title: [Comparison of ultrasound and nerve stimulation techniques for brachial plexus block for regional hemodynamic changes of upper extremity].
abstract: OBJECTIVE
  To compare ultrasound guidance versus nerve stimulator guidance supraclavicular brachial plexus block for regional hemodynamic changes of upper extremity.
  
  
  METHODS
  Sixty ASA I-II patients scheduled for upper extremity operation were randomly assigned to receive a supraclavicular brachial plexus block guided by either ultrasound (U group, n = 30) or nerve stimulation (N group, n = 30).20 ml mixture of equal volumes of 2% lidocaine and 0.75% ropivacaine was injected in both groups. Regional hemodynamic parameters were measured in the ipsilateral ulnar artery and radial artery, using pulsed-wave Doppler ultrasound, before and 30 minutes after the block. Regional hemodynamic parameters included peak systolic velocity (PSV), end-diastolic velocity (EDV), time averaged maximum velocity (TAMAX), resistance index (RI), pulsatility index (PI), cross-sectional area (Area) and Blood flow (Q). The intensity of sensory block was measured at 30 minutes after the block.
  
  
  RESULTS
  There was no significant difference in the hemodynamic parameters of ulnar artery and radial artery before the block between two groups. Compared with N group, EDV, TAMAX and Q of ulnar artery were higher in U group (1.88-fold, 1.71-fold and 1.84-fold)(P < 0.01 or P < 0.05), PI and RI of ulnar artery were lower in U group (P < 0.01) at 30 minutes after the block, EDV of radial artery was higher in U group (1.47-fold) (P < 0.01), PI and RI of radial artery were lower in U group (P < 0.05) at 30 minutes after the block. Comparing the hemodynamic parameters of ulnar artery and radial artery with complete block between two groups at 30 minutes after the block, EDV, TAMAX and Q of ulnar artery in U group were higher than that in N group (1.68-fold, 1.55-fold and 1.62-fold) (P < 0.01 or P < 0.05), PI of ulnar artery in U group was lower than that in N group (P < 0.01), EDV and TAMAX of radial artery in U group was higher than that in N group (1.54-fold and 1.26-fold) (P < 0.01 or P < 0.05), PI and RI of radial artery in U group was lower than that in N group (P < 0.05). The rate of complete block in U group was higher than that in N group (28/30 vs 22/30, P < 0.05).
  
  
  CONCLUSIONS
  Ultrasound-guided supraclavicular brachial plexus block enhance the degree of sympathetic block of upper extremity, especially of ulnar artery and increase the blood flow of ulnar artery compared with nerve stimulator.
authors.affiliation: Department of Anesthesiology, Wenzhou Medical College, Wenzhou, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.forename: Xian-hua
authors.initials: XH
authors.lastname: Ye
authors.forename: Yang
authors.initials: Y
authors.lastname: Nan
authors.forename: Tong
authors.initials: T
authors.lastname: Shi
authors.forename: Qi-gang
authors.initials: QG
authors.lastname: Ye
authors.forename: Jian-feng
authors.initials: JF
authors.lastname: Ma
authors.forename: Jun
authors.initials: J
authors.lastname: Li
mesh_terms: D000328:Adult; D001917:Brachial Plexus / Q000000981:diagnostic imaging* / Q000601:surgery; D004599:Electric Stimulation Therapy / Q000295:instrumentation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods; D018617:Ultrasonography, Doppler, Pulsed; D018084:Ultrasonography, Interventional; D034941:Upper Extremity