Evaluation of a New Training Model for Ultrasound Guided Regional Anesthesia - A Feasibility Study
Condition: Regional Anesthesia
Study type: Interventional

Summary: 
      The use of Ultrasound Guided Regional Anaesthesia (USRA) has increased over the last decade.
      Theoretically, ultrasound imaging may increase efficacy and safety by allowing visualization
      of the needle pathway and local anaesthetic spread around the nerve. In addition to knowledge
      of anatomy and general principles of ultrasonography, USRA requires learning new skills such
      as image interpretation, needle-beam alignment, and needle trajectory tracking. The hand-eye
      coordination required during needle advancement requires practice to master because the
      needle must be properly aligned with the ultrasound probe in order to maintain the needle
      path in the beam at all times. Adding to the difficulty, hand and needle movements can occur
      in three axes, but an ultrasound image is seen in only two dimensions. Since the ability to
      acquire the necessary skills to perform USRA is subjective and not yet validated, it is
      difficult to recommend a single, effective training pathway.

      Currently, the only method of supervised training before performing an USRA procedure on an
      actual patient involves practicing needle insertion in a phantom or cadaver. Studies
      assessing the impact of learning using these methods are lacking. It is possible that some
      practitioners may choose alternative one-off learning methods. Such methods are not
      standardized and are thus difficult to evaluate.
    

Detailed description: 
      This was a single site, prospective, pre-test-post-test, randomized study conducted after
      Institutional Review Board (IRB) approval. Thirty subjects, including medical students,
      practicing anaesthesiologists and anaesthesia residents in training at the Penn State Hershey
      Medical Center, were recruited by formal email invitation to participate. Written consent was
      obtained from each participant before their inclusion in the study and each participant
      completed a pre-study form. Once enrolled in the study, participants were given 10 minutes to
      familiarize themselves with both the ultrasound equipment (SonoSite, MTurbo, Bothell, WA,
      USA) and the phantom model (MiniSim™ Upper Extremity Series, Life tech Inc., Stafford, Texas,
      USA). They also viewed a pre-recorded video demonstrating the task they were to perform. As a
      pre-test, participants performed the required Needle Insertion Accuracy (NIA) task 3
      consecutive times and were assessed using a scoring form adapted from the Mayo Clinic. After
      completing the pre-test, participants were randomly divided into two groups, experimental and
      control, by a computer-generated randomization list (SAS Institute, Cary, NC). Participants
      were blinded to their group assignment.

      Previously, we have reported details of the new learning tool. Briefly, all spatial movements
      occur in three dimensions which can be labeled the x-axis, the y-axis and the z-axis. A video
      camera records movement in two axes. By placing a second video camera at 90 degrees to the
      first camera, the third axis can be recorded as well as one axis in common with the first
      camera. Video recordings are stored electronically on a hard-drive and can be reviewed
      individually or in combination, at normal speed, or slowed if necessary. Still images can
      also be obtained.

      The experimental group was allowed to practice the same pre-test task using the same
      ultrasound machine and phantom model. On a single computer screen, they were able to
      visualize their hand and needle movements along with the position of the ultrasound probe.
      The control group was allowed to practice the same pre-test task using the same ultrasound
      machine and phantom model but without the added visual aid. Both groups were allowed to
      practice their pre-test tasks for a maximum of 30 minutes, and recorded their self-assessment
      as proficient or not proficient at that time. Both groups then performed the post-test, which
      was the same task used for the pre-test, and each trainee was evaluated using the same
      scoring tool. To avoid subjective variations and inter-rater variability, all evaluations
      were recorded by a single blinded investigator.

      Statistical analysis Pre- and post-test mean scores (ranging from 5 to15) were analyzed using
      statistical methods to determine whether this new learning tool improved NIA skills required
      with USRA. Pre-test and post-test scores (ranging from 5 to 15) were obtained in triplicate
      and averaged to produce a representative assessment for each participant. The primary
      endpoint was change in NIA score from baseline, i.e., the score difference obtained by
      subtracting the mean pre-test score from the mean post-test score. A sample size of 15
      subjects per group (experimental and control) provides 80% power to detect an effect size of
      1, based on a two-sided t-test with a 5% error probability (calculated using G*Power version
      3.1). Analysis of the primary endpoint utilized a two-sided, two-sample t-test at the 5%
      level of significance. Secondary analyses evaluated the intervention effect on novice
      trainees, and trainees with prior USRA experience. Score differences for individual NIA
      skills (movement, alignment, approach, target, location) were also analyzed.
    

Intervention name(s): tool developed using cameras and a computer
Intervention type(s): Other
Intervention description(s): cameras allowing subject to be able to visualize hand and needle movements as well s the position of the transducers along with the image from the ultrasound on a computer screen
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Ultrasound; Image; Learning Tool; Ultrasound Guide Procedures; Simulated Setting