The prognostic value of improving congestion on lung ultrasound during treatment for acute heart failure differs based on patient characteristics at admission.

BACKGROUND: Lung ultrasound congestion scoring (LUS-CS) is a congestion severity biomarker. The BLUSHED-AHF trial demonstrated feasibility for LUS-CS-guided therapy in acute heart failure (AHF). We investigated two questions: 1) does change (∆) in LUS-CS from emergency department (ED) to hospital-discharge predict patient outcomes, and 2) is the relationship between in-hospital decongestion and adverse events moderated by baseline risk-factors at admission? METHODS: We performed a secondary analysis of 933 observations/128 patients from 5 hospitals in the BLUSHED-AHF trial receiving daily LUS. ∆LUS-CS from ED arrival to inpatient discharge (scale -160 to +160, where negative = improving congestion) was compared to a primary outcome of 30-day death/AHF-rehospitalization. Cox regression was used to adjust for mortality risk at admission [Get-With-The-Guidelines HF risk score (GWTG-RS)] and the discharge LUS-CS. An interaction between ∆LUS-CS and GWTG-RS was included, under the hypothesis that the association between decongestion intensity (by ∆LUS-CS) and adverse outcomes would be stronger in admitted patients with low-mortality risk but high baseline congestion. RESULTS: Median age was 65 years, GWTG-RS 36, left ventricular ejection fraction 36 %, and ∆LUS-CS -20. In the multivariable analysis ∆LUS-CS was associated with event-free survival (HR = 0.61; 95 % CI: 0.38-0.97), while discharge LUS-CS (HR = 1.00; 95%CI: 0.54-1.84) did not add incremental prognostic value to ∆LUS-CS alone. As GWTG-RS rose, benefits of LUS-CS reduction attenuated (interaction p < 0.05). ∆LUS-CS and event-free survival were most strongly correlated in patients without tachycardia, tachypnea, hypotension, hyponatremia, uremia, advanced age, or history of myocardial infarction at ED/baseline, and those with low daily loop diuretic requirements. CONCLUSIONS: Reduction in ∆LUS-CS during AHF treatment was most associated with improved readmission-free survival in heavily congested patients with otherwise reassuring features at admission. ∆LUS-CS may be most useful as a measure to ensure adequate decongestion prior to discharge, to prevent early readmission, rather than modify survival.

Comparison of outcomes between pulseless electrical activity by electrocardiography and pulseless myocardial activity by echocardiography in out-of-hospital cardiac arrest; secondary analysis from a large, prospective study.

OBJECTIVE: To measure prevalence of discordance between electrical activity recorded by electrocardiography (ECG) and myocardial activity visualized by echocardiography (echo) in patients presenting after cardiac arrest and to compare survival outcomes in cohorts defined by ECG and echo. METHODS: This is a secondary analysis of a previously published prospective study at twenty hospitals. Patients presenting after out-of-hospital arrest were included. The cardiac electrical activity was defined by ECG and contemporaneous myocardial activity was defined by bedside echo. Myocardial activity by echo was classified as myocardial asystole--the absence of myocardial movement, pulseless myocardial activity (PMA)--visible myocardial movement but no pulse, and myocardial fibrillation--visualized fibrillation. Primary outcome was the prevalence of discordance between electrical activity and myocardial activity. RESULTS: 793 patients and 1943 pauses in CPR were included. 28.6% of CPR pauses demonstrated a difference in electrical activity (ECG) and myocardial activity (echo), 5.0% with asystole (ECG) and PMA (echo), and 22.1% with PEA (ECG) and myocardial asystole (echo). Twenty-five percent of the 32 pauses in CPR with a shockable rhythm by echo demonstrated a non-shockable rhythm by ECG and were not defibrillated. Survival for patients with PMA (echo) was 29.1% (95%CI-23.9-34.9) compared to those with PEA (ECG) (21.4%, 95%CI-17.7-25.6). CONCLUSION: Patients in cardiac arrest commonly demonstrate different electrical (ECG) and myocardial activity (echo). Further research is needed to better define cardiac activity during cardiac arrest and to explore outcome between groups defined by electrical and myocardial activity.

Use of Critical Items in Determining Point-of-Care Ultrasound Competence.

We previously developed a workplace-based tool for assessing point of care ultrasound (POCUS) skills and used a modified Delphi technique to identify critical items (those that learners must successfully complete to be considered competent). We performed a standard setting procedure to determine cut scores for the full tool and a focused critical item tool. This study compared ratings by 24 experts on the two checklists versus a global entrustability rating. All experts assessed three videos showing an actor performing a POCUS exam on a patient. The performances were designed to show a range of competences and one included potentially critical errors. Interrater reliability for the critical item tool was higher than for the full tool (intraclass correlation coefficient = 0.84 [95% confidence interval [CI] 0.42-0.99] vs. 0.78 [95% CI 0.25-0.99]). Agreement with global ratings of competence was higher for the critical item tool (κ = 0.71 [95% CI 0.55-0.88] vs 0.48 [95% CI 0.30-0.67]). Although sensitivity was higher for the full tool (85.4% [95% CI 72.2-93.9%] vs. 81.3% [95% CI 67.5-91.1%]), specificity was higher for the critical item tool (70.8% [95% CI 48.9-87.4%] vs. 29.2% [95% CI 12.6-51.1%]). We recommend the use of critical item checklists for the assessment of POCUS competence.

Consensus-Based Expert Development of Critical Items for Direct Observation of Point-of-Care Ultrasound Skills.

BACKGROUND: Point-of-care ultrasound (POCUS) is increasingly used in a number of medical specialties. To support competency-based POCUS education, workplace-based assessments are essential. OBJECTIVE: We developed a consensus-based assessment tool for POCUS skills and determined which items are critical for competence. We then performed standards setting to set cut scores for the tool. METHODS: Using a modified Delphi technique, 25 experts voted on 32 items over 3 rounds between August and December 2016. Consensus was defined as agreement by at least 80% of the experts. Twelve experts then performed 3 rounds of a standards setting procedure in March 2017 to establish cut scores. RESULTS: Experts reached consensus for 31 items to include in the tool. Experts reached consensus that 16 of those items were critically important. A final cut score for the tool was established at 65.2% (SD 17.0%). Cut scores for critical items are significantly higher than those for noncritical items (76.5% ± SD 12.4% versus 53.1% ± SD 12.2%, P < .0001). CONCLUSIONS: We reached consensus on a 31-item workplace-based assessment tool for identifying competence in POCUS. Of those items, 16 were considered critically important. Their importance is further supported by higher cut scores compared with noncritical items.

Correlation of OSCE performance and point-of-care ultrasound scan numbers among a cohort of emergency medicine residents.

BACKGROUND: Point-of-care ultrasound (POCUS) is an important clinical tool for a growing number of medical specialties. The current American College of Emergency Physicians (ACEP) Ultrasound Guidelines recommend that trainees perform 150-300 ultrasound scans as part of POCUS training. We sought to assess the relationship between ultrasound scan numbers and performance on an ultrasound-focused observed structured clinical examination (OSCE). METHODS: This was a cross-sectional cohort study in which the number of ultrasound scans residents had previously performed were obtained from a prospective database and compared with their total score on an ultrasound OSCE. Ultrasound fellowship trained emergency physicians administered a previously published OSCE that consisted of standardized questions testing image acquisition and interpretation, ultrasound machine mechanics, patient positioning, and troubleshooting. Residents were observed while performing core applications including aorta, biliary, cardiac, deep vein thrombosis, Focused Assessment with Sonography in Trauma (FAST), pelvic, and thoracic ultrasound imaging. RESULTS: Twenty-nine postgraduate year (PGY)-3 and PGY-4 emergency medicine (EM) residents participated in the OSCE. The median OSCE score was 354 [interquartile range (IQR) 343-361] out of a total possible score of 370. Trainees had previously performed a median of 341 [IQR 289-409] total scans. Residents with more than 300 ultrasound scans had a median OSCE score of 355 [IQR 351-360], which was slightly higher than the median OSCE score of 342 [IQR 326-361] in the group with less than 300 total scans (p = 0.04). Overall, a LOWESS curve demonstrated a positive association between scan numbers and OSCE scores with graphical review of the data suggesting a plateau effect. CONCLUSION: The results of this small single residency program study suggest a pattern of improvement in OSCE performance as scan numbers increased, with the appearance of a plateau effect around 300 scans. Further investigation of this correlation in diverse practice environments and within individual ultrasound modalities will be necessary to create generalizable recommendations for scan requirements as part of overall POCUS proficiency assessment.

Test performance of point-of-care ultrasound for gastric content.

OBJECTIVE: We sought to determine test performance characteristics of emergency physician ultrasound for the identification of gastric contents. METHODS: Subjects were randomized to fast for at least 10 h or to consume food and water. A sonologist blinded to the patient's status performed an ultrasound of the stomach 10 min after randomization and oral intake, if applicable. The sonologist recorded their interpretation of the study using three sonographic windows. Subsequently 2 emergency physicians reviewed images of each study and provided an interpretation of the examination. Test performance characteristics and inter-rater agreement were calculated. RESULTS: 45 gastric ultrasounds were performed. The sonologist had excellent sensitivity (92%; 95% CI 73%-99%) and specificity (85%; 95% CI 62%-92%). Expert review demonstrated excellent sensitivity but lower specificity. Inter-rater agreement was very good (κ = 0.64, 95%CI 0.5-0.78). CONCLUSION: Emergency physician sonologists were sensitive but less specific at detecting stomach contents using gastric ultrasound.

Correlation of carotid blood flow and corrected carotid flow time with invasive cardiac output measurements.

BACKGROUND: Non-invasive measures that can accurately estimate cardiac output may help identify volume-responsive patients. This study seeks to compare two non-invasive measures (corrected carotid flow time and carotid blood flow) and their correlations with invasive reference measurements of cardiac output. Consenting adult patients (n = 51) at Massachusetts General Hospital cardiac catheterization laboratory undergoing right heart catheterization between February and April 2016 were included. Carotid ultrasound images were obtained concurrently with cardiac output measurements, obtained by the thermodilution method in the absence of severe tricuspid regurgitation and by the Fick oxygen method otherwise. Corrected carotid flow time was calculated as systole time/√cycle time. Carotid blood flow was calculated as π × (carotid diameter)2/4 × velocity time integral × heart rate. Measurements were obtained using a single carotid waveform and an average of three carotid waveforms for both measures. RESULTS: Single waveform measurements of corrected flow time did not correlate with cardiac output (ρ = 0.25, 95% CI -0.03 to 0.49, p = 0.08), but an average of three waveforms correlated significantly, although weakly (ρ = 0.29, 95% CI 0.02-0.53, p = 0.046). Carotid blood flow measurements correlated moderately with cardiac output regardless of if single waveform or an average of three waveforms were used: ρ = 0.44, 95% CI 0.18-0.63, p = 0.004, and ρ = 0.41, 95% CI 0.16-0.62, p = 0.004, respectively. CONCLUSIONS: Carotid blood flow may be a better marker of cardiac output and less subject to measurements issues than corrected carotid flow time.

Point-of-Care Ultrasound Use, Accuracy, and Impact on Clinical Decision Making in Rwanda Hospitals.

OBJECTIVES: Few studies of point-of-care ultrasound training and use in low resource settings have reported the impact of examinations on clinical management or the longer-term quality of trainee-performed studies. We characterized the long-term effect of a point-of-care ultrasound program on clinical decision making, and evaluated the quality of clinician-performed ultrasound studies. METHODS: We conducted point-of-care ultrasound training for physicians from Rwandan hospitals. Physicians then used point-of-care ultrasound and recorded their findings, interpretation, and effects on patient management. Data were collected for 6 months. Trainee studies were reviewed for image quality and accuracy. RESULTS: Fifteen participants documented 1158 ultrasounds; 590 studies (50.9%) had matched images and interpretations for review. Abdominal ultrasound for free fluid was the most frequently performed application. The mean image quality score was 2.36 (95% confidence interval, 2.28-2.44). Overall sensitivity and specificity for trainee-performed examinations was 94 and 98%. Point-of-care ultrasound use most commonly changed medications administered (42.4%) and disposition (30%). CONCLUSIONS: A point-of-care ultrasound training intervention in a low-resource setting resulted in high numbers of diagnostic-quality studies over long-term follow-up. Ultrasound use routinely changed clinical decision making.

International Federation for Emergency Medicine Consensus Statement: Sonography in hypotension and cardiac arrest (SHoC): An international consensus on the use of point of care ultrasound for undifferentiated hypotension and during cardiac arrest.

Introduction The International Federation for Emergency Medicine (IFEM) Ultrasound Special Interest Group (USIG) was tasked with development of a hierarchical consensus approach to the use of point of care ultrasound (PoCUS) in patients with hypotension and cardiac arrest. METHODS: The IFEM USIG invited 24 recognized international leaders in PoCUS from emergency medicine and critical care to form an expert panel to develop the sonography in hypotension and cardiac arrest (SHoC) protocol. The panel was provided with reported disease incidence, along with a list of recommended PoCUS views from previously published protocols and guidelines. Using a modified Delphi methodology the panel was tasked with integrating the disease incidence, their clinical experience and their knowledge of the medical literature to evaluate what role each view should play in the proposed SHoC protocol. RESULTS: Consensus on the SHoC protocols for hypotension and cardiac arrest was reached after three rounds of the modified Delphi process. The final SHoC protocol and operator checklist received over 80% consensus approval. The IFEM-approved final protocol, recommend Core, Supplementary, and Additional PoCUS views. SHoC-hypotension core views consist of cardiac, lung, and inferior vena vaca (IVC) views, with supplementary cardiac views, and additional views when clinically indicated. Subxiphoid or parasternal cardiac views, minimizing pauses in chest compressions, are recommended as core views for SHoC-cardiac arrest; supplementary views are lung and IVC, with additional views when clinically indicated. Both protocols recommend use of the "4 F" approach: fluid, form, function, filling. CONCLUSION: An international consensus on sonography in hypotension and cardiac arrest is presented. Future prospective validation is required.

Pilot Point-of-Care Ultrasound Curriculum at Harvard Medical School: Early Experience.

INTRODUCTION: Point-of-care ultrasound (POCUS) is expanding across all medical specialties. As the benefits of US technology are becoming apparent, efforts to integrate US into pre-clinical medical education are growing. Our objective was to describe our process of integrating POCUS as an educational tool into the medical school curriculum and how such efforts are perceived by students. METHODS: This was a pilot study to introduce ultrasonography into the Harvard Medical School curriculum to first- and second-year medical students. Didactic and hands-on sessions were introduced to first-year students during gross anatomy and to second-year students in the physical exam course. Student-perceived attitudes, understanding, and knowledge of US, and its applications to learning the physical exam, were measured by a post-assessment survey. RESULTS: All first-year anatomy students (n=176) participated in small group hands-on US sessions. In the second-year physical diagnosis course, 38 students participated in four sessions. All students (91%) agreed or strongly agreed that additional US teaching should be incorporated throughout the four-year medical school curriculum. CONCLUSION: POCUS can effectively be integrated into the existing medical school curriculum by using didactic and small group hands-on sessions. Medical students perceived US training as valuable in understanding human anatomy and in learning physical exam skills. This innovative program demonstrates US as an additional learning modality. Future goals include expanding on this work to incorporate US education into all four years of medical school.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence.

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest.

BACKGROUND: Point-of-care ultrasound has been suggested to improve outcomes from advanced cardiac life support (ACLS), but no large studies have explored how it should be incorporated into ACLS. Our aim was to determine whether cardiac activity on ultrasound during ACLS is associated with improved survival. METHODS: We conducted a non-randomized, prospective, protocol-driven observational study at 20 hospitals across United States and Canada. Patients presenting with out-of-hospital arrest or in-ED arrest with pulseless electrical activity or asystole were included. An ultrasound was performed at the beginning and end of ACLS. The primary outcome was survival to hospital admission. Secondary outcomes included survival to hospital discharge and return of spontaneous circulation. FINDINGS: 793 patients were enrolled, 208 (26.2%) survived the initial resuscitation, 114 (14.4%) survived to hospital admission, and 13 (1.6%) survived to hospital discharge. Cardiac activity on US was the variable most associated with survival at all time points. On multivariate regression modeling, cardiac activity was associated with increased survival to hospital admission (OR 3.6, 2.2-5.9) and hospital discharge (OR 5.7, 1.5-21.9). No cardiac activity on US was associated with non-survival, but 0.6% (95% CI 0.3-2.3) survived to discharge. Ultrasound identified findings that responded to non-ACLS interventions. Patients with pericardial effusion and pericardiocentesis demonstrated higher survival rates (15.4%) compared to all others (1.3%). CONCLUSION: Cardiac activity on ultrasound was the variable most associated with survival following cardiac arrest. Ultrasound during cardiac arrest identifies interventions outside of the standard ACLS algorithm.

Intensive point-of-care ultrasound training with long-term follow-up in a cohort of Rwandan physicians.

OBJECTIVE: We delivered a point-of-care ultrasound training programme in a resource-limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice. METHODS: This was a prospective cohort study of 17 Rwandan physicians participating in a point-of-care ultrasound training programme. The follow-up period was 1 year. Participants completed a 10-day ultrasound course, with follow-up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image-based assessment completed at three points. RESULTS: Trainees reported minimal structured ultrasound education and little confidence using point-of-care ultrasound before the training. Mean scores on the image-based assessment increased from 36.9% (95% CI 32-41.8%) before the initial 10-day training to 74.3% afterwards (95% CI 69.4-79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78-85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58-week follow up was 84.9% (95% CI 80.9-88.9%). CONCLUSIONS: Physicians providing acute care in a resource-limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction.

Predicting ureteral stones in emergency department patients with flank pain: an external validation of the STONE score.

PURPOSE: The ability to objectively predict which emergency department patients are likely to have a ureteral stone may aid in cost-effectiveness and patient-centered diagnostic imaging decisions. We performed an external validation of the STONE score, a clinical prediction rule for the presence of uncomplicated ureteral stones in emergency department patients developed at Yale University School of Medicine. METHODS: Five hundred thirty-six (536) consecutive patients evaluated in an urban tertiary care emergency department for the possible diagnosis of ureteral stone were retrospectively reviewed. The STONE score uses five factors (gender, duration of pain, race, nausea/vomiting, erythrocytes on urine dipstick) to categorize patients into low, medium, and high probability of having a ureteral stone. The total STONE score risk is 0-13 and divided into three groups: low risk = 0-5, moderate risk = 6-9, and high risk = 10-13. RESULTS: Of the 536 patients evaluated for suspected ureteral stone, 257 (47.8 %) had a ureteral stone. Mean patient age was 45.9 years (SD 16.3), and gender distribution was 43.9 % female and 56.1 % male. Distribution of STONE score risk was 24.1 % low, 48.1 % moderate, and 27.7 % high. Diagnosis of ureteral stone by STONE score risk was 14 % for low-risk group, 48.3 % for moderate-risk group, and 75.8 % for high-risk group. This distribution is consistent with internal validation at Yale University School of Medicine, where values were 8.3-9.2 % for low risk, 51.3-51.6 % for moderate risk, and 88.6-89.6 % for high risk. CONCLUSIONS: Our study validates the use of the STONE clinical score to categorize patients as low, moderate, and high risk for ureteral stone. This could help guide development of clinical decision rules for diagnostic studies and imaging in the future.

Accuracy of Inferior Vena Cava Ultrasound for Predicting Dehydration in Children with Acute Diarrhea in Resource-Limited Settings.

INTRODUCTION: Although dehydration from diarrhea is a leading cause of morbidity and mortality in children under five, existing methods of assessing dehydration status in children have limited accuracy. OBJECTIVE: To assess the accuracy of point-of-care ultrasound measurement of the aorta-to-IVC ratio as a predictor of dehydration in children. METHODS: A prospective cohort study of children under five years with acute diarrhea was conducted in the rehydration unit of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). Ultrasound measurements of aorta-to-IVC ratio and dehydrated weight were obtained on patient arrival. Percent weight change was monitored during rehydration to classify children as having "some dehydration" with weight change 3-9% or "severe dehydration" with weight change > 9%. Logistic regression analysis and Receiver-Operator Characteristic (ROC) curves were used to evaluate the accuracy of aorta-to-IVC ratio as a predictor of dehydration severity. RESULTS: 850 children were enrolled, of which 771 were included in the final analysis. Aorta to IVC ratio was a significant predictor of the percent dehydration in children with acute diarrhea, with each 1-point increase in the aorta to IVC ratio predicting a 1.1% increase in the percent dehydration of the child. However, the area under the ROC curve (0.60), sensitivity (67%), and specificity (49%), for predicting severe dehydration were all poor. CONCLUSIONS: Point-of-care ultrasound of the aorta-to-IVC ratio was statistically associated with volume status, but was not accurate enough to be used as an independent screening tool for dehydration in children under five years presenting with acute diarrhea in a resource-limited setting.

Can ureteral stones cause pain without causing hydronephrosis?

INTRODUCTION: While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. METHODS: Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. RESULTS: Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis. CONCLUSIONS: In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.