Fast education: a comparison of teaching models for trauma sonography1

The Journal of Emergency Medicine, Vol 20, No 4, pp 421– 425, 2001 Copyright © 2001 Elsevier Science Inc. Printed in the USA. All rights reserved 0736-4679/01 $–see front matter

PII S0736-4679(01)00297-9

Education

FAST EDUCATION: A COMPARISON OF TEACHING MODELS FOR TRAUMA SONOGRAPHY Philip Salen, MD,* Robert O’Connor, MD,† Brent Passarello, MD,† Diana Pancu, Scott Melanson, MD,* Stephen Arcona, PhD,* and Michael Heller, MD*

MD,*

*Department of Emergency Medicine, St. Luke’s Hospital, Bethlehem, Pennsylvania, †Department of Emergency Medicine, Christiana Care Health Systems, Newark, Delaware Reprint Address: Philip Salen, MD, Emergency Medicine Residency, St. Luke’s Hospital, 801 Ostrum Street, Bethlehem, PA 18015

e Abstract—This study’s objective was to evaluate the peritoneal dialysis and mannequin simulator models for the hands-on portion of a 4-h focused abdominal sonography for trauma (FAST) course. After an introductory lecture about trauma sonography and practice on normal models, trainees were assigned randomly to two groups. They practiced FAST on one of the two simulator models. After the didactic and hands-on portions of the seminar, FAST interpretation testing revealed mean scores of 82% and 78% for the peritoneal dialysis and mannequin simulator groups, respectively (p ⴝ 0.95). Post-course surveys demonstrated mean satisfaction scores for peritoneal dialysis and mannequin simulator models of 3.85 and 3.25, respectively, on a 4-point Likert scale (p ⴝ 0.317). A FAST educational seminar, which provides both didactic and hands-on instruction, can be completed in 4 h; the hands-on instruction phase can incorporate both normal models and abnormal simulation models, such as the peritoneal dialysis model and the multimedia mannequin simulator.

INTRODUCTION Focused abdominal sonography for trauma (FAST) is becoming a standard procedure in the assessment of trauma victims. The primary goal of FAST is to determine whether blood is present in the peritoneal, pericardial, or pleural cavities. A major issue in incorporating trauma sonography into emergency and surgical practice is the development of appropriate curricula. Both the American College of Emergency Physicians (ACEP) and the American College of Surgeons (ACS) have included trauma ultrasound as a necessary aspect of residency training (1,2). Although much attention has focused on the amount of experience necessary for performing FAST adequately, there has been little in the medical literature regarding appropriate duration and content of FAST educational courses (3– 8). Currently, there are no uniform educational recommendations or standards for courses in trauma sonography. Table 1 summarizes the variability in FAST training courses described in the literature. FAST educators, challenged by access to quality teaching models, have begun to use mannequin simulators as teaching aids. This study’s objective was to compare two different models for hands-on FAST training: the peritoneal dialysis model and the multimedia mannequin simulator.

e Keywords—FAST; intraperitoneal free fluid; Morison’s pouch; simulation models

Abstract was presented at the ACEP Scientific Assembly Research Forum, Las Vegas, NV, October 1999.

Education is coordinated by Stephen R. Hayden, Diego, California

RECEIVED: 2 June 2000; FINAL SUBMISSION ACCEPTED: 22 November 2000

RECEIVED:

MD,

of the University of California San Diego Medical Center, San

9 November 2000; 421

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Table 1. Educational and Experiential Recommendations for FAST Training

Author

Year

Didactic

Practical

Ma et al. (3) Thomas et al. (4)

1995 1997

10 hours* ™™™™™™™™ 3 8 hours* ™™™™™™™™™ 3

Rozycki et al. (5)

1998

Not ™™™™™™™™™™™™™™ 3 Specified*

Smith et al. (6) Scalea et al. (7)

1998 1999

4 hours 4 hours

Shackford et al. (8)

1999

8 hours

4 hours 4 hours Not Specified

Type of Model

No. of Practice Exams

Recommended No. of Exams Prior to Certification

Cred. Exam

Video Normal Normal Peritoneal Dialysis Video Normal Abnormal Normal Peritoneal Dialysis Not Specified

15–20 15

Practice Exams Sufficient 50

No No

Not Specified

50

Yes

10 200*

25

No No

Normal

10

50

No

* Combined.

METHODS Figure 1 illustrates the design of the trauma sonography course provided to 20 Emergency Medicine (EM) resident physicians with no prior sonographic experience and 10 other EM physicians with varying levels of sonographic experience. Institutional Review Board approval was obtained. The course consisted of a 1-h didactic presentation followed by a 3-h hands-on training session. The sonography instructors were four emergency physi-

Figure 1. Trauma sonography course description.

cians with extensive experience in sonography. All trainees were introduced to the performance of trauma sonography by first visualizing normal anatomy on healthy subjects under the direct supervision of the instructors. The EM resident trainees were randomly assigned to train on either the peritoneal dialysis model or the mannequin simulator model. Each trainee was given proctored instruction for 10 min on one of the models in the assigned group. Participants were given sufficient time to practice until they felt confident with their ability to

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utilizing a 4-point Likert scale (1 ⫽ least beneficial, 4 ⫽ most beneficial) queried trainees in regards to: the opportunity to practice FAST one on one with an instructor, whether the mannequin simulator accurately simulated a live patient, whether the visualization of intraperitoneal free fluid was beneficial to their understanding of pathologic views in trauma sonography, and how beneficial was each model. The emergency physicians with varying ultrasound experience received the same training. Because of their prior sonographic experience, only their subjective opinions regarding the course were included in the final statistical analysis. The peritoneal dialysis models were reimbursed volunteers and instilled 2 L of dialysate before the scanning session. The multimedia mannequin simulator models were UltraSim威 sonographic training models made by MedSim威 (Figure 2). The UltraSim威 models were programmed to simulate a large amount of intraperitoneal free fluid. This research project received no financial support from MedSim威 or any other source; MedSim威 was reimbursed for use of the simulator. Wilcoxon Sign Rank Tests were used to compare mean trainee satisfaction with the three different models. The Student’s t-test was used to compare differences in the mean test scores of the 2 training groups, and also to calculate the power analysis. Alpha was set at 0.05, 2-tailed. Figure 2. UltraSim姞 sonographic training model made by MedSim姞.

RESULTS

independently identify the four anatomical areas of fluid collection in FAST: Morison’s pouch, the suprapubic area, the splenorenal area, and the pericardial area. The trainees were then tested on their ability to identify or refute the presence of intraperitoneal free fluid on 25 photographic images of varying FAST views. Each group then practiced the FAST examination on the models that they had not yet examined. A post-course survey

Course participants rated the opportunity to practice FAST on normal models individually with an instructor with a mean score of 3.7. They considered the mannequin simulator an accurate simulation of a live human model and gave it a mean score of 3.0. The importance of visualizing intraperitoneal free fluid in the understanding of positive sonographic findings in trauma sonography was rated a mean score of 3.7. Figure 3 documents

Figure 3. Trainee satisfaction with ultrasound models.

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trainee satisfaction scores with each of the models. The mean trainee satisfaction score for the peritoneal dialysis model was 3.85. This did not vary significantly from the mean scores of the normal, 3.79, and mannequin simulator models, 3.25 ( p ⫽ 0.42 and p ⫽ 0.32, respectively). Post-hoc power analysis to detect a difference between the satisfaction scores of the peritoneal dialysis model and the mannequin simulator model was 45% for this sample. The peritoneal dialysis group had a mean score on the post-course test of 82% ⫾ 7 while the mannequin simulator group had a mean score of 78% ⫾ 8 (P ⫽ 0.95). Post hoc power analysis to detect this difference between the two groups with this sample size was 8%.

DISCUSSION FAST educators have used different simulation models for training physicians in the performance of trauma sonography. Possibilities for learning and practicing the FAST examination include didactic image presentation, video review of actual cases, animal models, mannequin simulator models, cadavers, normal human models, and peritoneal dialysis models (11,12). Normal human models may be useful models for FAST instruction because they are readily available and demonstrate normal anatomic landmarks to novice sonographers. Peritoneal dialysis models may be advantageous because the peritoneal dialysate closely resembles the sonographic appearance of hemoperitoneum. UltraSim威 by MedSim威 (Figure 2) is a combination of a mock ultrasound scanner and a mannequin on which scanning is performed in order to mimic the scanning experience. Different compact discs with various FAST examinations ranging from no intraperitoneal free fluid to a large amount are available for the UltraSim威 model for trauma sonography education. Figure 3 shows the trainees’ satisfaction with both the peritoneal dialysis model and the mannequin simulator models. The groups combined to rate the importance of visualizing intraperitoneal free fluid as 3.7. Although the difference between the two groups was not significant statistically, trainees gave the peritoneal dialysis model higher mean satisfaction scores. This may reflect a preference for scanning living human models or using a genuine ultrasound scanner instead of a simulation scanner. In spite of higher satisfaction scores with the peritoneal dialysis models over the mannequin simulators, there was not a significant difference between the groups on the FAST interpretation test. As some studies have shown that FAST skills improve with formal ultrasound courses and with experience reading positive examinations, FAST educators should consider utilizing at least a few teaching models that allow for visualization of actual or simulated intra-

peritoneal free fluid (12–15). Simulation ensures that trainees have had some practice prior to performing FAST in the trauma bay (13). Although using simulation models avoids having to learn on genuine trauma victims, who are often critically ill, the ideal learning model has not been identified. Peritoneal dialysis models allow trainees to gain experience evaluating human models with free intraperitoneal fluid, the amount and appearance of which can vary depending on the amount of dialysate instilled and patient positioning. Mannequin simulators may be advantageous because they are available at any time to fit curriculum needs, they provide the trainee with a great diversity of sonographic findings and pathology in a single hands-on course, and patient privacy is not an issue (11). A possible benefit of mannequin simulators in the future is that they could help to provide a standardized educational experience and testing that would permit direct comparison of students’ sonographic performance.

STUDY LIMITATIONS Of note, all course participants got the experience of practicing FAST on the models with intraperitoneal free fluid prior to taking the FAST interpretation test; there was no control group. Our sonographic interpretation test to determine how well course participants can recognize intraperitoneal free fluid has limitations. Notably, it does not test the trainees’ ability to generate adequate sonographic images for the FAST examination and has not been formally validated. Also, it is important to acknowledge limitations of the models used in this course. Peritoneal dialysis models often have non-standard anatomy, such as atrophic bladders and kidneys. They are often frail secondary to their co-morbid conditions, which limits their availability as training models, and they may need to remove and reinstill their dialysate periodically, which limits training time during the course. On the other hand, the cost of the simulators, the cost of maintenance, and the frequency and cost of technical and software upgrades are important issues for mannequin simulator models. Finally, using a mannequin simulator may not fully mimic the experience of sonographically scanning a live human with the current available technology.

CONCLUSION Both normal models and models that simulate intraperitoneal free blood, including peritoneal dialysis patients and mannequin simulators, are viable options for the “hands on” phase of a trauma sonography course.

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REFERENCES 1. Allison EJ, Aghababian RV, Barsan WJ, et al. Core Content for emergency medicine. Task Force on the Core Content for Emergency Medicine Revision. Ann Emerg Med 1997;29:792– 811. 2. Rozycki G. Surgeon-performed ultrasound: its use in clinical practice. Ann Surg 1998;228:16. 3. Ma OJ, Mateer JR, Ogata M, et al. Prospective analysis of a rapid trauma ultrasound examination performed by emergency physicians. J Trauma 1995;38:879. 4. Thomas B, Falcone RE, Vasquez D, et al. Ultrasound evaluation of blunt abdominal trauma: program implementation, initial experience, and learning curve. J Trauma 1997;42:384. 5. Rozycki GS, Ballard RB, Feliciano DV, et al. Surgeon-performed ultrasound for the assessment of truncal injuries. Ann Surg 1998; 228:557. 6. Smith RS, Kern SJ, Fry WR, et al. Institutional learning curve of surgeon-performed trauma ultrasound. Arch Surg 1998;133:530. 7. Scalea TM, Rodriguez A, Chiu WC, et al. Focused assessment with sonography for trauma (FAST): results from an international consensus conference. J Trauma 1999;46:466. 8. Shackford SR, Rogers FB, Osler TM, et al. Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum. J Trauma 1999;46:553. 9. Issenberg SB, McGaghie WC, Hart IR, et al. Simulation technol-

10.

11. 12. 13. 14. 15. 16.

ogy for health care professional skills training and assessment. JAMA 1999;282:861– 6. Sisley AC, Johnson SB, Erickson W, Fortune JB. Use of an Objective Structures Clinical Examination (OSCE) for the assessment of physician performance in the ultrasound evaluation of trauma. J Trauma 1999;47:627–31. Salen PS, Melanson SW, Heller M. The FAST Exam: considerations and Recommendations for Training Physicians in the Use of a New Clinical Tool. Ann Emerg Med 2000;7:162– 8. Frezza EE, Solis RL, Silich RJ, Spence RK, Martin M. Competency based instruction to improve the surgical resident technique and accuracy of trauma ultrasound. Am Surg 1999;65:884 – 8. Melanson SW, Salen PN, Pronchik D, Heller M. A model for trauma sonography: the peritoneal dialysis patient. ACEP Scientific Assembly Research Forum 1998. Ali J, Rozychi GS, Campbell JP, Boulanger BR, Waddell JP, Gana TJ. Trauma ultrasound workshop improves physician detection of peritoneal and pericardial fluid. J Surg Res 1996;63:275–9. Ali J, Campbell JP, Gana T, Burns PN, Ochsner MG. Swine and dynamic ultrasound models for trauma ultrasound testing of surgical residents. J Surg Res 1998;7:17–21. Issenberg SB, McGaghie WC, Hart IR, et al. Simulation technology for health care professional skills training and assessment. JAMA 1999;282:861– 6.