title: Using stimulating catheters for continuous sciatic nerve block shortens onset time of surgical block and minimizes postoperative consumption of pain medication after halux valgus repair as compared with conventional nonstimulating catheters.
abstract: We prospectively tested the hypothesis that the use of a stimulating catheter improves the efficacy of continuous posterior popliteal sciatic nerve block in 100 randomized patients scheduled for elective orthopedic foot surgery. After eliciting a sciatic mediated muscular twitch at < or = 0.5 mA nerve stimulation output, the perineural catheter was advanced 2-4 cm beyond the tip of the introducer either blindly (Group C; n = 50) or stimulating via the catheter (Group S; n = 50). A bolus dose of 25 mL of 1.5% mepivacaine was followed by a postoperative patient-controlled infusion of 0.2% ropivacaine (basal infusion: 3 mL/h; incremental dose: 5 mL; lockout time: 30 min). Propacetamol 2 g IV was administered every 8 h, and opioid rescue analgesia was available if required. Catheter placement required 7 +/- 2 min in Group S and 5 +/- 2 min in Group C (P = 0.056). A significantly shorter onset time of both sensory and motor blocks was noted in Group S. No difference in quality of pain relief at rest and during motion was reported between the groups. Median (range) local anesthetic consumption during the first 48 h after surgery was 239 mL (175-519 mL) and 322 mL (184-508 mL) in Groups S and C, respectively (P = 0.002). Rescue opioid analgesia was required by 12 (25%) and 28 (58%) patients in Groups S and C, respectively (P = 0.002). We conclude that the use of a stimulating catheter results in shorter onset time of posterior popliteal sciatic nerve block, similar pain relief with reduced postoperative consumption of local anesthetic solution, and less rescue opioid consumption.
  
  
  CONCLUSIONS
  This prospective, randomized, blind investigation demonstrated that the use of a stimulating catheter for continuous posterior popliteal sciatic nerve block resulted in shorter onset time of sensory and motor blocks and less local anesthetic consumption and need for rescue pain medication after elective orthopedic foot surgery compared with blind catheter advancement.
authors.affiliation: *Department of Anesthesiology and Pain Therapy, University of Parma; †Vita-Salute University of Milano, IRCCS San Raffaele Hospital, Milano, Italy; ‡Department of Anesthesiology, Université Catholique de Louvain School of Medicine, St. Luc Hospital, Brussels, Belgium; and §Department of Anesthesia and Operative Services, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Andrea
authors.initials: A
authors.lastname: Casati
authors.forename: Guido
authors.initials: G
authors.lastname: Fanelli
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Koscielniak-Nielsen
authors.forename: Gianluca
authors.initials: G
authors.lastname: Cappelleri
authors.forename: Giorgio
authors.initials: G
authors.lastname: Aldegheri
authors.forename: Giorgio
authors.initials: G
authors.lastname: Danelli
authors.forename: Régis
authors.initials: R
authors.lastname: Fuzier
authors.forename: François
authors.initials: F
authors.lastname: Singelyn
mesh_terms: D000328:Adult; D000368:Aged; D002404:Catheterization; D004311:Double-Blind Method; D005260:Female; D006215:Hallux Valgus / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy*; D011446:Prospective Studies; D012584:Sciatic Nerve; D013997:Time Factors