Association of a longitudinal, preclinical ultrasound curriculum with medical student performance.

INTRODUCTION: Point-of-care ultrasound (US) is used in clinical practice across many specialties. Ultrasound (US) curricula for medical students are increasingly common. Optimal timing, structure, and effect of ultrasound education during medical school remains poorly understood. This study aims to retrospectively determine the association between participation in a preclinical, longitudinal US curriculum and medical student academic performance. METHODS: All first-year medical students at a medical school in the Midwest region of the United States were offered a voluntary longitudinal US curriculum. Participants were selected by random lottery. The curriculum consisted of five three-hour hands on-sessions with matching asynchronous content covering anatomy and pathologic findings. Content was paired with organ system blocks in the standard first year curriculum at our medical school. Exam scores between the participating and non-participating students were compared to evaluate the objective impact of US education on performance in an existing curriculum. We hypothesized that there would be an association between participation in the curriculum and improved medical student performance. Secondary outcomes included shelf exam scores for the surgery, internal medicine, neurology clerkships and USMLE Step 1. A multivariable linear regression model was used to evaluate the association of US curriculum participation with student performance. Scores were adjusted for age, gender, MCAT percentile, and science or engineering degree. RESULTS: 76 of 178 students applied to participate in the curriculum, of which 51 were accepted. US curriculum students were compared to non-participating students (n = 127) from the same class. The US curriculum students performed better in cardiovascular anatomy (mean score 92.1 vs. 88.7, p = 0.048 after adjustment for multiple comparisons). There were no significant differences in cumulative cardiovascular exam scores, or in anatomy and cumulative exam scores for the gastroenterology and neurology blocks. The effect of US curriculum participation on cardiovascular anatomy scores was estimated to be an improvement of 3.48 points (95% CI 0.78-6.18). No significant differences were observed for USMLE Step 1 or clerkship shelf exams. There were no significant differences in either preclinical, clerkship or Step 1 score for the 25 students who applied and were not accepted and the 102 who did not apply. CONCLUSIONS: Participation in a preclinical longitudinal US curriculum was associated with improved exam performance in cardiovascular anatomy but not examination of other cardiovascular system concepts. Neither anatomy or comprehensive exam scores for neurology and gastrointestinal organ system blocks were improved.

Undifferentiated Dyspnea with Point-of-Care Ultrasound, Primary Emergency Physician Compared with a Dedicated Emergency Department Ultrasound Team.

BACKGROUND: Emergency physicians (EPs) perform critical actions while operating with diagnostic uncertainty. Point-of-care ultrasound (POCUS) is useful in evaluation of dyspneic patients. In prior studies, POCUS is often performed by ultrasound (US) teams without patient care responsibilities. OBJECTIVES: This study evaluates the effectiveness of POCUS in narrowing diagnostic uncertainty in dyspneic patients when performed by treating EPs vs. separate US teams. METHODS: This multicenter, prospective noninferiority cohort study investigated the effect of a POCUS performing team in patient encounters for dyspnea. Before-and-after surveys assessing medical decision-making were administered to attending physicians. Primary outcome was change in most likely diagnosis after POCUS. This was assessed for noninferiority between encounters where the primary or US team performed POCUS. Secondary outcomes included change in differential diagnosis, confidence in diagnosis, interventions considered, and image quality. RESULTS: There were 156 patient encounters analyzed. In the primary team group, most likely diagnosis changed in 40% (95% confidence interval 28-52%) of encounters vs. 32% (95% confidence interval 22-41%) in the US team group. This was noninferior using an a priori specified margin of 20% (p < .0001). Post-POCUS differential decreased by a mean 1.8 diagnoses and was equivalent within a margin of 0.5 diagnoses between performing teams (p = 0.034). Other outcomes were similar between groups. CONCLUSION: POCUS performed by primary teams was noninferior to POCUS performed by US teams for changing the most likely diagnosis, and equivalent when considering mean reduction in number of diagnoses. POCUS performed by treating EPs reduces cognitive burden in dyspneic patients.

Extended dwell and standard ultrasound guided peripheral intravenous catheters: Comparison of durability and reliability.

Background Vascular access is a critical component of emergency department (ED) care. Ultrasound guided placement of peripheral intravenous (USIV) catheters is increasingly common. However, USIV are thought to suffer from reduced durability and higher complication rates. Extended dwell catheters (EDC) are long peripheral IVs placed under combined ultrasound and wire guidance. The goal of this study is to compare dwell times and complication rates of EDC to standard peripheral USIV. Methods We performed a retrospective cohort study at a tertiary care adult ED comparing IV placements during a 17-month period (8/1/2018-12/31/2019), stratified by standard USIV versus EDC. The primary outcome was catheter dwell time and secondary outcomes included need for inpatient vascular access team (VAST) consultation, peripherally inserted central catheter (PICC) insertions, and radiocontrast extravasations. Multivariable Cox regression time-to-event analyses were used to evaluate dwell times, adjusting for age, gender, BMI and end-stage renal disease. Results 359 EDC and 4190 standard USIV were included for analysis. Most USIV (95.6%) and EDC (98.3%) were placed by ED technicians trained in ultrasound vascular access. EDC median dwell time (5.9 days [95%CI: 5.1-6.7]) exceeded standard USIV (3.8 days [95% CI: 3.6-4.0]). Patients with EDC placed in the ED required less VAST consultation (0.84 vs 0.99 charges/encounter), had similar rates of PICC line use (8.0% vs 8.4% of encounters) and had no radiocontrast extravasation events. Multivariable Cox regression demonstrated survival benefit (longer dwell time) favoring EDC (HR 0.70 [95%CI 0.60-0.81]). Conclusion Use of EDC results in longer dwell time and reduces subsequent use of vascular access resources, while maintaining low complication rates. EDC demonstrate superior durability which may justify their selection over standard USIV in some patients.

Creation of a Flight Nurse Critical Care Ultrasound Program.

OBJECTIVE: Our objectives were 2-fold: to describe the creation of a flight nurse (FN) ultrasound (US) program and to evaluate whether critical care US performed by nonphysician providers in the prehospital setting can clarify patient assessment. METHODS: Twenty FNs completed a didactic and hands-on US curriculum focusing on critical care modalities. FNs displayed competency by successful completion of an objective-structured clinical examination. Portable US devices were used during patient transports when deemed clinically indicated by the FN. If US was subsequently performed, the FN was asked if US use prompted a change in assessment. Associations were evaluated with chi-square and bivariate logistic regression analyses. RESULTS: FNs reported US use during 102 (12.3%) patient transports, of which intensive care unit (ICU) to ICU (58.8%) constituted the majority of cases followed by emergency department (ED) to ED (28.4%), ED to ICU (4.9%), and scene to ED (2.9%). FNs agreed or strongly agreed that US use clarified the cause of patient symptoms in 67.4% of transports. CONCLUSION: FNs were more likely to perform US when they expressed lower confidence in their initial patient assessment. FNs reported that US helped to clarify patient assessments.

Defining a Theory-Driven Ultrasound Curriculum for Prehospital Providers.

Advances in point-of-care ultrasound technology have allowed for the extension of emergency medicine ultrasound beyond the walls of the emergency department. Emergency medical system providers may benefit from the use of ultrasound. It has previously been shown that with a brief introductory course, novices can obtain and correctly interpret focused ultrasound examinations. The purpose of this study was to design a theory-driven point-of-care ultrasound curriculum to assess and develop ultrasound skill in prehospital providers. The resultant curriculum outlined in this paper encompasses a large array of skills that may be useful for different prehospital services to use to develop curriculum for their own needs.

Continuous Inferior Vena Cava Diameter Tracking through an Iterative Kanade-Lucas-Tomasi-Based Algorithm.

Ultrasound assessment of the respiratory-induced change in size of the inferior vena cava is a useful technique in the evaluation and management of critically ill patients. We have developed an automated technique based on the Kanade-Lucas-Tomasi feature tracker and pyramidal segmentation to continuously track the diameter of the inferior vena cava during ultrasound. To test the accuracy of this automated process, the inferior vena cava of 47 spontaneously breathing patients were measured by trained ultrasound physicians and compared against the results obtained via the automated tracking. Good agreement between the techniques was found, with intra-class correlation coefficients for maximum vessel diameter, minimum diameter and caval index of 0.897, 0.967 and 0.975, respectively. More than 95% of the difference between physicians and automated measurements agreed to within 10% of the inferior vena cava collapse. Furthermore a phenomenon of cardiac collapsibility index variability was observed and reported. The accuracy and precision of this algorithmic technique provide a foundation for future automated measures for critical care ultrasound.

Structure-function analysis of inositol hexakisphosphate-induced autoprocessing in Clostridium difficile toxin A.

The action of Clostridium difficile toxins A and B depends on inactivation of host small G-proteins by glucosylation. Cellular inositol hexakisphosphate (InsP6) induces an autocatalytic cleavage of the toxins, releasing an N-terminal glucosyltransferase domain into the host cell cytosol. We have defined the cysteine protease domain (CPD) responsible for autoprocessing within toxin A (TcdA) and report the 1.6 A x-ray crystal structure of the domain bound to InsP6. InsP6 is bound in a highly basic pocket that is separated from an unusual active site by a beta-flap structure. Functional studies confirm an intramolecular mechanism of cleavage and highlight specific residues required for InsP6-induced TcdA processing. Analysis of the structural and functional data in the context of sequences from similar and diverse origins highlights a C-terminal extension and a pi-cation interaction within the beta-flap that appear to be unique among the large clostridial cytotoxins.

An analysis of advocacy: a collaborative essay.

OBJECTIVES: To review the development of advocacy and its influence on health policy from the perspective of AIDS, the American Cancer Society, the Cancer Leadership Council, and the Patient Advocacy Foundation. DATA SOURCES: Published articles, news articles, books and personal experience. CONCLUSIONS: Advocacy on behalf of patients in the health care arena is a powerful force in modern life. Advocacy organizations have been influential in the development of health policy. IMPLICATIONS FOR NURSING PRACTICE: There are a variety of advocacy organizations in which nurses can commit their energies in the support of advocacy.