title: Ultrasonographic guidance improves the success rate of interscalene brachial plexus blockade.
abstract: OBJECTIVE
  The use of ultrasonography in regional anesthetic blocks has rapidly evolved over the past few years. It has been speculated that ultrasound guidance might increase success rates and reduce complications. The aim of our study is to compare the success rate and quality of interscalene brachial plexus blocks performed either with direct ultrasound visualization or with the aid of nerve stimulation to guide needle placement.
  
  
  METHODS
  A total of 160 patients (American Society of Anesthesiologists physical status classification I-III) scheduled for trauma-related upper arm surgery were included in this randomized study and grouped according to the guidance method used to deliver 20 mL of ropivacaine 0.75% for interscalene brachial plexus blockade. In the ultrasound group (n = 80), the brachial plexus was visualized with a linear 5 to 10 MHz probe and the spread of the local anesthetic was assessed. In the nerve stimulation group (n = 80), the roots of the brachial plexus were located using a nerve stimulator (0.5 mA, 2 Hz, and 0.1 millisecond bandwidth). The postblock neurologic assessment was performed by a blinded investigator.
  
  
  RESULTS
  Sensory and motor blockade parameters were recorded at different points of time. Surgical anesthesia was achieved in 99% of patients in the ultrasound vs 91% of patients in the nerve stimulation group (P < .01). Sensory, motor, and extent of blockade was significantly better in the ultrasound group when compared with the nerve stimulation group.
  
  
  CONCLUSIONS
  The use of ultrasound to guide needle placement and monitor the spread of local anesthetic improves the success rate of interscalene brachial plexus block.
authors.affiliation: Department of Anaesthesia and General Intensive Care Medicine, Herz-Jesu Hospital, Vienna, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kapral
authors.forename: Manfred
authors.initials: M
authors.lastname: Greher
authors.forename: Gudrun
authors.initials: G
authors.lastname: Huber
authors.forename: Harald
authors.initials: H
authors.lastname: Willschke
authors.forename: Stephan
authors.initials: S
authors.lastname: Kettner
authors.forename: Richard
authors.initials: R
authors.lastname: Kdolsky
authors.forename: Peter
authors.initials: P
authors.lastname: Marhofer
mesh_terms: D000368:Aged; D001134:Arm Injuries / Q000601:surgery; D001917:Brachial Plexus / Q000000981:diagnostic imaging*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007267:Injections / Q000379:methods; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009339:Needles; D009407:Nerve Block / Q000295:instrumentation* / Q000379:methods; D012677:Sensation / Q000187:drug effects / Q000502:physiology; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional