title: [Interscalene block for total shoulder arthroplasty: comparative study (ultrasound vs. neurostimulation)].
abstract: BACKGROUND
  Modern anesthesiology has integrated the use of ultrasonography as a tool that has displaced neurostimulation as a technique for locating peripheral nerves. The aim of this study was to determine which procedure is more effective for guiding interscalene block for total shoulder arthroplasty.
  
  
  METHODS
  We carried out a comparative, prospective non-randomized study comprised of the group guided by neurostimulation interscalene block and the group guided by ultrasound. All patients in both groups were scheduled for total shoulder arthroplasty. Latency, degree of sensory and motor block, success rate, postoperative pain intensity at 6, 12, and 24 h, patient satisfaction and complications were measured.
  
  
  RESULTS
  We included 110 patients, 55 per group. Patients were placed in beach chair position and the deltopectoral approach was used. There were no differences in demographic characteristics. Results for neurostimulation vs. ultrasound group: latency 19.11 ± 2.27 vs. 17.24 ± 1.42 min, p= 0.23. Block sensitivity in both groups was grade 0 motor block grade 0 in 76.4% and grade 1 in 23.6% vs. grade 0 to 100%. There was 100% success rate for both groups. Postoperative pain at 6 h was 0.13 ± 0.54 vs. 0.11 ± 0.13 p= 0.90, at 12 h 1.67 ± 1.15 vs. 1.65 ± 0.59 p= 0.89 and at 24 h 3.15 ± 1.66 vs. 2.99 ± 1.15 p= 0.78. Satisfaction 54.5% very satisfied and 45.5% satisfied 96.36% vs 3.6% very satisfied and satisfied. Complications 18.18% vs. 3.6% p= 0.023.
  
  
  CONCLUSIONS
  Ultrasound-guided interscalene nerve block is the technique of choice in elective total shoulder arthroplasty.
authors.affiliation: División de Anestesiología, Instituto Nacional de Rehabilitación, Xochimilco, México DF, Mexico. gisibyg@yahoo.com.mx.
authors.forename: Gabriel Enrique
authors.initials: GE
authors.lastname: Mejía-Terrazas
authors.affiliation: División de Anestesiología, Instituto Nacional de Rehabilitación, Xochimilco, México DF, Mexico.
authors.forename: Michell
authors.initials: M
authors.lastname: Ruiz-Suárez
authors.affiliation: División de Anestesiología, Instituto Nacional de Rehabilitación, Xochimilco, México DF, Mexico.
authors.forename: Sandra Patricia
authors.initials: SP
authors.lastname: Gaspar-Carrillo
authors.affiliation: División de Anestesiología, Instituto Nacional de Rehabilitación, Xochimilco, México DF, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valero-González
authors.affiliation: División de Anestesiología, Instituto Nacional de Rehabilitación, Xochimilco, México DF, Mexico.
authors.forename: David
authors.initials: D
authors.lastname: Unzueta-Navarro
authors.affiliation: Servicio de Ortopedia, Fundación Clínica Médica Sur, Xochimilco, México DF, Mexico.
authors.forename: Iván
authors.initials: I
authors.lastname: Encalada-Díaz
mesh_terms: D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D019643:Arthroplasty, Replacement; D001917:Brachial Plexus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D006732:Horner Syndrome / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010292:Paresthesia / Q000209:etiology; D017060:Patient Satisfaction; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D011446:Prospective Studies; D011930:Reaction Time; D012677:Sensation; D012785:Shoulder Joint / Q000601:surgery*; D018084:Ultrasonography, Interventional
chemical_list: D000779:Anesthetics, Local
keywords: anestesia regional; artroplastia de hombro; bloqueo de nervios periféricos; bloqueo interescalénico; interscalene block; peripheral nerve block; regional anesthesia; shoulder arthroplasty; ultrasonido; ultrasonography