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Abstract
Ultrasound-guided (US-guided) peripheral nerve blocks (PNB) are widely considered an essential component of modern anesthesia.
The learning process in US – guided blocks require residents to learn different cognitive, technical and behavioral skills. Most important cognitive skills are knowledge in anatomy and sonoanatomy, equipment for blocks and ultrasound, ultrasound physics, local anesthetic pharmacology and stages of block procedures. Lectures, hands-on practical sessions, books of regional anesthesia, online applications, video and practical demonstrations, interactive learning experiences, radiological imaging can be used depending on availability in local hospitals and universities. Furthermore, essentials of ultrasound, ergonomics and positioning are fundamental knowledge for residents when they initially start to work with the ultrasound for the first time.
From behavioral skills it is important to understand the concept of teamwork. For some residents the most difficult component is to develop technical skills: imaging acquisition and interpretation, eye-hand coordination and 3D thinking, transducer orientation, manipulation with a probe and needle, identification of artefacts. Particulary, visualization of the needle insertion and injection often is challenging and must be explained and supervised during the procedure. Independent predictors of the needle visibility are type of needle (p < 0.001) and plane of insertion (p = 0.08). It is known that visibility of echogenic needles are superior to the non-echogenic needles if the needle insertion angle ranges between 60° and 70°. Therefore, echogenic needles in conjunction with peripheral nerve stimulation could be helpful tools for deep or difficult blocks in the teaching process.
How should we bridge the gap between theoretical knowledge to good practical skills? Simulation based medical education and training skills including cadaveric sessions, US-guided training on simulated participants, on manikins or on 3D phantom models may be useful since they increase acquisition of clinical knowledge and skills.
Residents had reported feeling more confident in recognizing anatomical structures after practice on cadavers. Additionally, Liu et al. evaluated three different types of simulators for regional anesthesia and concluded that new practitioners decrease the number of errors in a simulated block with each additional practice attempt in simulation, regardless of the type of simulator used. Therefore, ultrasound models increase accessibility for residents to gain early exposure in a safe manner.
More recently artificial intelligence for image interpretation and needle insertion may facilitate US-guided teaching in RA as well.
We know that learning practical (motor) skills requires constant practice and repeating procedures multiple times to assimilate psychomotor skill interaction. There are three stages:
cognitive – resident behave timidly, inconsistently, and inaccurately; make many mistakes while doing the task; and need help interacting with the environment.
associative – movements get more fluid, there are fewer mistakes, and resident can interact with the care team or patient.
autonomous – movements are consistent, mistakes are rare, and resident can recognize them, solve unexpected situations, concentrate on other issues, and connect with the care team and patient.
How many blocks are required for competency? Strong association between number of blocks performed (> 20 vs. 0 - 5 blocks), and self-reported ability to perform blocks independently exist, OR 20.9 (95% CI 9.38e53.2). Therefore, the importance of clinical experience and access to training in regional anaesthesia is essential for residents to develop practical skills.
Although, in each University and hospital teaching methods may differ depending on education opportunities, the safe teaching process theoretically consist of 6 steps: Learn, See, Practice, Prove, Do, and Maintain as described by T. Sawyer et al. which should be adopted for residents teaching. Learn - acquire cognitive knowledge. See – observe the procedure. Practice - practice on a simulator. Prove - simulation-based mastery learning is employed to allow the trainee to prove competency prior to performing the procedure on a patient. Do - once competency is demonstrated on a simulator, the trainee is allowed to perform the procedure on patients with direct supervision, until they can be entrusted to perform the procedure independently. Maintain - continue clinical practice, supplemented by simulation-based training as needed.
It is essential to identify the level of clinical competence of your trainee before allowing the practical performance of blocks on a patient. Miller’s Pyramid of clinical competences might be a relevant tool for assessment of competences. At the pyramid’s base lies ‘Knows,’ where residents acquire factual knowledge about RA techniques, relevant anatomy, and pharmacology. Moving up, ‘Knows How’ reflects their ability to demonstrate the procedural steps and principles in controlled environments, such as simulation labs. The next level, ‘Shows How,’ pertains to their ability to apply RA under direct supervision in natural clinical settings. The final and more recent level ‘Is Trusted’.
Trainers must ask and be informed about the competence level of the resident (supervision level and autonomously), difficulty of the block and appropriate patient. 7 Plan A blocks (femoral block, popliteal block, interscalene block, axillary block, rectus sheath block, serratus block and erector spine plane block) and more superficial PNB approaches under supervision would be appropriate to start for those who are at competence level ‘knows how’ as reflected by Miller’s Pyramid. 7 Plan A blocks are those that cover the key areas of surgery/acute pain and is suggested that every anesthetist should know as defined by RA-UK. Additionally, ESA have listed superficial PNB that seems to be safer regarding to bleeding risk (femoral nerve; axillary block; sciatic popliteal level and others). Those ‘safe’ blocks increase the level of success which builds confidence and motivation of residents. However, all residents must be informed about safety issues of PNB before practical performance on a patient: nerve injury, vascular injury and local anesthetic toxicity. Although, the risk of nerve injury after RA is very low compared to nerve injury after surgery (0.04% vs.4%), residents should always follow these guidelines: do not perform PNB in patients under general anesthesia, use a short bevel needle, avoid needle – nerve contact and reduce the number of needle passes.
After evaluating practical steps of the procedure: level of supervision required, case complexity, patient safety, decision-making, PNB efficiency, communication skills, documentation, adherence to guidelines and problem-solving skills of the trainee, self-assessment and reflection and continuous feedback should be provided. Feedback - allows the residents to compare their previous concepts of the tasks with their actual performance, helping to understand strengths and areas for growth of the resident.
In conclusion, there is not a fully standardized educational approach for training residents and teaching methods. However, evidence shows that combination of theoretical knowledges with access to simulation-based training and regular, supervised clinical practice may enhance the confidence and practical skills of residents in US-guided regional anesthesia.
References
Hargett MJ, et al. RAPM, 2005;30(3).
Haskins SC, et al. RAPM, 2021;46(12).
Vanka A, et al. The Clinical Teacher. 2019;16(6):570-574.
Slater RJ, et al. RAPM, 2014;39(3):230-239.
Kim TE, Tsui BCH. Korean Journal of Anesthesiology. 2019;72(1):13-23.
Bosse HM, et al. BMC Medical Education. 2015;15:22.
Chen XX, et al. RAPM. 2017;42(6):741-750.
Beller B, et al. BJA Open, 2023;8(C):100241.
Reg Anesth Pain Med.2009 Jan-Feb;34(1):40-6.
By prof. Ki-Jinn Chin, Fundamentals of US-guided nerve block.
Liu Y, et al. Simul Healthc. 2013;8(6):368–375.
Bowness J, et al. Anaesthesia 2021;76:602-607.
Gadsden JC. Anaesthesia 2021;76 (suppl.1):65-73.
T Sawyer, et al. Acad Med. 2015 Aug; 90(8).
Ten Cate O, et al. Entrustment decision making: Extending Miller’s pyramid. Acad Med 2021 Feb 1;96(2):199-204.
https://www.ra-uk.org/
Eur J Anaesthesiol 2022;39:100-132.
Ecoffey, et al. EJA 2014.