Longitudinal accuracy analysis of ultrasound performed during a four-year emergency medicine residency.

BACKGROUND: The objective of this study was to analyze patterns of point-of-care ultrasound (POCUS) performance over 4 years of emergency medicine (EM) residency. Specifically, we aimed to study how accuracy and adherence to standards of scanning changed by postgraduate year (PGY). METHODS: This was a retrospective observational study of resident-performed POCUS at an academic emergency department over 6 years. We reviewed records of POCUS scans performed by PGY-1 to -4 residents that had been collected for quality assurance purposes. Data that were collected about EM residents' performance included the total number and type of scans per year, rate of technically limited scans (TLS), and accuracy on interpreting ultrasound images. Resident performances in each year (PGY-1 to -4) were independently evaluated and reported. RESULTS: During a 6-year period, 137 different EM residents performed 50,815 ultrasound scans. The median number of scans was 177 for PGY-1, 124 for PGY-2, 118 for PGY-3, and 76 for residents in PGY-4. The accuracy of scan interpretations were high across all PGY levels (>97%), but slight degradation was observed as residents progressed through residency. The TLS rate increased from 4.7% among PGY-1s to 13.6% as PGY-4s. CONCLUSIONS: In this large cohort of POCUS studies by EM residents, POCUS accuracy rates decreased and rates of TLS significantly increased as residents progressed through residency.

Carotid Ultrasound in Assessing Fluid Responsiveness in Patients with Hypotension and Suspected Sepsis.

PURPOSE: We sought to assess whether ultrasound (US) measurements of carotid flow time (CFTc) and carotid blood flow (CBF) predict fluid responsiveness in patients with suspected sepsis. METHODS: This was a prospective observational study of hypotensive (systolic blood pressure < 90) patients "at risk" for sepsis receiving intravenous fluids (IVF) in the emergency department. US measurements of CFTc and CBF were performed at time zero and upon completion of IVF. All US measurements were repeated after a passive leg raise (PLR) maneuver. Fluid responsiveness was defined as normalization of blood pressure without persistent hypotension or need for vasopressors. RESULTS: A convenience sample of 69 patients was enrolled. The mean age was 65; 49% were female. Fluid responders comprised 52% of the cohort. CFTc values increased significantly with both PLR (P = 0.047) and IVF administration (P = 0.003), but CBF values did not (P = 0.924 and P = 0.064 respectively). Neither absolute CFTc or CBF measures, nor changes in these values with PLR or IVF bolus, predicted fluid responsiveness, mortality, or the need for intensive care unit admission. CONCLUSION: In patients with suspected sepsis, a fluid challenge resulted in a significant change in CFTc, but not CBF. Neither absolute measurement nor delta measurements with fluid challenge predicted clinical outcomes.

Left Ventricular Dysfunction Correlates With Mortality in Pulmonary Embolism.

BACKGROUND: Risk stratification of patients with pulmonary embolism (PE) is essential to guide advanced interventional management and proper disposition. OBJECTIVES: In this study, we sought to assess individual echocardiographic markers of right ventricular (RV) strain and left ventricular (LV) function in patients with high-risk PE and identify their association with the need for advanced intervention (such as thrombolysis) and 30-day mortality. METHODS: This was a retrospective study of ED patients with PE who were subject to a pulmonary embolism response team activation over a 5-year period. Cardiac point-of-care ultrasound studies were performed as part of patient care and later assessed for septal bowing, RV hypokinesis, McConnell sign, RV enlargement, tricuspid annular place systolic excursion, and LV systolic dysfunction. Outcome variables included need for advanced intervention and 30-day mortality. RESULTS: The pulmonary embolism response team was activated in 893 patients, of which 718 had a confirmed PE. Of these, 90 had adequate cardiac point-of-care ultrasound images available for review. Patients who needed an advanced intervention were more likely to have septal bowing (odds ratio [OR] 8.69, 95% confidence interval [CI] 2.37-31.86), RV enlargement (OR 4.02, 95% CI 1.43-11.34), and a McConnell sign (OR 2.79, 95% CI 1.09-7.13). LV dysfunction was the only statistically significant predictor of 30-day mortality (OR 9.63, 95% CI 1.74-53.32). CONCLUSION: In patients with PE in the ED, sonographic findings of RV strain that are more commonly associated with advanced intervention included septal bowing, McConnell sign, and RV enlargement. LV dysfunction was associated with a higher 30-day mortality. These findings can help inform decisions about ED management and disposition of patients with PE.

Clinical Integration of Point-of-care Ultrasound by Emergency Medicine Residents: A Single-center Mixed-methods Study.

BACKGROUND: Point-of-care ultrasound (POCUS) competence consists of image acquisition, image interpretation, and clinical integration. Limited data exist on POCUS usage patterns and clinical integration by emergency medicine (EM) residents. We sought to determine actual POCUS usage and clinical integration patterns by EM residents and to explore residents' perspectives on POCUS clinical integration. METHODS: We conducted an explanatory sequential mixed-methods study at a 4-year EM residency program. In phase 1, EM ultrasound (US) attendings observed PGY-4 EM residents' clinical integration of POCUS in real time while on shift in the emergency department (ED). EM US attendings evaluated residents on their intent to perform POCUS, actual POCUS usage, and competence per patient encounter. We used logistic regression to analyze these parameters. In phase 2, we conducted semi-structured interviews with the observed PGY-4 residents regarding POCUS usage and clinical integration in the ED. We analyzed qualitative data for themes. RESULTS: Emergency medicine US attendings observed 10 PGY-4 EM residents during 254 high-acuity patient encounters from December 2018 to March 2019. EM US attendings considered POCUS indicated for 26% (66/254) of patients, possibly indicated for 12% (30/254) and not indicated for 62% (158/254). Of the 66 patients for whom EM US attendings considered POCUS indicated, PGY-4s intended to perform POCUS for patient management 61% (40/66) of the time. PGY-4s subsequently incorporated POCUS into patient management 73% (48/66) of the time. EM US attendings considered PGY-4s entrustable to perform POCUS independently 81% (206/254) of the time. We did not find a statistically significant association between shift volume, shift type, or POCUS application, and resident intent to perform POCUS nor competence. Interviews identified three factors that influence PGY-4's POCUS clinical integration: motivations to use POCUS, barriers to utilization, and POCUS educational methods. CONCLUSIONS: This mixed-methods study identified a significant gap in POCUS utilization and clinical integration by PGY-4 EM residents for clinically indicated cases identified by EM US attendings. As clinical integration is a cornerstone of POCUS competence, it is important to ensure that EM resident POCUS curricula emphasize training on clinical utilization and indications for POCUS while on shift in the ED.