Research Article

A Randomized, Double-Blind, Comparative Study of the Analgesic Efficacy of Perineural Dexmedetomidine as Adjuvant to Ropivacaine versus Ropivacaine Alone in Ultrasound Guided Saphenous Nerve Block after Anterior Cruciate Ligament Reconstruction Surgery


Background: The saphenous nerve block has been effectively used for pain treatment after knee surgeries, however, a single-shot saphenous nerve block with a long-acting local anesthetic usually provides a relatively short duration of postoperative analgesia. Dexmedetomidine is a highly selective alpha-2 adrenoceptors agonist and its perineural injection as an additive to local anesthetics has been shown to improve postoperative analgesia. The aim of this prospective, randomized double-blind study was to evaluate the effects of adding dexmedetomidine to ropivacaine on the quality of postoperative analgesia with ultrasound-guided saphenous nerve block after anterior cruciate ligament reconstruction surgery of the knee.
Methods: 40 ASA class I–II patients undergoing arthroscopic anterior cruciate ligament reconstruction surgery under general anesthesia were randomly divided into 2 groups of 20 patients each. At the end of surgery, ultrasound-guided saphenous nerve block was performed with either 10 ml ropivacaine 0.5% alone, or 1 µg/kg dexmedetomidine added to 10 ml of ropivacaine 0.5%. The total volume of injected solutions was increased to 12 ml by adding normal saline. The postoperative pain scores as well as fentanyl consumption through intravenous patient-controlled analgesia pump, hemodynamic parameters, sedation scores, and adverse effects were assessed every 1 hour to 6 hours and then every 2 hours to 24 hours.
Results: There were significantly lower postoperative pain scores in the ropivacaine plus dexmedetomidine group compared to ropivacaine alone group at all postoperative measured time points. The total amount of fentanyl consumption and sedation scores after surgery was significantly higher in group ropivacaine alone than in group ropivacaine plus dexmedetomidine. Systolic blood pressure and heart rate within 24 hours after surgery were significantly lower in the dexmedetomidine+ ropivacaine group than in the ropivacaine alone group. However, no bradycardia and hypotension were detected in any of the patients.
Conclusion: Perineural administration of 1 µg/kg of dexmedetomidine as an adjuvant to ropivacaine 0.5% for ultrasound guided saphenous nerve block significantly reduced pain scores and opioid requirements in the first 24 h after ACLR surgery compared to ropivacaine alone without any significant side effects.

[1] Secrist ES, Freedman KB, Ciccotti MG, Mazur DW, Hammoud S. Pain Management After Outpatient Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials. Am J Sports Med. 2016; 44(9):2435-47.
[2] Chisholm MF, Bang H, Maalouf DB, Marcello D, Lotano MA, Marx RG, et al. Postoperative analgesia with saphenous block appears equivalent to femoral nerve block in ACL reconstruction. HSSJ. 2014; 10(3):245–51.
[3] Bonet A, Koo M, Sabate A, Otero I, Bocos J, Pi A. Ultrasound-guided saphenous nerve block is an effective technique for perioperative analgesia in ambulatory arthroscopic surgery of the internal knee compartment. Rev Esp Anestesiol Reanim. 2015; 62(8): 428–35.
[4] Abdallah FW, Whelan DB, Chan VW, Prasad GA, Endersby RV, Theodoropolous J, et al. Adductor Canal Block Provides Noninferior Analgesia and Superior Quadriceps Strength Compared with Femoral Nerve Block in Anterior Cruciate Ligament Reconstruction. Anesthesiology. 2016; 124(5):1053-64.
[5] Jæger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor canal block versus femoral nerve block and quadriceps strength. A randomized, double-blind, placebo-controlled, crossover study in healthy volunteers. Anesthesiology. 2013; 118(2): 409-15.
[6] Swain A, Nag DS, Sahu S, Saaddar DP. Adjuvants to local anesthetics: Current understanding and future trends. World J Clin Cases. 2017; 5(8): 307-23.
[7] Brummett CM, Williams BA. Additives to local anesthetics for peripheral nerve blockade. Int anesthesiol Clin. 2011; 49(4): 104-16.
[8] Andersen JH, Grevstad U, Siegel H, Dahl JB, Mathiesen O, Jæger P. Does Dexmedetomidine Have a Perineural Mechanism of Action When Used as an Adjuvant to Ropivacaine?: A Paired, Blinded, Randomized Trial in Healthy Volunteers. Anesthesiology. 2017; 126(1):66-73.
[9] Yu J, Shan S, Nie Y. Impact of local administration of various doses of dexmedetomidine on ropivacaine-induced lumbar plexus‑sciatic nerve block. Exp Ther Med. 2018; 16(2): 711-17.
[10] Ahuja V, Thapa D, Chander A, Gombar S, Gupta R, Gupta S. Role of dexmedetomidine as adjuvant in postoperative sciatic popliteal and adductor canal analgesia in trauma patients: a randomized controlled trial. Korean J Pain. 2020; 33(2):166-75.
[11] Obayah GM, Refaie A, Aboushanab O, Ibraheem N, Abdelazees M. Addition of dexmedetomidine to bupivacaine for greater palatine nerve block prolongs postoperative analgesia after cleft palate repair. Eur J Anaesthesiol. 2010; 27(3):280–84.
[12] Ghosh A, Chaudhury S. Morphology of saphenous nerve in cadavers: a guide to saphenous block and surgical interventions. Anat Cell Biol. 2019; 52(3):262-268.
[13] Lundblad M, Kapral S, Marhofer P, Lönnqvist PA. Ultrasound-guided infrapatellar nerve block in human volunteers: description of a novel technique. Br J Anaesth. 2006; 97(5):710-4.
[14] Halaszynski TM. Dexmedetomidine: A look at a promising new avenue of use. Saudi J Anaesth. 2012; 6(2):104-6.
[15] Marhofer D, Kettner SC, Marhofer P, Pils S, Weber M, Zeitlinger M. Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: a volunteer study. Br J Anaesth. 2013; 110(3):438-42.
[16] Abdallah FW, Brull R. Facilitatory effects of perineural dexmedetomidine on neuraxial and peripheral nerve block: a systematic review and meta-analysis. Br J Anaesth. 2013; 110 (6): 915–25.
[17] Esmaoglu A, Yegenoglu F, Akin A, Turk CY. Dexmedetomidine added to levobupivacaine prolongs axillary brachial plexus block. Anesth Analg. 2010; 111(6): 1548–51.
[18] Chinnappa J, Shivanna S, Pujari VS, Anandaswamy TC. Efficacy of dexmedetomidine with ropivacaine in supraclavicular brachial plexus block for upper limb surgeries. J Anaesthesiol Clin Pharmacol. 2017; 33(1):81-5.
[19] Palsule VS, Shah AP, Kanzariya HH. Dexmedetomidine in supraclavicular block: Effects on quality of block and analgesia. Indian J Pain. 2017; 31(1):28-34.
[20] Thapa D, Ahuja V, Pandey K, Gombar S, Gupta R. Evaluation of analgesic efficacy of dexmedetomidine as adjuvant with ropivacaine in ultrasound-guided adductor canal block in patients following anterior cruciate ligament reconstruction surgeries. Br J Pain. 2019; 13(2): 91–8.
[21] Ortiz-Gomez JR, Pereperez-Candel M, Vazquez-Torres JM, Rodriguez-Del Río JM, Torrón-Abad B, Fornet-Ruiz I, et al. Postoperative analgesia for elective total knee arthroplasty under subarachnoid anesthesia with opioids: comparison between epidural, femoral block and adductor canal block techniques (with and without perineural adjuvants). A prospective, randomized, clinical trial. Minerva Anestesiol. 2017; 83(1): 50–8.
[22] Sharma B, Rupal S, Swami AC, Lata S. Effect of addition of dexmedetomidine to ropivacaine 0.2% for femoral nerve block in patients undergoing unilateral total knee replacement: A randomised double-blind study. Indian J Anaesth. 2016; 60(6):403-8.
[23] Abdulatif M, Fawzy M, Nassar H, Hasanin A, Ollaek M, Mohamed H. The effects of perineural dexmedetomidine on the pharmacodynamic profile of femoral nerve block: a dose-finding randomised, controlled, double-blind study. Anaesthesia. 2016, 71(10), 1177–85.
[24] Packiasabapathy SK, Kashyap L, Arora MK, Batra RK, Mohan VK, Prasad G, et al. Effect of dexmedetomidine as an adjuvant to bupivacaine in femoral nerve block for perioperative analgesia in patients undergoing total knee replacement arthroplasty: A dose–response study. Saudi J Anaesth. 2017; 11(3):293-8.
IssueVol 7 No 3 (2021): Summer QRcode
SectionResearch Article(s)
Dexmedetomidine Ropivacaine Nerve block Postoperative period Analgesia Anterior cruciate ligament reconstruction

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
Dabir S, Mosaffa F, Tanghatari H, Hosseini B. A Randomized, Double-Blind, Comparative Study of the Analgesic Efficacy of Perineural Dexmedetomidine as Adjuvant to Ropivacaine versus Ropivacaine Alone in Ultrasound Guided Saphenous Nerve Block after Anterior Cruciate Ligament Reconstruction Surgery. Arch Anesth & Crit Care. 2021;7(3):123-128.