Background: Our goal is to develop metrics that quantify the translation of performance from cadavers to patients. Our primary objective was to develop steps and error checklists from a Delphi questionnaire. Our second objective was to show that our test scores were valid and reliable. Methods: Sixteen UK experts identified 15 steps conducive to good performance and 15 errors to be avoided during interscalene block on the soft-embalmed cadaver and patients. Thereafter, six experts and six novices were trained, and then tested. Training consisted of psychometric assessment, an anatomy tutorial, volunteer scanning, and ultrasoundguided needle insertion on a pork phantom and on a soft-embalmed cadaver. For testing, participants conducted a single interscalene block on a dedicated soft-embalmed cadaver whilst wearing eye tracking glasses. Results: We developed a 15-step checklist and a 15-error checklist. The internal consistency of our steps measures were 0.83 (95% confidence interval [CI]: 0.78e0.89) and 0.90 (95% CI: 0.87e0.93) for our error measures. The experts completed more steps (mean difference: 3.2 [95% CI: 1.5e4.8]; P<0.001), had less errors (mean difference: 4.9 [95% CI: 3.5e6.3]; P<0.001), had better global rating scores (mean difference: 6.8 [95% CI: 3.6e10.0]; P<0.001), and more eye-gaze fixations (median of differences: 128 [95% CI: 0e288]; P¼0.048). Fixation count correlated negatively with steps (r¼e0.60; P¼0.04) and with errors (r¼0.64; P¼0.03). Conclusions: Our tests to quantify ultrasound-guided interscalene nerve block training and performance were valid and reliable.

Summary Visibility of the needle tip is difficult to maintain during ultrasound‐guided nerve block. A new needle has been developed that incorporates a piezo element 2–2.3 mm from the tip, activated by ultrasound. The electrical signal manifests as a coloured circle surrounding the needle tip, and allows real‐time tracking. We hypothesised that novice regional anaesthetists would perform nerve block better with the tracker turned on rather than off. Our primary objective was to evaluate the new needle by measuring the performance of novice anaesthetists conducting simulated sciatic block on the soft embalmed Thiel cadaver. Training consisted of a lecture, scanning in volunteers and practice on cadavers. Testing entailed scanning the sciatic nerve of a cadaver and conducting 20 in‐plane sciatic blocks in the mid‐to‐upper thigh region. Subjects were randomised equally, in groups of five, according to the sequence: tracker on/off/on/off; or tracker off/on/off/on. Video recordings were assessed by six raters for steps performed correctly and errors committed. Eight subjects were recruited and 160 videos were analysed. Using the tracking needle, five correct steps improved and one error reduced. The benefits included: better identification of the needle tip before advancing the needle, OR (95%CI) 3.4 (1.6–7.7; p < 0.001); better alignment of the needle to the transducer, 3.1 (1.3–8.7; p = 0.009); and better visibility of the needle tip 3.0 (1.4–7.3; p = 0.005). In conclusion, use of the tracker needle improved the sciatic block performance of novices on the soft embalmed cadaver.

Multiple medical interventions require percutaneous instrumentation of the anterior abdominal wall, all of which carry a potential for vascular trauma. We assessed the presence, position, and size of the anterior abdominal wall superior and inferior (deep) epigastric arteries to determine the safest site with respect to vascular anatomy of the rectus sheath. In a review of 100 arterial phase, contrast‐enhanced abdominal computed tomography scans, anterior abdominal wall arteries were assessed bilaterally at three axial planes: transpyloric, umbilicus, and anterior superior iliac spine (ASIS). The mean age of patients was 69.2 years (SD ± 15), with 62 male and 38 female. An artery was visible least frequently at the transpyloric plane (5%), compared with the umbilicus (72–79%) and ASIS (93–96%), on the left (χ2(4) = 207.272; P < 0.001) and right (χ2(4) = 198.553; P < 0.001), with a moderate strength association (Cramer's V = 0.588 (left) and 0.575 (right)). The arteries were most commonly observed within the rectus abdominis muscle at the level of the umbilicus and ASIS on both sides (62–68%). The inferior epigastric artery was observed to be larger in diameter, start more laterally, and move medially as it travelled superiorly. These data suggest that the safest site to instrument the rectus sheath, with respect to vascular anatomy, is at the transpyloric plane. This information on anatomical variation of the anterior abdominal wall vasculature may be of particular interest to anesthetists performing rectus sheath block and surgeons during laparoscopic port insertion. Clin. Anat. 33:350–354, 2020. © 2019 Wiley Periodicals, Inc.

Summary In this study, we measured the performance of medical students and anaesthetists using a new tracker needle during simulated sciatic nerve block on soft embalmed cadavers. The tracker needle incorporates a piezo element near its tip that generates an electrical signal in response to insonation. A circle, superimposed on the ultrasound image surrounding the needle tip, changes size and colour according to the position of the piezo element within the ultrasound beam. Our primary objective was to compare sciatic block performance with the tracker switched on and off. Our secondary objectives were to record psychometrics, procedure efficiency, participant self‐regulation and focused attention using eye‐tracking technology. Our primary outcome measures were the number of steps successfully performed and the number of errors committed during each block. Videos were scored by trained experts using validated checklists. Sequential tracker activation and deactivation was randomised equally within subjects. With needle activation, steps improved in 10 (25%) subjects and errors reduced in six (15%) subjects. The most important steps were: needle tip identification before injection, OR (95%CI) 2.12 (1.61–2.80; p < 0.001); and needle tip identification before advance of the needle, 1.80 (1.36–2.39; p < 0.001). The most important errors were: failure to identify the needle tip before injection, 2.40 (1.78–3.24; p < 0.001); and failure to quickly regain needle tip position when tip visibility was lost, 2.03 (1.5–2.75; p < 0.001). In conclusion, needle‐tracking technology improved performance in a quarter of subjects.

mapping extended beyond their normal pain area and the L5 dorsal rami was found to be the most common nerve whose mapping extended the pain beyond the usual area. The areas not covered by suprathreshold stimulation were much higher than expected areas for the stimulated nerves, implying the need for stimulation at higher level. Thus we conclude that it is possible to reliably map the painful area using suprathreshold stimulation such that the procedure may be used to select the nerve for radiofrequency denervation in future. Acknowledgement BJA/RCoA iBSc John Snow award to KF.