Abstract
Femoral nerve block (FNB) is by far the most useful lower extremity regional anesthetic technique for the anesthesiologist, and high‐resolution ulrrasonography is a useful tool with which to guide the performance of FNB. However, the relationships between the femoral nerve and the femoral artery in different lower extremity positions have rarely been discussed. The purpose of this study was to evaluate the relative positions of the femoral nerve and artery at different lateral rotational angles of the lower extremities using ultrasonographic imaging. We enrolled 41 healthy volunteers in this study Two‐dimensional ultrasonographic images of the femoral nerve were obtained using an ultrasound unit, in the inguinal crease, for four positions of the bilateral lower extremities: 0°, 15°, 30° and 45° lateral rotation of each extremity. The following assessments were made in each position: minimal skin‐to‐nerve distance (SN) and deviation of nerve‐to‐landmark (femoral artery pulsation) horizontal distance (NF). A trend towards lateral rotation of both lower extremities was identified. The Pearson correlation values between rotational degree to SN and rotational degree to NF were −0.216 and 0.430, with p values of 0.001 and less than 0.001, respectively. Body mass index had a good correlation (r=0.76‐0.78) with SN. The results of our ultrasound study revealed that the more lateral the rotation of both lower extremities, the closer the femoral nerve was to the skin and the farther away it was from the femoral artery. In order to increase the success rate and decrease the rate of complications, a suggested lateral 45° rotation of both lower extremities is strongly recommended when performing FNB using the peripheral nerve stimulator technique or the field block technique. In any situation, individual ultrasound guidance is recommended for FNB whenever possible.
Keywords: femoral artery, femoral nerve, regional anesthesia, ultrasonography
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References
- 1. James P, Joseph M, Christopher M. Regional Anesthesia: The Requisites in Anesthesiology. 1st edition. Philadelphia: Elsevier Mosby. 2004, 92–95. [Google Scholar]
- 2. Sites BD, Beach M, Gallagher JD, et al. A single injection ultrasound‐assisted femoral nerve block provides side effect‐sparing analgesia when compared with intrathecal morphine in patients undergoing total knee arthroplasty. Anesth Analg. 2004; 99: 1539–1543. [DOI] [PubMed] [Google Scholar]
- 3. Sukhani R, Candido KD, Doty R Jr, et al. Infraglutealparabiceps sciatic nerve block: an evaluation of a novel approach using a single‐injection technique. Anesth Analg. 2003; 96: 868–873. [DOI] [PubMed] [Google Scholar]
- 4. Delfaut EM, Demondion X, Bieganski A, et al. Imaging of foot and ankle nerve entrapment syndromes: from well‐demonstrated to unfamiliar sites. Radiographics. 2003; 23: 613–623. [DOI] [PubMed] [Google Scholar]
- 5. Heinemeyer O, Riemers CD. Ultrasound of radial, ulnar, median, and sciatic nerves in healthy subjects and patients with hereditary motor and sensory neuropathies. Ultrasound Med Biol. 1999; 25: 481–485. [DOI] [PubMed] [Google Scholar]
- 6. Benyahya E, Etaouil N, Janani S, et al. Sciatica as the first manifestation of a leiomyosarcoma of the buttock. Rev Rhum Engl Ed. 1997; 64: 135–137. [PubMed] [Google Scholar]
- 7. Dubuisson A, Fissette J, Vivario M, et al. A benign tumor of the sciatic nerve: case report and a review of the literature. Acta Neurol Belg. 1991; 91: 5–11. [PubMed] [Google Scholar]
- 8. Singelyn F, Deyaert M, Pebdeville E, et al. Effects of intravenous patients‐controlled analgesia with morphine, continuous epidural analgesia, three‐in‐one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty. Anesth Analg. 1998; 87: 88–92. [DOI] [PubMed] [Google Scholar]
- 9. Casati A, Magistris L, Fanelli G, et al. Small‐dose clonidine prolongs postoperative analgesia after sciaticfemoral nerve block with 75% ropivacaine for foot surgery. Anesth Analg. 2000; 91: 388–392. [DOI] [PubMed] [Google Scholar]
- 10. Greher M, Retzl G, Niel P, et al. Ultrasonographic assessment of topographic anatomy in volunteers suggests a modification of the infraclavicular vertical brachial plexus block. Br J Anaesth. 2002; 88: 632–636. [DOI] [PubMed] [Google Scholar]
- 11. Vloka JD, Hadzic A, April E, et al. Anterior approach to the sciatic nerve block: the effects of leg rotation. Anesth Analg. 2001; 92: 460–462. [DOI] [PubMed] [Google Scholar]
- 12. Rice AS, Andreev NY, McMahon SB. The consequences of microneurography electrode‐induced injury of peripheral nerves observed in the rat and man. Pain. 1994; 59: 385–393. [DOI] [PubMed] [Google Scholar]
- 13. Inglis JT, Leeper JB, Wilson LR, et al. The development of conduction block in single human axons following a focal nerve injury. J Physiol. 1998; 513: 127–133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Noseir RK, Ficke DJ, Kundu A, et al. Sympathetic and vascular consequences from remifentanil in humans. Anesth Analg. 2003; 96: 1645–1650. [DOI] [PubMed] [Google Scholar]
- 15. International Organization for Standardization . ISO 9626: Stainless Steel Needle Tubing for the Manufacturer of Medical Devices. 1st edition. Geneva: International Organization for Standardization. 1991, 1–2. [Google Scholar]
- 16. Schafhalter‐Zoppoth I, Zeitz ID, Gray AT. Inadvertent femoral nerve impalement and intraneural injection visualized by ultrasound. Anesth Analg. 2004; 99: 627–628. [DOI] [PubMed] [Google Scholar]
- 17. Schulz‐Stubner S, Henszel A, Hata JS. A new rule for femoral nerve blocks. Reg Anesth Pain Med. 2005; 30: 473–477. [DOI] [PubMed] [Google Scholar]
- 18. Schafhalter‐Zoppoth I, Moriggl B. Aspects of femoral nerve block. Reg Anesth Pain Med. 2006; 31: 92–93. [DOI] [PubMed] [Google Scholar]