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.

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.

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.

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.

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.

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.

Access to and Use of Point-of-Care Ultrasound in the Emergency Department

INTRODUCTION

Growing evidence supports emergency physician (EP)-performed point-of-care ultrasound (PoC US). However, there is a utilization gap between academic emergency departments (ED) and other emergency settings. We elucidated barriers to PoC US use in a multistate sample of predominantly non-academic EDs to inform future strategies to increase PoC US utilization, particularly in non-academic centers.

METHODS

In 2010, we surveyed ED directors in five states (Arkansas, Hawaii, Minnesota, Vermont, and Wyoming; n=242 EDs) about general ED characteristics. In four states we determined barriers to PoC US use, proportion of EPs using PoC US, use privileges, and whether EPs can bill for PoC US.

RESULTS

Response rates were >80% in each state. Overall, 47% of EDs reported PoC US availability. Availability varied by state, from 34% of EDs in Arkansas to 85% in Vermont. Availability was associated with higher ED visit volume, and percent of EPs who were board certified/board eligible in emergency medicine. The greatest barriers to use were limited training (70%), expense (39%), and limited need (perceived or real) (32%). When PoC US was used by EPs, 50% used it daily, 44% had privileges not requiring radiology confirmation, and 34% could bill separately for PoC US. Only 12% of EPs used it ≥80% of the time when placing central venous lines.

CONCLUSION

Only 47% of EDs in our five-state sample of predominantly non-academic EDs had PoC US immediately available. When available, the greatest barriers to use were limited training, expense, and limited need. Recent educational and technical advancements may help overcome these barriers.

The irregular diaphragmatic pleural interface: a novel sonographic sign facilitating the diagnosis of pneumonia

Pneumonia, a disease that has been reported to be the sixth leading cause of death in the United States, has worsening mortality with delays in diagnosis. As the history and physical examination are excessively inaccurate in the diagnosis of pneumonia, we often rely on chest radiography to rule in or out disease. However, it is found to lack sufficient accuracy when computed tomography is used as the reference standard. Sonography has emerged as a viable alternative to chest radiography in the diagnosis of pneumonia. Here, we describe a novel sonographic sign that can be used to assist in the diagnosis of pneumonia.

Diagnostic emergency imaging utilization at an academic trauma center from 1996 to 2012

PURPOSE

The aim of this study was to retrospectively review the growth rate in emergency radiology volume at an urban academic trauma center from 1996 to 2012.

METHODS

The authors reviewed aggregated billing data, for which the requirement for institutional review board approval was waived, from 1,458,230 diagnostic radiologic examinations ordered for emergency department (ED) visits from 1996 to 2012. The growth rate was calculated as the average annual percentage change in imaging examinations per ED visits. The growth rates between 1996 to 2003 and 2004 to 2012 were statistically compared using a t test.

RESULTS

ED patient visits showed continual growth at an average of 3% per year. Total imaging per ED visit grew from 1996 to 2003 at 4 ± 4% per year but significantly decreased from 2004 to 2012 at -2 ± 3% per year (P = .01). By modality, statistically significant decreased growth was observed in CT and MRI from 2004 to 2012. Ultrasound and x-ray showed unchanged growth from 1996 through 2012. ED physician ultrasound data available for 2002 to 2011 also showed increased growth.

CONCLUSIONS

When adjusting ED imaging volume by ED visits, significantly decreased growth of overall ED imaging, specifically CT and MRI, was observed during the past 9 years. This may be due to slowing of new imaging indications, improved awareness of practice guidelines, and increased use of ultrasound. Although the national health care discussion focuses on continual imaging growth, these results demonstrate that long-term stability in ED imaging utilization is achievable.

Assessing volume status and fluid responsiveness in the emergency department

Resuscitation with intravenous fluid can restore intravascular volume and improve stroke volume. However, in unstable patients, approximately 50% of fluid boluses fail to improve cardiac output as intended. Increasing evidence suggests that excess fluid may worsen patient outcomes. Clinical examination and vital signs are unreliable predictors of the response to a fluid challenge. We review the importance of fluid management in the critically ill, methods of evaluating volume status, and tools to predict fluid responsiveness.

Ultrasonography versus computed tomography for suspected nephrolithiasis

BACKGROUND

There is a lack of consensus about whether the initial imaging method for patients with suspected nephrolithiasis should be computed tomography (CT) or ultrasonography.

METHODS

In this multicenter, pragmatic, comparative effectiveness trial, we randomly assigned patients 18 to 76 years of age who presented to the emergency department with suspected nephrolithiasis to undergo initial diagnostic ultrasonography performed by an emergency physician (point-of-care ultrasonography), ultrasonography performed by a radiologist (radiology ultrasonography), or abdominal CT. Subsequent management, including additional imaging, was at the discretion of the physician. We compared the three groups with respect to the 30-day incidence of high-risk diagnoses with complications that could be related to missed or delayed diagnosis and the 6-month cumulative radiation exposure. Secondary outcomes were serious adverse events, related serious adverse events (deemed attributable to study participation), pain (assessed on an 11-point visual-analogue scale, with higher scores indicating more severe pain), return emergency department visits, hospitalizations, and diagnostic accuracy.

RESULTS

A total of 2759 patients underwent randomization: 908 to point-of-care ultrasonography, 893 to radiology ultrasonography, and 958 to CT. The incidence of high-risk diagnoses with complications in the first 30 days was low (0.4%) and did not vary according to imaging method. The mean 6-month cumulative radiation exposure was significantly lower in the ultrasonography groups than in the CT group (P<0.001). Serious adverse events occurred in 12.4% of the patients assigned to point-of-care ultrasonography, 10.8% of those assigned to radiology ultrasonography, and 11.2% of those assigned to CT (P=0.50). Related adverse events were infrequent (incidence, 0.4%) and similar across groups. By 7 days, the average pain score was 2.0 in each group (P=0.84). Return emergency department visits, hospitalizations, and diagnostic accuracy did not differ significantly among the groups.

CONCLUSIONS

Initial ultrasonography was associated with lower cumulative radiation exposure than initial CT, without significant differences in high-risk diagnoses with complications, serious adverse events, pain scores, return emergency department visits, or hospitalizations. (Funded by the Agency for Healthcare Research and Quality.).

Diagnosis of megaureter by point-of-care ultrasound

BACKGROUND

Presentation of congenital megaureter in adult life is rare; patients usually become symptomatic in childhood.

CASE REPORT

A 32-year-old man presented to the Emergency Department (ED) with dyspnea, tongue swelling, and a rash, which he attributed to amoxicillin he had taken shortly prior to onset of symptoms. He was hypotensive on arrival to the ED. To further evaluate the hypotension, point-of-care ultrasound of the heart, lungs, and abdomen were performed while treatment for anaphylaxis was initiated. Ultrasound examination did not identify a cause for hypotension, but the treating physician noted an anechoic structural abnormality posterior to the bladder, suggestive of megaureter. The patient responded well to treatment of anaphylaxis; further history and diagnostic imaging subsequently confirmed a diagnosis of congenital megaureter.

CONCLUSION

We report an unusual case of congenital megaureter, identified by point-of-care ultrasound performed to evaluate hypotension. Clinicians performing limited ultrasound examinations must be attentive to incidental findings that will require follow-up.

The core content of clinical ultrasonography fellowship training

The purpose of developing a core content for subspecialty training in clinical ultrasonography (US) is to standardize the education and qualifications required to provide oversight of US training, clinical use, and administration to improve patient care. This core content would be mastered by a fellow as a separate and unique postgraduate training, beyond that obtained during an emergency medicine (EM) residency or during medical school. The core content defines the training parameters, resources, and knowledge of clinical US necessary to direct clinical US divisions within medical specialties. Additionally, it is intended to inform fellowship directors and candidates for certification of the full range of content that might appear in future examinations. This article describes the development of the core content and presents the core content in its entirety.

Pulmonary ultrasound examination for edema, effusion, and thromboembolism

Bedside, or point-of-care, ultrasound (US) has increasingly been used in various clinical settings to provide clinicians with rapid clinical information without the use of ionizing radiation. Lung US has been demonstrated as a valuable tool in the diagnosis and evaluation of pulmonary edema, pleural effusions, and pulmonary thromboembolism. Lung US enables the clinician to more quickly identify and initiate treatment for these potentially life-threatening conditions without the need for patient transportation to the radiology suite. Additionally, lung US can repeatedly be implemented to assess clinical changes without concern for repeated radiation exposure and is cost-effective given its ability to decrease the need for additional radiological and laboratory testing to confirm a suspected diagnosis. This review focuses on the application of lung US in the evaluation and management of pulmonary edema, pleural effusions, and pulmonary thromboembolism.

Automated B-line scoring on thoracic sonography

With the proliferation of portable sonography and the increase in nontraditional users, there is an increased need for automated decision support to standardize results. We developed algorithms to evaluate the presence or absence of "B-lines" on thoracic sonography as a marker for interstitial fluid. Algorithm performance was compared against an average of scores from 2 expert clinical sonographers. On the set for algorithm development, 90% of the scores matched the average expert scores with differences of 1 or less. On the independent set, a perfect match was achieved. We believe that these are the first reported results in computerized B-line scoring.

Faculty staff-guided versus self-guided ultrasound training for internal medicine residents

OBJECTIVES

Ultrasonography is of growing importance within internal medicine (IM), but the optimal method of training doctors to use it is uncertain. In this study, the authors provide the first objective comparison of two approaches to training IM residents in ultrasonography.

METHODS

In this randomised trial, a simulation-based ultrasound training curriculum was implemented during IM intern orientation at a tertiary care teaching hospital. All 72 incoming interns attended a lecture and were given access to online modules. Interns were then randomly assigned to a 4-hour faculty-guided (FG) or self-guided (SG) ultrasound training session in a simulation laboratory with both human and manikin models. Interns were asked to self-assess their competence in ultrasonography and underwent an objective structured clinical examination (OSCE) to assess their competence in basic and procedurally oriented ultrasound tasks. The primary outcome was the score on the OSCE.

RESULTS

Faculty-guided training was superior to self-guided training based on the OSCE scores. Subjects in the FG training group achieved significantly higher OSCE scores on the two subsets of task completion (0.9-point difference, 95% confidence interval [CI] 0.27-1.54; p = 0.008) and ultrasound image quality (2.43-point difference, 95% CI 1.5-3.36; p < 0.001). Both training groups demonstrated an increase in self-assessed competence after their respective training sessions and there was little difference between the groups. Subjects rated the FG training group much more favourably than the SG training group.

CONCLUSIONS

Both FG and SG ultrasound training curricula can improve the self-reported competence of IM interns in ultrasonography. However, FG training was superior to SG training in both skills acquisition and intern preference. Incorporating mandatory ultrasound training into IM residencies can address the perceived need for ultrasound training, improve confidence and procedural skills, and may enhance patient safety. However, the optimal training method may require significant faculty input.

Bedside ultrasound maximizes patient satisfaction

BACKGROUND

Bedside ultrasound (US) is associated with improved patient satisfaction, perhaps as a consequence of improved time to diagnosis and decreased length of stay (LOS).

OBJECTIVES

Our study aimed to quantify the association between beside US and patient satisfaction and to assess patient attitudes toward US and perception of their interaction with the clinician performing the examination.

METHODS

We enrolled a convenience sample of adult patients who received a bedside US. The control group had similar LOS and presenting complaints but did not have a bedside US. Both groups answered survey questions during their emergency department (ED) visit and again by telephone 1 week later. The questionnaire assessed patient perceptions and satisfaction on a 5-point Likert scale.

RESULTS

Seventy patients were enrolled over 10 months. The intervention group had significantly higher scores on overall ED satisfaction (4.69 vs. 4.23; mean difference 0.46; 95% confidence interval [CI] 0.17-0.75), diagnostic testing (4.54 vs. 4.09; mean difference 0.46; 95% CI 0.16-0.76), and skills/abilities of the emergency physician (4.77 vs. 4.14; mean difference 0.63; 95% CI 0.29-0.96). A trend to higher scores for the intervention group persisted on follow-up survey.

CONCLUSIONS

Patients who had a bedside US had statistically significant higher satisfaction scores with overall ED care, diagnostic testing, and with their perception of the emergency physician. Bedside US has the potential not only to expedite care and diagnosis, but also to maximize satisfaction scores and improve the patient-physician relationship, which has increasing relevance to health care organizations and hospitals that rely on satisfaction surveys.

International evidence-based recommendations for point-of-care lung ultrasound

BACKGROUND

The purpose of this study is to provide evidence-based and expert consensus recommendations for lung ultrasound with focus on emergency and critical care settings.

METHODS

A multidisciplinary panel of 28 experts from eight countries was involved. Literature was reviewed from January 1966 to June 2011. Consensus members searched multiple databases including Pubmed, Medline, OVID, Embase, and others. The process used to develop these evidence-based recommendations involved two phases: determining the level of quality of evidence and developing the recommendation. The quality of evidence is assessed by the grading of recommendation, assessment, development, and evaluation (GRADE) method. However, the GRADE system does not enforce a specific method on how the panel should reach decisions during the consensus process. Our methodology committee decided to utilize the RAND appropriateness method for panel judgment and decisions/consensus.

RESULTS

Seventy-three proposed statements were examined and discussed in three conferences held in Bologna, Pisa, and Rome. Each conference included two rounds of face-to-face modified Delphi technique. Anonymous panel voting followed each round. The panel did not reach an agreement and therefore did not adopt any recommendations for six statements. Weak/conditional recommendations were made for 2 statements, and strong recommendations were made for the remaining 65 statements. The statements were then recategorized and grouped to their current format. Internal and external peer-review processes took place before submission of the recommendations. Updates will occur at least every 4 years or whenever significant major changes in evidence appear.

CONCLUSIONS

This document reflects the overall results of the first consensus conference on "point-of-care" lung ultrasound. Statements were discussed and elaborated by experts who published the vast majority of papers on clinical use of lung ultrasound in the last 20 years. Recommendations were produced to guide implementation, development, and standardization of lung ultrasound in all relevant settings.

Ultrasound for high altitude research

This review describes ultrasound techniques of potential use to high altitude researchers and discusses technical issues related to using ultrasound for high altitude research. Ultrasound allows portable, noninvasive evaluation of many physiologic parameters of interest to high altitude researchers. We discuss techniques that have been extensively used and emerging techniques that can be used to assess parameters of particular interest to high altitude researchers. We do not provide a definitive description of all ultrasound scanning methods but references to instructive sources are included. Potential drawbacks of ultrasound use, such as the need for sometimes extensive training and the potential for interobserver variation, are discussed and strategies for mitigating these are suggested. This review is meant to encourage other high altitude researchers to consider using ultrasound, either as a primary investigative modality or as an adjunct for monitoring parameters of interest in studies of physiology, altitude illness, or therapeutics.

Prognostic utility of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI)

Background

We sought to evaluate the test characteristics of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) in relation to 30-day major adverse cardiac events (MACE) among patients who presented to the Emergency Department with symptoms suggestive of an acute coronary syndrome. We then examined the test characteristics of various dichotomous ACI-TIPI cut points.

Methods

We prospectively recruited a cohort of Emergency Department (ED) patients with acute chest pain at two urban university hospitals between June and September 2006. Upon enrollment, baseline demographics and cardiac risk factors were collected. An electrocardiogram (ECG) was performed and analyzed with the built-in ACI-TIPI multiple regression model software. An ACI-TIPI probability score was recorded for each patient. Diagnostic test characteristics of ACI-TIPI for MACE (non-ST elevation myocardial infarction (NSTEMI), percutaneous coronary intervention, coronary artery bypass grafting, and all-cause mortality) within 30 days were determined.

Results

Of 144 patients enrolled (mean age 59.1 ± 14.1 years, 59% men), 19 (13%) patients suffered MACE within 30 days. Receiver-operating characteristics (ROC) for ACI-TIPI yielded a c-statistic of 0.69 (95% CI 0.59-0.80, p < 0.01). An ACI-TIPI score of ≥ 20 had 100% sensitivity (95% CI 82-100), 100% negative predictive value (95% CI 86-100), and 21% specificity (14-31%).

Conclusions

These preliminary results suggest that, while ACI-TIPI has limited discriminatory value for MACE overall, a score of < 20 may have 30-day prognostic utility to allow for safe outpatient management in patients with acute chest pain.

Real-time video streaming of sonographic clips using domestic internet networks and free videoconferencing software

OBJECTIVES

As the use of point-of-care sonography spreads, so too does the need for remote expert over-reading via telesonogrpahy. We sought to assess the feasibility of using familiar, widespread, and cost-effective existent technology to allow remote over-reading of sonograms in real time and to compare 4 different methods of transmission and communication for both the feasibility of transmission and image quality.

METHODS

Sonographic video clips were transmitted using 2 different connections (WiFi and 3G) and via 2 different videoconferencing modalities (iChat [Apple Inc, Cupertino, CA] and Skype [Skype Software Sàrl, Luxembourg]), for a total of 4 different permutations. The clips were received at a remote location and recorded and then scored by expert reviewers for image quality, resolution, and detail.

RESULTS

Wireless transmission of sonographic clips was feasible in all cases when WiFi was used and when Skype was used over a 3G connection. Images transmitted via a WiFi connection were statistically superior to those transmitted via 3G in all parameters of quality (average P = .031), and those sent by iChat were superior to those sent by Skype but not statistically so (average P = .057).

CONCLUSIONS

Wireless transmission of sonographic video clips using inexpensive hardware, free videoconferencing software, and domestic Internet networks is feasible with retention of image quality sufficient for interpretation. WiFi transmission results in greater image quality than transmission by a 3G network.

Using lung ultrasound to differentiate patients in acute dyspnea in the prehospital emergency setting

The diagnosis and treatment of dyspnea in the emergency department and in the prehospital setting is a challenge faced by the emergency physician and other prehospital care providers. While the use of lung ultrasound as a diagnostic tool in dyspneic patients has been well researched, there has been limited evaluation of its use in the prehospital setting. In the previous issue of Critical Care, Prosen and colleagues study the accuracy of lung ultrasound compared with both N-terminal pro-brain natriuretic peptide and the clinical examination for differentiating between acute decompensated congestive heart failure and chronic obstructive pulmonary disease exacerbations for patients in the prehospital setting. Their article adds to the growing body of evidence demonstrating the diagnostic efficacy of lung ultrasound in differentiating between these two disease processes in the acutely dyspneic patient.

Quantification of diaphragm function using ultrasound: evaluation of a novel technique

A novel method of image analysis for quantifying diaphragmatic motion is described using ultrasound. Nineteen patients scheduled for thoracic surgery were evaluated with ultrasound preoperatively and through their postoperative hospital stay. Diaphragmatic motion was measured using a horizontal on-screen ruler, allowing for quantification and tracking of dynamic diaphragm function. A percentage (73.5%) of all attempted measurements was quantifiable. Preoperative measurements of left and right diaphragm movement were correlated and there was no significant difference between the two. Postoperative diaphragm movement ipsilateral to the incision was statistically significantly less when compared to the contralateral side (p = 0.02 vs. p = 0.19). While not universally feasible in all patients, this method for quantifying diaphragmatic function is the only known imaging technique that can be performed at the bedside. Further evaluation of the impact of diaphragmatic dysfunction on patients undergoing thoracic surgery and its correlation with dyspnea is planned.

Ultrasound assessment of severe dehydration in children with diarrhea and vomiting

OBJECTIVES

The objective of this study was to determine the test characteristics for two different ultrasound (US) measures of severe dehydration in children (aorta to inferior vena cava [IVC] ratio and IVC inspiratory collapse) and one clinical measure of severe dehydration (the World Health Organization [WHO] dehydration scale).

METHODS

The authors enrolled a prospective cohort of children presenting with diarrhea and/or vomiting to three rural Rwandan hospitals. Children were assessed clinically using the WHO scale and then underwent US of the IVC by a second clinician. All children were weighed on admission and then fluid-resuscitated according to standard hospital protocols. A percent weight change between admission and discharge of greater than 10% was considered the criterion standard for severe dehydration. Receiver operating characteristic (ROC) curves were created for each of the three tests of severe dehydration compared to the criterion standard.

RESULTS

Children ranged in age from 1 month to 10 years; 29% of the children had severe dehydration according to the criterion standard. Of the three different measures of dehydration tested, only US assessment of the aorta/IVC ratio had an area under the ROC curve statistically different from the reference line. At its best cut-point, the aorta/IVC ratio had a sensitivity of 93% and specificity of 59%, compared with 93% and 35% for IVC inspiratory collapse and 73% and 43% for the WHO scale.

CONCLUSIONS

Ultrasound of the aorta/IVC ratio can be used to identify severe dehydration in children presenting with acute diarrhea and may be helpful in guiding clinical management.

Focused maternal ultrasound by midwives in rural Zambia

Point-of-care ultrasound is being increasingly implemented in resource-poor settings in an ad hoc fashion. We developed a focused maternal ultrasound-training program for midwives in a rural health district in Zambia. Four hundred forty-one scans were recorded by 21 midwives during the 6-month study period. In 74 scans (17%), the ultrasound findings prompted a change in clinical decision-making. Eight of the midwives were evaluated with a 14-question observed structured clinical examination (OSCE) and demonstrated a slight overall improvement with mean scores at 2 and 6 months of 10.0/14 (71%) and 11.6/14 (83%), respectively. Our pilot project demonstrates that midwives in rural Zambia can be trained to perform basic obstetric ultrasound and that it impacts clinical decision-making. Ultrasound skills were retained over the study period. More data is necessary to determine whether the introduction of ultrasound ultimately improves outcomes of pregnant women in rural Zambia.

Decreased sensitivity of lung ultrasound limited to the anterior chest in emergency department diagnosis of cardiogenic pulmonary edema: a retrospective analysis

Purposes

B-lines are vertical echogenic artifacts seen on lung ultrasound that allow bedside diagnosis of pulmonary edema. The BLUE protocol, published by Lichtenstein and Mezière, suggests that cardiogenic pulmonary edema is sufficiently ruled out in the ICU setting when B-lines are not predominant in the anterior chest (the B-profile). Our analysis sought to evaluate the sensitivity of the B-profile for ruling out pulmonary edema in the ED patient population.

Methods

The ultrasound lung scans of patients with confirmed official diagnoses of acute decompensated heart failure (ADHF) from two ED databases were retrospectively analyzed. 170 acutely dyspneic patients had complete studies (130 from one database and 40 from the other). The scans were reviewed using the B-profile definition for ruling out pulmonary edema and comparing that to an alternate scanning protocol that includes ultrasound evaluation of the lateral and anterior chest.

Results

Of the 170 ED patients with ADHF diagnoses, the B-profile missed 16.5% (n = 28) for a sensitivity of 83.5% (95% CI 77–89%). These 28 patients did not show anterior bilateral B-lines that fit the criteria for positive under the BLUE protocol. Moreover, 25% (7/28) of these missed patients had only lateral B-lines on their lung scans and B-lines would have been detected only by including scans of the lateral zones.

Conclusions

Limiting the sonographic lung examination to the anterior chest areas only will miss cases of ADHF in the dyspneic ED patients. The BLUE protocol (B-profile) may need to be modified to include examination of the lateral chest as necessary for ED patients with ADHF.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock

Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

Derivation and validation of a sensitive IMA cutpoint to predict cardiac events in patients with chest pain

OBJECTIVES

In patients with acute chest pain, we derived a cutpoint for ischaemia-modified albumin (IMA) and prospectively validated this cutpoint to predict 30-day major adverse cardiac events (MACEs).

METHODS

We prospectively recruited a derivation cohort (18-month period) to establish a serum IMA cutpoint targeting 80% sensitivity. This was followed by a prospective validation cohort study of emergency department patients with acute chest pain at two university hospitals over a 3-month period. A MACE was defined as myocardial infarction, revascularisation or death at 30-day follow-up.

RESULTS

In the derivation cohort of 151 patients, the IMA cutpoint that achieved 80% sensitivity for MACEs was 75 KU/litre. The sensitivity was prospectively validated in 171 patients consecutively enrolled, of whom 106 underwent multiple-biomarker analysis (19.8% MACE rate, 81% sensitivity of IMA). Furthermore, IMA by itself (81%, p<0.01) and in combination with initial highly sensitive cardiac troponin T (hsTnT) (90%, p<0.001) had significantly higher sensitivity than initial hsTnT (29%) for prediction of MACEs.

CONCLUSIONS

We prospectively validated the sensitive IMA cutpoint of 75 KU/litre with 80% sensitivity for MACEs in patients with acute chest pain. Our data suggest that IMA alone and in combination with initial hsTnT are more sensitive than the initial hsTnT for MACEs.

Financial impact of emergency department ultrasound

OBJECTIVES

There is limited information on the financial implications of an emergency department ultrasound (ED US) program. The authors sought to perform a fiscal analysis of an integrated ED US program.

METHODS

A retrospective review of billing data was performed for fiscal year (FY) 2007 for an urban academic ED with an ED US program. The ED had an annual census of 80,000 visits and 1,101 ED trauma activations. The ED is a core teaching site for a 4-year emergency medicine (EM) residency, has 35 faculty members, and has 24-hour availability of all radiology services including formal US. ED US is utilized as part of evaluation of all trauma activations and for ED procedures. As actual billing charges and reimbursement rates are institution-specific and proprietary information, relative value units (RVUs) and reimbursement based on the Centers for Medicare & Medicaid Services (CMS) 2007 fee schedule (adjusted for fixed diagnosis-related group [DRG] payments and bad debt) was used to determine revenue generated from ED US. To estimate potential volume, assumptions were made on improvement in documentation rate for diagnostic scans (current documentation rates based on billed volume versus diagnostic studies in diagnostic image database), with no improvements assumed for procedural ED US. Expenses consist of three components-capital costs, training costs, and ongoing operational costs-and were determined by institutional experience. Training costs were considered sunken expenses by this institution and were thus not included in the original return on investment (ROI) calculation, although for this article a second ROI calculation was done with training cost estimates included. For the purposes of analysis, certain key assumptions were made. We utilized a collection rate of 45% and hospitalization rates (used to adjust for fixed DRG payments) of 33% for all diagnostic scans, 100% for vascular access, and 10% for needle placement. An optimal documentation rate of 95% was used to estimate potential revenue.

RESULTS

In FY 2007, 486 limited echo exams of abdomen (current procedural terminology [CPT] 76705) and 480 limited echo cardiac exams were performed (CPT 93308) while there were 78 exams for US-guided vascular access (CPT 76937) and 36 US-guided needle placements when performing paracentesis, thoracentesis, or location of abscess for drainage (CPT 76492). Applying the 2007 CMS fee schedule and above assumptions, the revenue generated was 578 RVUs and $35,541 ($12,934 in professional physician fees and $22,607 in facility fees). Assuming optimal documentation rates for diagnostic ED US scans, ED US could have generated 1,487 RVUs and $94,593 ($33,953 in professional physician fees and $60,640 in facility fees). Program expenses include an initial capital expense (estimated at $120,000 for two US machines) and ongoing operational costs ($68,640 per year to cover image quality assurance review, continuing education, and program maintenance). Based on current revenue, there would be an annual operating loss, and thus an ROI cannot be calculated. However, if potential revenue is achieved, the annual operating income will be $22,846 per year with an ROI of 4.9 years to break even with initial investment.

CONCLUSIONS

Determining an ROI is a required procedure for any business plan for establishing an ED US program. Our analysis demonstrates that an ED US program that captures charges for trauma and procedural US and achieves the potential billing volume breaks even in less than 5 years, at which point it would generate a positive margin.