title: Nerve stimulator-guided supplemental popliteal sciatic nerve block after a failed sciatic block does not increase the incidence of transient postoperative neurologic sequelae.
abstract: BACKGROUND
  Supplemental peripheral nerve blocks are not commonly performed in adults because of concerns of cumulative exposure of the nerve to the local anesthetic as well as increased ischemia from epinephrine. The purpose of this study was to compare the incidence of postoperative neurologic symptoms after a failed subgluteal sciatic nerve block and a supplemental popliteal sciatic nerve block.
  
  
  METHODS
  Five hundred twelve adult patients undergoing ambulatory surgery were prospectively studied (1 yr). Sciatic nerve blocks were performed using levobupivacaine 0.625% with epinephrine 1:200,000 (0.5 ml/kg). Patients who failed to achieve sensory and motor anesthesia at 30-60 min were given a popliteal sciatic nerve block (lidocaine 2% 10 ml + levobupivacaine 0.5% 10 ml). Subjects were contacted at 24 h to 48 h, 2 weeks, and 1 month. Symptomatic patients were contacted biweekly and reevaluated during follow-up surgeon visits until symptom resolution.
  
  
  RESULTS
  Four hundred thirty-nine subjects were analyzed. Fifty-six received a popliteal sciatic nerve block. Four subjects (0.9%) had self-reported neurologic symptoms in the distribution of the sciatic nerve. Investigator-initiated follow-up revealed 33 subjects (8.7%) who received a single subgluteal sciatic block and 4 subjects (7.1%) after a supplemental sciatic nerve block with neurologic symptoms (P = 0.80). The median duration of symptoms was 4 weeks (95% CI 3-5) in the subgluteal and 4 weeks (95% CI 3-5) weeks in the popliteal group (P = 0.98). All symptoms resolved by 14 weeks postprocedure.
  
  
  CONCLUSIONS
  Blocking the sciatic nerve at a more distal site after a failed subgluteal sciatic nerve block does not appear to influence the incidence or duration of neurologic sequelae.
authors.affiliation: Department of Anesthesiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Antoun
authors.initials: A
authors.lastname: Nader
authors.forename: Mark C
authors.initials: MC
authors.lastname: Kendall
authors.forename: Robert
authors.initials: R
authors.lastname: Doty
authors.forename: Alexander
authors.initials: A
authors.lastname: DeLeon
authors.forename: Edward
authors.initials: E
authors.lastname: Yaghmour
authors.forename: Armen S
authors.initials: AS
authors.lastname: Kelikian
authors.forename: Robert J
authors.initials: RJ
authors.lastname: McCarthy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle / Q000601:surgery; D001182:Arthroscopy; D002908:Chronic Disease / Q000453:epidemiology; D004558:Electric Stimulation; D005260:Female; D005528:Foot / Q000601:surgery; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009422:Nervous System Diseases / Q000453:epidemiology* / Q000209:etiology; D019637:Orthopedic Procedures; D010147:Pain Measurement; D011183:Postoperative Complications / Q000453:epidemiology*; D012584:Sciatic Nerve; D013710:Tendons / Q000601:surgery; D017211:Treatment Failure; D016896:Treatment Outcome