Background: The need for surgeons to become proficient in performing and interpreting ultrasound examinations has been well recognized in recent years, but providing standardized training remains a significant challenge. The UltraSim (MedSim, Ft. Lauderdale, Fla) ultrasound simulator is a modified ultrasound machine that stores patient data in three-dimensional images. By scanning on the UltraSim mannequin, the student can reconstruct these images in real-time, eliminating the need for finding normal and abnormal models, while providing an objective method of both teaching and testing. The objective of this study was to compare the posttest results between residents trained on a real-time ultrasound simulator versus those trained in a traditional hands-on patient format. We hypothesized that both methods of teaching would yield similar results as judged by performance on the interpretive portion of a standardized posttest. It is designed as a prospective, cohort study from two university trauma centers involving residents at the beginning of their first or second postgraduate year of training. The main outcome measure was performance on a standardized posttest, which included interpretation of ultrasound cases recorded on videotape.
Methods: Students first took a written pretest to evaluate their baseline knowledge of ultrasound physics as well as their ability to interpret basic ultrasound images. The didactic portion of the course used the same teaching materials for all residents and included lectures on ultrasound physics, ultrasound use in trauma/critical care, and a series of instructional videos. This didactic session was followed by 1 hour for each student of hands-on training on medical models/medical patients (group I) or by training on the ultrasound simulator (group II). The pretest was repeated at the completion of the course (posttest). Data were stratified by postgraduate year, i.e., PG1 or PG2.
Results: A total of 74 residents were trained and tested in this study (PG1 = 48, PG2 = 26). All residents showed significant improvement in their pretest and posttest scores (p = 0.00) in both their knowledge of ultrasound physics and in their interpretation of ultrasound images. Importantly, we could not demonstrate any significant difference between groups trained on models/patients (group I) versus those trained on the simulator (group II) when comparing their posttest interpretation of ultrasound images presented on videotapes (PG1, group I mean score 6.9 +/- 1.4 vs. PG1, group II mean score 6.5 +/- 1.6, p = 0.32; PG2, group I mean score 7.7 +/- 1.4 vs. PG2, group II mean score 7.9 +/- 1.2, p = 0.70).
Conclusion: The use of a simulator is a convenient and objective method of introducing ultrasound to surgery residents and compares favorably with the experience gained with traditional hands-on patient models.