Novel Scoring Scale for Quality Assessment of Lung Ultrasound in the Emergency Department.

Introduction: The use of a reliable scoring system for quality assessment (QA) is imperative to limit inconsistencies in measuring ultrasound acquisition skills. The current grading scale used for QA endorsed by the American College of Emergency Physicians (ACEP) is non-specific, applies irrespective of the type of study performed, and has not been rigorously validated. Our goal in this study was to determine whether a succinct, organ-specific grading scale designed for lung-specific QA would be more precise with better interobserver agreement. Methods: This was a prospective validation study of an objective QA scale for lung ultrasound (LUS) in the emergency department. We identified the first 100 LUS performed in normal clinical practice in the year 2020. Four reviewers at an urban academic center who were either emergency ultrasound fellowship-trained or current fellows with at least six months of QA experience scored each study, resulting in a total of 400. The primary outcome was the level of agreement between the reviewers. Our secondary outcome was the variability of the scores given to the studies. For the agreement between reviewers, we computed the intraclass correlation coefficient (ICC) based on a two-way random-effect model with a single rater for each grading scale. We generated 10,000 bootstrapped ICCs to construct 95% confidence intervals (CI) for both grading systems. A two-sided one-sample t-test was used to determine whether there were differences in the bootstrapped ICCs between the two grading systems. Results: The ICC between reviewers was 0.552 (95% CI 0.40-0.68) for the ACEP grading scale and 0.703 (95% CI 0.59-0.79) for the novel grading scale (P < 0.001), indicating significantly more interobserver agreement using the novel scale compared to the ACEP scale. The variance of scores was similar (0.93 and 0.92 for the novel and ACEP scales, respectively). Conclusion: We found an increased interobserver agreement between reviewers when using the novel, organ-specific scale when compared with the ACEP grading scale. Increased consistency in feedback based on objective criteria directed to the specific, targeted organ provides an opportunity to enhance learner education and satisfaction with their ultrasound education.

Inter-rater reliability of optic nerve sheath diameter measurement using real-time ultrasonography.

OBJECTIVES: Ultrasound measurement of the optic nerve sheath diameter (ONSD) is a rapid, non-invasive means to indirectly assess intracranial pressure. Previous research has demonstrated the ability of emergency physicians to measure ONSD accurately with bedside ultrasound when compared to CT scan or MRI, however the reliability of this measurement between two or more operators has been called into question (Hassen et al. in J Emerg Med 48:450-457, 2015; Shirodkar et al. in Ind J Crit Care Med 19:466-470, 2015). Given the need for accurate and precise measurement to use this as a screening exam, we sought to determine the inter-rater reliability between ONSD measurements obtained in real time by fellowship-trained emergency ultrasound physicians. METHODS: Three ultrasound fellowship-trained emergency physicians measured bilateral ONSD of 10 healthy volunteers using a high-frequency linear transducer. The physicians were blinded to the other scanners' measurements, and no instructions were given other than to obtain the ONSD. Each sonographer measured the ONSD in real time and it was recorded by a research coordinator. All measurements were recorded in millimeters. Intraclass correlation coefficients (ICCs) were calculated to estimate the inter-rater reliability. RESULTS: A total of 60 measurements of ONSD were obtained. The average measurement was 4.3 mm (3.83-4.77). Very little variation was found between the three physicians, with a calculated ICC of 0.82 (95% confidence interval 0.63-0.92). CONCLUSIONS: ONSD measurement obtained by ultrasound fellowship-trained emergency medicine physicians is a reliable measurement with a high degree of correlation between scanners.

Novel Approach to Ultrasound-Guided Thoracostomy.

OBJECTIVES: Thoracostomy is often a required treatment in patients with thoracic trauma; however, performing a thoracostomy using traditional techniques can have complications. Ultrasound can be a beneficial tool for identifying the correct thoracostomy insertion site. We designed a randomized prospective study to assess if ultrasound guidance can improve thoracostomy site identification over traditional techniques. METHODS: Emergency medicine residents were randomly assigned to use palpation or ultrasound to identify a safe insertion site for thoracostomy placement. The target population comprised of hemodynamically stable trauma patients who received an extended focused assessment with sonography for trauma (EFAST) and a chest computed tomography (CT) exam. The resident placed a radiopaque marker on the skin of the patient where a safe intercostal space was believed to be located, either by palpation or ultrasound. Clinical ultrasound faculty reviewed the CT to confirm marker placement relative to the diaphragm. A Fischer's exact test was used to analyze the groups. RESULTS: One hundred and forty-seven patients were enrolled in the study, 75 in the ultrasound group and 72 in the landmark group. This resulted in the placement of 271 total thoracostomy site markers, 142 by ultrasound and 129 by palpation and landmarks. The ultrasound group correctly identified thoracostomy insertion sites above the diaphragm in 97.2% (138/142) of patients, while the palpation group identified a safe insertion site in 88.4% (114/129) of patients (P = .0073). CONCLUSION: This study found that emergency medicine residents are more likely to identify a safe tube thoracostomy insertion site in trauma patients by using ultrasound, as compared to using landmarks and palpation.

A retrospective evaluation of point of care ultrasound for acute cholecystitis in a tertiary academic hospital setting.

BACKGROUND: In 2008 the Council of Emergency Medicine Residency Directors delineated consensus recommendations for training in biliary ultrasound for the "detection of biliary pathology". OBJECTIVES: While studies have looked at the accuracy of emergency provider performed clinical ultrasound (ECUS), we sought to evaluated if ECUS could be diagnostic for acute cholecystitis and thus obviate the need for follow-up imaging. METHOD: We reviewed all ECUS performed between 2012 and 2017 that had a matching radiology performed ultrasound (RADUS) and a discharge diagnosis. 332 studies were identified. The sensitivity and specificity of both ECUS and RADUS were compared to the patient's discharge diagnosis. The agreement between the ECUS and RADUS was assessed using an unweighted Cohen's Kappa. The time from patient arrival to diagnosis by ECUS and RADUS was also compared. RESULTS: Using discharge diagnosis as the gold standard ECUS was 67% (56-78%) sensitive, 88% (84-92%) specific, NPV 90% (87-95%), PPV 60% (50-71%), +LR 5.6 (3.9-8.2), -LR 0.37 (0.27-0.52) for acute cholecystitis. RADUS was 76% (66-87%) sensitive, 97% (95-99%) specific, NPV 95% (092-97%), PPV 86% (76-95%), +LR 25.6 (12.8-51.4), and -LR 0.24 (0.15-0.38). ECUS was able to detect gallstones with 93% (89-96%) sensitivity and 94% (90-98%) specificity leading to a NPV 90% (85-95%), PPV of 95% (92-98%), +LR 14.5 (7.7-27.4), -LR 0.08 (0.05-0.13). The unweighted kappa between ECUS and RADUS was 0.57. The median time between obtaining ECUS vs. RADUS diagnosis was 124 min. CONCLUSIONS: ECUS can be beneficial in ruling out acute cholecystitis, but lacks the test characteristics to be diagnostic for acute cholecystitis.

Central Venous Catheter Confirmation by Ultrasonography: A Novel Instructional Protocol.

OBJECTIVES: Ultrasound (US)-only confirmation of central venous catheter (CVC) placement has proven to be accurate and fast when compared with the current standard chest radiograph. This procedure depends on the detection of appropriately timed atrial bubbles during central line flushing, called the rapid atrial swirl sign (RASS). The most obvious barrier to increasing the use of this technique is appropriate education and training; therefore, we proposed a novel educational approach to training emergency department (ED) physicians in the confirmation of CVC location using US and then tested its effectiveness. METHODS: Using an online educational model, participants were taught the background and procedural steps to confirm CVC placement using US. Subsequently, they were asked to use this knowledge to place central lines in simulation and confirm them using US. They were tested with various scenarios, including correctly and incorrectly placed lines. Their accuracy was measured, and a survey was used to assess their satisfaction with the training and applicability to practice. RESULTS: A total of 47 ED physicians completed the online training module and 24 completed the simulation testing that followed. Results showed 100% accuracy in detecting appropriately timed RASS (<2 seconds), delayed RASS (>2 seconds), and no RASS in simulation. All of the participants "agreed" or "strongly agreed" that the didactic and simulation sessions improved their understanding of US confirmation of central line placement. CONCLUSIONS: The use of US to confirm central line placement can be effectively taught to ED physicians using short didactic and simulation-based training. This is a reasonable approach to integrate this protocol into practice, and allow for more widespread use of this emerging technique.

Ability of Critical Care Medics to Confirm Endotracheal Tube Placement by Ultrasound.

INTRODUCTION: The Advanced Cardiac Life Support (ACLS) guidelines were recently updated to include ultrasound confirmation of endotracheal tube (ETT) location as an adjunctive tool to verify placement. While this method is employed in the emergency department under the guidance of the most recent American College of Emergency Physicians (ACEP; Irving, Texas USA) guidelines, it has yet to gain wide acceptance in the prehospital setting where it has the potential for greater impact. The objective of this study to is determine if training critical care medics using simulation was a feasible and reliable method to learn this skill. METHODS: Twenty critical care paramedics with no previous experience with point-of-care ultrasound volunteered for advanced training in prehospital ultrasound. Four ultrasound fellowship trained emergency physicians proctored two three-hour training sessions. Each session included a brief introduction to ultrasound "knobology," normal sonographic neck and lung anatomy, and how to identify ETT placement within the trachea or esophagus. Immediately following this, the paramedics were tested with five simulated case scenarios using pre-obtained images that demonstrated a correctly placed ETT, an esophageal intubation, a bronchial intubation, and an improperly functioning ETT. Their accuracy, length of time to respond, and comfort with using ultrasound were all assessed. RESULTS: All 20 critical care medics completed the training and testing session. During the five scenarios, 37/40 (92.5%) identified the correct endotracheal placements, 18/20 (90.0%) identified the esophageal intubations, 18/20 (90.0%) identified the bronchial intubation, and 20/20 (100.0%) identified the ETT malfunctions correctly. The average time to diagnosis was 10.6 seconds for proper placement, 15.5 seconds for esophageal, 15.6 seconds for bronchial intubation, and 11.8 seconds for ETT malfunction. CONCLUSIONS: The use of ultrasound to confirm ETT placement can be effectively taught to critical care medics using a short, simulation-based training session. Further studies on implementation into patient care scenarios are needed.

Comparison of Ultrasound-Guided and Landmark-Based Lumbar Punctures in Inexperienced Resident Physicians.

OBJECTIVES: We sought to determine whether US-guided lumbar puncture reduced the rate of lumbar puncture failures for providers at an academic teaching hospital with variable lumbar puncture and US experience compared to the traditional landmark-based technique. METHODS: We conducted a prospective randomized controlled trial to compare US-guided lumbar puncture to the traditional landmark technique in an academic emergency department. Thirty-five patients were randomized to either have their lumbar puncture performed either via the landmark or US-guided technique. All procedures were completed by an emergency medicine resident with variable lumbar puncture and US experience. Procedural failures, the number of attempts, the time to completion, and patient pain scores were all recorded. RESULTS: The adjusted odds ratio of successfully obtaining cerebrospinal fluid (CSF) in the US-guided lumbar puncture group was 2.31 compared to the landmark-based lumbar puncture group (P = .377). It took 1.54 times more attempts to obtain CSF in the landmark group as it did in the US group (P = .046). It seemed to have no effect on postprocedural pain or the time to obtain CSF. CONCLUSIONS: The use of US guidance to assist in lumbar punctures did not improve the procedural success rate over traditional landmark techniques in an academic setting with novice providers. Although using US for procedural guidance significantly decreased the number of attempts, it seemed to have no effect on postprocedural pain or the time to obtain CSF.

Strategic Questioning in Emergency Medicine Training.

Strategic questioning is a technique that can enhance the unique learning environment of emergency medicine (EM) training. By incorporating this into the routine expert-learner encounters of daily practice, it can be used to engage learners, explore their knowledge base, probe for gaps, encourage development, and grow critical thinking skills. We propose that this become routinely used in EM training as a tool to strengthen residency education.

Ultrasound-guided thoracostomy site identification in healthy volunteers.

BACKGROUND: Traditional landmark thoracostomy technique has a known complication rate up to 30%. The goal of this study is to determine whether novice providers could more accurately identify the appropriate intercostal site for thoracostomy by ultrasound guidance. METHODS: 33 emergency medicine residents and medical students volunteered to participate in this study during routine thoracostomy tube education. A healthy volunteer was used as the standardized patient for this study. An experienced physician sonographer used ultrasound to locate a site at mid-axillary line between ribs 4 and 5 and marked the site with invisible ink that can only be revealed with a commercially available UV LED light. Participants were asked to identify the thoracostomy site by placing an opaque marker where they would make their incision. The distance from the correct insertion site was measured in rib spaces. The participants were then given a brief hands-on training session using ultrasound to identify the diaphragm and count rib spaces. The participants were then asked to use ultrasound to identify the proper thoracostomy site and mark it with an opaque marker. The distance from the proper insertion site was measured and recorded in rib spaces. RESULTS: The participants correctly identified the pre-determined intercostal space using palpation 48% (16/33) of the time, versus the ultrasound group who identified the proper intercostal space 91% (30/33) of the time. On average, the traditional technique was placed 0.88 rib spaces away (95 CI 0.43-1.03), while the ultrasound-guided technique was placed 0.09 rib spaces away (95 CI 0.0-0.19) [P = 0.003]. CONCLUSIONS: The ability to accurately locate the correct intercostal space for thoracostomy incision was improved under ultrasound guidance. Further studies are warranted to determine if this ultrasound-guided technique will decrease complications with chest tube insertion and improve patient outcomes.

Emergency Physician-performed Transesophageal Echocardiography in Simulated Cardiac Arrest.

INTRODUCTION: Transesophageal echocardiography (TEE) is a well-established method of evaluating cardiac pathology. It has many advantages over transthoracic echocardiography (TTE), including the ability to image the heart during active cardiopulmonary resuscitation. This prospective simulation study aims to evaluate the ability of emergency medicine (EM) residents to learn TEE image acquisition techniques and demonstrate those techniques to identify common pathologic causes of cardiac arrest. METHODS: This was a prospective educational cohort study with 40 EM residents from two participating academic medical centers who underwent an educational model and testing protocol. All participants were tested across six cases, including two normals, pericardial tamponade, acute myocardial infarction (MI), ventricular fibrillation (VF), and asystole presented in random order. Primary endpoints were correct identification of the cardiac pathology, if any, and time to sonographic diagnosis. Calculated endpoints included sensitivity, specificity, and positive and negative predictive values for emergency physician (EP)-performed TEE. We calculated a kappa statistic to determine the degree of inter-rater reliability. RESULTS: Forty EM residents completed both the educational module and testing protocol. This resulted in a total of 80 normal TEE studies and 160 pathologic TEE studies. Our calculations for the ability to diagnose life-threatening cardiac pathology by EPs in a high-fidelity TEE simulation resulted in a sensitivity of 98%, specificity of 99%, positive likelihood ratio of 78.0, and negative likelihood ratio of 0.025. The average time to diagnose each objective structured clinical examination case was as follows: normal A in 35 seconds, normal B in 31 seconds, asystole in 13 seconds, tamponade in 14 seconds, acute MI in 22 seconds, and VF in 12 seconds. Inter-rater reliability between participants was extremely high, resulting in a kappa coefficient across all cases of 0.95. CONCLUSION: EM residents can rapidly perform TEE studies in a simulated cardiac arrest environment with a high degree of precision and accuracy. Performance of TEE studies on human patients in cardiac arrest is the next logical step to determine if our simulation data hold true in clinical practice.

Confocal laser scanning microscopic photoconversion: a new method to stabilize fluorescently labeled cellular elements for electron microscopic analysis.

Photoconversion, the method by which a fluorescent dye is transformed into a stable, osmiophilic product that can be visualized by electron microscopy, is the most widely used method to enable the ultrastructural analysis of fluorescently labeled cellular structures. Nevertheless, the conventional method of photoconversion using widefield fluorescence microscopy requires long reaction times and results in low-resolution cell targeting. Accordingly, we have developed a photoconversion method that ameliorates these limitations by adapting confocal laser scanning microscopy to the procedure. We have found that this method greatly reduces photoconversion times, as compared to conventional wide field microscopy. Moreover, region-of-interest scanning capabilities of a confocal microscope facilitate the targeting of the photoconversion process to individual cellular or subcellular elements within a fluorescent field. This reduces the area of the cell exposed to light energy, thereby reducing the ultrastructural damage common to this process when widefield microscopes are employed.

Photoconversion using confocal laser scanning microscopy: A new tool for the ultrastructural analysis of fluorescently labeled cellular elements.

Photoconversion, the method by which a fluorescent dye is transformed into a stable, osmiophilic product that can be visualized by transmission electron microscopy, is the most widely used method to enable the ultrastructural analysis of fluorescently labeled cellular structures. Nevertheless, the conventional method of photoconversion using widefield fluorescence microscopy requires long reaction times and results in low resolution cell targeting which limit its utility. Accordingly, we developed a photoconversion method that ameliorates these limitations by adapting confocal laser scanning microscopy to the procedure. We confirmed that photoconversion times were dramatically reduced when using a confocal laser scanning microscope in the photoconversion process. We also demonstrated that the region of interest scanning capabilities of a confocal laser scanning microscope equipped with an acousto-optical tunable filter represented a unique tool to facilitate the targeting of the photoconversion process to individual cellular or subcellular elements within a fluorescent field. Moreover, region of interest scanning greatly reduced the area of the cell exposed to light energy, ameliorating the ultrastructural damage common to this process when widefield microscopes are employed. The potential of this new methodology extends beyond the neurosciences to any scientific modality which requires ultrastructural analysis of fluorescently labeled specimens, especially those where discrete photoconversion on a cellular or subcellular basis could be beneficial.