The effect of an ultrasound-activated needle tip tracker needle on the performance of sciatic nerve block on a soft embalmed Thiel cadaver

The educational impact of technology-enhanced learning in regional anaesthesia: a scoping review

BACKGROUND

Effective training in regional anaesthesia (RA) is paramount to ensuring widespread competence. Technology-based learning has assisted other specialties in achieving more rapid procedural skill acquisition. If applicable to RA, technology-enhanced training has the potential to provide an effective learning experience and to overcome barriers to RA training. We review the current evidence base for use of innovative technologies in assisting learning of RA.

METHODS

Using scoping review methodology, three databases (MEDLINE, Embase, and Web of Science) were searched, identifying 158 relevant citations. Citations were screened against defined eligibility criteria with 27 studies selected for inclusion. Data relating to study details, technological learning interventions, and impact on learner experience were extracted and analysed.

RESULTS

Seven different technologies were used to train learners in RA: artificial intelligence, immersive virtual reality, desktop virtual reality, needle guidance technology, robotics, augmented reality, and haptic feedback devices. Of 27 studies, 26 reported a positive impact of technology-enhanced RA training, with different technologies offering benefits for differing components of RA training. Artificial intelligence improved sonoanatomical knowledge and ultrasound skills for RA, whereas needle guidance technologies enhanced confidence and improved needling performance, particularly in novices. Immersive virtual reality allowed more rapid acquisition of needling skills, but its functionality was limited when combined with haptic feedback technology. User friendly technologies enhanced participant experience and improved confidence in RA; however, limitations in technology-assisted RA training restrict its widespread use.

CONCLUSIONS

Technology-enhanced RA training can provide a positive and effective learning experience, with potential to reduce the steep learning curve associated with gaining RA proficiency. A combined approach to RA education, using both technological and traditional approaches, should be maintained as no single method has been shown to provide comprehensive RA training.

The Advances and Utility of Artificial Intelligence and Robotics in Regional Anesthesia: An Overview of Recent Developments

The integration of artificial intelligence (AI) and robotics in regional anesthesia has brought about transformative changes in acute pain management for surgical procedures. This review explores the evolving landscape of AI and robotics applications in regional anesthesia, outlining their potential benefits, challenges, and ethical considerations. AI-driven pain assessment, real-time guidance for needle placement during nerve blocks, and predictive modeling solutions for nerve blocks have the potential to enhance procedural precision and improve patient outcomes. Robotic technology aids in accurate needle insertion, reducing complications and improving pain relief. This review also highlights the ethical and safety considerations surrounding AI implementation, emphasizing data security and professional training. While challenges such as costs and regulatory hurdles exist, ongoing research and clinical trials demonstrate the practical utility of these technologies. In conclusion, AI and robotics have the potential to reshape regional anesthesia practice, ultimately improving patient care and procedural accuracy in pain management.

Patterns of Skills Acquisition in Anesthesiologists During Simulated Interscalene Block Training on a Soft Embalmed Thiel Cadaver: Cohort Study

BACKGROUND

The demand for regional anesthesia for major surgery has increased considerably, but only a small number of anesthesiologists can provide such care. Simulations may improve clinical performance. However, opportunities to rehearse procedures are limited, and the clinical educational outcomes prescribed by the Royal College of Anesthesiologists training curriculum 2021 are difficult to attain. Educational paradigms, such as mastery learning and dedicated practice, are increasingly being used to teach technical skills to enhance skills acquisition. Moreover, high-fidelity, resilient cadaver simulators are now available: the soft embalmed Thiel cadaver shows physical characteristics and functional alignment similar to those of patients. Tissue elasticity allows tissues to expand and relax, fluid to drain away, and hundreds of repeated injections to be tolerated without causing damage. Learning curves and their intra- and interindividual dynamics have not hitherto been measured on the Thiel cadaver simulator using the mastery learning and dedicated practice educational paradigm coupled with validated, quantitative metrics, such as checklists, eye tracking metrics, and self-rating scores.

OBJECTIVE

Our primary objective was to measure the learning slopes of the scanning and needling phases of an interscalene block conducted repeatedly on a soft embalmed Thiel cadaver over a 3-hour period of training.

METHODS

A total of 30 anesthesiologists, with a wide range of experience, conducted up to 60 ultrasound-guided interscalene blocks over 3 hours on the left side of 2 soft embalmed Thiel cadavers. The duration of the scanning and needling phases was defined as the time taken to perform all the steps correctly. The primary outcome was the best-fit linear slope of the log-log transformed time to complete each phase. Our secondary objectives were to measure preprocedural psychometrics, describe deviations from the learning slope, correlate scanning and needling phase data, characterize skills according to clinical grade, measure learning curves using objective eye gaze tracking and subjective self-rating measures, and use cluster analysis to categorize performance irrespective of grade.

RESULTS

The median (IQR; range) log-log learning slopes were -0.47 (-0.62 to -0.32; -0.96 to 0.30) and -0.23 (-0.34 to -0.19; -0.71 to 0.27) during the scanning and needling phases, respectively. Locally Weighted Scatterplot Smoother curves showed wide variability in within-participant performance. The learning slopes of the scanning and needling phases correlated: ρ=0.55 (0.23-0.76), P<.001, and ρ=-0.72 (-0.46 to -0.87), P<.001, respectively. Eye gaze fixation count and glance count during the scanning and needling phases best reflected block duration. Using clustering techniques, fixation count and glance were used to identify 4 distinct patterns of learning behavior.

CONCLUSIONS

We quantified learning slopes by log-log transformation of the time taken to complete the scanning and needling phases of interscalene blocks and identified intraindividual and interindividual patterns of variability.

Traumatic needle damage to nerves during regional anesthesia: presentation of a novel mechanotransduction hypothesis

Despite advances in needle positioning techniques, nerve damage still occurs after regional anesthesia. Recognized causes include local anesthetic toxicity, subperineural injection, high subepineural fluid injection pressures and subepineural hematoma after forceful needle--nerve contact.We hypothesize that subperineural injection is still possible, but less likely to be the cause of nerve damage because needle penetration of fascicles and mechanical damage is difficult to achieve. High-resolution (75 µm) 40 MHz micro-ultrasound images of pig axillae show short-bevelled 22 g, 0.7 mm wide block needles that are three times larger than the average fascicle. Fascicular bundles are extremely difficult to puncture because they spin away on needle contact. Histology from fresh cadavers after supposed intrafascicular injection shows fluid spread within perineurium and intrafascicular perineural septae, but no breach of endoneurium or axons.We propose that mechanotransduction, the cellular changes that occur in response to force, contributes to nerve damage. Piezo ion channel proteins transduce force into electrical activity by rapid entry of cations into cells. Excessive Ca2+ influx into cells has the potential to inhibit nerve regeneration. Cellular changes include regulation of gene expression. The forces associated with purposeful needle insertion are generally unknown. Our experiments in the soft embalmed Thiel cadaver showed a lognormal range of forces between 0.6 N and 16.8 N on epineural penetration.We hypothesize that forceful needle injury may cause nerve damage by activation of Piezo receptors and release of intracellular Ca2.

Intelligent Three-Dimensional Reconstruction Algorithm-Based Ultrasound-Guided Nerve Block in Intraoperative Anesthesia and Postoperative Analgesia of Orthopedic Surgery

This research was aimed at analyzing the role of ultrasound-guided nerve block based on intelligent three-dimensional (3D) reconstruction algorithm in intraoperative anesthesia and postoperative analgesia of orthopedic surgery. 68 elderly patients were undergoing orthopedic surgery on the lower extremities, and they were randomly rolled into two groups with 34 patients in each group. The patients in control group received sciatic nerve block anesthesia (SNBA), and the patients in the experimental group received ultrasound-guided SNBA (UG-SNBA) under 3D reconstruction algorithm to analyze and compare the anesthesia effect and the postoperative analgesia effect. The results showed that compared with other algorithms, the evaluation index of ultrasound images processed by the 3D reconstruction algorithm was better. In terms of anesthesia effect, there was no significant difference in systolic blood pressure, diastolic blood pressure, and heart rate between the two groups before surgery ( $P>0.05$ ). Intraoperative and postoperative indicators of the experimental group were significantly better than those of the control group; the drug dosage (61 mg) was less than that of the control group (78 mg). In addition, the onset time of anesthesia, the time of pain blockade, and the postoperative awake time (5 minutes, 8 minutes, and 8 minutes, respectively) were shorter than those in the control group (13 minutes, 15 minutes, and 15 minutes, respectively). The visual analogue scale (VAS) scores of the experimental group were better than those of the control group on the day after surgery, one day after surgery, two days after surgery, and three days after surgery, with significant differences ( $P<0.05$ ). In summary, 3D reconstruction algorithm-based ultrasound image effect was clearer, the effect of UG-SNBA was more stable, and the postoperative analgesic effect was better. This work provided a higher reference for the selection of safe and effective anesthesia options in orthopedic surgery.

A paired comparison of nerve dimensions using B-Mode ultrasound and shear wave elastography during regional anaesthesia

Introduction:

Shear wave elastography (SWE) presents nerves in colour, but the dimensions of its colour maps have not been validated with paired B-Mode nerve images. Our primary objective was to define the bias and limits of agreement of SWE with B-Mode nerve diameter. Our secondary objectives were to compare nerve area and shape, and provide a clinical standard for future application of new colour imaging technologies such as artificial intelligence.

Materials and Methods:

Eleven combined ultrasound-guided regional nerve blocks were conducted using a dual-mode transducer. Two raters outlined nerve margins on 110 paired B-Mode and SWE images every second for 20 s before and during injection. Bias and limits of agreement were plotted on Bland-Altman plots. We hypothesized that the bias of nerve diameter would be <2.5% and that the percent limits of agreement would lie ±0.67% (2 SD) of the bias.

Results:

There was no difference in the bias (95% confidence interval (CI) limits of agreement) of nerve diameter measurement, 0.01 (−0.14 to 0.16) cm, P = 0.85, equivalent to a 1.4% (−56.6% to 59.5) % difference. The bias and limits of agreement were 0.03 (−0.08 to 0.15) cm2, P = 0.54 for cross-sectional nerve area; and 0.02 (−0.03 to 0.07), P = 0.45 for shape. Reliability (ICC) between raters was 0.96 (0.94–0.98) for B-Mode nerve area and 0.91 (0.83–0.95) for SWE nerve area.

Conclusions:

Nerve diameter measurement from B-Mode and SWE images fell within a priori measures of bias and limits of agreement.

Needle insertion forces and fluid injection pressures during targeting of nerves in a soft embalmed cadaver model

PURPOSE

Forceful needle-nerve contact and high subepineural pressures and are recognised causes of nerve damage. Pressure and force measurements are necessary to inform the mechanisms of nerve injury, build virtual simulator environments and provide operator feedback during simulation training. However, the range of pressures and forces encountered at tissue layers during targeted needle insertion and fluid injection are not known.

METHODS

We built a needle that recorded in-line pressure during fluid injection and continuously measured force at the needle tip. Two anaesthetists were randomised to insert a 21 g block needle at 48 nerve sites on both sides of 3 soft embalmed Thiel cadavers. Our objective was to measure pressure and force during the course of targeted nerve injection at epimysium, in perineural tissue, on epineurium and during subepineural injection. At each interface, we infused a 0.5 ml bolus of embalming solution at a rate of 12 ml min^-1 and recorded the pressure response. Force was measured continuously in the background throughout the procedure.

RESULTS

Pressure was greater at epineurium and within subepineurium than perineural tissue, geometric ratio (95% CI) 4.7 (3.0-7.3) kPa and 3.8 (2.5-5.7) kPa, respectively, both P < 0.0001. Force on nerve contact and on nerve penetration was greater than force in perineural tissue, geometric ratios (95% CI) 3.0 (1.9-4.7) N and 3.6 (2.2-7.5) N, respectively, both P < 0.0001. On nerve contact, 1 in 6 insertions were ≥ 5 N CONCLUSIONS: Despite valid infusion pressures, anaesthetists exerted excessive force on nerves.