KNEE The effect of magnesium added to levobupivacaine for femoral nerve block on postoperative analgesia in patients undergoing ACL reconstruction Perihan Ekmekci • Zuleyha Kazak Bengisun • Burak Akan • Baturay Kansu Kazbek • Kemal Sefa Ozkan • Arif Hikmet Suer Received: 30 October 2011 / Accepted: 4 June 2012 / Published online: 14 June 2012 Ó Springer-Verlag 2012 Abstract Purpose The aim of this prospective randomised double- blind study is to investigate the effect of magnesium added to local anaesthetics on postoperative VAS scores, total opioid consumption, time to first mobilisation, patient satisfaction and rescue analgesic requirements in arthro- scopic ACL reconstruction surgery. Methods A total of 107 American Society of Anaesthe- siologists physical status grade I and II patients between 18 and 65 years of age who were scheduled to undergo elec- tive anterior crucial ligament (ACL) reconstruction with hamstring autografts were enrolled in the study. The patients were randomly allocated to Groups L (n = 51) and LM (n = 56) using the closed-envelope method. Group LM was administered 19 ml of 0.25 % levobupivacaine and 1 ml of 15 % magnesium sulphate, while Group L was administered 20 ml of 0.25 % levobupivacaine for femoral blockade. General anaesthesia was administered using laryngeal airway masks following neural blockade in both groups. The patients were evaluated for heart rate and mean arterial pressure, oxygen saturation, visual analogue score (VAS), verbal rating scale (VRS), rescue analgesic requirements, total opioid consumption, side effects and time to first mobilisation at the 1st, 2nd, 4th, 6th, 12th and 24th hours postoperatively. Results There was no statistically significant difference in terms of demographic data, mean arterial pressure, heart rate or oxygen saturation between groups. The area under the curve VAS and VRS scores were lower at 4, 6, 12 and 24 h in Group LM (p = 0.001, p = 0.016, respectively). The rescue analgesic requirement and the total opioid consumption were significantly lower in Group LM (p = 0.015, p = 0.019, respectively). The time to first mobilisation and the Likert score (completely comfortable; quite comfortable; slight discomfort; painful; very painful) were higher, and the block onset time was lower in Group LM (p = 0.014 and p = 0.012, respectively). There was no difference in terms of side effects. Conclusions The addition of magnesium to levobupiva- caine prolongs the sensory and motor block duration without increasing side effects, enhances the quality of postoperative analgesia and increases patient satisfaction; however, the addition of magnesium delays the time to first mobilisation and decreases rescue analgesic requirements. Keywords Postoperative analgesia Á Femoral block Á Magnesium sulphate Á Anterior cruciate ligament reconstruction Introduction Arthroscopic knee surgery is an outpatient surgery that is commonly performed . In addition to postoperative anal- gesia with narcotic analgesics and postoperative intraar- ticular local anaesthetic infiltration [12, 16] and hamstring donor-site block [3], femoral nerve block is an effective technique for analgesia following arthroscopic knee sur- gery [7, 14, 20]. Agents such as clonidine and magnesium are used as adjuvants in peripheral nerve blockade [6, 19]. P. Ekmekci Á Z. K. Bengisun Á B. K. Kazbek Á K. S. Ozkan Á A. H. Suer Department of Anaesthesiology and Reanimation, Faculty of Medicine, Ufuk University, Ankara, Turkey B. Akan (&) Department of Orthopaedic and Traumatology, Faculty of Medicine, Ufuk University, Evleri 9/B No 28 Keklikpinari Cankaya, Ankara 06420, Turkey e-mail: burakakan1977@yahoo.co.uk 123 Knee Surg Sports Traumatol Arthrosc (2013) 21:1119–1124 DOI 10.1007/s00167-012-2093-4