Femoral nerve block with ropivacaine or bupivacaine in day case anterior crucial ligament reconstruction H. WULF 1 , J. LO ¨ WE 2 , K-H. GNUTZMANN 3 and T. STEINFELDT 1 1 Department of Anesthesiology and Intensive Care Medicine, Hospital of the Philipps University, Marburg, Germany, 2 Department of Orthopedic Surgery, Lubinus Hospital, Kiel, Germany and 3 Department of Anesthesia, Centre for Ambulatory Surgery, Kronshagen, Germany Background/Objective: Our aim was to evaluate analgesia, motor block and pharmacokinetics of ropivacaine 0.2% and 0.75% in a femoral nerve block (FNB) in day case patients for anterior crucial ligament (ACL)-reconstruction com- pared with bupivacaine 0.25% and placebo. Methods: Following ethics committee approval and informed consent, 280 patients were randomly allocated to four groups for single-shot FNB [30ml ropivacaine 0.2% (group RO2.0), 0.75% (RO7.5), bupivacaine 0.25% (BU2.5) and NaCl 0.9% (NaCl)]. Analgesia (pain scores, primary outcome) and motor block were assessed at 4 h (dismissal) and up to 24 h. Plasma concentration was determined up to 240min thereafter. Results: Pain scores at 4h were significantly higher for NaCl 4 (0–8) (median, range) (vs.) BU2.5 2 (0–8), RO2.0 3 (0–9) and RO7.5 2 (0–8) (NS within the LA groups). Patients of the NaCl group needed analgesics significantly more often (93%) within 4 h after surgery vs. 16% of group RO2.0, 19% of group RO7.5 and 19% of group BU2.5. Motor block was significantly increased with all local anesthetics without a significant difference within the LA groups 3 (0– 5) in RO2.0, 3 (0–5) in RO7.5 and 3 (0–4) in BU2.5 vs. 0 (0–3) in group NaCl (median (range); scale from 0 5 full strength to 5 5 complete paralysis). Peak plasma concentrations differed significantly: RO7.5: 1.4 Æ 0.4 (0.73–2.6) [mg/ml, mean Æ SD (range)] after 33 Æ 14 (10–40) min, RO2.0: 0.6 Æ 0.3 (0.13–1.0) after 22117 (10–60) and BU2.5: 0.3 Æ 0.16 (0.05–0.62) at 31 Æ 17 (10–60), respectively. Conclusion: FNB for ACL reconstruction with ropivacaine or bupivacaine provided better post-operative analgesia than placebo without reaching toxic plasma concentra- tions. Significant motor block was observed after 4 h in all groups including the lowest concentration of ropiva- caine but occurred even with placebo. Accepted for publication 29 November 2009 r 2010 The Authors Journal compilation r 2010 The Acta Anaesthesiologica Scandinavica Foundation H IGH expectations regarding post-operative pain management and early mobilization and phy- siotherapy have popularized regional anesthesia in major knee surgery. 1,2 Especially in day case arthro- scopic reconstruction of the anterior crucial ligament (ACL), patients with the combined general-regional anesthesia technique showed improved recovery pro- files and lower unexpected readmission rates. 1–4 With femoral nerve block (FNB), we have to compromise between two goals for early ambulation: pain relief and muscle strength. Therefore, we evaluated pain relief (primary study goal), motor block and plasma concentration of ropivacaine following a FNB for ACL reconstruction in order to find a suitable solution for the compromise of pain relief and lack of motor block. Methods Adult patients (n 5 280) with ASA classifications of I–II, who were undergoing arthroscopic reconstruc- tion of the ACL on an ambulatory basis (setting of an ambulatory surgery center), were prospectively enrolled in this study in two subsets. The anesthe- siologist in charge allocated the next available number of a computer-generated randomization list on entry into the trial. In the first randomized subset (n 5 160) a placebo group was included in addition to three local anesthetic groups to ensure sufficient sensitivity of the study design to detect differences in pain scores or use of escape medica- tion, respectively. In the second subset (n 5 120), patients were randomized only to verum (local anesthetic) groups. The two-phase study design was chosen in order to keep the number of patients exposed to placebo injections as low as possible. The study protocol had been approved by our Institutional Ethics Committee, and written in- formed consent was obtained from all patients. ACL reconstruction was performed according to a standardized procedure. 414 Acta Anaesthesiol Scand 2010; 54: 414–420 Printed in Singapore. All rights reserved r 2010 The Authors Journal compilation r 2010 The Acta Anaesthesiologica Scandinavica Foundation ACTA ANAESTHESIOLOGICA SCANDINAVICA doi: 10.1111/j.1399-6576.2009.02200.x