title: [Guidance of axillary multiple injection technique for plexus anesthesia. Ultrasound versus nerve stimulation].
abstract: BACKGROUND
  Ultrasound guidance is still a young method in regional anesthesia when compared to nerve stimulation and only a few studies exist comparing these two techniques in an axillary multiple injection approach.
  
  
  OBJECTIVE
  This prospective, randomized, observer-blinded study compared an ultrasound-guided (SONO) quadruple injection axillary block (out of plane, perineural) with a nerve stimulation-guided (STIM) triple injection axillary block for upper limb surgery.
  
  
  METHODS
  A total of 60 patients were randomized to either the SONO (n = 30) or STIM (n = 30) group. For the block 40-50 ml mepivacaine 1.5 % (plexus) and 5-10 ml mepivacaine 0.5 % (subcutaneous in the medial skin of the arm) was used. Anesthesia time was recorded as the primary end point. After evaluation of block-related pain using a visual analog scale (VAS) a blinded observer tested sensory and motor function of the median nerve (MED), ulnar nerve (ULN), radial nerve (RAD), musculocutaneous nerve of the upper limb (MUC) and medial cutaneous nerve of the forearm (CAM) at defined times. The main outcome variable was onset time (defined loss of sensory/motor function).
  
  
  RESULTS
  No differences were observed between the groups in terms of onset time (single nerves 10-20 min, plexus 20-25 min) and success rate (SONO 90 %, STIM 89 %). Patient satisfaction as measured by block-related pain score (VAS 2 cm), complications (vascular puncture SONO 7 %, STIM 11 %; paresthesia SONO 21 %, STIM 22 %) and patient acceptance (SONO 92 %, STIM 91 %) showed no differences. Performance time was shorter in the SONO group (6.68 ± 1.72 min vs. 8.05 ± 2.58, p = 0.02).
  
  
  CONCLUSIONS
  Nerve stimulation-guided axillary plexus blocks performed by trained anesthesiologists may result in similar onset times and success rates compared to ultrasound-guided blocks.
authors.affiliation: Klinik für Anästhesiologie, Universitätsmedizin Mainz, Langenbeckstr. 1, 55131, Mainz, Deutschland, j.t.meierhofer@gmail.com.
authors.forename: J T
authors.initials: JT
authors.lastname: Meierhofer
authors.forename: M
authors.initials: M
authors.lastname: Anetseder
authors.forename: N
authors.initials: N
authors.lastname: Roewer
authors.forename: C
authors.initials: C
authors.lastname: Wunder
authors.forename: U
authors.initials: U
authors.lastname: Schwemmer
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects; D001917:Brachial Plexus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D010525:Peripheral Nerves / Q000000981:diagnostic imaging; D011446:Prospective Studies; D018084:Ultrasonography, Interventional
chemical_list: D000779:Anesthetics, Local; D008619:Mepivacaine