Physical and biophysical markers of assessment in medical training: A scoping review of the literature.

PURPOSE: Assessment in medical education has changed over time to measure the evolving skills required of current medical practice. Physical and biophysical markers of assessment attempt to use technology to gain insight into medical trainees' knowledge, skills, and attitudes. The authors conducted a scoping review to map the literature on the use of physical and biophysical markers of assessment in medical training. MATERIALS AND METHODS: The authors searched seven databases on 1 August 2022, for publications that utilized physical or biophysical markers in the assessment of medical trainees (medical students, residents, fellows, and synonymous terms used in other countries). Physical or biophysical markers included: heart rate and heart rate variability, visual tracking and attention, pupillometry, hand motion analysis, skin conductivity, salivary cortisol, functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS). The authors mapped the relevant literature using Bloom's taxonomy of knowledge, skills, and attitudes and extracted additional data including study design, study environment, and novice vs. expert differentiation from February to June 2023. RESULTS: Of 6,069 unique articles, 443 met inclusion criteria. The majority of studies assessed trainees using heart rate variability (n = 160, 36%) followed by visual attention (n = 143, 32%), hand motion analysis (n = 67, 15%), salivary cortisol (n = 67, 15%), fMRI (n = 29, 7%), skin conductivity (n = 26, 6%), fNIRs (n = 19, 4%), and pupillometry (n = 16, 4%). The majority of studies (n = 167, 38%) analyzed non-technical skills, followed by studies that analyzed technical skills (n = 155, 35%), knowledge (n = 114, 26%), and attitudinal skills (n = 61, 14%). 169 studies (38%) attempted to use physical or biophysical markers to differentiate between novice and expert. CONCLUSION: This review provides a comprehensive description of the current use of physical and biophysical markers in medical education training, including the current technology and skills assessed. Additionally, while physical and biophysical markers have the potential to augment current assessment in medical education, there remains significant gaps in research surrounding reliability, validity, cost, practicality, and educational impact of implementing these markers of assessment.

Evaluation of a Novel Point-of-Care Ultrasound Curriculum for First-Year Pediatric Residents.

OBJECTIVE: The aim of the study is to evaluate a novel point-of-care ultrasound (POCUS) educational curriculum for pediatric residents. METHODS: The cohort study in graduate medical education was completed from January 2017 to March 2019. Postgraduate year 1 (PGY1) pediatric residents attended the educational curriculum that consisted of 3 half-day sessions over a 3-month period. Each session consisted of a lecture (introduction, extended focused assessment with sonography for trauma, soft tissue/musculoskeletal, cardiac, and resuscitative applications) followed by supervised hands-on scanning sessions. Group ratio was 3 learners to 1 machine/expert instructor. Main outcome measures included pre- and post-written test scores, as well as objective structured clinical examination (OSCE) scores. RESULTS: Forty-nine PGY1 residents (78% women) completed the curriculum. The mean (SD) pretest score was 68% (8.5), and the mean posttest score was 83% (8.3) with a difference of 15 (95% confidence interval, 12.5-17.6; P < 0.001). Mean (SD) focused assessment with sonography for trauma OSCE score after the curriculum was 88.7% (11.9). The number of PGY1 pediatric residents that were comfortable performing POCUS examinations increased from pretraining to posttraining for soft tissue/musculoskeletal (14%-61%, P < 0.001), extended focused assessment with sonography for trauma (24%-90%, P < 0.001), and cardiac (18%-86%, P < 0.001). All participants found the curriculum useful, and 42 of 49 (86%) stated the curriculum increased their ability to acquire and interpret images. CONCLUSIONS: Postgraduate year 1 pediatric residents learned the basics of POCUS through 3 brief educational sessions. The increase in posttest scores demonstrated improved POCUS knowledge, and the high OSCE score demonstrated their ability to acquire ultrasound images. Point-of-care ultrasound guidelines are needed for pediatric residency programs.

Emergency Ultrasound Literature and Adherence to Standards for Reporting of Diagnostic Accuracy Criteria.

BACKGROUND: Given the wide usage of emergency point-of-care ultrasound (EUS) among emergency physicians (EPs), rigorous study surrounding its accuracy is essential. The Standards for Reporting of Diagnostic Accuracy (STARD) criteria were established to ensure robust reporting methodology for diagnostic studies. Adherence to the STARD criteria among EUS diagnostic studies has yet to be reported. OBJECTIVES: Our objective was to evaluate a body of EUS literature shortly after STARD publication for its baseline adherence to the STARD criteria. METHODS: EUS studies in 5 emergency medicine journals from 2005-2010 were evaluated for their adherence to the STARD criteria. Manuscripts were selected for inclusion if they reported original research and described the use of 1 of 10 diagnostic ultrasound modalities designated as "core emergency ultrasound applications" in the 2008 American College of Emergency Physicians Ultrasound Guidelines. Literature search identified 307 studies; of these, 45 met inclusion criteria for review. RESULTS: The median STARD score was 15 (interquartile range [IQR] 12-17), representing 60% of the 25 total STARD criteria. The median STARD score among articles that reported diagnostic accuracy was significantly higher than those that did not report accuracy (17 [IQR 15-19] vs. 11 [IQR 9-13], respectively; p < 0.0001). Seventy-one percent of articles met ≥50% of the STARD criteria (56-84%) and 4% met >80% of the STARD criteria. CONCLUSIONS: Significant opportunities exist to improve methodological reporting of EUS research. Increased adherence to the STARD criteria among diagnostic EUS studies will improve reporting and improve our ability to compare outcomes.

Teaching Point-of-Care Lung Ultrasound to Novice Pediatric Learners: Web-Based E-Learning Versus Traditional Classroom Didactic.

OBJECTIVE: To assess whether Web-based teaching is at least as effective as traditional classroom didactic in improving the proficiency of pediatric novice learners in the image acquisition and interpretation of pneumothorax and pleural effusion using point-of-care ultrasound (POCUS). METHODS: We conducted a randomized controlled noninferiority study comparing the effectiveness of Web-based teaching to traditional classroom didactic. The participants were randomized to either group A (live classroom lecture) or group B (Web-based lecture) and completed a survey and knowledge test. They also received hands-on training and completed an objective structured clinical examination. The participants were invited to return 2 months later to test for retention of knowledge and skills. RESULTS: There were no significant differences in the mean written test scores between the classroom group and Web group for the precourse test (absolute difference, -2.5; 95% confidence interval [CI], -12 to 6.9), postcourse test (absolute difference, 2.0; 95% CI, -1.4, 5.3), and postcourse 2-month retention test (absolute difference, -0.8; 95% CI, -9.6 to 8.1). Similarly, no significant differences were noted in the mean objective structured clinical examination scores for both intervention groups in postcourse (absolute difference, 1.9; 95% CI, -4.7 to 8.5) and 2-month retention (absolute difference, -0.6; 95% CI, -10.7 to 9.5). CONCLUSIONS: Web-based teaching is at least as effective as traditional classroom didactic in improving the proficiency of novice learners in POCUS. The usage of Web-based tutorials allows a more efficient use of time and a wider dissemination of knowledge.

Predictors of False-Negative Focused Assessment With Sonography for Trauma Examination in Pediatric Blunt Abdominal Trauma.

OBJECTIVES: This study investigated associations between patient and injury characteristics and false-negative (FN) focused assessment with sonography for trauma (FAST) in pediatric blunt abdominal trauma (BAT). We also evaluated the effects of FN FAST on in-hospital mortality and length of stay (LOS) variables. METHODS: This retrospective cohort studied children younger than 18 years between January 1, 2002, and December 31, 2013, with BAT, documented FAST, and pathologic fluid on computed tomography, surgery, or autopsy. Multivariable and bivariate analyses were used to assess associations between FN FAST and patient injury characteristics, mortality, and hospital LOS. RESULTS: A total of 141 pediatric BAT patients with pathologic free fluid were included. There were no patient or injury characteristics, which conferred increased odds of an FN FAST. Splenic and bladder injury were negatively associated with FN FAST odds ratio of 0.4 (95% confidence interval [CI], 0.2-0.8) and 0.1 (95% CI, 0-0.8). Abbreviated Injury Scale score of 4 or greater to the abdomen and extremity was negatively associated with FN FAST odds ratio of 0.1 (95% CI, 0-0.3) and 0.3 (95% CI, 0.1-0.9). There was no association between FN FAST and mortality. Patients with an FN FAST had increased hospital LOS after controlling for sex, age, and Injury Severity Score. CONCLUSIONS: Clinicians need to be cautious applying a single initial FAST to patients with minor abdominal trauma or with suspected injuries to organs other than the spleen or bladder. Formalized studies to develop risk stratification tools could allow clinicians to integrate FAST into the pediatric patient population in the safest manner possible.

Establishing an Ultrasound Curriculum in Undergraduate Medical Education: How Much Time Does It Take?

OBJECTIVES: Over the years, the use of ultrasound in the medical profession has become a common occurrence. As a result, many medical schools are considering an ultrasound curriculum for first- and second-year medical students. The question posed by many of these programs is how much time and effort are required to establish such a curriculum. We at the University of Colorado School of Medicine sought to quantify the resources and time required. METHODS: We conducted a cohort study that analyzed the time spent teaching, as well as the types of instructors (eg, faculty, resident, and peer student) that contributed to our ultrasound curriculum. The study population consisted of instructors who participated in the curriculum during the 2014-2015 academic year. We analyzed the amount of time that facilitators spent teaching and tabulated these data using their specialty. RESULTS: Our data revealed that within an academic year, a combined total of 484 hours were spent teaching ultrasound to first- and second-year medical students combined. A total of 6 days were required to teach ultrasound to first-year medical students, and a total of 5 days were required for second-year medical students. It required 1 instructor for every 8 students, and most the faculty who volunteered time were from the field of emergency medicine, followed by family medicine and radiology. CONCLUSIONS: We describe the number of hours and instructors required to implement an ultrasound curriculum for undergraduate medical education.

Effect of Emergency Physician-Performed Point-of-Care Ultrasound and Radiology Department-Performed Ultrasound Examinations on the Emergency Department Length of Stay Among Pregnant Women at Less Than 20 Weeks' Gestation.

OBJECTIVES: We sought to confirm retrospective studies that measured an approximately 20% reduction in emergency department (ED) length of stay (LOS) in early-gestation pregnant women who receive emergency physician-performed point-of-care ultrasound (US) examinations rather than radiology department-performed US examinations for evaluation of intrauterine pregnancy (IUP). METHODS: A randomized controlled clinical trial was performed at an urban academic safety net hospital and 2 Naval medical centers in the United States. The allocation was concealed before enrollment. Clinically stable adult pregnant women at less than 20 weeks' gestation who presented to the ED with abdominal pain or vaginal bleeding were randomized to receive a point-of-care or radiology US to assess for IUP. The primary outcome measure was the ED LOS. RESULTS: A total of 224 patients (point-of-care US, n = 118; radiology US, n = 106) were included for the analysis. The ED LOS was 20 minutes shorter in the point-of-care US arm (95% confidence interval [CI], -54 to 7 minutes). Adjusting for variability due to the location, the ED LOS was calculated to be 31 minutes shorter (95% CI, -64 to 1 minute) than for patients in the radiology US arm. Excluding patients in the point-of-care US arm who crossed over to radiology US after an inconclusive point-of-care US examination, the ED LOS was 75 minutes shorter than in the radiology US arm (95% CI, -97 to -53 minutes). CONCLUSIONS: Early-gestation pregnant ED patients requiring pelvic US were discharged earlier when point-of-care US was used rather than radiology US; however, this trial did not achieve our target of 30 minutes. Nevertheless, our data support the routine use of ED point-of-care US for IUP, saving the most time if a conclusive IUP is identified.

Critical care ultrasound: A national survey across specialties.

PURPOSE: Management of the critically ill patient requires rapid assessment and differentiation. Point-of-care ultrasound (POCUS) improves diagnostic accuracy and guides resuscitation. This study sought to describe the use of critical care related POCUS amongst different specialties. METHODS: This study was conducted as an online 18-question survey. Survey questions queried respondent demographics, preferences for POCUS use, and barriers to implementation. RESULTS: 2735 recipients received and viewed the survey with 416 (15.2%) responses. The majority of respondents were pulmonary and critical care medicine (62.5%) and emergency medicine (19.9%) providers. Respondents obtained training through educational courses (26.5%), fellowship (23.9%), residency (21.6%), or self-guided learning (17.2%). POCUS use was common for diagnostic and procedural guidance. Emergency medicine providers were more likely to utilize POCUS to evaluate undifferentiated hypotension (98.5%, P < .001), volume status and fluid responsiveness (88.2%, P = .005), and cardiopulmonary arrest (94.1%, P < .001) compared to other specialties. Limited training, competency, or credentialing were the most common barriers, in up to 39.4% of respondents. CONCLUSION: Study respondents utilize POCUS in a variety of clinical applications. However, a disparity in utilization still exists among clinicians who care for critically ill patients. Overcoming barriers, such as a lack of formalized training, competency, or credentialing, may lead to increased utilization.

Transcriptome and proteome dynamics in chemostat culture reveal how Campylobacter jejuni modulates metabolism, stress responses and virulence factors upon changes in oxygen availability.

Campylobacter jejuni, the most frequent cause of food-borne bacterial gastroenteritis worldwide, is a microaerophile that has to survive high environmental oxygen tensions, adapt to oxygen limitation in the intestine and resist host oxidative attack. Here, oxygen-dependent changes in C. jejuni physiology were studied at constant growth rate using carbon (serine)-limited continuous chemostat cultures. We show that a perceived aerobiosis scale can be calibrated by the acetate excretion flux, which becomes zero when metabolism is fully aerobic (100% aerobiosis). Transcriptome changes in a downshift experiment from 150% to 40% aerobiosis revealed many novel oxygen-regulated genes and highlighted re-modelling of the electron transport chains. A label-free proteomic analysis showed that at 40% aerobiosis, many proteins involved in host colonisation (e.g., PorA, CadF, FlpA, CjkT) became more abundant. PorA abundance increased steeply below 100% aerobiosis. In contrast, several citric-acid cycle enzymes, the peptide transporter CstA, PEB1 aspartate/glutamate transporter, LutABC lactate dehydrogenase and PutA proline dehydrogenase became more abundant with increasing aerobiosis. We also observed a co-ordinated response of oxidative stress protection enzymes and Fe-S cluster biogenesis proteins above 100% aerobiosis. Our approaches reveal key virulence factors that respond to restricted oxygen availability and specific transporters and catabolic pathways activated with increasing aerobiosis.

Incidental Findings in Student Ultrasound Models: Implications for Instructors.

As ultrasonography continues to become integrated into undergraduate medical education, there have been concerns raised about the use of volunteer models and the ability to maintain patient privacy during scanning sessions. To date, there have been no reports on how instructors should manage situations in which incidental findings are made during educational ultrasonography sessions. We present three different examples of incidental findings that occurred at our institution and the various approaches taken by the instructors. Furthermore, we outline an approach that can be utilized by other medical schools to better maintain patient confidentiality.

Number of Weeks Rotating in the Emergency Department Has a Greater Effect on Ultrasound Milestone Competency Than a Dedicated Ultrasound Rotation.

OBJECTIVES: Ultrasound (US) is vital to modern emergency medicine (EM). Across residencies, there is marked variability in US training. The "goal-directed focused US" part of the Milestones Project states that trainees must correctly acquire and interpret images to achieve a level 3 milestone. Standardized methods by which programs teach these skills have not been established. Our goal was to determine whether residents could achieve level 3 with or without a dedicated US rotation. METHODS: Thirty-three first- and second-year residents were assigned to control (no rotation) and intervention (US rotation) groups. The intervention group underwent a 2-week curriculum in vascular access, the aorta, echocardiography, focused assessment with sonography for trauma, and pregnancy. To test acquisition, US-trained emergency medicine physicians administered an objective structured clinical examination. To test interpretation, residents had to identify normal versus abnormal findings. Mixed-model logistic regression tested the association of a US rotation while controlling for confounders: weeks in the emergency department (ED) as a resident, medical school US rotation, and postgraduate years. RESULTS: For image acquisition, medical school US rotation and weeks in the ED as a resident were significant (P = .03; P = .04) whereas completion of a US rotation and postgraduate years were not significant. For image interpretation, weeks in the ED as a resident was the only significant predictor of performance (P = .002) whereas completion of a US rotation and medical school US rotation were not significant. CONCLUSIONS: To achieve a level 3 milestone, weeks in the ED as a resident were significant for mastering image acquisition and interpretation. A dedicated US rotation did not have a significant effect. A medical school US rotation had a significant effect on image acquisition but not interpretation. Further studies are needed to best assess methods to meet US milestones.

Emergency Physicians Who Produce Higher Relative Value Units Per Hour Spend Similar Amounts of Time at Patient Bedsides as Their Colleagues.

BACKGROUND: Emergency physicians (EPs) are expected to deliver quality care while maintaining high levels of efficiency and productivity as measured by the relative value unit (RVU). OBJECTIVES: We sought to determine whether academic EPs with higher RVUs spend less time at the bedside than their colleagues. METHODS: This was a prospective, observational, cohort study. A 13-item task list was generated, pilot-tested, and placed onto a computerized tablet. RESULTS: There was no difference among EPs in terms of time spent at bedside, 26.7% of total time, 17.31 min (95% confidence interval [CI] 14.43-20.19), p = 0.052; resident interaction 13.1%, 8.46 min (95% CI 4.68-12.25), p = 0.959; charting, 11.1%, 7.17 min (95% CI .746-5.65), p = 0.055; information search, 10.5%, 6.80 min (95% CI 0.84-8.52), p = 0.320; walking, 9.0%, 5.86 min (95% CI 5.17-6.54), p = 0.112; consultant interaction, 8.2%, 5.28 min (95% CI 3.18-7.40), p = 0.404; writing orders, 6.5%, 4.19 min (95% CI 3.22-5.15), p = 0.109; nursing interaction, 5.6%, 3.65 min (95% CI 2.54-4.76), p = 0.260; other, 5.2%, 3.65 min (95% CI 1.76-5.02), p = 0.785; medical student interaction, 4.2%, 2.75 min (95% CI 0.53-4.97), p = 0.102; physician assistant interaction, 2.8%, 1.79 min (95% CI 1.08-2.50), p = 0.959; clerical interaction, 1.7%, 1.13 min (95% CI .69-1.57), p = 0.335; and electrocardiogram interpretation, 0.7%, 0.45 min (95% CI .32-.58), p = 0.793. CONCLUSIONS: Despite differences in RVU-based productivity data, academic EPs spend similar amounts of time involved in the daily tasks of taking care of patients, underscoring that direct physician-patient interaction is one practice parameter that is not compromised among these EPs.

A Survey of Ultrasound Milestone Incorporation Into Emergency Medicine Training Programs.

OBJECTIVES: With the introduction of the Emergency Medicine Milestone Project in 2013, residencies now assess emergency ultrasound (US) skills at regular intervals. However, it is unclear how programs are implementing the emergency US milestones and assessing competency. With the use of the milestone tool, a survey was distributed to emergency US educators to determine when programs are providing emergency US education, when residents are expected to attain competency, and whether the milestones reflect their expectations of trainees. METHODS: We conducted a prospective cross-sectional survey study distributed electronically to designated emergency US experts at 169 programs. Participants were queried on education and competency evaluation within the context of the milestones by designating a postgraduate year when the 5 milestone levels were taught and competency was expected. Survey findings were reported as percentages of total respondents from descriptive statistics. RESULTS: Responses were received from 53% of programs, and 99% were familiar with the milestones. Most programs provide level 1 (88%) and 2 (85%) instruction during postgraduate year 1. Most programs expect level 1 competency before residency (61%) and expect mastery of level 2 by the end of postgraduate year 1 (60%). Sixty-two percent believe the milestones do not accurately reflect their expectations, citing insufficient minimum scan numbers, lack of specificity, and unattainable level 5 requirements. CONCLUSIONS: There is substantial variability in the frequency and methods of competency evaluation using the emergency US milestones. However, most responders agree that residents should obtain level 2 competency by postgraduate year 1. Variation exists regarding what year and what skills define level 3 or greater competency.

Test Characteristics of Emergency Physician-Performed Limited Compression Ultrasound for Lower-Extremity Deep Vein Thrombosis.

BACKGROUND: The current literature suggests that emergency physician (EP)-performed limited compression ultrasound (LCUS) is a rapid and accurate test for deep vein thrombosis (DVT). OBJECTIVE: Our primary objective was to determine the sensitivity and specificity of LCUS for the diagnosis of DVT when performed by a large heterogeneous group of EPs. METHODS: This was a prospective diagnostic test assessment of LCUS conducted at two urban academic emergency departments. The scanning protocol involved compression at the common femoral, superficial femoral, and popliteal veins. Patients were eligible if undergoing radiology department ultrasound of the lower extremity with moderate or high pretest probability for DVT, or low pretest probability for DVT with a positive d-dimer. The enrolling EP performed LCUS before radiology department ultrasound of the same lower extremity. Sensitivity, specificity, and associated 95% confidence intervals (CIs) were calculated with the radiologist interpretation of the radiology department ultrasound as the criterion standard. RESULTS: A total of 56 EPs enrolled 296 patients for LCUS, with a median age of 50 years and 50% female. Fifty (17%) DVTs were identified by radiology department ultrasound, and another five (2%) cases were deemed indeterminate. The sensitivity and specificity of EP-performed LCUS was 86% (95% CI 73-94%) and 93% (95% CI 89-96%), respectively. CONCLUSIONS: A large heterogeneous group of EPs with limited training can perform LCUS with intermediate diagnostic accuracy. Unfortunately, LCUS performed by EPs with limited ultrasound training is not sufficiently sensitive or specific to rule out or diagnose DVT as a single testing modality.

Effect of Interventional Program on the Utilization of PACS in Point-of-Care Ultrasound.

While the implementation of Picture Archiving and Communication Systems (PACS) has revolutionized the field of radiology, there has been considerably less utilization of PACS by emergency physicians with point-of-care ultrasound. Benefits of PACS archival of images include improved quality assurance, preservation of image quality, and accessibility of images. Our objective was to determine if a simple interventional program would influence the utilization of PACS in point-of-care ultrasound. A before-after study was conducted in an urban, academic emergency department. Data was collected during a 4-week baseline period, a 12-week intervention period, and a 12-week post-intervention period. The percentage of ultrasound studies archived to PACS was recorded during each week of the study. Interventions were designed to encourage the utilization of PACS. A significant increase in the mean percentage of PACS studies was found between the baseline and intervention period (59.4 %; 95 % CI: 34.76-84.08 %; p < 0.001). Mean percentage of PACS studies at 1-month (74.3 %), 2-month (61.0 %), and 3-month (74.8 %) post-intervention periods remained elevated and were all significantly increased compared to baseline values (p < 0.001). Mean percentages of PACS studies at 1-month, 2-month, and 3-month post-intervention periods were not statistically significant from the intervention period (p = 0.977, p = 0.849, p = 0.967, respectively). A simple interventional program for emergency physicians can significantly increase and sustain the utilization of PACS for point-of-care ultrasound.

Is long-axis view superior to short-axis view in ultrasound-guided central venous catheterization?

OBJECTIVE: To evaluate whether using long-axis or short-axis view during ultrasound-guided internal jugular and subclavian central venous catheterization results in fewer skin breaks, decreased time to cannulation, and fewer posterior wall penetrations. DESIGN: Prospective, randomized crossover study. SETTING: Urban emergency department with approximate annual census of 60,000. SUBJECTS: Emergency medicine resident physicians at the Denver Health Residency in Emergency Medicine, a postgraduate year 1-4 training program. INTERVENTIONS: Resident physicians blinded to the study hypothesis used ultrasound guidance to cannulate the internal jugular and subclavian of a human torso mannequin using the long-axis and short-axis views at each site. MEASUREMENTS AND MAIN RESULTS: An ultrasound fellow recorded skin breaks, redirections, and time to cannulation. An experienced ultrasound fellow or attending used a convex 8-4 MHz transducer during cannulation to monitor the needle path and determine posterior wall penetration. Generalized linear mixed models with a random subject effect were used to compare time to cannulation, number of skin breaks and redirections, and posterior wall penetration of the long axis and short axis at each cannulation site. Twenty-eight resident physicians participated: eight postgraduate year 1, eight postgraduate year 2, five postgraduate year 3, and seven postgraduate year 4. The median (interquartile range) number of total internal jugular central venous catheters placed was 27 (interquartile range, 9-42) and subclavian was six catheters (interquartile range, 2-20). The median number of previous ultrasound-guided internal jugular catheters was 25 (interquartile range, 9-40), and ultrasound-guided subclavian catheters were three (interquartile range, 0-5). The long-axis view was associated with a significant decrease in the number of redirections at the internal jugular and subclavian sites, relative risk 0.4 (95% CI, 0.2-0.9) and relative risk 0.5 (95% CI, 0.3-0.7), respectively. There was no significant difference in the number of skin breaks between the long axis and short axis at the subclavian and internal jugular sites. The long-axis view for subclavian was associated with decreased time to cannulation; there was no significant difference in time between the short-axis and long-axis views at the internal jugular site. The prevalence of posterior wall penetration was internal jugular short axis 25%, internal jugular long axis 21%, subclavian short axis 64%, and subclavian long axis 39%. The odds of posterior wall penetration were significantly less in the subclavian long axis (odds ratio, 0.3; 95% CI, 0.1-0.9). CONCLUSIONS: The long-axis view for the internal jugular was more efficient than the short-axis view with fewer redirections. The long-axis view for subclavian central venous catheterization was also more efficient with decreased time to cannulation and fewer redirections. The long-axis approach to subclavian central venous catheterization is also associated with fewer posterior wall penetrations. Using the long-axis view for subclavian central venous catheterization and avoiding posterior wall penetrations may result in fewer central venous catheter-related complications.

Using Ultrasound to Enhance Medical Students' Femoral Vascular Physical Examination Skills.

OBJECTIVES: To determine whether the addition of ultrasound to traditional physical examination instruction improves junior medical students' abilities to locate the femoral pulse. METHODS: Initially, 150 second-year medical students were taught the femoral pulse examination using traditional bedside teaching on standardized patients and online didactic videos. Students were then randomized into 2 groups: group 1 received ultrasound training first and then completed the standardized examination; and group 2 performed the standardized examination first and then received ultrasound training. On the standardized patients, the femoral artery was marked with invisible ink before the sessions using ultrasound. Compared to these markers, students were then evaluated on the accuracy of femoral artery pulse palpation and the estimated location of the femoral vein. All students completed a self-assessment survey after the ultrasound sessions. RESULTS: Ultrasound training improved the students' ability to palpate the femoral pulse (P= .02). However, ultrasound did not facilitate correct estimation of the femoral vein's anatomic location (P = .09). Confidence levels in localizing the femoral artery and vein were equal between groups at baseline, and both increased after the ultrasound sessions. CONCLUSIONS: The addition of ultrasound teaching to traditional physical examination instruction enhanced medical student competency and confidence with the femoral vascular examination. However, understanding of anatomy may require emphasis on precourse didactic material, but further study is required.

Acute hematogenous osteomyelitis of the rib identified on bedside ultrasound.

BACKGROUND: Osteomyelitis is a challenging and commonly considered diagnosis in the emergency department. Early recognition and treatment with appropriate antibiotic therapy is crucial to prevent complications. OBJECTIVE: This case reviews relevant literature and typical ultrasound features of osteomyelitis. It highlights a previously undescribed and practical application of emergency department bedside ultrasonography, adding to the diagnostic armamentarium for this disease process. CASE REPORT: A 48-year-old woman presented with fever and left chest wall pain. She had been seen previously for a right axillary abscess requiring incision and drainage. Examination revealed a focal area of chest tenderness without cutaneous changes. Chest x-ray study and laboratory evaluation were nondiagnostic. Bedside ultrasound diagnosed acute hematogenous osteomyelitis of a rib. CONCLUSIONS: Bedside ultrasound holds great promise in investigating osteomyelitis when suspicion is high and traditional initial testing is nondiagnostic. Further study is required to quantify this benefit in the emergency department setting and explore utility of negative results.

Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron-sulphur cluster enzymes from oxidative damage.

Microaerophilic bacteria are adapted to low oxygen environments, but the mechanisms by which their growth in air is inhibited are not well understood. The citric acid cycle in the microaerophilic pathogen Campylobacter jejuni is potentially vulnerable, as it employs pyruvate and 2-oxoglutarate:acceptor oxidoreductases (Por and Oor), which contain labile (4Fe-4S) centres. Here, we show that both enzymes are rapidly inactivated after exposure of cells to a fully aerobic environment. We investigated the mechanisms that might protect enzyme activity and identify a role for the hemerythrin HerA (Cj0241). A herA mutant exhibits an aerobic growth defect and reduced Por and Oor activities after exposure to 21% (v/v) oxygen. Slow anaerobic recovery of these activities after oxygen damage was observed, but at similar rates in both wild-type and herA strains, suggesting the role of HerA is to prevent Fe-S cluster damage, rather than promote repair. Another hemerythrin (HerB; Cj1224) also plays a protective role. Purified HerA and HerB exhibited optical absorption, ligand binding and resonance Raman spectra typical of µ-oxo-bridged di-iron containing hemerythrins. We conclude that oxygen lability and poor repair of Por and Oor are major contributors to microaerophily in C. jejuni; hemerythrins help prevent enzyme damage microaerobically or during oxygen transients.

E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction.

OBJECTIVES: Rapid assessment of left ventricular ejection fraction (LVEF) may be critical among emergency department (ED) patients. This study examined the predictive relationship between ED physician performed bedside mitral-valve E-point septal separation (EPSS) measurements to the quantitative, calculated LVEF. We further evaluated the relationship between ED physician visual estimates of global cardiac function (GCF) and calculated LVEF values. METHODS: A prospective observational study was conducted on a sequential convenience sample of patients receiving comprehensive transthoracic echocardiography (TTE). Three ED ultrasound fellows performed bedside ultrasound examinations to obtain both EPSS measurements and subjective visual GCF estimates. A linear regression analysis was conducted to examine the relation of EPSS to the calculated LVEF from the comprehensive TTE. Agreement (modified Cohen κ) between ED ultrasound fellow GCF estimates and the calculated LVEF was also assessed. RESULTS: Linear regression analyses revealed a significant correlation (r=0.73, P<.001) between bedside EPSS and the calculated LVEF. The sensitivity and specificity of an EPSS measurement of greater than 7 mm for severe systolic dysfunction (LVEF≤30%) were 100.0% (95% confidence interval, 62.9-100.0) and 51.6% (95% confidence interval, 38.6-64.5), respectively. Subjective estimates of GCF were moderately correlated with calculated LVEF (Cohen κ=0.58). CONCLUSIONS: Measurements of EPSS by ED physicians were significantly associated with the calculated measurements of LVEF from comprehensive TTE. Subjective visual estimates of GCF, however, demonstrated only moderate agreement with the calculated LVEF. An EPSS measurement greater than 7 mm was uniformly sensitive at identifying patients with severely reduced LVEF.