The effect of display size on ultrasound interpretation.

OBJECTIVES: Ultrasound (US) is an essential component of emergency department patient care. US machines have become smaller and more affordable. Handheld ultrasound (HUS) machines are even more portable and easy to use at the patient's bedside. However, miniaturization may come with consequences. The ability to accurately interpret ultrasound on a smaller screen is unknown. This pilot study aims to assess how screen size affects the ability of emergency medicine clinicians to accurately interpret US videos. METHODS: This pilot study enrolled a prospective convenience sample of emergency medicine physicians. Participants completed a survey and were randomized to interpret US videos starting with either a phone-sized screen or a laptop-sized screen, switching to the other device at the halfway point. 50 unique US videos depicting right upper quadrant (RUQ) views of the Focused Assessment with Sonography in Trauma (FAST) examination were chosen for inclusion in the study. There were 25 US videos per device. All of the images were previously obtained on a cart-based machine (Mindray M9) and preselected by the study authors. Participants answered "Yes" or "No" in response to whether they identified free fluid. The time that each participant took to interpret each video was also recorded. Following the assessment, participants completed a post-interpretation survey. The goal of the pilot was to determine the accuracy of image interpretation on a small screen as compared to a laptop-sized screen. Statistical analyses were performed using MATLAB (The MathWorks, Inc., Natick, MA). Nonparametric statistical tests were utilized to compare subgroups, with a Wilcoxon signed rank test used for paired data and a Wilcoxon rank sum test for unpaired data. RESULTS: 52 emergency medicine physicians were enrolled in the study. The median accuracy of US interpretation for phone versus laptop image screen was 88.0% and 87.6% (p = 0.67). The mean time to interpret with phone versus laptop screen was 293 and 290 s (p = 0.66). CONCLUSIONS: The study found no statistically significant difference in the accuracy of US interpretation nor time spent interpreting when the pre-selected RUQ videos generated on a cart-based ultrasound machine were reviewed on a phone-sized versus a laptop-sized screen. This pilot study suggests that the accuracy of US interpretation may not be dependent upon the size of the screen utilized.

Use of the color Doppler twinkle artifact for teaching ultrasound guided peripheral vascular access.

BACKGROUND: The optimal method for teaching ultrasound guided peripheral IV (USGPIV) insertion is unknown. Poor needle tip visualization has been cited for USGPIV failure. Twinkle artifact (TA), visualized with color Doppler, is used in other clinical settings. Our objective was to investigate whether teaching students USGPIV placement utilizing TA would enhance needle tip visualization and improve first pass success. METHODS: This was a prospective, randomized study of premedical and preclinical medical students without prior USGPIV experience. Students were given a standardized didactic session on USGPIV placement before being randomized and separated to learn and practice USGPIV with or without TA (control). The students were given 5 min to perform USGPIV on phantom models. The primary outcome was the rate of first pass success. Secondary outcomes included total time to cannulation, rate of posterior venous wall puncture, and total number of attempts. RESULTS: Rates of first pass success were similar in both the TA (82%) and control groups (57%), p = 0.095. There was a difference in the mean time to cannulation. The TA group achieved success at 50.76 s (SD 26.93) while the control group achieved success at 85.30 s (SD 65.47), p = 0.048. CONCLUSION: In this study of utilizing TA to aid in USGPIV placement, students were able to achieve successful cannulation in a shorter amount of time. There was no significant difference in first pass success. Future studies should utilize a larger sample size and evaluate the utility of TA when placing USGPIV on patients.

A comparison of homemade vascular access ultrasound phantom models for peripheral intravenous catheter insertion.

BACKGROUND: Ultrasound (U/S) guided peripheral IV catheter (PIV) placement is often needed after unsuccessful traditional IV attempts. Commercial U/S PIV training phantoms are expensive and difficult to alter. Non-commercial phantoms have been described; however, there has been no comparison of these models. The primary objectives of this study were to compare the echogenic and haptic properties of various non-commercial phantoms. Secondary objectives were to characterize the cost and ease of making the phantoms. METHODS: This prospective observational study trialed six unique phantom models: Amini Ballistics; Morrow Ballistics; University of California San Diego (UCSD) gelatin; Rippey Chicken; Nolting Spam; and Johnson Tofu. Total cost and creation time were noted. Emergency Ultrasound Fellowship trained physicians performed U/S guided PIV placement on each model to evaluate their resemblance to human tissue haptic and echogenicity properties, utility for training, and comparability to commercial phantoms (Likert scale 1-5; higher performance = 5). RESULTS: The Rippey model scored highest for each primary objective with an aggregate score of 4.8/5. UCSD ranked second and Nolting last for all primary objectives, with aggregate scores 3.7/5 and 1.3/5 respectively. Cost of production ranged from $4.39 (Johnson) to $29.76 (UCSD). Creation times ranged from 10 min (Johnson) to 120 min (UCSD). CONCLUSION: In our study the Rippey model performed best and offered a mid-level cost and creation time. Non-commercial U/S phantoms may represent cost-effective and useful PIV practice tools. Future studies should investigate the utility of these phantoms in teaching U/S guided PIV to novices and compare non-commercial to commercial phantoms.

Cross-specialty Collaboration and Education for Neurosurgical Trainees: Teaching Arterial Line Placement Under Ultrasound Guidance.

Introduction Interprofessional collaboration (IPC) increases patient safety. IPC is learned through task-based exercises, such as ultrasound (U/S)-guided arterial lines. We set out to teach U/S-guided arterial lines as a framework to improve IPC between emergency medicine and neurosurgery residents. The objectives of the study were to provide a U/S session to teach the proper arterial line placement technique, to assess post-workshop arterial line placement competency and attitude toward U/S for procedural guidance, and to improve interdepartmental relationships through IPC. Methods The course was completed in 2018 and consisted of pre-workshop assignments, the workshop, a competency assessment, and a post-workshop survey for neurosurgical residents. After a didactic and hands-on training session, trainees completed a simulated U/S-guided arterial line placement. Trainees then completed a post-workshop assessment. Results There were a total of 21 participants out of 24 total residents, an 87.5% participation rate. Prior to the workshop, on a 5-point Likert scale, where 1 is not at all likely and 5 is very likely, the residents reported they would use U/S 1.7/5, with 57% of respondents answering 1 out of 5. After the workshop, on the same Likert scale, the residents reported using U/S first 3.6/5 (P < 0.05) with 52% of the respondents answering 4 out of 5. After the course, the belief that the landmark technique is non-inferior decreased to 28.6% of respondents. Conclusions The overall goal of this workshop was to improve patient care through continuing education. Using IPC as the framework, the workshop significantly increased the reported likelihood of using U/S for arterial line placement.

A Three-dimensional Printed Low-cost Anterior Shoulder Dislocation Model for Ultrasound-guided Injection Training.

Anterior shoulder dislocations are the most common, large joint dislocations that present to the emergency department (ED). Numerous studies support the use of intraarticular local anesthetic injections for the safe, effective, and time-saving reduction of these dislocations. Simulation training is an alternative and effective method for training compared to bedside learning. There are no commercially available ultrasound-compatible shoulder dislocation models. We utilized a three-dimensional (3D) printer to print a model that allows the visualization of the ultrasound anatomy (sonoanatomy) of an anterior shoulder dislocation. We utilized an open-source file of a shoulder, available from embodi3D® (Bellevue, WA, US). After approximating the relative orientation of the humerus to the glenoid fossa in an anterior dislocation, the humerus and scapula model was printed with an Ultimaker-2 Extended+ 3D® (Ultimaker, Cambridge, MA, US) printer using polylactic acid filaments. A 3D model of the external shoulder anatomy of a live human model was then created using Structure Sensor®(Occipital, San Francisco, CA, US), a 3D scanner. We aligned the printed dislocation model of the humerus and scapula within the resultant external shoulder mold. A pourable ballistics gel solution was used to create the final shoulder phantom. The use of simulation in medicine is widespread and growing, given the restrictions on work hours and a renewed focus on patient safety. The adage of "see one, do one, teach one" is being replaced by deliberate practice. Simulation allows such training to occur in a safe teaching environment. The ballistic gel and polylactic acid structure effectively reproduced the sonoanatomy of an anterior shoulder dislocation. The 3D printed model was effective for practicing an in-plane ultrasound-guided intraarticular joint injection. 3D printing is effective in producing a low-cost, ultrasound-capable model simulating an anterior shoulder dislocation. Future research will determine whether provider confidence and the use of intraarticular anesthesia for the management of shoulder dislocations will improve after utilizing this model.