A Single Preoperative Dose of Gabapentin (800 Milligrams) Does Not Augment Postoperative Analgesia in Patients Given Interscalene Brachial Plexus Blocks for Arthroscopic Shoulder Surgery Fre ´de ´ric Adam, MD* Christophe Me ´nigaux, MD* Daniel I. Sessler, MD†‡ Marcel Chauvin, MD§ BACKGROUND: Inadequate analgesia is common after shoulder arthroscopy. Both interscalene blocks and gabapentin are effective methods of pain management under various circumstances. We tested the hypothesis that gabapentin augments postoperative analgesia provided by interscalene brachial plexus block in patients having ambulatory arthroscopic shoulder surgery. METHODS: Sixty patients were randomly assigned to receive oral gabapentin, 800 mg, or placebo 2 h before surgery. An interscalene brachial plexus block with 0.3 mL/kg of 0.5% ropivacaine was performed. General anesthesia was maintained with sevoflurane and included a single 1-g/kg dose of remifentanil. Postoperative analgesia was initially provided with morphine and subsequently with ketopro- fene (150 mg orally twice daily) and a combination of 400 mg acetaminophen and 30 mg dextropropoxyphene as needed. Pain scores, analgesic requirements, and side effects were assessed in the ambulatory unit and at home for 48 h. RESULTS: Emergence from general anesthesia was similar in both groups. There were no significant differences in pain scores, first postoperative request for analgesia, or oral analgesic consumption. The incidence of side effects was comparable in both groups, except that headaches were less frequent in the gabapentin group. CONCLUSION: A single preoperative dose of gabapentin (800 mg) does not augment postoperative analgesia in patients given interscalene brachial plexus blocks for arthroscopic shoulder surgery. (Anesth Analg 2006;103:1278 –82) Pain management is often inadequate after ambu- latory surgery (1). This is especially the case after arthroscopic shoulder surgery, an especially painful procedure. Supplementing general anesthesia with a single-dose interscalene brachial plexus block reduces pain scores, delays first analgesic use, and decreases overall opioid requirements (2). Effective regional blocks also help prevent surgery-induced central sen- sitization by suppressing the peripheral nociceptive inputs from injured sites (3). Supplementing regional anesthesia with antihyper- algesic drugs such as N-methyl-d-aspartate antago- nists in a multimodal approach reduces postoperative pain in patients undergoing abdominal or orthopedic surgery (3,4). Gabapentin is an antihyperalgesic drug that is effective for neuropathic pain, diabetic neurop- athy, postherpetic neuralgia, and reflex sympathetic dystrophy. It selectively affects the nociceptive pro- cess involving central sensitization (5), by presynapti- cally binding to the  2  subunit of voltage-dependent calcium channels (6), which reduces neurotransmitter release. Gabapentin has been shown to decrease postoperative pain and morphine consumption after surgery (7,8). Regional anesthesia and gabapentin (as an adju- vant) are thus reasonable choices in the management of postoperative pain. However, the combination has yet to be evaluated. We tested the hypothesis that a single preoperative oral dose of gabapentin improves postoperative pain after ambulatory arthroscopic shoul- der surgery in patients with an interscalene brachial plexus block. From the *Department of Anesthesia, Ho ˆ pital Ambroise Pare ´, Assistance Publique-Ho ˆ pitaux de Paris; †Department of Outcomes Research, The Cleveland Clinic, Cleveland, Ohio; ‡Outcomes Re- search Institute, University of Louisville, Louisville, KY; and §De- partment of Anesthesia and INSERM E 332, Ho ˆ pital Ambroise Pare ´. Accepted for publication June 20, 2006. None of the authors has a personal financial interest in this research. Supported by NIH Grant GM 061655 (Bethesda, MD), the Gheens Foundation (Louisville, KY), the Joseph Drown Foundation (Los Angeles, CA), and the Commonwealth of Kentucky Research Challenge Trust Fund (Louisville, KY). Address correspondence and reprint requests to Fre ´de ´ric Adam, MD, Ho ˆ pital Ambroise Pare ´, Assistance Publique-Ho ˆ pitaux de Paris, 9 Ave. Charles de Gaulle, 92100 Boulogne, France. Address e-mail to frederic.adam@apr.ap-hop-paris.fr. Copyright © 2006 International Anesthesia Research Society DOI: 10.1213/01.ane.0000237300.78508.f1 Vol. 103, No. 5, November 2006 1278