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Echogenic Technology Can Improve Needle Visibility During Ultrasound-Guided Regional Anesthesia
  1. Simon Hebard, MBChB, BSc, MRCP, FRCA* and
  2. Graham Hocking, MBChB, DMCC, FRCA, FANZCA, FFPMANZCA*,
  1. From the *Sir Charles Gairdner Hospital, Perth; and
  2. School of Medicine and Pharmacology, The University of Western Australia, Crawley, Western Australia, Australia.
  1. Address correspondence to: Graham Hocking, MBChB, DMCC, FRCA, FANZCA, FFPMANZCA, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, Perth, Western Australia 6009 (e-mail: graham.hocking{at}


Needle tip visualization is fundamental to the safety and efficacy of ultrasound-guided regional anesthesia (UGRA). It can be extremely challenging especially at steep insertion angles. We assessed whether an echogenic needle improved tip visibility during UGRA by anesthesiologists performing their normal in-plane technique. The visibility of the Pajunk Sonoplex (echogenic) and the Pajunk Uniplex (control) needle were compared during 60 nerve blocks (30 femoral, 30 sciatic) in this randomized controlled trial. All ultrasound imaging was recorded for analysis. The anesthesiologist subjectively estimated the percentage time they had visualized the needle tip (5-point scale: 1 [0%-20%], 2 [20%-40%], 3 [40%-60%], 4 [60%-80%], 5 [80%-100%]). The actual time the tip was in view, angle of needle insertion, target depth, and procedure time were subsequently measured objectively by a single investigator. The Sonoplex group had both subjectively and objectively better tip visibility (P = 0.002), despite having larger mean body mass index (29.0 vs 25.0 kg/m2, P = 0.01) and steeper mean insertion angle (31 vs 22 degrees, P = 0.03). Objective percentage tip visibility, during in-plane UGRA, reduced by 12% for every 10-degree increase in insertion angle with the control. Tip visibility with the Sonoplex was independent of insertion angle over the range studied (0-57 degrees, P = 0.95). This finding occurred when nonexpert anesthesiologists performed their standard UGRA technique. A needle that is visible for a greater percentage of time has potential safety and efficacy implications.

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  • The anesthesiologist who designed the Pajunk Sonoplex needle works part-time within the same Department of Anesthesia as the authors. He was given no opportunity to contribute to study design, execution, data analysis, or conclusions. The authors have no financial or other interest in the needle, nor do they have any financial or other affiliation with Pajunk.

  • Parts of the data were presented at the Australian Society of Anaesthetists National Scientific Congress, Melbourne, October 2-5, 2010, where it was awarded second prize in the scientific poster section.