Assessment of ultrasound-guided procedures in preclinical years

Intern Emerg Med DOI 10.1007/s11739-016-1525-4 EM - ORIGINAL Assessment of ultrasound-guided procedures in preclinical years Richard Amini1 • Lori Ann Stolz1 • Elliot Breshears2 • Asad E. Patanwala3 • Nicholas Stea1 • Nicolaus Hawbaker1 • Matthew Thompson1 • Arthur Barry Sanders1 Srikar Adhikari1 • Received: 3 March 2016 / Accepted: 12 August 2016 Ó SIMI 2016 Abstract Medical graduates entering residency often lack confidence and competence in procedural skills. Implementation of ultrasound (US)-guided procedures into undergraduate medical education is a logical step to addressing medical student procedural competency. The objective of our study was to determine the impact of an US teaching workshop geared toward training medical students in how to perform three distinct US-guided procedures. Cross-sectional study at an urban academic medical center. Following a 1-h didactic session, a sample of 11 students out of 105 (10.5 %) were asked to perform three procedures each (total 33 procedures) to establish a baseline of procedural proficiency. Following a 1-h didactic session, students were asked to perform 33 procedures using needle guidance with ultrasound to establish a baseline of student proficiency. Also, a baseline survey regarding student opinions, self-assessment of skills, and US procedure knowledge was administered before and after the educational intervention. After the educational workshop, students’ procedural competency was assessed by trained ultrasound clinicians. One-hundred-and-five third-year medical students participated in this study. The average score for the knowledge-based test improved from 46 % (SD 16 %) to 74 % (SD 14 %) (p \ 0.05). Students’ overall confidence in needle guidance improved from 3.1 & Richard Amini [email protected] 1 Department of Emergency Medicine, University of Arizona, Tucson, AZ, USA 2 College of Medicine, University of Arizona, Tucson, AZ, USA 3 Department of Pharmacy Practice and Science, University of Arizona, Tucson, AZ, USA (SD 2.4) to 7.8 (SD 1.5) (p \ 0.05). Student assessment of procedural competency using an objective and validated assessment tool demonstrated statistically significant (p \ 0.05) improvement in all procedures. The one-day US education workshop employed in this study was effective at immediately increasing third-year medical students’ confidence and technical skill at performing US-guided procedures. Keywords Point-of-care ultrasound
Undergraduate medical education
Ultrasound-guided procedures
Nerve blocks
Needle aspiration
Intravenous access Introduction Medical graduates entering residency often lack confidence and competence in procedural skills [1, 2]. Implementation of ultrasound (US)-guided procedures into undergraduate medical education is a logical step to addressing medical student technical skill deficiencies and lack of confidence within the boundaries of the current education model, and some programs have begun to use cadavers for procedural training [3, 4]. Although medical graduates often learn procedural competency by practicing in clinical settings, numerous learning techniques have been developed to increase safe exposure. The use of simulators for procedural training has been demonstrated to increase confidence and decrease rates of complications [4]. Furthermore, studies have demonstrated translation of simulation-based skills into clinical scenarios [5, 6]. Also, direct observation and feedback by experts are highly effective components of establishing procedural proficiency [7]. Previously, a 1-day, ultrasound workshop conducted at our institution demonstrated that ultrasound 123 Intern Emerg Med education was engaging and educational; however, objective evaluation of student knowledge or skill was not conducted, and student comfort with needle guidance was not achieved [8]. The objective of this study was to evaluate the impact of an US education workshop focused on training medical students in needle guidance with ultrasound in three distinct procedures: needle aspiration, nerve block and central line placement. Materials and methods optimize the learning experience. In the 1-h didactic lecture, the students were provided a basic review of US physics, commonly used US device controls, review of the difference between in-plane and out-of-plane imaging, benefits of in-plane needle guidance, and a short review of the selected US-guided procedures (needle aspiration, nerve block and central line placement). A description of the phantoms used for each station is provided in Table 1. There were two stations for each skill (six stations total). One ultrasound machine was assigned to each room in no particular order. The machines used are as follows: Phillips Sparq (1), Zonare Z.onepro (1), Mindray M7 (4). Study design and setting Assessment This cross-sectional study was conducted at an academic medical center. The study was reviewed and approved by the Institutional Review Board. Study participants were third-year medical students, midway through their third year of training, with minimal or no prior US training experience. Participation in the study was voluntary. Data were collected from December 2014 to January 2015. Study protocol As part of the curriculum for third-year medical students at our institution, students receive periodic breaks from clinical rotations to meet in small groups in a classroom setting. During these week-long sessions, a multi-disciplinary team of physicians provides didactics, workshops, and lectures on clinically relevant topics to solidify clinical knowledge, and to provide opportunities for reflection. Integrated into one of these week-long sessions was a 1-day US education workshop. Instructors for this workshop were composed of senior Emergency Medicine residents, fellows, and faculty with ultrasound fellowship training, or greater than 2 years of ultrasound experience. The ultrasound machines used for this study include Phillips Sparq (Phillips, China), Zonare (Mindray, China), and Mindray M9 (Mindray, China). Educational curriculum and objectives The ultrasound curriculum consisted of asynchronous learning, a didactic lecture, one round of hands-on education of three ultrasound-guided procedures, and one round of competency assessment of the three procedures. Prior to meeting in the classroom, students were provided with procedure-relevant (needle guidance) asynchronous learning assignments in the form of readings, YouTube hyperlinks, and educational US websites. The websites used were https://www.sonosite.com/education/education and http://www3.gehealthcare.com/en/education, and specific links within these websites were sent to students to 123 One day prior to the ultrasound workshop, a sample of 11 students (10.5 %) performed the three US-guided procedures, and they were assessed using a validated five-point technical skills rating scale to establish a baseline of student proficiency [9]. The purpose for the sample cohort was to objectively establish a baseline of procedural skill prior to the educational workshop. For the workshop, students were divided into small groups of five or six, and rotated through three hands-on educational stations. At each educational station, students were able to practice a single USguided procedure numerous times, while receiving direct feedback from a dedicated instructor. All three stations taught the in-plane needle approach to ultrasound-guided procedures. A description of each station’s learning objectives is found in Table 2. Following the completion of all educational stations, students rotated through the three stations to complete a procedural competency assessment. During the assessment stations, instructors evaluated the students’ ability to perform each US-guided procedure using the same validated five-point technical skills rating scale that was used on the 11-student (10.5 %) sample population. Students were also asked to self-assess their confidence in performing each US-guided procedure using a ten-point Likert scale prior to and after completing each station. Last, data were gathered from an online questionnaire that was administered to students prior to and after the workshop (Appendix). The questionnaire assessed students’ knowledge of the selected US-guided procedures using multiple-choice questions. Data analysis All analyses were conducted in Stata 11 (StataCorp LP, College Station, TX, USA). Data are presented as means with standard deviations (SD) and percentages with 95 % confidence intervals (CI). A paired t test was used for comparison of paired samples. The statistical level of significance was set at p \ 0.05. Intern Emerg Med Table 1 Description of the phantoms used at each station Station Phantoms Sonographic skills station Description of the phantom used Needle aspiration The phantoms for this station were created by filling small balloons with fabric softener and wrapping the balloon with a chicken breast. It is important to remove as much air as possible from the balloon prior to tying it. The fabric softener was sufficiently viscous so as to mimic a small abscess. The sonographic images were representative of a real clinical setting (Fig. 1) Intravenous access The Blue Phantom Branched Two-Vessel Ultrasound Training Block Model and Blue phantom 2nd Generation Ultrasound Central Line Training Model were used in this station. The phantoms for this station were created by inserting angel hair pasta (bundles of 5–15) into Tofu bricks. Crosssectional sonographic imaging of the model was similar to clinical images (Fig. 2) Nerve block Table 2 Skills station descriptions Ultrasound-guided procedures Sonographic skills station Learning objectives Needle aspiration (30 min) How to perform needle aspiration with ultrasound guidance and key concepts 1. Remember to keep the US beams parallel to needle to improve in-plane imaging of the entire needle. 2. What is the sonographic squish sign 3. Linear probe is better for superficial anatomy and provides better quality imaging. Intravenous access (30 min) How to perform intravenous access with ultrasound guidance and key concepts 1. Remember to keep the US beams parallel to needle to improve in-plane imaging of the entire needle 2. When measuring a vessel in long axis, you can slip and under measure—called cylinder tangent effect 3. Compression can help distinguish artery from vein 4. Please explain how to rotate from out-of-plane to in-plane. I did not cover this in didactics and it is crucial to them mastering this skill Nerve block (30 min) How to perform an ultrasound-guided peripheral nerve block and key concepts. 1. Remember to keep the US beams parallel to needle to improve in-plane imaging of the entire needle 2. 10-20 cc of Lidocaine is sufficient for both small and large nerves w US 3. Learn how to navigate the needle above and below the nerve. Explain you want to completely bathe the nerve 4. Remind them that going into the nerve will cause nerve damage 5. Sonographic honeycomb appearance of nerves 6. Mention that you can get LAST—lidocaine associated systemic toxicity 7. Antidote to LAST—intralipid Results One hundred-and-five third-year medical students participated in this study. Eighty-eight percent (92/105) of the students completed the online pre-workshop questionnaire, and 78 % (82/105) completed the online post-workshop questionnaire. On the pre-workshop questionnaire, 90 % (95 % CI 84–96 %) of students disagreed with the statement, ‘‘I can perform US-guided procedures by myself without any assistance with simultaneous probe manipulation and needle advancement.’’ In contrast, only 6 % (95 % CI 1–11 %) of students disagreed with this statement on the post-workshop questionnaire. The objective, five-point technical skills rating tool was used to evaluate each student for competency in each USguided procedure, and the results are demonstrated in Table 3. Average student technical skill rating, using the validated assessment tool, demonstrated statistically significant improvement in all three of the US-guided procedures. Student self-reported procedural confidence was assessed on a ten-point scale. The average student selfreported confidence for each US-guided procedure is shown in Table 4. Average student self-reported procedural confidence in overall in-plane needle guidance increased from 3.1 (SD 2.4 %) on the pre-workshop questionnaire to 7.8 (SD 1.5 %) on the post-workshop 123 Intern Emerg Med Table 4 Skills station descriptions Student self-reported procedural confidence (10-point Likert scale) Sonographic Skill Confidence before Confidence after p value Needle aspiration 2.8 (SD 2.1) 7.8 (SD 1.3) \0.001 Intravenous access 3.0 (SD 2.4) 7.8 (SD 1.3) \0.001 Nerve block 2.1 (SD 1.8) 7.5 (SD 1.4) \0.001 Needle guidance 3.1 (SD 2.2) 7.9 (SD 1.1) \0.001 Discussion Fig. 1 Needle aspiration phantom Fig. 2 Nerve block phantom Table 3 Objective Skills Assessment Five-Point Technical Skills Score (N = 33 procedures) Sonographic skill Score before Score after p value Needle aspiration 2.2 (SD 1.1) 3.7 (SD 0.7) \0.001 Intravenous access 1.8 (SD 1.0) 4.7 (SD 0.5) \0.001 Nerve block 2.7 (SD 1.5) 4.1 (SD 0.7) \0.001 Overall procedural skills 2.2 (SD 1.2) 4.2 (SD 0.6) \0.001 questionnaire. In addition, student self-reported confidence demonstrated statistically significant improvement for each individual US-guided procedure. On the multiple-choice portion of the online questionnaire, designed to test students’ knowledge of US procedures, the average score increased by 28 %, from 46 % (SD 16 %) on the preworkshop questionnaire to 74 % (SD 14 %) on the postworkshop questionnaire. 123 Concerns regarding patient safety have created barriers to providing medical students adequate procedural training in clinical settings [4]. Furthermore, studies have demonstrated that simulation-based skill acquisition can be translated to the patient care setting [5, 6]. As a result, it is reasonable to require that students reach a standardized level of procedural competence under simulated conditions. Safe and standardized strategies need to be implemented into undergraduate medical school curricula to ensure that medical students develop both the confidence and technical ability to perform basic procedures. The ultrasound-guided procedural workshop described in our study is an example of a strategy, which uses high fidelity phantoms in low-risk settings to improve student competence and confidence at needle guidance with ultrasound. The nerve block and needle aspiration phantoms used in our workshop were inexpensive and easy to make. In our study, we incorporated the use of Blue Phantom models (CAE inc. Canada) into the vascular access station; however, low-cost homemade vascular access models are easily available [10, 11]. Although there are numerous US applications that would be valuable for medical students to learn, US needle guidance is essential due to its use in nearly all US-guided procedures. The stations we chose vary with regarding to difficulty in the clinical setting; however, the purpose was to create distinct sonographic tissue backgrounds where students could ‘‘hone in’’ needle guidance skills. Furthermore, with the rapid advancement of asynchronous educational material available online for students; it is important for instructors to search for the latest innovative videos and tutorials prior to developing similar stations. We taught in-plane needle guidance, because it has been shown to reduce procedure-related complications [12, 13]. Despite the benefits of in-plane imaging, the skills we chose to teach require an understanding of both in-plane and out-of-plane. In the nerve block and vascular access stations, students learned to image the anatomy (and compress vessels) while out-of-plane, rotate between inplane and out-of-plane, and then use needle guidance using Intern Emerg Med the in-plane technique. Also, our workshop allowed the students to practice the procedures numerous times at each station, while receiving immediate feedback by trained faculty. Practice is essential to success with ultrasoundguided procedures, because students must begin to develop mental maps of regional anatomy. It is the combination of hand–eye coordination and a basic understanding of how the procedure-relevant anatomy will appear sonographically that is pivotal for successful completion of these procedures [14]. Varga et al. created a cadaver-based model to teach resident physicians vascular procedures and evaluate the similarities between cadaver models and live human models; however, the authors did not evaluate any educational interventions [4]. Hoyer et al. created a vascular procedure-based model to evaluate student-reported confidence with procedures on cadavers; however, no objective assessment data were gathered [3]. Previous ultrasound educational studies have relied solely on student selfassessment or opinion in attempts to correlate effective curricula [3, 8, 15–18]. Although a portion of our data did include self-assessment, we used expert instructors to evaluate students with a validated five-point technical skills rating scale [9]. This tool provided objective measurements for comparing the improvement of student competency after our intervention. Finally, our procedural knowledgebased questionnaire also provided objective data, further demonstrating that the workshop was effective at immediate knowledge transfer. Limitations Our study has several limitations including the small sample size (33 procedures) used for the pre-workshop assessment. However, given that there were significant difference between pre- and post-assessments, by definition, there was no Type II error. Although 88 % (92/105) of students responded to the pre-workshop questionnaire, fewer students responded to the post-workshop questionnaire (78 %), which may have been a bias from a sample that represents the students with greater interest in ultrasound. A portion of our results was based on student selfassessment, which lacks objective measure. Furthermore, the educational curriculum utilized in the study was not pilot-tested or validated prior to implementation. Our simulation-based education relied on fixed ultrasound models, which are less realistic than clinical scenarios; as a result, students may develop an overestimated confidence [19]. It is unknown if overestimated confidence will lead students to perform procedures without asking for help. Although simulation-based skill acquisition has been shown to translate into clinical scenarios, it is uncertain if simulation-based skills have a direct impact on patient outcomes. Finally, our educational curriculum was limited in time; as a result, we chose only to teach in-plane needle guidance. Conclusions The one-day US education workshop employed in this study was effective at immediately increasing third-year medical students’ confidence and technical skill at performing US-guided procedures. Acknowledgments Authors thank Blue Phantom (Ontario, Canada) for the use of their vascular access phantoms, and Mindray Medical International (Shenzhen, China) for providing ultrasound machines for this event. Compliance with ethical standards Conflict of interest The authors declare that they have no conflict of interest. Statement of human and animal rights All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent Informed consent from participants was not required per our IRB. Appendix: Questionnaire 1. I am confident that I can perform Ultrasound-guided procedures by myself without any assistance with simultaneous probe manipulation and needle advancement. a. b. c. d. Strongly agree Somewhat agree Somewhat disagree Strongly disagree 2. Please rank your confidence in performing or assessing the following procedures, from Low (1) to High (10). a. b. c. d. Ultrasound-guided Peripheral IV Placement Ultrasound-guided Needle Aspiration Ultrasound-guided Peripheral Nerve Block Needle guidance with Ultrasound 3. When performing ultrasound-guided peripheral IVs, the metallic needle creates which of the following artifacts? a. b. c. d. Shadowing artifact Reverberation artifact Edge artifact Propagation error artifact 123 Intern Emerg Med 4. When using ultrasound, what technique can be performed to differentiate a vein from an artery? c. d. a. b. c. d. 11. Lidocaine associated systemic toxicity (LAST) can occur if an excess amount of Lidocaine is administered or if Lidocaine is injected directly into vasculature. What is the antidote and dosage? Short axis compression Color doppler Pulse wave doppler All of the above 5. When measuring a cylindrical structure (blood vessel) in long axis, it is possible to underestimate the diameter of said cylinder. What is this measurement error called? a. b. c. d. Cylinder tangent effect Cylinder sinus effect Cylinder cosign effect Slip sign 6. To improve needle visibility during ultrasound-guided procedures, the angle of needle insertion should be __________ to ultrasound beams. a. b. c. d. Perpendicular Parallel Stronger Symmetric 7. In regards to abscess evaluation and management, how can the operator distinguish abscess fluid from dense soft-tissue mass like lipoma or sebaceous cyst? 1. 2. 3. 4. Cut the abscess open Demonstrate the sonographic squish sign Demonstrate the sonographic line sign Use Color Doppler 8. What kind of probe should be used when performing ultrasound-guided nerve blocks or peripheral IV access? a. b. c. d. Low frequency curved array probe High frequency curved array probe Low frequency Linear array probe High frequency Linear array probe 9. Describe the sonographic appearance of peripheral nerves. a. b. c. d. Hyperechoic structure with shadowing artifact Hypoechoic circular structures that compress with pressure Hyperechoic triangular honeycomb appearing structures All of the above 10. How much anesthetic solution (1 % Lidocaine) would be sufficient to anesthetize a femoral nerve with ultrasound guidance? a. b. 5 cc/5 ml 10–20 cc/10–20 ml 123 a. b. c. d. 20–40 cc/20–40 ml 50 cc/50 ml Intralipid: 1.5 ml/kg bolus over 1–2 min Propofol: 1 mg/kg bolus over 1–2 min Glucagon 2 mg very slowly Atropine 1.5 ml/kg bolus over 1–2 min 12. 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