Diagnostic accuracy of prehospital lung ultrasound for acute decompensated heart failure: A systematic review and Meta-analysis

BACKGROUND

Lung ultrasound (LUS) reduces time to diagnosis and treatment of acute decompensated heart failure (ADHF) in emergency department (ED) patients with undifferentiated dyspnea. We conducted a systematic review to evaluate the diagnostic accuracy and clinical impact of LUS for ADHF in the prehospital setting.

METHODS

We performed a keyword search of multiple databases from inception through June 1, 2023. Included studies were those enrolling prehospital patients with undifferentiated dyspnea or suspected ADHF, and specifically diagnostic studies comparing prehospital LUS to a gold standard and intervention studies with a non-US comparator group. Title and abstract screening, full text review, risk of bias (ROB) assessments, and data extraction were performed by multiple authors. and adjudicated. The primary outcome was pooled sensitivity, specificity, and diagnostic likelihood ratios (LR) for prehospital LUS. A test-treatment threshold of 0.7 was applied based on prior ADHF literature in the ED. Intervention outcomes included mortality, mechanical ventilation, and time to HF specific treatment.

RESULTS

Eight diagnostic studies (n = 691) and two intervention studies (n = 70) met inclusion criteria. No diagnostic studies were low-ROB. Both intervention studies were critical-ROB, and not pooled. Pooled sensitivity and specificity of prehospital LUS for ADHF were 86.7% (95%CI:70.8%-94.6%) and 87.5% (78.2%-93.2%), respectively, with similar performance by physician vs. paramedic LUS and number of lung zones evaluated. Pooled LR+ and LR- were 7.27 (95% CI: 3.69-13.10) and 0.17 (95% CI: 0.06-0.34), respectively. Area under the summary receiver operating characteristic curve was 0.922. At the observed 42.4% ADHF prevalence (pre-test probability), positive pre-hospital LUS exceeded the 70% threshold to initiate treatment (post-test probability 84%, 80-88%).

CONCLUSIONS

LUS had similar diagnostic test characteristics for ADHF diagnosis in the prehospital setting as in the ED. A positive prehospital LUS may be sufficient to initiate early ADHF treatment based on published test-treatment thresholds. More studies are needed to determine the clinical impact of prehospital LUS.

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.

Prehospital lung ultrasound in acute heart failure: Impact on diagnosis and treatment

OBJECTIVE

Patients with acute heart failure (AHF) are commonly misdiagnosed and undertreated in the prehospital setting. These delays in diagnosis and treatment have a direct negative impact on patient outcomes. The goal of this study was to determine the diagnostic accuracy of paramedics with and without the use of lung ultrasound (LUS) for the diagnosis of AHF in patients with dyspnea in the prehospital setting. Secondarily, we assessed LUS impact on rate of and time to initiation of HF therapies.

METHODS

This was a prospective interventional study on a consecutive sample of patients transported to the hospital by one emergency medical services agency. Adult patients (>18 years) with a chief complaint of dyspnea were included. LUS was performed by trained paramedics and was defined as positive for AHF if both anterior-superior lung zones had greater than or equal to three B-lines or bilateral B-lines were visualized on a four-view protocol. Paramedic diagnosis was compared to hospital discharge diagnosis which served as the criterion standard.

RESULTS

Of the 264 included patients, 94 (35%) had a final diagnosis of AHF. Forty total patients had a LUS performed; 17 of these patients had a final diagnosis of AHF. Sensitivity and specificity for AHF by paramedics were 23% (95% confidence interval [CI] 0.14-0.34) and 97% (95% CI 0.92-0.99) without LUS and 71% (95% CI 0.44-0.88) and 96% (95% CI 0.76-0.99) with the use of LUS. In the 94 patients with AHF, 14% (11/77) received HF therapy prehospital without the use of LUS and 53% (9/17) with the use of LUS. LUS improved frequency of treatment by 39%. Median time to treatment was 21 min with LUS and 169 min without.

CONCLUSIONS

LUS improved paramedic sensitivity and accuracy for diagnosing AHF in the prehospital setting. LUS use led to higher rates of prehospital HF therapy initiation and significantly decreased time to treatment.

Comparison of pulmonary congestion severity using artificial intelligence-assisted scoring versus clinical experts: A secondary analysis of BLUSHED-AHF

AIM

Acute decompensated heart failure (ADHF) is the leading cause of cardiovascular hospitalizations in the United States. Detecting B-lines through lung ultrasound (LUS) can enhance clinicians' prognostic and diagnostic capabilities. Artificial intelligence/machine learning (AI/ML)-based automated guidance systems may allow novice users to apply LUS to clinical care. We investigated whether an AI/ML automated LUS congestion score correlates with expert's interpretations of B-line quantification from an external patient dataset.

METHODS AND RESULTS

This was a secondary analysis from the BLUSHED-AHF study which investigated the effect of LUS-guided therapy on patients with ADHF. In BLUSHED-AHF, LUS was performed and B-lines were quantified by ultrasound operators. Two experts then separately quantified the number of B-lines per ultrasound video clip recorded. Here, an AI/ML-based lung congestion score (LCS) was calculated for all LUS clips from BLUSHED-AHF. Spearman correlation was computed between LCS and counts from each of the original three raters. A total of 3858 LUS clips were analysed on 130 patients. The LCS demonstrated good agreement with the two experts' B-line quantification score (r = 0.894, 0.882). Both experts' B-line quantification scores had significantly better agreement with the LCS than they did with the ultrasound operator's score (p < 0.005, p < 0.001).

CONCLUSION

Artificial intelligence/machine learning-based LCS correlated with expert-level B-line quantification. Future studies are needed to determine whether automated tools may assist novice users in LUS interpretation.

External validation of the ultrasound competency assessment tool

Objective

Point-of-care ultrasound (POCUS) is a core component of emergency medicine (EM) residency training. No standardized competency-based tool has gained widespread acceptance. The ultrasound competency assessment tool (UCAT) was recently derived and validated. We sought to externally validate the UCAT in a 3-year EM residency program.

Methods

This was a convenience sample of PGY-1 to -3 residents. Utilizing the UCAT and an entrustment scale, as described in the original study, six different evaluators split into two groups graded residents in a simulated scenario involving a patient with blunt trauma and hypotension. Residents were asked to perform and interpret a focused assessment with sonography in trauma (FAST) examination and apply the findings to the simulated scenario. Demographics, prior POCUS experience, and self-assessed competency were collected. Each resident was evaluated simultaneously by three different evaluators with advanced ultrasound training utilizing the UCAT and entrustment scales. Intraclass correlation coefficient (ICC) between evaluators was calculated for each assessment domain; analysis of variance was used to compare UCAT performance and PGY level and prior POCUS experience.

Results

Thirty-two residents (14 PGY-1, nine PGY-2, and nine PGY-3) completed the study. Overall, ICC was 0.9 for preparation, 0.57 for image acquisition, 0.3 for image optimization, and 0.46 for clinical integration. There was moderate correlation between number of FAST examinations performed and entrustment and UCAT composite scores. There was poor correlation between self-reported confidence and entrustment and UCAT composite scores.

Conclusions

We had mixed results in our attempt to externally validate the UCAT with poor correlation between faculty and moderate to good correlation with faculty to diagnostic sonographer. More work is needed to validate the UCAT before adoption.

Evaluation of Point-of-Care Ultrasound Training for Family Physicians Using Teleultrasound

BACKGROUND AND OBJECTIVES

The goal of this study was to assess family physicians' change in knowledge and ability to perform abdominal aorta ultrasound after implementation of a novel teleultrasound curriculum.

METHODS

This was a prospective, observational study conducted at a single academic institution. Family physicians completed a preassessment, test, and objective structured clinical evaluation (OSCE). Physicians then individually completed a standard curriculum consisting of online content and an hour-long, hands-on training session on abdominal aorta ultrasound using teleultrasound technology. Physicians then performed a minimum of 10 independent examinations over a period of 8 weeks. After physicians completed the training curriculum and 10 independent scans, we administered a postassessment, test, and OSCE. We analyzed differences between pre- and postcurriculum responses using Fisher exact and Wilcoxon signed rank tests.

RESULTS

Thirteen family physicians completed the curriculum. Comparing pre- to postcurriculum responses, we found significant reductions in barriers to using aorta POCUS and improved confidence in using, obtaining, and interpreting aorta POCUS (P<0.01). Knowledge improved from a median score of 70% to 90% (P<0.01), and OSCE scores improved from a median of 80% to 100% (P=0.012). Overall, 211 aorta ultrasound examinations were independently acquired with a median image quality of 4 (scale 1 to 4).

CONCLUSIONS

After an 8-week teleultrasound curriculum, family physicians with minimal experience with POCUS showed improved knowledge and psychomotor skill in abdominal aorta POCUS.

Gamification of POCUS: Are Students Learning?

INTRODUCTION

While gamification of point-of-care ultrasound (POCUS) is well received by learners, little is known about the knowledge gained from material taught during these events. We set out to determine whether a POCUS gamification event improved knowledge of interpretation and clinical integration of POCUS.

METHODS

This was a prospective observational study of fourth-year medical students who participated in a 2.5-hour POCUS gamification event consisting of eight objective-oriented stations. Each station had one to three learning objectives associated with the content taught. Students completed a pre-assessment; they then participated in the gamification event in groups of three to five per station and subsequently completed a post-assessment. Differences between pre- and post-session responses were matched and analyzed using Wilcoxon signed-rank test and Fisher's exact test.

RESULTS

We analyzed data from 265 students with matched pre- and post-event responses; 217 (82%) students reported no to little prior POCUS experience. Most students were going into internal medicine (16%) and pediatrics (11%). Knowledge assessment scores significantly improved from pre- to post-workshop, 68% vs 78% (P=0.04). Self-reported comfort with image acquisition, interpretation, and clinical integration all significantly improved from pre- to post-gamification event (P<0.001).

CONCLUSION

In this study we found that gamification of POCUS, with clear learning objectives, led to improved student knowledge of POCUS interpretation, clinical integration, and self-reported comfort with POCUS.

Bedside lung ultrasound for the diagnosis of pneumonia in children presenting to an emergency department in a resource-limited setting

BACKGROUND

Lung ultrasound (LUS) is an effective tool for diagnosing pneumonia; however, this has not been well studied in resource-limited settings where pneumonia is the leading cause of death in children under 5 years of age.

OBJECTIVE

The objective of this study was to evaluate the diagnostic accuracy of bedside LUS for diagnosis of pneumonia in children presenting to an emergency department (ED) in a resource-limited setting.

METHODS

This was a prospective cross-sectional study of children presenting to an ED with respiratory complaints conducted in Nepal. We included all children under 5 years of age with cough, fever, or difficulty breathing who received a chest radiograph. A bedside LUS was performed and interpreted by the treating clinician on all children prior to chest radiograph. The criterion standard was radiographic pneumonia, diagnosed by a panel of radiologists using the Chest Radiography in Epidemiological Studies methodology. The primary outcome was sensitivity and specificity of LUS for the diagnosis of pneumonia. All LUS images were later reviewed and interpreted by a blinded expert sonographer.

RESULTS

Three hundred and sixty-six children were enrolled in the study. The median age was 16.5 months (IQR 22) and 57.3% were male. Eighty-four patients (23%) were diagnosed with pneumonia by chest X-ray. Sensitivity, specificity, positive and negative likelihood ratios for clinician's LUS interpretation was 89.3% (95% CI 81-95), 86.1% (95%CI 82-90), 6.4, and 0.12 respectively. LUS demonstrated good diagnostic accuracy for pneumonia with an area under the curve of 0.88 (95% CI 0.83-0.92). Interrater agreement between clinician and expert ultrasound interpretation was excellent (k = 0.85).

CONCLUSION

Bedside LUS when used by ED clinicians had good accuracy for diagnosis of pneumonia in children in a resource-limited setting.

Key lessons from the COVID-19 public health response in Australia

Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts. Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decision-making that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a 'standing threat', 10) regional and global solidarity is important. It should be acknowledged that we were unable to capture all relevant nuances and context specific differences. However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region.

Artificial Intelligence-Augmented Pediatric Lung POCUS: A Pilot Study of Novice Learners

OBJECTIVE

Respiratory symptoms are among the most common chief complaints of pediatric patients in the emergency department (ED). Point-of-care ultrasound (POCUS) outperforms conventional chest X-ray and is user-dependent, which can be challenging to novice ultrasound (US) users. We introduce a novel concept using artificial intelligence (AI)-enhanced pleural sweep to generate complete panoramic views of the lungs, and then assess its accuracy among novice learners (NLs) to identify pneumonia.

METHODS

Previously healthy 0- to 17-year-old patients presenting to a pediatric ED with cardiopulmonary chief complaint were recruited. NLs received a 1-hour training on traditional lung POCUS and the AI-assisted software. Two POCUS-trained experts interpreted the images, which served as the criterion standard. Both expert and learner groups were blinded to each other's interpretation, patient data, and outcomes. Kappa was used to determine agreement between POCUS expert interpretations.

RESULTS

Seven NLs, with limited to no prior POCUS experience, completed examinations on 32 patients. The average patient age was 5.53 years (±1.07). The median scan time of 7 minutes (minimum-maximum 3-43; interquartile 8). Three (8.8%) patients were diagnosed with pneumonia by criterion standard. Sensitivity, specificity, and accuracy for NLs AI-augmented interpretation were 66.7% (confidence interval [CI] 9.4-99.1%), 96.5% (CI 82.2-99.9%), and 93.7% (CI 79.1-99.2%). The average image quality rating was 2.94 (±0.16) out of 5 across all lung fields. Interrater reliability between expert sonographers was high with a kappa coefficient of 0.8.

CONCLUSION

This study shows that AI-augmented lung US for diagnosing pneumonia has the potential to increase accuracy and efficiency.

Piloting a Graduate Medical Education Point-of-Care Ultrasound Curriculum

Objective

As point-of-care ultrasound (POCUS) use grows, training in graduate medical education (GME) is increasingly needed. We piloted a multispecialty GME POCUS curriculum and assessed feasibility, knowledge, and comfort with performing POCUS exams.

Methods

Residents were selected from the following residency programs: internal medicine, family medicine, emergency medicine, and a combined internal medicine/pediatrics program. Didactics occurred through an online curriculum that consisted of five modules: physics and machine operation, cardiac, lung, soft tissue, and extended focused sonography in trauma applications. Residents completed a pre- and post-curriculum questionnaire, as well as knowledge assessments before and after each module. One-hour hands-on training sessions were held for each module. Differences between pre- and post-participation questionnaire responses were analyzed using the Wilcoxon rank sum.

Results

Of the 24 residents selected, 21 (86%) were post-graduate year two or three, and 16 (65%) were from the internal medicine program. Eighteen (67%) residents reported limited prior POCUS experience. All pre- to post-knowledge assessment scores increased (p<0.05). Statistically significant increases pre- to post-curriculum were found for frequency of POCUS use (p = 0.003), comfort in using POCUS for assessing for abdominal aortic aneurysm, soft tissue abscess detection, undifferentiated hypotension and dyspnea, cardiac arrest and heart failure (p<0.025); and competency in machine use, acquiring and interpreting images and incorporating POCUS into clinical practice (p<0.001). All participants felt the skills learned during this curriculum were essential to their future practice.

Conclusions

In this pilot, we found using a combination of online and hands-on training to be feasible, with improvement in residents’ knowledge, comfort, and use of POCUS.

Prehospital Diagnosis and Treatment of Patients With Acute Heart Failure

Introduction 

Early diagnosis and optimization of heart failure therapies in patients with acute heart failure (AHF), including in the prehospital setting, is crucial to improving outcomes. However, making the diagnosis of AHF in the prehospital setting is difficult. The goal of this study was to evaluate the accuracy of prehospital diagnosis (AHF versus not heart failure [HF]) in patients with acute dyspnea when compared to final hospital diagnosis.

Methods

We conducted a retrospective study of adult patients transported by emergency medical services (EMS) with a primary or secondary complaint of shortness of breath. Patients were identified through an EMS electronic database (ESO) and matched to their hospital encounter. ESO was reviewed for prehospital diagnosis and management. Hospital electronic medical records were reviewed to determine final hospital diagnosis, management in the emergency department and hospital, disposition, and length of stay. The primary outcome compared prehospital diagnosis to final hospital diagnosis, which served as our criterion standard.

Results

Of 199 included patients, 50 (25%) had a final diagnosis of AHF. Prehospital paramedic sensitivity and accuracy for AHF were 14% (7/50; confidence interval [CI] 0.06-0.26) and 77% (CI 0.70-0.82), respectively. In the 50 patients with AHF, 14 (28%) received nitroglycerin in the prehospital setting, while 27 (54.0%) patients were inappropriately treated with albuterol.

Conclusion

Prehospital paramedics had poor sensitivity and moderate accuracy for the diagnosis of AHF. A small percentage of patients ultimately diagnosed with AHF had HF therapy initiated in the prehospital setting. This data highlights the fact that AHF is difficult to diagnose in the prehospital setting and is commonly missed.

Point-of-Care Ultrasound Education During a Pandemic: From Webinar to Progressive Dinner-Style Bedside Learning

Objective: Point-of-care ultrasound (POCUS), traditionally, requires the proximity of learners and educators, making POCUS education challenging during the COVID-19 pandemic. We set out to evaluate three alternate approaches to teaching POCUS in UME. Sessions progressed from an online seminar to a remote, interactive simulation to a “progressive dinner” style session, as precautions evolved throughout the pandemic.

Methods: This prospective study details a series of three POCUS workshops that were designed to align with prevailing social distancing precautions during the COVID-19 pandemic. Overall, 656 medical students were included. The first and second workshops used web-based conferencing technology with real-time ultrasound imaging, with the second workshop focusing on clinical integration through simulation. As distancing precautions were updated, a novel “progressive dinner” technique was used for the third workshop. Surveys were conducted after each session to obtain feedback on students’ attitudes toward alternative teaching techniques and quantitative and qualitative analyses were used.

Results: The initial, remote POCUS workshop was performed for 180 medical students. Ninety-nine (177) percent of students felt the session was “intellectually challenging” and “stimulating.” Ninety-nine percent of students (340/344), after the second workshop, indicated the session was intellectually challenging, stimulating, and a positive learning experience. Students' ability to correctly identify pathologic images increased post-session evaluation from in-session polling. For workshop three, 99% (107/108) of students indicated that the session was “informative.” There was a significant improvement in pre- to post-workshop knowledge regarding image acquisition, interpretation, and clinical integration.

Conclusion: While image acquisition skills are best conveyed at the bedside, these modified POCUS teaching techniques developed and delivered in alignment with COVID-19 pandemic restrictions during a series of three workshops were shown to be effective surrogates for traditional teaching approaches when social distancing requirements, a large learner pool, or lack of local expertise exist.

The State of Point-of-Care Ultrasound Training in Undergraduate Medical Education: Findings From a National Survey

PURPOSE

The primary aim of this study was to evaluate the current state of point-of-care ultrasound (POCUS) integration in undergraduate medical education (UME) at MD-granting medical schools in the United States.

METHOD

In 2020, 154 clinical ultrasound directors and curricular deans at MD-granting medical schools were surveyed. The 25-question survey collected data about school characteristics, barriers to POCUS training implementation, and POCUS curriculum details. Descriptive analysis was conducted using frequency and percentage distributions.

RESULTS

One hundred twenty-two (79%) of 154 schools responded to the survey, of which 36 were multicampus. Sixty-nine (57%) schools had an approved POCUS curriculum, with 10 (8%) offering a longitudinal 4-year curriculum. For a majority of schools, POCUS instruction was required during the first year (86%) and second year (68%). Forty-two (61%) schools were teaching fundamentals, diagnostic, and procedural ultrasound. One hundred fifteen (94%) schools identified barriers to implementing POCUS training in UME, which included lack of trained faculty (63%), lack of time in current curricula (54%), and lack of equipment (44%). Seven (6%) schools identified no barriers.

CONCLUSIONS

Over half of the responding medical schools in the United States had integrated POCUS instruction into their UME curricula. Despite this, a very small portion had a longitudinal curriculum and multiple barriers existed for implementation, with the most common being lack of trained faculty. The data from this study can be used by schools planning to add or expand POCUS instruction within their current curricula.

Success of implementation of a systemwide point-of-care ultrasound privileging program for emergency medicine faculty

OBJECTIVES

Point-of-care ultrasound (POCUS) is widely used in the emergency department (ED). Not all practicing emergency physicians received POCUS training during residency, leaving a training gap that is reflected in POCUS privileging. The purpose of this study was to evaluate the success of meeting privileging criteria as well as associated factors, following implementation of a basic POCUS training and privileging program within a large emergency medicine department.

METHODS

We implemented a POCUS training and privileging program, based on national guidelines, for faculty physicians who worked at one of the following EDs staffed by the same emergency medicine department: a pediatric tertiary site, two tertiary academic sites, and seven community sites. POCUS examinations included aorta, cardiac, first-trimester obstetrics (OB), and extended focused assessment with sonography in trauma. Pediatric emergency medicine faculty were taught soft tissue and thoracic US instead of aorta and OB. Completion of the program required 16 h of didactics, ≥25 quality-assured US examinations by examination type, and passing a series of knowledge-based examinations. Descriptive statistics were calculated. Associations between physician characteristics and successfully becoming privileged in POCUS were modeled using Firth's logistic regression.

RESULTS

A total of 176 faculty physicians were eligible. A total of 145 (82.4%) achieved basic POCUS privileging during the study period. Different pathways were used including 86 (48.9%) practice-based, nine (5.1%) fellowship-based, and 82 (46.9%) residency-based. POCUS privileging was lower for those working in a community versus academic setting (odds ratio 0.3, 95% confidence interval 0.1-0.9). A greater number of scans completed prior to the privileging program was associated with greater success.

CONCLUSIONS

Implementation of a POCUS training and privileging program can be successful in a large emergency medicine department that staffs hospitals in a large-scale health care system composed of both academic and community sites. Faculty physicians with at least some prior exposure to POCUS were more successful.

Design and implementation of a basic and global point of care ultrasound (POCUS) certification curriculum for emergency medicine faculty

Point of care ultrasound (POCUS) use in the emergency department is associated with improved patient outcomes and increased patient satisfaction. When used for procedural guidance, it has been shown to increase first pass success and decrease complications. As of 2012, ultrasound has been identified as a core skill required for graduating emergency medicine (EM) residents. Despite this, only a minority of EM faculty who trained prior to 2008 are credentialed in POCUS. Half of all EM training programs in the United States have less than 50% of their faculty credentialed to perform and teach POCUS to learners. As the use of POCUS continues to grow in medicine, it is especially important to have a pathway for faculty to attain competence and become credentialed in POCUS. The goal of this paper was to outline an implementation process of a curriculum designed to credential EM faculty in POCUS.

Teaching Seasoned Doctors New Technology: An Intervention to Reduce Barriers and Improve Comfort With Clinical Ultrasound

Introduction Although clinical ultrasound (CUS) is a core skill that is a requirement for emergency medicine (EM) residency graduation, only a fraction of EM practitioners who trained prior to this requirement are certified in CUS. The objective of the study was to implement a CUS workshop for practicing EM physicians, identify barriers to utilization, and assess comfort with the machine, obtaining and interpreting images, and incorporating CUS into clinical practice. Methods This was a prospective descriptive cohort study of EM physician faculty who participated in an interactive 5-hour CUS workshop intervention that introduced four core CUS modalities via didactics and hands-on scanning stations. Pre- and post-surveys were administered to identify barriers to utilization and assess perceived comfort with CUS using a 5-point Likert scale. Results were analyzed using Fisher's exact and paired t-tests. Results Thirty-five EM physicians participated with a 100% survey response rate. Only five of the physicians were ultrasound certified at the time of the workshop. On average, physicians were 16 years post-residency. Prior to the workshop, 29% had minimal ultrasound experience and 43% had not performed more than 50 ultrasounds. In the pre-course survey, every physician expressed at least one barrier to CUS utilization. Post-workshop, physicians felt significantly more comfortable using the ultrasound machine (p=0.0008), obtaining and interpreting images (p=0.0009 and p=0.0004), and incorporating CUS into clinical practice (p=0.002). Conclusion This workshop is an effective tool to expose practicing physicians to core concepts of CUS, improve their comfort level, and reduce barriers to ultrasound utilization.

Lung Ultrasound-Guided Emergency Department Management of Acute Heart Failure (BLUSHED-AHF): A Randomized Controlled Pilot Trial

OBJECTIVES

The goal of this study was to determine whether a 6-hour lung ultrasound (LUS)-guided strategy-of-care improves pulmonary congestion over usual management in the emergency department (ED) setting. A secondary goal was to explore whether early targeted intervention leads to improved outcomes.

BACKGROUND

Targeting pulmonary congestion in acute heart failure remains a key goal of care. LUS B-lines are a semi-quantitative assessment of pulmonary congestion. Whether B-lines decrease in patients with acute heart failure by targeting therapy is not well known.

METHODS

A multicenter, single-blind, ED-based, pilot trial randomized 130 patients to receive a 6-hour LUS-guided treatment strategy versus structured usual care. Patients were followed up throughout hospitalization and 90 days' postdischarge. B-lines ≤15 at 6 h was the primary outcome, and days alive and out of hospital (DAOOH) at 30 days was the main exploratory outcome.

RESULTS

No significant difference in the proportion of patients with B-lines ≤15 at 6 hours (25.0% LUS vs 27.5% usual care; P = 0.83) or the number of B-lines at 6 hours (35.4 ± 26.8 LUS vs 34.3 ± 26.2 usual care; P = 0.82) was observed between groups. There were also no differences in DAOOH (21.3 ± 6.6 LUS vs 21.3 ± 7.1 usual care; P = 0.99). However, a significantly greater reduction in the number of B-lines was observed in LUS-guided patients compared with those receiving usual structured care during the first 48 hours (P = 0.04).

CONCLUSIONS

In this pilot trial, ED use of LUS to target pulmonary congestion conferred no benefit compared with usual care in reducing the number of B-lines at 6 hours or in 30 days DAOOH. However, LUS-guided patients had faster resolution of congestion during the initial 48 hours. (B-lines Lung Ultrasound-Guided ED Management of Acute Heart Failure Pilot Trial; NCT03136198).

Lung ultrasound training and evaluation for proficiency among physicians in a low-resource setting

Background

Lung ultrasound (LUS) is helpful for the evaluation of patients with dyspnea in the emergency department (ED). However, it remains unclear how much training and how many LUS examinations are needed for ED physicians to obtain proficiency. The objective of this study was to determine the threshold number of LUS physicians need to perform to achieve proficiency for interpreting LUS on ED patients with dyspnea.

Methods

A prospective study was performed at Patan Hospital in Nepal, evaluating proficiency of physicians novice to LUS. After eight hours of didactics and hands-on training, physicians independently performed and interpreted ultrasounds on patients presenting to the ED with dyspnea. An expert sonographer blinded to patient data and LUS interpretation reviewed images and provided an expert interpretation. Interobserver agreement was performed between the study physician and expert physician interpretation. Cumulative sum analysis was used to determine the number of scans required to attain an acceptable level of training.

Results

Nineteen physicians were included in the study, submitting 330 LUS examinations with 3288 lung zones. Eighteen physicians (95%) reached proficiency. Physicians reached proficiency for interpreting LUS accurately when compared to an expert after 4.4 (SD 2.2) LUS studies for individual zone interpretation and 4.8 (SD 2.3) studies for overall interpretation, respectively.

Conclusions

Following 1 day of training, the majority of physicians novice to LUS achieved proficiency with interpretation of lung ultrasound after less than five ultrasound examinations performed independently.

B-line quantification: comparing learners novice to lung ultrasound assisted by machine artificial intelligence technology to expert review

BACKGROUND

The goal of this study was to assess the ability of machine artificial intelligence (AI) to quantitatively assess lung ultrasound (LUS) B-line presence using images obtained by learners novice to LUS in patients with acute heart failure (AHF), compared to expert interpretation.

METHODS

This was a prospective, multicenter observational study conducted at two urban academic institutions. Learners novice to LUS completed a 30-min training session on lung image acquisition which included lecture and hands-on patient scanning. Learners independently acquired images on patients with suspected AHF. Automatic B-line quantification was obtained offline after completion of the study. Machine AI counted the maximum number of B-lines visualized during a clip. The criterion standard for B-line counts was semi-quantitative analysis by a blinded point-of-care LUS expert reviewer. Image quality was blindly determined by an expert reviewer. A second expert reviewer blindly determined B-line counts and image quality. Intraclass correlation was used to determine agreement between machine AI and expert, and expert to expert.

RESULTS

Fifty-one novice learners completed 87 scans on 29 patients. We analyzed data from 611 lung zones. The overall intraclass correlation for agreement between novice learner images post-processed with AI technology and expert review was 0.56 (confidence interval [CI] 0.51-0.62), and 0.82 (CI 0.73-0.91) between experts. Median image quality was 4 (on a 5-point scale), and correlation between experts for quality assessment was 0.65 (CI 0.48-0.82).

CONCLUSION

After a short training session, novice learners were able to obtain high-quality images. When the AI deep learning algorithm was applied to those images, it quantified B-lines with moderate-to-fair correlation as compared to semi-quantitative analysis by expert review. This data shows promise, but further development is needed before widespread clinical use.

Nasopharyngeal Pneumococcal Colonization Density is Associated with Severe Pneumonia in Young Children in the Lao PDR

Background

No studies have explored the association between pneumococcal nasopharyngeal density and severe pneumonia using the World Health Organization (WHO) 2013 definition. In Lao People’s Democratic Republic (Lao PDR), we determine the association between nasopharyngeal pneumococcal density and severe pneumonia in children.

Methods

A prospective observational study was undertaken at Mahosot Hospital, Vientiane, from 2014 to mid-2018. Children <5 years admitted with acute respiratory infections (ARIs) were included. Clinical and demographic data were collected alongside nasopharyngeal swabs for pneumococcal quantification by lytA real-time quantitative polymerase chain reaction. Severe pneumonia was defined using the 2013 WHO definition. For pneumococcal carriers, a logistic regression model examined the association between pneumococcal density and severe pneumonia, after adjusting for potential confounders including demographic and household factors, 13-valent pneumococcal conjugate vaccine status, respiratory syncytial virus co-detection, and preadmission antibiotics.

Results

Of 1268 participants with ARI, 32.3% (n = 410) had severe pneumonia and 36.9% (n = 468) had pneumococcal carriage. For pneumococcal carriers, pneumococcal density was positively associated with severe pneumonia (adjusted odds ratio, 1.4 [95% confidence interval, 1.1–1.8]; P = .020).

Conclusions

Among children with ARIs and pneumococcal carriage, pneumococcal carriage density was positively associated with severe pneumonia in Lao PDR. Further studies may determine if pneumococcal density is a useful marker for pneumococcal conjugate vaccine impact on childhood pneumonia.

Development and implementation of a point of care ultrasound curriculum at a multi-site institution

In 2014, over 60% of medical schools were incorporating point of care ultrasound (POCUS) into their curriculum. Today, over 6 years later, many more schools are teaching POCUS or are in the planning stages of implementing a POCUS curriculum. In 2019, the AAMC reported that 53 schools or over one-third of US medical schools have multi-site campuses for undergraduate medical education. Implementation of a POCUS educational initiative at a multi-site campus presents unique challenges for teaching a uniform curriculum statewide. This article will discuss the POCUS curriculum and implementation process at a large multi-site institution.

Training the Trainer: Faculty From Across Multiple Specialties Show Improved Confidence, Knowledge and Skill in Point of Care Ultrasound After a Short Intervention

Objectives  Lack of faculty skill and confidence in performing and teaching point-of-care ultrasound (POCUS) remains a significant barrier to implementation of a longitudinal ultrasound curriculum in undergraduate medical education. Our objective was to assess faculty comfort, knowledge and skill with performing and teaching POCUS before and after a focused workshop. Methods  This was a prospective study assessing faculty from multiple specialties. Faculty completed a pre- and post-workshop survey and ultrasound knowledge assessment, and a post-workshop objective structured clinical examination (OSCE) to assess ability to perform POCUS. Differences between pre- and post-workshop responses were analyzed using Fisher's Exact and Wilcoxon tests, and statistical significance was accepted for p<0.05. Results We analyzed data on 78 faculty from multiple disciplines. Faculty had a median of 7.5 years of experience with medical student teaching. Sixty-eight percent of faculty had performed <25 prior ultrasound (US) examinations. Comparing pre- to post-workshop responses, we found significant reductions in barriers to using US, and improved confidence with using, obtaining and interpreting POCUS (p<0.01). Faculty felt significantly more comfortable with the idea of teaching medical students POCUS (p<0.01). POCUS knowledge improved from 50% to 86% (p<0.01). On the post-workshop OSCE, 90% of anatomic structures were correctly identified with a median image quality of 4 out of 5. Conclusion After attending a six-hour workshop, faculty across multiple specialties had increased confidence with using and teaching POCUS, showed improved knowledge, and were able to correctly identify pertinent anatomic structures with ultrasound while obtaining good image quality.

What are the minimum requirements to establish proficiency in lung ultrasound training for quantifying B-lines?

AIMS

The goal of this study was to determine the number of scans needed for novice learners to attain proficiency in B-line quantification compared with expert interpretation.

METHODS AND RESULTS

This was a prospective, multicentre observational study of novice learners, physicians and non-physicians from three academic institutions. Learners received a 2 h lung ultrasound (LUS) training session on B-line assessment, including lecture, video review to practice counting and hands-on patient scanning. Learners quantified B-lines using an eight-zone scanning protocol in patients with suspected acute heart failure. Ultrasound (US) machine settings were standardized to a depth of 18 cm and clip length of 6 s, and tissue harmonics and multibeam former were deactivated. For quantification, the intercostal space with the greatest number of B-lines within each zone was used for scoring. Each zone was given a score of 0-20 based on the maximum number of B-lines counted during one respiratory cycle. The B-line score was determined by multiplying the percentage of the intercostal space filled with B-lines by 20. We compared learner B-line counts with a blinded expert reviewer (five US fellowship-trained faculty with > 5 years of clinical experience) for each lung zone scanned; proficiency was defined as an intraclass correlation of > 0.7. Learning curves for each learner were constructed using cumulative sum method for statistical analysis. The Wilcoxon rank-sum test was used to compare the number of scans required to reach proficiency between different learner types. Twenty-nine learners (21 research associates, 5 residents and 3 non-US-trained emergency medicine faculty) scanned 2629 lung zones with acute pulmonary oedema. After a mean of 10.8 (standard deviation 14.0) LUS zones scanned, learners reached the predefined proficiency standard. The number of scanned zones required to reach proficiency was not significantly different between physicians and non-physicians (P = 0.26), learners with no prior US experience vs. > 25 prior patient scans (P = 0.64) and no prior vs. some prior LUS experience (P = 0.59). The overall intraclass correlation for agreement between learners and experts was 0.74 and 0.80 between experts.

CONCLUSIONS

Our results show that after a short, structured training, novice learners are able to achieve proficiency for quantifying B-lines on LUS after scanning 11 zones. These findings support the use of LUS for B-line quantification by non-physicians in clinical and research applications.

Impact of bedside lung ultrasound on physician clinical decision-making in an emergency department in Nepal

Background

Lung ultrasound is an effective tool for the evaluation of undifferentiated dyspnea in the emergency department. Impact of lung ultrasound on clinical decisions for the evaluation of patients with dyspnea in resource-limited settings is not well-known. The objective of this study was to evaluate the impact of lung ultrasound on clinical decision-making for patients presenting with dyspnea to an emergency department in the resource-limited setting of Nepal.

Methods

A prospective, cross-sectional study of clinicians working in the Patan Hospital Emergency Department was performed. Clinicians performed lung ultrasounds on patients presenting with dyspnea and submitted ultrasounds with their pre-test diagnosis, lung ultrasound interpretation, post-test diagnosis, and any change in management.

Results

Twenty-two clinicians participated in the study, completing 280 lung ultrasounds. Diagnosis changed in 124 (44.3%) of patients with dyspnea. Clinicians reported a change in management based on the lung ultrasound in 150 cases (53.6%). Of the changes in management, the majority involved treatment (83.3%) followed by disposition (13.3%) and new consults (2.7%).

Conclusions

In an emergency department in Nepal, bedside lung ultrasound had a significant impact on physician clinical decision-making, especially on patient diagnosis and treatment.

Abscess Size and Depth on Ultrasound and Association with Treatment Failure without Drainage

Introduction

Skin and soft tissue infections (SSTI) occur along a continuum from cellulitis to abscess. Point-of-care ultrasound (POCUS) is effective in differentiating between these two diagnoses and guiding acute management decisions. Smaller and more superficial abscesses may not require a drainage procedure for cure. The goal of this study was to evaluate the optimal abscess size and depth cut-off for determining when a drainage procedure is necessary.

Methods

We conducted a retrospective study of adult patients with a SSTI who had POCUS performed. Patients were identified through an ultrasound database. We reviewed examinations for the presence, size, and depth of abscess. Medical records were reviewed to determine acute ED management and assess outcomes. The primary outcome evaluated the optimal abscess size and depth when a patient could be safely discharged without a drainage procedure. We defined a treatment failure as a return visit within seven days requiring admission, change in antibiotics, or drainage procedure.

Results

A total of 162 patients had an abscess confirmed on POCUS and were discharged from the ED without a drainage procedure. The optimal cut-off to predict treatment failure by receiver operating curve analysis was 1.3 centimeters (cm) in longest dimension with a sensitivity of 85% and specificity of 37% (area under the curve [AUC] 0.60, 95% confidence interval [CI], 0.44–0.76), and 0.4cm in depth with a sensitivity of 85% and specificity of 68% (AUC 0.83, 95% CI, 0.74–93).

Conclusion

This retrospective data suggests that abscesses greater than 0.4 cm in depth from the skin surface may require a drainage procedure. Those less than 0.4 cm in depth may not require a drainage procedure and may be safely treated with antibiotics alone. Further prospective data is needed to validate these findings and to assess for an optimal size cut-off when a patient with a skin abscess may be discharged without a drainage procedure.

Design and rationale of the B-lines lung ultrasound guided emergency department management of acute heart failure (BLUSHED-AHF) pilot trial

BACKGROUND

Medical treatment for acute heart failure (AHF) has not changed substantially over the last four decades. Emergency department (ED)-based evidence for treatment is limited. Outcomes remain poor, with a 25% mortality or re-admission rate within 30days post discharge. Targeting pulmonary congestion, which can be objectively assessed using lung ultrasound (LUS), may be associated with improved outcomes.

METHODS

BLUSHED-AHF is a multicenter, randomized, pilot trial designed to test whether a strategy of care that utilizes a LUS-driven treatment protocol outperforms usual care for reducing pulmonary congestion in the ED. We will randomize 130 ED patients with AHF across five sites to, a) a structured treatment strategy guided by LUS vs. b) a structured treatment strategy guided by usual care. LUS-guided care will continue until there are ≤15 B-lines on LUS or 6h post enrollment. The primary outcome is the proportion of patients with B-lines ≤ 15 at the conclusion of 6 h of management. Patients will continue to undergo serial LUS exams during hospitalization, to better understand the time course of pulmonary congestion. Follow up will occur through 90days, exploring days-alive-and-out-of-hospital between the two arms. The study is registered on ClinicalTrials.gov (NCT03136198).

CONCLUSION

If successful, this pilot study will inform future, larger trial design on LUS driven therapy aimed at guiding treatment and improving outcomes in patients with AHF.

Clinical Ultrasound Is Safe and Highly Specific for Acute Appendicitis in Moderate to High Pre-test Probability Patients

Introduction

Clinical ultrasound (CUS) is highly specific for the diagnosis of acute appendicitis but is operator-dependent. The goal of this study was to determine if a heterogeneous group of emergency physicians (EP) could diagnose acute appendicitis on CUS in patients with a moderate to high pre-test probability.

Methods

This was a prospective, observational study of a convenience sample of adult and pediatric patients with suspected appendicitis. Sonographers received a structured, 20-minute CUS training on appendicitis prior to patient enrollment. The presence of a dilated (>6 mm diameter), non-compressible, blind-ending tubular structure was considered a positive study. Non-visualization or indeterminate studies were considered negative. We collected pre-test probability of acute appendicitis based on a 10-point visual analog scale (moderate to high was defined as >3), and confidence in CUS interpretation. The primary objective was measured by comparing CUS findings to surgical pathology and one week follow-up.

Results

We enrolled 105 patients; 76 had moderate to high pre-test probability. Of these, 24 were children. The rate of appendicitis was 36.8% in those with moderate to high pre-test probability. CUS were recorded by 33 different EPs. The sensitivity, specificity, and positive and negative likelihood ratios of EP-performed CUS in patients with moderate to high pre-test probability were 42.8% (95% confidence interval [CI] [25–62.5%]), 97.9% (95% CI [87.5–99.8%]), 20.7 (95% CI [2.8–149.9]) and 0.58 (95% CI [0.42–0.8]), respectively. The 16 false negative scans were all interpreted as indeterminate. There was one false positive CUS diagnosis; however, the sonographer reported low confidence of 2/10.

Conclusion

A heterogeneous group of EP sonographers can safely identify acute appendicitis with high specificity in patients with moderate to high pre-test probability. This data adds support for surgical consultation without further imaging beyond CUS in the appropriate clinical setting.

Diagnostic use of lung ultrasound compared to chest radiograph for suspected pneumonia in a resource-limited setting

Background

Lung ultrasound is an effective tool for diagnosing pneumonia in developed countries. Diagnostic accuracy in resource-limited countries where pneumonia is the leading cause of death is unknown. The objective of this study was to evaluate the sensitivity of bedside lung ultrasound compared to chest X-ray for pneumonia in adults presenting for emergency care in a low-income country.

Methods

Patients presenting to the emergency department with suspected pneumonia were evaluated with bedside lung ultrasound, single posterioranterior chest radiograph, and computed tomography (CT). Using CT as the gold standard, the sensitivity of lung ultrasound was compared to chest X-ray for the diagnosis of pneumonia using McNemar’s test for paired samples. Diagnostic characteristics for each test were calculated.

Results

Of 62 patients included in the study, 44 (71%) were diagnosed with pneumonia by CT. Lung ultrasound demonstrated a sensitivity of 91% compared to chest X-ray which had a sensitivity of 73% (p = 0.01). Specificity of lung ultrasound and chest X-ray were 61 and 50% respectively.

Conclusions

Bedside lung ultrasound demonstrated better sensitivity than chest X-ray for the diagnosis of pneumonia in Nepal.

Trial registration

ClinicalTrials.gov, registration number NCT02949141. Registered 31 October 2016.

High rate of isolated right ventricular dysfunction in patients with non-significant CT pulmonary angiography

BACKGROUND

Right ventricular (RV) dysfunction and pulmonary hypertension (PH) are commonly unrecognized in the emergency department (ED), but are associated with poor outcomes. Prior research has found a 30% prevalence of isolated RV dysfunction in ED patients after non-significant computed tomographic pulmonary angiography (CTPA). We aimed to prospectively define the prevalence of RV dysfunction and/or PH in short of breath ED patients, and assess outcomes.

METHODS

Prospective observational study of patients with a non-significant CTPA. Isolated RV dysfunction and/or PH was defined as normal left ventricular function plus RV dilation, moderate to severe tricuspid regurgitation or RV systolic pressure>40mmHg on comprehensive echocardiography.

RESULTS

Of 83 patients, 20 (24%, 95% [confidence interval] CI: 16-34%) had isolated RV dysfunction and/or PH. These patients had 40% ED recidivism and 30% hospital readmission at 30-days. When compared to patients with normal echocardiographic function, they had significantly longer intensive care unit and hospital length of stays.

CONCLUSIONS

In a prospective cohort of ED patients, we found a high prevalence of isolated RV dysfunction and/or PH after a non-significant CTPA. These patients had high rates of recidivism and hospital readmission. This data supports a continued need for ED based screening and specialty referral.

A novel genetic variant of Streptococcus pneumoniae serotype 11A discovered in Fiji

Objectives

As part of annual cross-sectional Streptococcus pneumoniae carriage surveys in Fiji (2012–2015), we detected pneumococci in over 100 nasopharyngeal swabs that serotyped as ‘11F-like’ by microarray. We examined the genetic basis of this divergence in the 11F-like capsular polysaccharide (cps) locus compared to the reference 11F cps sequence. The impact of this diversity on capsule phenotype, and serotype results using genetic and serologic methods were determined.

Methods

Genomic DNA from representative 11F-like S. pneumoniae isolates obtained from the nasopharynx of Fijian children was extracted and subject to whole genome sequencing. Genetic and phylogenetic analyses were used to identify genetic changes in the cps locus. Capsular phenotypes were evaluated using the Quellung reaction and latex agglutination.

Results

Compared to published 11F sequences, the wcwC and wcrL genes of the 11F-like cps locus are phylogenetically divergent, and the gct gene contains a single nucleotide insertion within a homopolymeric region. These changes within the DNA sequence of the 11F-like cps locus have modified the antigenic properties of the capsule, such that 11F-like isolates serotype as 11A by Quellung reaction and latex agglutination.

Conclusions

This study demonstrates the ability of molecular serotyping by microarray to identify genetic variants of S. pneumoniae and highlights the potential for discrepant results between phenotypic and genotypic serotyping methods. We propose that 11F-like isolates are not a new serotype but rather are a novel genetic variant of serotype 11A. These findings have implications for invasive pneumococcal disease surveillance as well as studies investigating vaccine impact.

Emergency Physicians Are Able to Detect Right Ventricular Dilation With Good Agreement Compared to Cardiology

OBJECTIVE

Focused cardiac ultrasound (FOCUS) is a useful tool in evaluating patients presenting to the emergency department (ED) with acute dyspnea. Prior work has shown that right ventricular (RV) dilation is associated with repeat hospitalizations and shorter life expectancy. Traditionally, RV assessment has been evaluated by cardiologist-interpreted comprehensive echocardiography. The primary goal of this study was to determine the inter-rater reliability between emergency physicians (EPs) and a cardiologist for determining RV dilation on FOCUS performed on ED patients with acute dyspnea.

METHODS

This was a prospective, observational study at two urban academic EDs; patients were enrolled if they had acute dyspnea and a computed tomographic pulmonary angiogram without acute disease. All patients had an EP-performed FOCUS to assess for RV dilation. RV dilation was defined as an RV to left ventricular ratio greater than 1. FOCUS interpretations were compared to a blinded cardiologist FOCUS interpretation using agreement and kappa statistics.

RESULTS

Of 84 FOCUS examinations performed on 83 patients, 17% had RV dilation. Agreement and kappa, for EP-performed FOCUS for RV dilation were 89% (95% confidence interval [CI] 80-95%) and 0.68 (95% CI 0.48-0.88), respectively.

CONCLUSIONS

Emergency physician sonographers are able to detect RV dilation with good agreement when compared to cardiology. These results support the wider use of EP-performed FOCUS to evaluate for RV dilation in ED patients with dyspnea.

Implementation of a national school-based Human Papillomavirus (HPV) vaccine campaign in Fiji: knowledge, vaccine acceptability and information needs of parents

Background

In 2008 Fiji implemented a nationwide Human Papillomavirus (HPV) vaccine campaign targeting all girls aged 9–12 years through the existing school-based immunisation program. Parents of vaccine-eligible girls were asked to provide written consent for vaccination. The purpose of this study was to describe parents’ knowledge, experiences and satisfaction with the campaign, the extent to which information needs for vaccine decision-making were met, and what factors were associated with vaccine consent.

Methods

Following vaccine introduction, a cross-sectional telephone survey was conducted with parents of vaccine-eligible girls from randomly selected schools, stratified by educational district. Factors related to vaccine consent were explored using Generalised Estimating Equations.

Results

There were 560 vaccine-eligible girls attending the participating 19 schools at the time of the campaign. Among these, 313 parents could be contacted, with 293 agreeing to participate (93.6 %). Almost 80 % of participants reported having consented to HPV vaccination (230/293, 78.5 %). Reported knowledge of cervical cancer and HPV prior to the campaign was very low. Most respondents reported that they were satisfied with their access to information to make an informed decision about HPV vaccination (196/293, 66.9 %). and this was very strongly associated with provision of consent. Despite their young age, the vaccine-eligible girls were often involved in the discussion and decision-making. Most consenting parents were satisfied with the campaign and their decision to vaccinate, with almost 90 % indicating they would consent to future HPV vaccination. However, negative media reports about the vaccine campaign created confusion and concern. Local health staff were cited as a trusted source of information to guide decision-making. Just over half of the participants who withheld consent cited vaccine safety fears as the primary reason (23/44, 52.3 %).

Conclusion

This is the first reported experience of HPV introduction in a Pacific Island nation. In a challenging environment with limited community knowledge of HPV and cervical cancer, media controversy and a short lead-time for community education, Fiji has implemented an HPV vaccine campaign that was largely acceptable to the community and achieved a high level of participation. Community sensitisation and education is critical and should include a focus on the local health workforce and the vaccine target group.

Focused Ultrasound in the Emergency Department for Patients with Acute Heart Failure

The emergency department (ED) plays a key role in the initial diagnosis and management of acute heart failure (AHF). Despite the advent of novel biomarkers and traditional methods of assessment, such as history, examination, and chest X-ray, diagnosis of the dyspnoeic ED patient is, at times, very challenging. Focused cardiac and pulmonary ultrasound has emerged as a valid, facile and efficient method to aid in the initial diagnosis and management of AHF.

Characterization of 19A-like 19F pneumococcal isolates from Papua New Guinea and Fiji

Molecular identification of Streptococcus pneumoniae serotype 19F is routinely performed by PCR targeting the wzy gene of the capsular biosynthetic locus. However, 19F isolates with genetic similarity to 19A have been reported in the United States and Brazil. We screened 78 pneumococcal carriage isolates and found six 19F wzy variants that originated from children in Papua New Guinea and Fiji. Isolates were characterized using multilocus sequence typing and opsonophagocytic assays. The 19F wzy variants displayed similar susceptibility to anti-19F IgG antibodies compared to standard 19F isolates. Our findings indicate that these 19F variants may be more common than previously believed.

Can emergency physicians diagnose and correctly classify diastolic dysfunction using bedside echocardiography?

OBJECTIVES

The goal of this study was to determine if emergency physicians (EPs) can correctly perform a bedside diastology examination (DE) and correctly grade the level of diastolic function with minimal additional training in echocardiography beyond what is learned in residency. We hypothesize that EPs will be accurate at detecting and grading diastolic dysfunction (DD) when compared to a criterion standard interpretation by a cardiologist.

METHODS

We conducted a prospective, observational study on a convenience sample of adult patients who presented to an urban emergency department with a chief concern of dyspnea. All patients had a bedside echocardiogram, including a DE, performed by an EP-sonographer who had 3 hours of didactic and hands-on echocardiography training with a cardiologist. The DE was interpreted as normal, grade 1 to 3 if DD was present, or indeterminate, all based on predefined criteria. This interpretation was compared to that of a cardiologist who was blinded to the EPs' interpretations.

RESULTS

We enrolled 62 patients; 52% had DD. Using the cardiology interpretation as the criterion standard, the sensitivity and specificity of the EP-performed DE to identify clinically significant diastolic function were 92% (95% confidence interval [CI], 60-100) and 69% (95% CI, 50-83), respectively. Agreement between EPs and cardiology on grade of DD was assessed using κ and weighted κ: κ = 0.44 (95% CI, 0.29-0.59) and weighted κ = 0.52 (95% CI, 0.38-0.67). Overall, EPs rated 27% of DEs as indeterminate, compared with only 15% by cardiology. For DEs where both EPs and cardiology attempted an interpretation (indeterminates excluded) κ = 0.45 (95% CI, 0.26 to 0.65) and weighted κ = 0.54 (95% CI, 0.36-0.72).

CONCLUSION

After limited diastology-specific training, EPs are able to accurately identify clinically significant DD. However, correct grading of DD, when compared to a cardiologist, was only moderate, at best. Our results suggest that further training is necessary for EPs to achieve expertise in grading DD.

Derivation of a screening tool to identify patients with right ventricular dysfunction or tricuspid regurgitation after negative computerized tomographic pulmonary angiography of the chest

Many dyspneic patients who undergo computerized tomographic pulmonary angiography (CTPA) for presumed acute pulmonary embolism (PE) have no identified cause for their dyspnea yet have persistent symptoms, leading to more CTPA scanning. Right ventricular (RV) dysfunction or overload can signal treatable causes of dyspnea. We report the rate of isolated RV dysfunction or overload after negative CTPA and derive a clinical decision rule (CDR). We performed secondary analysis of a multicenter study of diagnostic accuracy for PE. Inclusion required persistent dyspnea and no PE. Echocardiography was ordered at clinician discretion. A characterization of isolated RV dysfunction or overload required normal left ventricular function and RV hypokinesis, or estimated RV systolic pressure of at least 40 mmHg. The CDR was derived from bivariate analysis of 97 candidate variables, followed by multivariate logistic regression. Of 647 patients, 431 had no PE and persistent dyspnea, and 184 (43%) of these 431 had echocardiography ordered. Of these, 64 patients (35% [95% confidence interval (CI): 28%-42%]) had isolated RV dysfunction or overload, and these patients were significantly more likely to have a repeat CTPA within 90 days (P = .02, [Formula: see text] test). From univariate analysis, 4 variables predicted isolated RV dysfunction: complete right bundle branch block, normal CTPA scan, active malignancy, and CTPA with infiltrate, the last negatively. Logistic regression found only normal CTPA scanning significant. The final rule (persistent dyspnea + normal CTPA scan) had a positive predictive value of 53% (95% CI: 37%-69%). We conclude that a simple CDR consisting of persistent dyspnea plus a normal CTPA scan predicts a high probability of isolated RV dysfunction or overload on echocardiography.

Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath

BACKGROUND

Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients.

METHODS

A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation.

RESULTS

A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%).

CONCLUSION

This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes.

Diagnosing acute heart failure in patients with undifferentiated dyspnea: a lung and cardiac ultrasound (LuCUS) protocol

OBJECTIVES

The primary goal of this study was to determine accuracy for diagnosing acutely decompensated heart failure (ADHF) in the undifferentiated dyspneic emergency department (ED) patient using a lung and cardiac ultrasound (LuCUS) protocol. Secondary objectives were to determine if US findings acutely change management and if findings are more accurate than clinical gestalt.

METHODS

This was a prospective, observational study of adult patients presenting to the ED with undifferentiated dyspnea. The intervention consisted of a 12-view LuCUS protocol performed by experienced emergency physician sonographers. The primary objective was measured by comparing US findings to the final diagnosis independently determined by two physicians blinded to the LuCUS result. Acute treatment changes based on US findings were tracked in real time through a standardized data collection form.

RESULTS

Data on 99 patients were analyzed; ADHF was the final diagnosis in 36%. The LuCUS protocol had sensitivity of 83% (95% confidence interval [CI] = 67% to 93%), specificity of 83% (95% CI = 70% to 91%), positive likelihood ratio of 4.8 (95% CI = 2.7 to 8.3), and negative likelihood ratio of 0.20 (95% CI = 0.09 to 0.42). Forty-seven percent of patients had changes in acute management, and 42% had changes in acute treatment. Observed agreement for the LuCUS protocol was 93% between coinvestigators. Overall, accuracy improved by 20% (83% vs. 63%, 95% CI = 8% to 31% for the difference) over clinical gestalt alone.

CONCLUSIONS

The LuCUS protocol may accurately identify ADHF and may improve acute clinical management in dyspneic ED patients. This protocol has improved diagnostic accuracy over clinical gestalt alone.

Accuracy of a novel ultrasound technique for confirmation of endotracheal intubation by expert and novice emergency physicians

Introduction

Recent research has investigated the use of ultrasound (US) for confirming endotracheal tube (ETT) placement with varying techniques, accuracies, and challenges. Our objective was to evaluate the accuracy of a novel, simplified, four-step (4S) technique.

Methods

We conducted a blinded, randomized trial of the 4S technique utilizing an adult human cadaver model. ETT placement was randomized to tracheal or esophageal location. Three US experts and 45 emergency medicine residents (EMR) performed a total of 150 scans. The primary outcome was the overall sensitivity and specificity of both experts and EMRs to detect location of ETT placement. Secondary outcomes included a priori subgroup comparison of experts and EMRs for thin and obese cadavers, time to detection, and level of operator confidence.

Results

Experts had a sensitivity of 100% (95% CI = 72% to 100%) and specificity of 100% (95% CI = 77% to 100%) on thin, and a sensitivity of 93% (95% CI = 66% to 100%) and specificity of 100% (95% CI = 75% to 100%) on obese cadavers. EMRs had a sensitivity of 91% (95% CI = 69% to 98%) and of specificity 96% (95% CI = 76% to 100%) on thin, and a sensitivity of 100% (95% CI = 82% to 100%) specificity of 48% (95% CI = 27% to 69%) on obese cadavers. The overall mean time to detection was 17 seconds (95% CI = 13 seconds to 20 seconds, range: 2 to 63 seconds) for US experts and 29 seconds (95% CI = 25 seconds to 33 seconds; range: 6 to 120 seconds) for EMRs. There was a statistically significant decrease in the specificity of this technique on obese cadavers when comparing the EMRs and experts, as well as an increased overall time to detection among the EMRs.

Conclusion

The simplified 4S technique was accurate and rapid for US experts. Among novices, the 4S technique was accurate in thin, but appears less accurate in obese cadavers. Further studies will determine optimal teaching time and accuracy in emergency department patients.

Serotype-specific avidity is achieved following a single dose of the 7-valent pneumococcal conjugate vaccine, and is enhanced by 23-valent pneumococcal polysaccharide booster at 12 months

AIM

To evaluate whether the avidity of serotype-specific IgG to pneumococcal serotypes is enhanced by an increased number of doses of the 7-valent pneumococcal conjugate vaccine (PCV) in infancy or by a 12 month 23-valent pneumococcal polysaccharide vaccine (23vPPS) booster, and/or subsequent re-exposure to a small dose of pneumococcal polysaccharide antigens (mPPS) at 17 months.

METHODS

Fijian infants aged 6 weeks were recruited, stratified by ethnicity and randomized to 8 groups to receive 0, 1, 2, or 3 doses of PCV, with or without 23vPPS at 12 months. All children received mPPS at 17 months of age. Avidity of serotype-specific IgG for PCV serotypes in the first 12 months and for all 23vPPS serotypes thereafter was assessed by EIA after sodium thiocyanate elution.

RESULTS

At one month post primary series, the 2 and 3 PCV dose groups demonstrated similar avidity, with the single dose group tending to have lower avidity. However, by age 9 months, the single dose group had similar avidity to the 2 and 3 PCV groups for most serotypes. The 23vPPS booster enhanced affinity maturation for most serotypes and this was most marked in those groups that received a single PCV dose. There was little further increase following the mPPS.

CONCLUSIONS

By 9 months of age, similar avidity can be induced following one, 2 or 3 doses of PCV. A 23vPPS booster at 12 months enhanced affinity maturation with an increase in antibody avidity for most serotypes. Subsequent re-challenge with mPPS at 17 months did not further enhance the avidity of serotype-specific response in the 12 month 23vPPS groups.

Opsonophagocytic activity following a reduced dose 7-valent pneumococcal conjugate vaccine infant primary series and 23-valent pneumococcal polysaccharide vaccine at 12 months of age

Opsonophagocytic activity (OPA) was measured following reduced infant doses of 7-valent pneumococcal conjugate vaccine (PCV-7) with or without 23-valent pneumococcal polysaccharide vaccine (PPV-23) at 12 months, and subsequent re-exposure to a small dose of pneumococcal polysaccharide antigens (mPPS) at 17 months. Fijian infants were randomized to receive 0, 1, 2, or 3 PCV-7 doses. Half received PPV-23 at 12 months and all received mPPS at 17 months. OPA was performed on up to 14 serotypes. Three and 2 PCV-7 doses resulted in similar OPA for most PCV-7 serotypes up to 9 months and for half of the serotypes at 12 months. A single dose improved OPA compared with the unvaccinated group. PPV-23 significantly improved OPA for all serotypes tested but in general, was associated with diminished responses following re-challenge.

Antibodies to serotype 9V exhibit novel serogroup cross-reactivity following infant pneumococcal immunization

Cross-reactivity within the pneumococcal immune response was examined in this study. Significant cross-reactivity between serotypes 9V, 15B and 19A was identified in infant post-immunization serum that could not be effectively titrated during specific IgG measurements. Pre-absorption using serotype 9V inhibited this cross-reactivity and normalized titratability in the WHO ELISA for serotypes 15B and 19A. However, this did not affect functional avid IgG and was associated with fewer pneumococcal conjugate vaccine (PCV) doses, suggesting that cross-reactive antibodies were of low avidity. The results in this study have important implications for assessment of vaccine immunogenicity.

Hyporesponsiveness to re-challenge dose following pneumococcal polysaccharide vaccine at 12 months of age, a randomized controlled trial

BACKGROUND

To evaluate the immunological impact of the 23-valent pneumococcal polysaccharide vaccine (23vPPS) at 12 months, for children who have received zero to three infant doses of seven-valent pneumococcal conjugate vaccine (PCV), on responses to a subsequent exposure to a small dose of 23vPPS (mPPS).

METHODS

Five hundred and fifty-two Fijian infants were stratified by ethnicity and randomized into eight groups to receive zero, one, two, or three PCV doses at 14 weeks, six and 14 weeks, or six, ten, and 14 weeks. Within each group, half received 23vPPS at 12 months and all received mPPS at 17 months. Sera were taken prior and one month post-mPPS.

FINDINGS

By 17 months, geometric mean antibody concentrations (GMC) to all 23 serotypes in 23vPPS were significantly higher in children who had received 23vPPS at 12 months compared to those who had not. Post-mPPS, children who had not received the 12 month 23vPPS had a significantly higher GMC for all PCV serotypes compared with those who had (each p<0.02). For the non-PCV serotypes, children who had not received the 12 month 23vPPS had significantly higher GMC for six of 16 non-PCV serotypes (7F, 9N, 12F, 19A, 22F, 33F) than those who did (each p<0.02). After adjusting for the pre-mPPS level, exposure to 23vPPS was associated with a lower response to mPPS for all serotypes (each p<0.001).

INTERPRETATION

Despite higher antibody concentrations at 17 months in children who had received 23vPPS at 12 months, the response to a re-challenge was poor for all 23 serotypes compared to children who had not received the 12 month 23vPPS.

Reduction of meningitis and impact on under-5 pneumonia after introducing the Hib vaccine in the Kingdom of Tonga

AIMS

To document the impact of Hib vaccine on Haemophilus influenzae (Hi) invasive disease, meningitis and inpatient pneumonia in children under 5 in the Kingdom of Tonga.

METHODS

Cases of meningitis and pneumonia were sourced from the paediatric discharge book from 1 January 2000 to 2 November 2007 and from computerised discharge records from Vaoila Hospital on the island of Tongatapu where approximately 70% of the total population resides. Laboratory-confirmed cases were sourced from the microbiology laboratory register over the same period.

RESULTS

Prior to the introduction of Hib vaccine in 2005, there were, on average, 5.6 cases of invasive Hi disease per year. In the 22 months after Hib vaccine introduction, there was only one case of invasive Hi disease. This corresponds to a fall in the annual incidence of invasive Hib disease from 54.3 to 5.1/100,000 children under 5 years of age. The annual incidence of inpatient pneumonia has fallen by 28.3% from 1007.6 to 722.8/100,000 children under 5 in the 22 months after introducing the vaccine.

CONCLUSION

Hib vaccine has reduced invasive Hi disease and Hi meningitis in Tonga. The reduction in inpatient pneumonia is more likely a reflection of annual fluctuations in viral pneumonia than of a reduction in Hib pneumonia, but ongoing surveillance is recommended.

High burden of invasive beta-haemolytic streptococcal infections in Fiji

We undertook a 5-year retrospective study of group A streptococcal (GAS) bacteraemia in Fiji, supplemented by a 9-month detailed retrospective study of beta-haemolytic streptococcal (BHS) infections. The all-age incidence of GAS bacteraemia over 5 years was 11.6/100,000. Indigenous Fijians were 4.7 times more likely to present with invasive BHS disease than people of other ethnicities, and 6.4 times more likely than Indo-Fijians. The case-fatality rate for invasive BHS infections was 28%. emm-typing was performed on 23 isolates: 17 different emm-types were found, and the emm-type profile was different from that found in industrialized nations. These data support the contentions that elevated rates of invasive BHS and GAS infections are widespread in developing countries, and that the profile of invasive organisms in these settings reflects a wide diversity of emm-types and a paucity of types typically found in industrialized countries.

As a bacterial culture medium, citrated sheep blood agar is a practical alternative to citrated human blood agar in laboratories of developing countries

Human blood agar (HuBA) is widely used in developing countries for the isolation of bacteria from clinical specimens. This study compared citrated sheep blood agar (CSBA) and HuBA with defibrinated horse blood agar and defibrinated sheep blood agar (DSBA) for the isolation and antibiotic susceptibility testing of reference and clinical strains of Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Reference and clinical strains of all organisms were diluted in brain heart infusion and a clinical specimen of cerebrospinal fluid and cultured on all agars. Viable counts, colony morphology, and colony size were recorded. Susceptibility testing for S. pneumoniae and S. pyogenes was performed on defibrinated sheep blood Mueller-Hinton agar, citrated sheep blood Mueller-Hinton agar (CSB MHA), and human blood Mueller-Hinton agar plates. For all organisms, the colony numbers were similar on all agars. Substantially smaller colony sizes and absent or minimal hemolysis were noted on HuBA for all organisms. Antibiotic susceptibility results for S. pneumoniae were similar for the two sheep blood agars; however, larger zone sizes were displayed on HuBA, and quality control for the reference strain failed on HuBA. For S. pyogenes, larger zone sizes were demonstrated on HuBA and CSBA than on DSBA. Poor hemolysis made interpretation of the zone sizes difficult on HuBA. CSBA is an acceptable alternative for the isolation of these organisms. The characteristic morphology is not evident, and hemolysis is poor on HuBA; and so HuBA is not recommended for use for the isolation or the susceptibility testing of any of these organisms. CSB MHA may be suitable for use for the susceptibility testing of S. pneumoniae.