and Respiratory Consequences of Ultrasound-Guided Interscalene Brachial Plexus Block. British Journal of Anaesthesia, 101, 549-556.
[15] Taboada Muniz, M., Rodriguez, J., Bermudez, M., Valino, C., Blanco, N., Amor, M., et al. (2008) Low Volume and High Concentration of Local Anaesthetic Is More Efficacious than High Volume and Low Concentration in Labat’s Sciatic Nerve Block: A Prospective, Randomized Comparison. Anesthesia & Analgesia, 107, 2085-2088.
[16] Sala-Blanch, X., de Riva, N., Carrera, A., López, A.M., Prats, A. and Hadzic, A. (2012) Ultrasound-Guided Popliteal Sciatic Block with a Single Injection at the Sciatic Division Results in Faster Block Onset than the Classical Nerve Stimulator Technique. Anesthesia & Analgesia, 114, 1121-1127.
[17] Gauiter, P., Vandepitte, C., Ramquet, C., DeCoopman, M., Xu, D. and Hadzic, A. (2011) The Minimum Effective Anesthetic Volume of 0.75% Ropivacaine in Ultrasound-Guided Interscalene Brachial Plexus Block. Anesthesia & Analgesia, 113, 951-955.
[18] Cuvillon, P., Nouvellon, E., Ripart, J., Boyer, J.C., Dehour, L., Mahamat, A., L’Hermite, J., Boisson, C., Vialles, N., Lefrant, J.Y. and de La Coussaye, J.E. (2009) A Comparison of the Pharmacodynamics and Pharmacokinetics of Bupivacaine, Ropivacaine (with Epinephrine) and Their Equal Volume Mixtures with Lidocaine Used for Femoral and Sciatic Nerve Blocks: A Double-Blind Randomized Study. Anesthesia & Analgesia, 108, 641-649.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.