title: Efficacy of an ultrasound-guided subsartorial approach to saphenous nerve block: a case series.
abstract: OBJECTIVE
  The saphenous nerve, a branch of the femoral nerve, is a pure sensory nerve that supplies the anteromedial aspect of the lower leg from the knee to the foot. There is limited evidence of the effectiveness of ultrasound-guided techniques to block the saphenous nerve. We therefore undertook a retrospective case series to investigate the efficacy of an ultrasound-guided subsartorial approach to saphenous nerve block.
  
  
  METHODS
  During a four-month period, all patients receiving a subsartorial saphenous nerve block for lower extremity surgery at our institution had their medical records reviewed. Patient demographics and data were recorded, including block characteristics, intraoperative anesthetic management, pre-block, post-block, and postoperative pain scores, as well as postoperative analgesic dosing. Preoperative block success was defined by minimal intraoperative analgesic administration and a pain score of 0 in the postanesthesia care unit not requiring analgesic supplementation. Postoperative block success was defined by reduction of pain score to 0 without need for additional analgesic dosing.
  
  
  RESULTS
  Thirty-nine consecutive patients were identified as receiving an ultrasound-guided subsartorial saphenous nerve block. Overall, this ultrasound-guided technique was found to have a 77% success rate.
  
  
  CONCLUSIONS
  This case series shows that an ultrasound-guided subsartorial approach to saphenous nerve blockade is a moderately effective means to anesthetize the anteromedial lower extremity. The success rate is based on stringent criteria with an endpoint of postoperative analgesia. A randomized prospective study would provide a more definitive answer regarding the efficacy of this technique for surgical anesthesia.
authors.affiliation: Department of Anesthesiology, Harbor-UCLA Medical Center, Torrance, CA 90509, USA. Tsai0058@umn.edu
authors.forename: Phil B
authors.initials: PB
authors.lastname: Tsai
authors.forename: Abhishek
authors.initials: A
authors.lastname: Karnwal
authors.forename: Clinton
authors.initials: C
authors.lastname: Kakazu
authors.forename: Vadim
authors.initials: V
authors.lastname: Tokhner
authors.forename: Inderjeet S
authors.initials: IS
authors.lastname: Julka
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology; D035002:Lower Extremity / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000453:epidemiology; D010525:Peripheral Nerves / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012585:Sciatica / Q000209:etiology; D013848:Thigh / Q000000981:diagnostic imaging / Q000294:innervation; D016896:Treatment Outcome; D014463:Ultrasonography; D055815:Young Adult