Perceived effectiveness of teaching methods for point of care ultrasound.

BACKGROUND: Point of care ultrasound (POCUS) is a rapidly expanding aspect of both the practice and education of emergency physicians. The most effective methods of teaching these valuable skills have not been explored. OBJECTIVE: This project aimed to identify those methods that provide the best educational value as determined by the learner. METHODS: Data was collected from pre- and post-course surveys administered to students of the introductory POCUS course provided to emergency medicine residents each year at our facility. Data were collected in 2010 and 2011. Participants were asked to evaluate the effectiveness of small- vs. large-group format, still images vs. video clips, and PowerPoint slides vs. live demonstration vs. hands-on scanning. RESULTS: Students felt the most effective methods to be small-group format, video-clip examples, and hands-on scanning sessions. Students also rated hands-on sessions, still images, and video images as more effective in post-course surveys as compared with pre-course surveys. CONCLUSIONS: The methods perceived as most effective for POCUS education are small-group format, video-clip examples, and hands-on scanning sessions.

False-negative FAST examination: associations with injury characteristics and patient outcomes.

STUDY OBJECTIVE: Focused assessment with sonography in trauma (FAST) is widely used for evaluating patients with blunt abdominal trauma; however, it sometimes produces false-negative results. Presenting characteristics in the emergency department may help identify patients at risk for false-negative FAST result or help the physician predict injuries in patients with a negative FAST result who are unstable or deteriorate during observation. Alternatively, false-negative FAST may have no clinical significance. The objectives of this study are to estimate associations between false-negative FAST results and patient characteristics, specific abdominal organ injuries, and patient outcomes. METHODS: This was a retrospective cohort study including consecutive patients who presented to an urban Level I trauma center between July 2005 and December 2008 with blunt abdominal trauma, a documented FAST, and pathologic free fluid as determined by computed tomography, diagnostic peritoneal lavage, laparotomy, or autopsy. Physicians blinded to the study purpose used standardized abstraction methods to confirm FAST results and the presence of pathologic free fluid. Multivariable modeling was used to assess associations between potential predictors of a false-negative FAST result and false-negative FAST result and adverse outcomes. RESULTS: During the study period, 332 patients met inclusion criteria. Median age was 32 years (interquartile range 23 to 45 years), 67% were male patients, the median Injury Severity Score was 27 (interquartile range 17 to 41), and 162 (49%) had a false-negative FAST result. Head injury was positively associated with false-negative FAST result (odds ratio [OR] 4.9; 95% confidence interval [CI] 1.5 to 15.7), whereas severe abdominal injury was negatively associated (OR 0.3; 95% CI 0.1 to 0.5). Injuries to the spleen (OR 0.4; 95% CI 0.24 to 0.66), liver (OR 0.36; 95% CI 0.21 to 0.61), and abdominal vasculature (OR 0.17; 95% CI 0.07 to 0.38) were also negatively associated with false-negative FAST result. False-negative FAST result was not associated with mortality (OR 0.89; 95% CI 0.42 to 1.9), prolonged ICU length of stay (relative risk 0.88; 95% CI 0.69 to 1.12), or total hospital length of stay (relative risk 0.92; 95% CI 0.76 to 1.12). However, patients with false-negative FAST results were substantially less likely to require therapeutic laparotomy (OR 0.31; 95% CI 0.19 to 0.52). CONCLUSION: Patients with severe head injuries and minor abdominal injuries were more likely to have a false-negative than true-positive FAST result. On the other hand, patients with spleen, liver, or abdominal vascular injuries are less likely to have false-negative FAST examination results. Adverse outcomes were not associated with false-negative FAST examination results, and in fact patients with false-negative FAST result were less likely to have a therapeutic laparotomy. Further studies are needed to assess the strength of these findings.

Is point-of-care ultrasound accurate and useful in the hands of military medical technicians? A review of the literature.

Over the past decade, point-of-care ultrasound (US) use by nonphysician providers has grown substantially. The purpose of this article is to (1) summarize the literature evaluating military medics' facility at US, (2) more clearly define the potential utility of military prehospital US technology, and (3) lay a pathway for future research of military prehospital US. The authors performed a keyword search using multiple search engines. Each author independently reviewed the search results and evaluated the literature for inclusion. Of 30 studies identified, five studies met inclusion criteria. The applications included evaluation of cardiac activity, pneumothorax evaluation, and fracture evaluation. Additionally, a descriptive study demonstrated distribution of US exam types during practical use by Army Special Forces Medical Sergeants. No studies evaluated retention of skills over prolonged periods. Multiple studies demonstrate the feasibility of training military medics in US. Even under austere conditions, the majority of studies conclude that medic can perform US with a high degree of accuracy. Lessons learned from these studies tend to support continued use of US in out-of-hospital settings and exploration of the optimal curriculum to introduce this skill.

Splenic injury sustained during body hardening drills and the utility of ultrasound in a prehospital combat medical environment.

This report describes a case of intra-abdominal hemorrhage from body hardening drills in a U.S. soldier during Operation Iraqi Freedom. In body hardening, participants allow themselves to be repeatedly punched and kicked in an effort to impart physical resilience. Portable sonography was used to diagnose hemoperitoneum and to guide the decision for urgent surgical evacuation, ultimately resulting in splenectomy. The case illustrates the risks of body hardening, the medical challenges unique to a prehospital combat environment, and the utility of ultrasound in this setting.

Cardiac pathological conditions in young soldiers: case series.

We briefly review the disease processes for four young healthy soldiers who presented to our emergency department with serious cardiac pathological conditions. We present two unusual cases of myocardial infarction, a coronary artery aneurysm, and a case of smallpox vaccine-induced myocarditis/pericarditis. Our intent is to encourage others in military medicine to maintain a high index of suspicion for cardiac conditions even in a relatively young healthy population.

Ultrasound detection of superior vena cava thrombus.

Superior vena cava (SVC) syndrome is most commonly the insidious result of decreased vascular flow through the SVC due to malignancy, spontaneous thrombus, infections, and iatrogenic etiologies. Clinical suspicion usually leads to computed tomography to confirm the diagnosis. However, when a patient in respiratory distress requires emergent airway management, travel outside the emergency department is not ideal. With the growing implementation of point-of-care ultrasound (POCUS), clinicians may make critical diagnoses rapidly and safely. We present a case of SVC syndrome due to extensive thrombosis of the deep venous system cephalad to the SVC diagnosed by POCUS.

Impact of decontamination therapy on ultrasound visualization of ingested pills.

INTRODUCTION: Acute toxic ingestion is a common cause of morbidity and mortality. Emergency physicians (EP) caring for overdose (OD) patients are often required to make critical decisions with incomplete information. Point of care ultrasound (POCUS) may have a role in assisting EPs manage OD patients. We evaluated the impact of different liquid adjuncts used for gastric decontamination on examiners' ability to identify the presence of tablets using POCUS, and assessed examiners' ability to quantify the numbers of tablets in a simulated massive OD. METHODS: This prospective, blinded, pilot study was performed at an academic emergency department. Study participants were volunteer resident and staff EPs trained in POCUS. Five nontransparent, sealed bags were prepared with the following contents: 1 liter (L) of water, 1 L of water with 50 regular aspirin (ASA) tablets, 1 L of water with 50 enteric-coated aspirin tablets (ECA), 1 L of polyethylene glycol (PEG) with 50 ECA, and 1 L of activated charcoal (AC) with 50 ECA. After performing POCUS on each of the bags using a 10-5 MHz linear array transducer, participants completed a standardized questionnaire composed of the following questions: (1) Were pills present? YES/NO; (2) If tablets were identified, estimate the number (1-10, 11-25, >25). We used a single test on proportions using the binomial distribution to determine if the number of EPs who identified tablets differed from 50% chance. For those tablets identified in the different solutions, another test on proportions was used to determine whether the type of solution made a difference. Since 3 options were available, we used a probability of 33.3%. RESULTS: Thirty-seven EPs completed the study. All (37/37) EP's correctly identified the absence of tablets in the bag containing only water, and the presence of ECA in the bags containing water and PEG. For Part 2 of the study, most participants - 25/37 (67.5%) using water, 23/37 (62.1%) using PEG, and all 37 (100%) using AC - underestimated the number of ECA pills in solution by at least 50%. CONCLUSION: There may be a potential role for POCUS in the evaluation of patients suspected of acute, massive ingested OD. EPs accurately identified the presence of ECA in water and PEG, but underestimated the number of tablets in all tested solutions.

Retrobulbar hematoma from warfarin toxicity and the limitations of bedside ocular sonography.

The following case describes a 26-year-old female who presented to the emergency department with a nontrauamtic retrobulbar hematoma associated with warfarin toxicity. The application and limitations of focused bedside ocular sonography for this condition are discussed.

Expressive aphasia and carotid dissection.

Ultrasound images of a patient presenting to the emergency department with expressive aphasia who was found to have carotid dissection. The first image is a standard two dimensional image that depicts the internal carotid with a visible flap within the lumen. The second image is a color Doppler image showing turbulent flow within the true lumen and visible flow within the false lumen. The case and the patient's outcome are summarized along with some teaching points about carotid dissection. Also, there is some background and research on using ultrasound to help identify dissection.

Presentation and management of a stage Ia lung cancer patient with a paraneoplastic factor VIII inhibitor.

Acquired inhibitors to clotting factors most commonly involve factor VIII and are associated with autoimmune disease. Factor VIII inhibitors can cause severe spontaneous and iatrogenic bleeding that is difficult to manage. Factor VIII inhibitors are rarely associated with solid tumors and only three cases of adenocarcinoma of the lung have been reported. This report describes the multidisciplinary management of a factor VIII inhibitor-producing stage Ia lung adenocarcinoma that ultimately resulted in complete resectability.