Citations

Abstract Intravital imaging studies have provided insights into the spatial and temporal variations of platelet activation and thrombin generation that occur during hemostasis; however, these studies are generally limited to small vessels due to the practical limitations of imaging in thicker tissues. Recent advances in cleared tissue fluorescence imaging as well as volume electron microscopy (vEM) coupled with machine learning–based image segmentation provide an opportunity for analysis of the 3-dimensional structure of complex tissues. We utilized these technologies to examine hemostatic plugs from murine jugular veins and carotid arteries to investigate the spatial distribution of platelet activation and biochemical responses in these disparate physiologic contexts. Both venous and arterial hemostatic plugs had a heterogeneous structure with regions of sparsely and densely packed platelets. Despite similar injury sizes, arterial hemostatic plugs were at least an order of magnitude larger than venous plugs. The difference in plug size was primarily due to a 19-fold increase in the population of densely packed platelets in the extravascular compartment. Venous plugs displayed significant platelet aggregation extending into the vessel lumen and developed distinctive fibrin and red blood cell–filled cavities. Complementary fluorescence microscopy revealed that platelet activation was spatially heterogeneous in both contexts, with α-granule secretion and phosphatidylserine exposure confined to specific microenvironments, highlighting tightly regulated thrombin activity. Overall, our findings reveal both conserved and distinct mechanisms of hemostatic thrombus formation in different physiologic contexts. They also demonstrate the power of vEM coupled with machine learning–based image segmentation for the quantitative analysis of large imaging data sets from complex tissues.

Abstract BACKGROUND Emergency medicine (EM) trainee comfort level with lumbar puncture (LP) has decreased over time due to changing practice guidelines, particularly amongst pediatric patients. We implemented a “just in time” (JIT) brief educational video based on a validated LP evaluation checklist to improve trainee efficiency and competence in LP performance. METHODS Our experimental study took place January-June 2022 within a large, academic Midwestern emergency department (ED) with an established 3-year EM residency program. All 9 interns performed a timed diagnostic LP on an infant LP model in January, scored according to a previously validated LP Performance Scoring Checklist. In June, interns repeated the timed LP procedure directly after watching a brief educational video based on major checklist steps. The study was deemed exempt by the Institutional Review Board. RESULTS All interns completed both assessments. At baseline, interns had logged performance of median 2 (IQR 0–5) LPs and spent 12.9 (10.3–14.4) minutes performing the procedure. Post-intervention, interns had logged an additional median 2 (0–5) LPs and completed the procedure faster with an average time of 10.3 (9.7–11.3) minutes (p = 0.004). A median of 5 (4–7) major steps were missed at baseline, compared to 1 (1–2) at time of post-intervention assessment (p = 0.015). CONCLUSION Development of a brief educational video improved efficiency and competency amongst our intern class in performing an infant LP when viewed Just-In-Time. Similar efforts may improve education and performance of other rare (or decreasing in frequency) procedures within EM training. Future research with other procedures, larger learner cohorts, and comparing JIT approaches will be necessary to determine whether JIT videos based on validated assessment checklists are truly “best practice”. Formal evaluation of the effect of similar “standardized” videos on cognitive load of learners and supervisors is also an important avenue of future research.

AbstractBackgroundIn 2013 the Accreditation Council for Graduate Medical Education (ACGME) introduced “Milestones” designed to nationally standardize the assessment of resident physicians. Previous studies compare resident self‐assessment on milestones to faculty assessment, with varying degrees of agreement, but integration of self‐assessment into the formative feedback process has not yet been directly studied. This study uses a conceptual framework of self‐determination theory, integrated with concepts from adult learning theory, to compare the perception of the feedback quality given in semiannual reviews before and after the incorporation of resident self‐assessment into the feedback process.MethodsThis was an interventional study conducted in a single emergency medicine residency program at a major academic hospital over 1 calendar year. Residents first engaged in a semiannual review without self‐assessment. At subsequent semiannual reviews, residents completed a Milestone‐based self‐assessment that was provided to the faculty member assigned to conduct their semiannual review. Residents and faculty completed surveys rating perception of feedback quality. Two‐sided Wilcoxon signed‐rank tests were used in comparison analysis.ResultsOne resident did not self‐assess prior to the semiannual review and was excluded leaving 25 paired surveys for analysis. Residents found feedback after the self‐assessment more actionable (p = 0.013), insightful (p = 0.010), and better overall (p = 0.025). Similarly, faculty felt the feedback they provided was more actionable (p < 0.001), more insightful (p < 0.001), and better communicated (p < 0.001); led to improved resident understanding of milestones (p < 0.001); and were overall more satisfied (p < 0.001). Free‐text comments explore pre‐ and postintervention perceptions of feedback.ConclusionsIntegration of self‐assessment into semiannual reviews improves perception of feedback given to residents as perceived by both residents and faculty. Although limited by sample size, the results are promising for a simple, evidence‐based intervention to improve feedback during an existing mandated feedback opportunity.