Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography

Acute Heart Failure: From The Emergency Department to the Intensive Care Unit

Acute heart failure (AHF) is a frequent cause of hospitalization around the world and is associated with high in-hospital and post-discharge morbidity and mortality. This review summarizes data on diagnosis and management of AHF from the emergency department to the intensive care unit. While more evidence is needed to guide risk stratification and care of patients with AHF, hospitalization is a key opportunity to optimize evidence-based medical therapy for heart failure. Close linkage to outpatient care is essential to improve post-hospitalization outcomes.

Point of Care Ultrasound for Diagnosis and Management in Heart Failure: A Targeted Literature Review

BACKGROUND

Cardiac point of care ultrasound (POCUS) has shown increasing utility as a tool for diagnosing and managing heart failure (HF). Within cardiology, intravascular volume assessment leveraging visualization of the inferior vena cava (IVC) is a central aspect of care, as IVC size correlates with central venous pressure. This targeted literature review aimed to examine the existing literature assessing the use of POCUS in diagnosis and management of HF patients utilizing POCUS-based IVC measurement either alone or in combination with secondary methods.

METHODS

A targeted PubMed and Ovid database search up until August 28, 2023 using a keyword search was completed. Studies that did not include IVC assessment with POCUS in HF were excluded.

RESULTS

The initial search using both PubMed and Ovid resulted in 370 journal publications. After exclusion criteria were used 15 studies were included in the review. Studies were grouped into three categories: 1) how well POCUS was able to identify HF, 2) whether POCUS-based findings correlated with other measures evaluating HF and was able to predict the effect of diuretic administration, and 3) whether POCUS-based findings served as a good prognostic indicator. The 5 studies that evaluated HF identification with POCUS found that both diagnostic sensitivity and specificity may reach 90%-100% when IVC measurement was coupled with a lung ultrasound assessing the presence of B-lines or pleural effusion. Five studies assessing POCUS findings correlating with other HF measures and diuretic effect found that IVC diameter changed significantly with diuretic administration (p<0.05). All 6 studies assessing POCUS as a predictor of long-term mortality or hospital readmission found measures that achieved statistical significance with p<0.05.

CONCLUSIONS

Including POCUS as standard-of-care - both as a diagnostic tool in the emergency department and a management tool in in-patient and out-patient facilities - may improve the treatment of HF.

Results of the implementation of a double-check protocol with point-of-care ultrasound for acute heart failure in the emergency department

OBJECTIVE

To determine the effectiveness of a double-check protocol using Point-of-Care Ultrasound in the management of patients diagnosed with Acute Heart Failure in an Emergency Department.

METHOD

Prospective analytical cross-sectional observational study with patients diagnosed with Acute Heart Failure by the outgoing medical team, who undergo multi-organ ultrasound evaluation including cardiac, pulmonary, and inferior vena cava ultrasound.

RESULTS

96 patients were included. An alternative diagnosis was found in 33% of them. Among the 77% where AHF diagnosis was confirmed, 73.4% had an underlying cause or condition not previously known (Left Ventricular Ejection Fraction less than 40% or moderate-severe valvulopathy). The introduction of the protocol had a clinically relevant impact on 47% of all included patients.

CONCLUSIONS

The implementation of a double-check protocol using POCUS, including cardiac, pulmonary, and inferior vena cava assessment in patients diagnosed with Acute Heart Failure, demonstrates a high utility in ensuring accurate diagnosis and proper classification of these patients.

Value of inferior vena cava collapsibility index as marker of heart failure in chronic obstructive pulmonary disease exacerbation

INTRODUCTION

Inferior vena cava (IVC) diameter variability with respiration measured by ultrasound was found to be useful for the diagnosis of heart failure (HF) in ED patients with acute dyspnea. Its value in identifying HF in acute exacerbation of chronic obstructive pulmonary disease exacerbation (AECOPD) was not specifically demonstrated.

OBJECTIVE

To determine the value of ΔIVC in the diagnosis of HF patients with AECOPD.

METHODS

This is a prospective study conducted in the ED of three Tunisian university hospitals including patients with AECOPD. During this period, 401 patients met the inclusion criteria. The final diagnosis of HF is based on the opinion of two emergency experts after consulting the data from clinical examination, cardiac echocardiography, and BNP level. The ΔIVC was calculated by two experienced emergency physicians who were blinded from the patient's clinical and laboratory data. A cut off of 15% was used to define the presence (< 15%) or absence of HF (≥ 15%). Left ventricular ejection fraction (LVEF) was also measured. The area under the ROC curve, sensitivity, specificity, and positive and negative predictive values were calculated to determine the diagnostic and predictive accuracy of the ΔIVC in predicting HF.

RESULTS

The study population included 401 patients with AECOPD, mean age 67.2 years with male (68.9%) predominance. HF was diagnosed in 165 (41.1%) patients (HF group) and in 236 patients (58.9%) HF was excluded (non HF group). The assessment of the performance of the ΔIVC in the diagnosis of HF showed a sensitivity of 37.4% and a specificity of 89.7% using the threshold of 15%. The positive predictive value was 70.9% and the negative predictive value was 66.7%. The area under the ROC curve was 0.71(95%, CI 0.65-0.76). ΔIVC values were not different between HF patients with reduced LVEF and those with preserved LVEF.

CONCLUSION

Our results showed that ΔIVC has a good value for ruling out HF in ED patients consulting for AECOPD.

EFSUMB Clinical Practice Guidelines for Point-of-Care Ultrasound: Part One (Common Heart and Pulmonary Applications) LONG VERSION

AIMS

 To evaluate the evidence and produce a summary and recommendations for the most common heart and lung applications of point-of-care ultrasound (PoCUS).

METHODS

 We reviewed 10 clinical domains/questions related to common heart and lung applications of PoCUS. Following review of the evidence, a summary and recommendation were produced, including assignment of levels of evidence (LoE) and grading of the recommendation, assessment, development, and evaluation (GRADE). 38 international experts, the expert review group (ERG), were invited to review the evidence presented for each question. A level of agreement of over 75 % was required to progress to the next section. The ERG then reviewed and indicated their level of agreement regarding the summary and recommendation for each question (using a 5-point Likert scale), which was approved if a level of agreement of greater than 75 % was reached. A level of agreement was defined as a summary of "strongly agree" and "agree" on the Likert scale responses.

FINDINGS AND RECOMMENDATIONS

 One question achieved a strong consensus for an assigned LoE of 3 and a weak GRADE recommendation (question 1). The remaining 9 questions achieved broad agreement with one assigned an LoE of 4 and weak GRADE recommendation (question 2), three achieving an LoE of 3 with a weak GRADE recommendation (questions 3-5), three achieved an LoE of 3 with a strong GRADE recommendation (questions 6-8), and the remaining two were assigned an LoE of 2 with a strong GRADE recommendation (questions 9 and 10).

CONCLUSION

 These consensus-derived recommendations should aid clinical practice and highlight areas of further research for PoCUS in acute settings.

Accuracy of Critical Care Ultrasonography Plus Arterial Blood Gas Analysis Based Algorithm in Diagnosing Aetiology of Acute Respiratory Failure

Introduction

Lung ultrasound when used in isolation, usually misses out metabolic causes of dyspnoea and differentiating acute exacerbation of COPD from pneumonia and pulmonary embolism is difficult, hence we thought of combining critical care ultrasonography (CCUS) with arterial blood gas analysis (ABG).

Aim of the study

The objective of this study was to estimate accuracy of Critical Care Ultrasonography (CCUS) plus Arterial blood gas (ABG) based algorithm in diagnosing aetiology of dyspnoea. Accuracy of traditional Chest X-ray (CxR) based algorithm was also validated in the following setting.

Methods

It was a facility based comparative study, where 174 dyspneic patients were subjected to CCUS plus ABG and CxR based algorithms on admission to ICU. The patients were classified into one of five pathophysiological diagnosis 1) Alveolar( Lung-pneumonia)disorder ; 2) Alveolar (Cardiac-pulmonary edema) disorder; 3) Ventilation with Alveolar defect (COPD) disorder ;4) Perfusion disorder; and 5) Metabolic disorder. We calculated diagnostic test properties of CCUS plus ABG and CXR based algorithm in relation to composite diagnosis and correlated these algorithms for each of the defined pathophysiological diagnosis.

Results

The sensitivity of CCUS and ABG based algorithm was 0.85 (95% CI-75.03-92.03) for alveolar (lung) ; 0.94 (95% CI-85.15-98.13) for alveolar (cardiac); 0.83 (95% CI-60.78-94.16) for ventilation with alveolar defect; 0.66 (95% CI-30-90.32) for perfusion defect; 0.63 (95% CI-45.25-77.07) for metabolic disorders.Cohn's kappa correlation coefficient of CCUS plus ABG based algorithm in relation to composite diagnosis was 0.7 for alveolar (lung), 0.85 for alveolar (cardiac), 0.78 for ventilation with alveolar defect, 0.79 for perfusion defect and 0.69 for metabolic disorders.

Conclusion

CCUS plus ABG algorithm is highly sensitive and it's agreement with composite diagnosis is far superior. It is a first of it's kind study, where authors have attempted combining two point of care tests and creating an algorithmic approach for timely diagnosis and intervention.

POCUS in dyspnea, nontraumatic hypotension, and shock; a systematic review of existing evidence

BACKGROUND

Point-of-care ultrasound (POCUS) has been adopted as a powerful tool in acute medicine. This systematic review aims to critically appraise the existing literature on point-of-care ultrasound in respiratory or circulatory deterioration.

METHODS

Original studies on POCUS and dyspnea, nontraumatic hypotension, and shock from March 2002 until March 2022 were assessed in the PubMed and Embase Databases. Two reviewers independently screened articles for inclusion, extracted data, and assessed the quality of included studies using an established checklist.

RESULTS

We included 89 articles in this review. Point-of-care ultrasound in the initial workup increases the diagnostic accuracy in patients with dyspnea, nontraumatic hypotension and shock in the ED, ICU and medical ward setting. No improvement is found in patients with severe sepsis in the ICU setting. POCUS is capable of narrowing the differential diagnoses and is faster, and more feasible in the acute setting than other diagnostics available. Results on outcome measures are heterogenous. The quality of the included studies is considered low most of the times, mainly because of performance and selection bias and absence of a gold standard as the reference test.

CONCLUSION

We conclude that POCUS contributes to a higher diagnostic accuracy in dyspnea, nontraumatic hypotension, and shock. It aides in narrowing the differential diagnoses and shortening the time to correct diagnosis and effective treatment.

TRIAL REGISTRY

INPLASY; Registration number: INPLASY202220020; URL: https://inplasy.com/.

A systemic review and meta-analysis comparing the ability of diagnostic of the third heart sound and left ventricular ejection fraction in heart failure

Objective

This study aimed to compare the sensitivity and specificity of diagnosis between the third heart sound (S3) and left ventricular ejection fraction (LVEF) in heart failure (HF).

Methods

Relevant studies were searched in PubMed, SinoMed, China National Knowledge Infrastructure, and the Cochrane Trial Register until February 20, 2022. The sensitivity, specificity, likelihood ratio (LR), and diagnostic odds ratio (DOR) were pooled. The symmetric receiver operator characteristic curve (SROC) and Fagan’s nomogram were drawn. The source of heterogeneity was explored by meta-regression and subgroup analysis.

Results

A total of 19 studies, involving 5,614 participants, were included. The combined sensitivity of S3 was 0.23 [95% confidence interval (CI) (0.15–0.33), specificity was 0.94 [95% CI (0.82–0.98)], area under the SROC curve was 0.49, and the DOR was 4.55; while the sensitivity of LVEF was 0.70 [95% CI (0.53–0.83)], specificity was 0.79 [95% CI (0.75–0.82)], area under the SROC curve was 0.79, and the DOR was 8.64. No publication bias was detected in Deeks’ funnel plot. The prospective design, partial verification bias, and blind contributed to the heterogeneity in specificity, while adequate description of study participants contributed to the heterogeneity in sensitivity. In Fagan’s nomogram, the post-test probability was 48% when the pre-test probability was set as 20%, while in LVEF, the post-test probability was 45% when the pre-test probability was set as 20%.

Conclusion

The use of S3 alone presented lower sensitivity in diagnosing HF compared with LVEF, whereas it was useful in early pathological assessment.

Diagnostic utility of lung echography for congestive heart failure performed by junior resident doctors

Background

Dyspnea is a high priority symptom in the emergency department, with heart failure (HF) as one of its leading causes. Recently, the “comet tail sign (CTS),” a pulmonary ultrasonographic sign, has been proposed as an efficacious tool for detecting pulmonary edema. However, to the best of our knowledge, there have been no published data regarding its utility when performed by non‐experts, including junior residents.

Methods

Between September 2017 and December 2018, patients with dyspnea, who were admitted to the ER, were enrolled. CTS was evaluated by junior residents at the ER. All patients were evaluated by cardiologists independently, and clinical HF was defined as requiring pharmacological intervention by a cardiologist. At the end of this study, we investigated the results of CTS, laboratory data, and available radiological images.

Results

A total of 95 patients were enrolled in the current study, wherein 42 patients were treated by cardiologists as those with clinical HF. Our results showed that CTS could identify clinical HF with a sensitivity of 71.4% and a specificity of 81.1%. The sensitivity of CTS against brain natriuretic peptide (BNP) (cut‐off value, 100 pg/ml) was calculated at 92.5%. Furthermore, when evaluated together with peripheral edema, CTS identified clinical HF with a sensitivity of 96%. False positives for CTS included bilateral pneumonia, hypoalbuminemia, and interstitial pneumonitis.

Conclusions

Our results indicate that CTS is a simple and effective tool for the use of non‐experts, including junior residents.

Inferior vena cava ultrasonography in the assessment of intravascular volume status and fluid responsiveness in the emergency department and intensive care unit: A critical analysis review

Rapid evaluation of intravascular volume status is vital; either excessive or limited fluid administration may result in adverse patient outcomes. In this narrative review, critical analysis of pertinent diagnostic accuracy studies is developed to delineate the role of inferior vena cava ultrasound measurements in the assessment of both intravascular volume status and fluid responsiveness in the emergency department and intensive care unit. In addition, limitations, and technical considerations of inferior vena cava ultrasound measurements as well as directions for future research are thoroughly discussed.

Quantification and treatment of congestion in heart failure: A clinical and pathophysiological overview

Renal sodium and water retention with resulting extracellular volume expansion and redistribution are hallmark features of heart failure syndromes. However, congestion assessment, monitoring, and treatment represent a real challenge in daily clinical practice. This document reviewed historical and contemporary evidence of available methods for determining volume status and discuss pharmacological aspects and pathophysiological principles that underlie diuretic use.

Assessing left ventricular systolic function by emergency physician using point of care echocardiography compared to expert: systematic review and meta-analysis

Assessing left ventricular systolic function (LVSF) by echocardiography assists in the diagnosis and management of a diverse range of patients presenting to the emergency department (ED). We evaluated the agreement between ED-based clinician sonographers and apriori-defined expert sonographers. We conducted a systematic review and meta-analysis based on Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines. We searched Medline, EMBASE, Cochrane, ClinicalTrials.gov, TRIP and Google Scholar for eligible studies from inception to February 2021. Risk of bias was evaluated using Quality Assessment Tool for Diagnostic Accuracy Studies-2 tool. The level of agreement between clinician and expert sonographers was measured using kappa, sensitivity, specificity, positive and negative likelihood ratio statistics using random-effects models. Twelve studies were included (1131 patients, 1229 scans and 159 clinician sonographers). Significant heterogeneity was identified in patient selection, methods of assessment of LVSF, reference standards and statistical methods for assessing agreement. The overall quality of studies was low, with most being small, single centre convenience samples. A meta-analysis including seven studies (786 scans) where visual estimation method was used by clinician sonographers demonstrated simple Kappa of 0.68 [95% confidence interval (CI), 0.57-0.79], and sensitivity, specificity, positive and negative likelihood ratio of 89% (95% CI, 80-94%), 85% (95% CI, 80-89%), 5.98 (95% CI, 4.13-8.68) and 0.13 (95% CI, 0.06-0.24), respectively, between clinician sonographer and expert sonographer for normal/abnormal LVSF. The weighted kappa for five studies (429 scans) was 0.70 (95% CI, 0.61-0.80) for normal/reduced/severely reduced LVSF. There is substantial agreement between ED-based clinician sonographers and expert sonographers for assessing LVSF using visual estimation and ranking it as normal/reduced, or normal/reduced/severely reduced, in patients presenting to ED.

Undifferentiated Dyspnea with Point-of-Care Ultrasound, Primary Emergency Physician Compared with a Dedicated Emergency Department Ultrasound Team

BACKGROUND

Emergency physicians (EPs) perform critical actions while operating with diagnostic uncertainty. Point-of-care ultrasound (POCUS) is useful in evaluation of dyspneic patients. In prior studies, POCUS is often performed by ultrasound (US) teams without patient care responsibilities.

OBJECTIVES

This study evaluates the effectiveness of POCUS in narrowing diagnostic uncertainty in dyspneic patients when performed by treating EPs vs. separate US teams.

METHODS

This multicenter, prospective noninferiority cohort study investigated the effect of a POCUS performing team in patient encounters for dyspnea. Before-and-after surveys assessing medical decision-making were administered to attending physicians. Primary outcome was change in most likely diagnosis after POCUS. This was assessed for noninferiority between encounters where the primary or US team performed POCUS. Secondary outcomes included change in differential diagnosis, confidence in diagnosis, interventions considered, and image quality.

RESULTS

There were 156 patient encounters analyzed. In the primary team group, most likely diagnosis changed in 40% (95% confidence interval 28-52%) of encounters vs. 32% (95% confidence interval 22-41%) in the US team group. This was noninferior using an a priori specified margin of 20% (p < .0001). Post-POCUS differential decreased by a mean 1.8 diagnoses and was equivalent within a margin of 0.5 diagnoses between performing teams (p = 0.034). Other outcomes were similar between groups.

CONCLUSION

POCUS performed by primary teams was noninferior to POCUS performed by US teams for changing the most likely diagnosis, and equivalent when considering mean reduction in number of diagnoses. POCUS performed by treating EPs reduces cognitive burden in dyspneic patients.

Quantification and Treatment of Congestion in Heart Failure: A Clinical and Pathophysiological Overview

Renal sodium and water retention with resulting extracellular volume expansion and redistribution are hallmark features of heart failure syndromes. However, congestion assessment, monitoring, and treatment represent a real challenge in daily clinical practice. This document reviewed historical and contemporary evidence of available methods for determining volume status and discuss pharmacological aspects and pathophysiological principles that underlie diuretic use.

Point-of-Care Ultrasonography in Patients With Acute Dyspnea: An Evidence Report for a Clinical Practice Guideline by the American College of Physicians

BACKGROUND

Dyspnea is a common and often debilitating symptom with a complex diagnostic work-up.

PURPOSE

To evaluate the benefits, harms, and diagnostic test accuracy of point-of-care ultrasonography (POCUS) in patients with acute dyspnea. (PROSPERO: CRD42019126419).

DATA SOURCES

Searches of multiple electronic databases without language limitations (January 2004 to August 2020) and reference lists of pertinent articles and reviews.

STUDY SELECTION

Five randomized controlled trials (RCTs) and 44 prospective cohort-type studies in patients with acute dyspnea evaluated POCUS as a diagnostic tool to determine the underlying cause of dyspnea. Two investigators independently screened the literature for inclusion.

DATA EXTRACTION

Data abstraction by a single investigator was confirmed by a second investigator; 2 investigators independently rated risk of bias and determined certainty of evidence.

DATA SYNTHESIS

Point-of-care ultrasonography, when added to a standard diagnostic pathway, led to statistically significantly more correct diagnoses in patients with dyspnea than the standard diagnostic pathway alone. In-hospital mortality and length of hospital stay did not differ significantly between patients who did or did not receive POCUS in addition to standard diagnostic tests. Finally, POCUS consistently improved the sensitivities of standard diagnostic pathways to detect congestive heart failure, pneumonia, pulmonary embolism, pleural effusion, or pneumothorax; specificities increased in most but not all studies.

LIMITATIONS

Most studies assessed diagnostic test accuracy, which has limited utility for clinical decision making. Studies rarely reported on the proportion of indeterminate sonography results, and no evidence is available on adverse health outcomes of false-positive or false-negative POCUS results.

CONCLUSION

Point-of-care ultrasonography can improve the correctness of diagnosis in patients with acute dyspnea.

PRIMARY FUNDING SOURCE

American College of Physicians.

Focused ultrasound of the caudal vena cava in dogs with cavitary effusions or congestive heart failure: A prospective, observational study

INTRODUCTION

Ultrasonographic indices of the inferior vena cava are useful for predicting right heart filling pressures in people.

OBJECTIVES

To determine whether ultrasonographic indices of caudal vena cava (CVC) differ between dogs with right-sided CHF (R-CHF), left-sided CHF (L-CHF), and noncardiac causes of cavitary effusion (NC).

MATERIALS AND METHODS

113 dogs diagnosed with R-CHF (n = 51), L-CHF (30), or NC effusion (32) were enrolled. Seventeen of the R-CHF dogs had pericardial effusion and tamponade. Focused ultrasound was performed prospectively to obtain 2-dimensional and M-mode subxiphoid measures of CVC maximal and minimal size (CVCmax and CVCmin), CVCmax indexed to aortic dimension (CVC:Ao), and CVC collapsibility index (CVC-CI). Variables were compared between study groups using Kruskal-Wallis and Dunn's-Bonferroni testing, and receiver operating characteristics curves were used to assess sensitivity and specificity.

RESULTS

All sonographic CVC indices were significantly different between R-CHF and NC dogs (P < 0.001). Variables demonstrating the highest diagnostic accuracy for discriminating R-CHF versus NC were CVC-CI <33% in 2D (91% sensitive and 96% specific) and presence of hepatic venous distension (84% sensitive and 90% specific). L-CHF dogs had higher CVC:Ao and lower CVC-CI compared to NC dogs (P = 0.016 and P = 0.043 in 2D, respectively) but increased CVC-CI compared to the R-CHF group (P < 0.001).

CONCLUSIONS

Ultrasonographic indices of CVC size and collapsibility differed between dogs with R-CHF compared to NC causes of cavitary effusions. Dogs with L-CHF have CVC measurements intermediate between R-CHF and NC dogs.

Operating bedside cardiac ultrasound program in emergency medicine residency: A retrospective observation study from the perspective of performance improvement

Background

Point-of-care ultrasound is one of useful diagnostic tools in emergency medicine practice and considerably depends on physician’s performance. This study was performed to evaluate performance improvements and favorable attitudes through structured cardiac ultrasound program for emergency medicine residents.

Methods

Retrospective observational study using the point-of-care ultrasound (PoCUS) database in one tertiary academic-teaching hospital emergency department has been conducted. Cardiac ultrasound education and rotation program has been implemented in emergency medicine residency program. Structured evaluation sheet for cardiac ultrasound and questionnaire toward PoCUS have been developed. An early-phase and a late-phase case were selected randomly for each participant. Two emergency medicine specialists with expertise in PoCUS evaluated saved images independently. We used a paired t-test to compare the performance score of each phase and the results of the questionnaire. Multivariable linear regression analysis was conducted to evaluate the association between the characteristics of participants and performance improvements.

Results

During the study period, a total of 1,652 bedside cardiac ultrasounds were administered. Forty-six examinations conducted by 23 emergency medicine residents were randomly selected for analysis. The performance score increased from 39.5 to 56.1 according to expert A and 45.3 to 62.9 according to expert B (p-value <0.01 for both). The average questionnaire score, which was analyzed for 17 participants, showed improvement from 18.9 to 20.7 (p-value <0.01). In multivariable linear regression analysis, younger age, higher early-phase score and higher confidence had a negative association with a greater improvement of performance, while the number of examinations had a positive association.

Conclusions

Bedside cardiac ultrasound performance and attitudes toward PoCUS have been improved through structured residency program.

Are there any further modalities for prediction of subclinical volume overload in advanced stages of chronic kidney disease?

BACKGROUND

Subclinical volume overload in chronic kidney disease (CKD) patient represents a debatable issue. Although many tools were used to detect volume overload in such patients, many non-specific results were due to presence of comorbidities. Bioimpedance spectroscopy is an objective fluid status assessment method, which is shown superior to classical methods in many studies. Combining some of these tools may improve their accuracy and specificity. Inferior vena cava collapsibility index (IVCCI) with brain natriuretic peptide (BNP) can be combined for more specific volume assessment. This study was performed to assess the usage of combined IVCCI and BNP levels in CKD patients to predict subclinical volume overload.

METHODS

One hundred and ten patients with CKD (stages 4 and 5) not on dialysis and having normal left ventricular systolic function were included in this study. Exclusion criteria were: (1) patients with other causes of raised BNP than volume overload and (2) patients on diuretics. A complete medical history was obtained, and thorough examination and laboratory tests were performed for all included patients. IVCCI and BNP serum levels were evaluated. The patients who exhibited an overhydration (OH)/extracellular water (ECW) ratio of >15% were considered to have volume overload.

RESULTS

Twenty-six patients (23.6%) had subclinical hypervolemia as diagnosed by OH/ECW ratio of >15%. IVCCI ≤ 38% had higher diagnostic performance than BNP ≥ 24 pg/mL. Combining both IVCCI ≤ 38% and BNP ≥ 24 pg/mL increased the specificity and positive predictive value for detection of subclinical hypervolemia.

CONCLUSION

Combined elevated BNP level and decreased IVCCI are more precise tools for subclinical volume overload detection in CKD patients.

Diagnostic accuracy of inferior vena cava ultrasound for heart failure in patients with acute dyspnoea: a systematic review and meta-analysis

BACKGROUND

Dyspnoea is the most common sign of heart failure (HF). Patients accessing the ED for HF-related symptoms require fast diagnosis and early treatment. Transthoracic echocardiography has a crucial role in HF diagnosis, but requires qualified staff and adequate time for execution. The measurement of inferior vena cava (IVC) diameter has been recently proposed as a rapid, simple and reliable marker of volume overload. The aim of this systematic review was to assess the accuracy of IVC-ultrasound as a stand-alone test for HF diagnosis in patients presenting to the ED with acute dyspnoea.

METHODS

Studies evaluating the diagnostic accuracy of the inferior vena cava collapsibility index (IVC-CIx) for HF diagnosis were systematically searched in the EMBASE and MEDLINE databases (up to January 2018). Quality Assessment of Diagnostic Accuracy Studies 2 tool was used for the quality assessment of the primary studies. A bivariate random-effects regression approach was used for summary estimates of both sensitivity and specificity.

RESULTS

Seven studies, for a total of 591 patients, were included. Three studies were at low-risk of bias. All studies used a proper reference test. Weighted mean prevalence of HF was 49.3% at random-effect model (I² index for heterogeneity=74.7%). IVC-CIx bivariate weighted mean sensitivity was 79.1% (95% CI 68.5% to 86.8%) and bivariate weighted mean specificity was 81.8% (95% CI 75.0% to 87.0%).

CONCLUSIONS

Our findings suggest that the sensitivity and specificity of IVC-CIx are suboptimal to rule in or rule out HF diagnosis in patients with acute dyspnoea in the ED setting. Therefore, IVC-CIx is not advisable as a stand-alone test, but may be useful when integrated in a specific diagnostic algorithm for the differential diagnosis of acute dyspnoea.

Ultrasound imaging of congestion in heart failure: examinations beyond the heart

Congestion, related to pressure and/or fluid overload, plays a central role in the pathophysiology, presentation and prognosis of heart failure and is an important therapeutic target. While symptoms and physical signs of fluid overload are required to make a clinical diagnosis of heart failure, they lack both sensitivity and specificity, which might lead to diagnostic delay and uncertainty. Over the last decades, new ultrasound methods for the detection of elevated intracardiac pressures and/or fluid overload have been developed that are more sensitive and specific, thereby enabling earlier and more accurate diagnosis and facilitating treatment strategies. Accordingly, we considered that a state-of-the-art review of ultrasound methods for the detection and quantification of congestion was timely, including imaging of the heart, lungs (B-lines), kidneys (intrarenal venous flow), and venous system (inferior vena cava and internal jugular vein diameter).

Focused Cardiac Ultrasound in Dyspnea of Unclear Etiology in the Emergency Department: Utility of the FLUID Score

OBJECTIVES

We evaluated the utility of focused cardiac ultrasound to predict the length of stay in patients presenting to the emergency department with dyspnea of unclear etiology.

METHODS

Patients with focused cardiac ultrasound examinations performed in the emergency department for dyspnea over a 34-month period were retrospectively identified. Patients were excluded if they had a prior diagnosis of heart failure, dialysis requirement, or an etiology of dyspnea unrelated to the volume status. Left ventricular function was categorized as normal or reduced, and the inferior vena cava was categorized as normal or increased volume. A fast limited ultrasound to investigate dyspnea (FLUID) score was calculated by adding 1 point for reduced left ventricular function and 1 point for increased volume, producing a score of 0, 1, or 2.

RESULTS

There were 123 patients included. There was a significant correlation between the FLUID score and length of stay, with longer stays for higher scores (FLUID score 0, 7.4 hours median; FLUID score 1, 2.34 days; FLUID score 2, 5.56 days; analysis of variance P < .001). Of the other variables collected, only age, hypertension, diabetes, heart rate, and brain natriuretic peptide were significantly correlated with the length of stay. A multivariate analysis including those variables and the FLUID score showed that the FLUID score was the strongest independent predictor of the length of stay.

CONCLUSIONS

Focused cardiac ultrasound and calculation of a FLUID score for patients with undifferentiated dyspnea can be a powerful tool to predict the hospital length of stay.

Contribution of caval index and ejection fraction estimated by e-point septal separation measured by emergency physicians in the clinical diagnosis of acute heart failure

OBJECTIVES

Although the reliability of e-point septal separation (EPSS) and caval index (CI) is proven in the diagnosis of acute heart failure (AHF), how much they contribute to the initial clinical impression is unclear. This study aimed to determine the diagnostic contribution of EPSS and CI to the initial clinical impression of AHF.

METHODS

This is a prospective observational study conducted in an academic emergency department (ED). The patients admitted to the ED with acute undifferentiated dyspnea were included. Primary diagnosis was made after an initial clinical evaluation, and a secondary diagnosis was made after EPSS and CI measurements. Independent cardiologists made the final diagnosis. The primary outcome was the diagnostic contribution of EPSS and CI to the primary diagnosis.

RESULTS

A total of 182 patients were included in the study. The primary diagnosis was found with a sensitivity of 0.55 and specificity of 0.84 and the secondary diagnosis was determined with a sensitivity of 0.78 and specificity of 0.83 in predicting the final diagnosis. The agreement coefficient between the primary and final diagnosis was 0.44 and between the secondary diagnosis and the final diagnosis was 0.61. When the primary diagnosis was coherent with secondary diagnosis, sensitivity and specificity were found to be 0.74 and 0.90, respectively.

CONCLUSION

Although a detailed history and physical examination are the essential factors in shaping clinical perception, CI and EPSS combined significantly contribute to the initial clinical impression.

Use of point-of-care ultrasound for the assessment of intravascular volume in five rural New Zealand hospitals

Introduction

Measuring the diameter of the inferior vena cava (IVC) or the height of the jugular venous pressure (JVP) with point-of-care ultrasound (POCUS) is a practical alternative method for estimating a patient's intravascular volume in the rural setting. This study aims to determine whether or not POCUS of the IVC or JVP generates additional useful clinical information over and above routine physical examination in this context.

Methods

Twenty generalist physicians, working in five New Zealand rural hospitals, recorded their estimation of a patient's intravascular volume based on physical examination and then again after performing POCUS of the IVC or JVP, using a visual scale from 1 to 11.

Results

Data were available for 150 assessments. There was an only moderate agreement between the pre- and post-test findings (Spearman's correlation coefficient = 0.46). In 28% (42/150) of cases, the difference was four or more points on the scale, and therefore, had the potential to be clinically significant.

Conclusion

In the rural context, POCUS provides new information that frequently alters the clinician's estimation of a patient's intravascular volume.

Lung Ultrasound Eight-Point Method in Diagnosing Acute Heart Failure in Emergency Patients with Acute Dyspnea: Diagnostic Accuracy and 72 h Monitoring

Background and Objectives: Acute dyspnea is a common chief complaint in the emergency department (ED), with acute heart failure (AHF) as a frequent underlying disease. Early diagnosis and rapid therapy are highly recommended by international guidelines. This study evaluates the accuracy of point-of-care B-line lung ultrasound in diagnosing AHF and monitoring the therapeutic success of heart failure patients. Materials and Methods: This is a prospective mono-center study in adult patients presenting with undifferentiated acute dyspnea to a German ED. An eight-zone pulmonary ultrasound was performed by experienced sonographers in the ED and 24 and 72 h after. Along with the lung ultrasound evaluation patients were asked to assess the severity of shortness of breath on a numeric rating scale. The treating ED physicians were asked to assess the probability of AHF as the underlying cause. Final diagnosis was adjudicated by two independent experts. Follow-up was done after 30 and 180 days. Results: In total, 102 patients were enrolled. Of them, 89 patients received lung ultrasound evaluation in the ED. The sensitivity of lung ultrasound evaluation in ED in diagnosing AHF was 54.2%, specificity 97.6%. As much as 96.3% of patients with a positive LUS test result for AHF in ED actually suffered from AHF. Excluding diuretically pretreated patients, sensitivity of LUS increased to 75% in ED. Differences in the sum of B-lines between admission time point, 24 and 72 h were not statistically significant. There were no statistically significant differences in the subjectively assessed severity of dyspnea between AHF patients and those with other causes of dyspnea. Of the 89 patients, 48 patients received the final adjudicated diagnosis of AHF. ED physicians assessed the probability of AHF in patients with a final diagnosis of AHF as 70%. Roughly a quarter (23.9%) of the overall cohort patients were rehospitalized within 30 days after admission, 38.6% within 180 days of follow-up. Conclusion: In conclusion, point-of-care lung ultrasound is a helpful tool for the early rule-in of acute heart failure in ED but only partially suitable for exclusion. Of note, the present study shows no significant changes in the number of B-lines after 24 and 72 h.

Automated Ultrasound Measurement of the Inferior Vena Cava: An Animal Study

Because of continuous movement and variation in diameter of the inferior vena cava (IVC) with respiration, the measurements on IVC are labor-intensive and with considerable inter-operator variations. Some computer-assisted techniques have been developed to track the movement of the IVC semi-automatically. However, existing methods predominantly rely on reference marker selection and require many manual inputs. In this study, we developed a cross-correlation (CC)-based method for automated IVC movement tracking and measurement, which requires minimal manual input and avoids manual selection of reference markers. Based on the CC method, two approaches, named direct and relative approaches, were used to calculate the maximum, minimum, and variation of the IVC diameter, and compared with the manual measurement. Fifty-four ultrasound cine-loops collected from nine pigs were tested. The results reveal that both the proposed approaches were well agreed with the manual measurement. The errors of the direct approach were less than 9%, while those of relative approach were as high as 26.7%. It is concluded that the proposed direct approach is superior for IVC diameter measurements, which can be comparable with manual counterpart, serving as an alternative to traditional IVC measurement.

Ultrasound indices of congestion in patients with acute heart failure according to body mass index

BACKGROUND

The inverse relationship between body mass index (BMI) and natriuretic peptide levels complicates the diagnosis of heart failure (HF) in obese patients. Assessment of congestion with ultrasound could facilitate HF diagnosis but it is unclear if any relationship exists amongst BMI, inferior vena cava (IVC) diameter and the number of B-lines.

METHODS

We performed a comprehensive echocardiographic evaluation within 24 h from hospital admission in patients with HF, including lung B-lines and IVC diameter, and studied their relationship with BMI and outcome.

RESULTS

216 patients (median age 81 (77-86) years) were enrolled. Median number of B-lines was 31 (IQR 26-38), median IVC diameter was 23 (22-25) mm and median BNP 991 (727-1601) pg/mL. BMI was inversely correlated with B-lines (r = - 0.50, p < 0.001), but not with IVC diameter (r = - 0.04, p = 0.58). Compared to overweight patients (BMI 25-29.9 kg/m2; n = 100) or with a normal BMI (BMI < 25 kg/m2; n = 59), obese patients (BMI ≥ 30 kg/m2; n = 57) had lower B-lines [28 (24-33) vs 30 (26-35), and vs 38 (32-42), respectively; p < 0.001] but similar IVC diameter. During the first 60 days of follow-up, there were 53 primary events: 29 patients died and 24 had a HF-related hospitalisation. B-lines and IVC diameter were independently associated with an increased risk. However, B-lines were less likely to predict outcome in the subgroup of patients with a BMI ≥ 30 kg/m².

CONCLUSIONS

Assessment of IVC diameter or B-lines in patients admitted with AHF identifies those at greater risk of death or HF readmission. However, assessment of B-lines might be influenced by BMI.

Point-of-care ultrasound modalities in terms of diagnosing acute decompensated heart failure in emergency department; a diagnostic accuracy study

This study aimed to compare the diagnostic accuracy of heart, lung and inferior vena cava (IVC) ultrasonography modalities, alone and combined, for possible added accuracy in diagnosing acute decompensated heart failure (ADHF), in a group of patients with the final diagnosis of ADHF based on plasma level of B-type natriuretic peptide (BNP) as the standard. The present study is a diagnostic accuracy study, which was carried out in the emergency department of Imam Khomeini hospital, affiliated to Tehran University of Medical Sciences, in 2014-2015. All patients over 18 years old, who were referred to emergency department with complaint of acute dyspnea were regarded as eligible and no exclusion criteria were considered. All ultrasounds were performed by a trained emergency medicine resident and then saved and classified for each patient, separately, and reviewed by the attending emergency medicine physician. In this study, patients with BNP levels higher than 500 pg/ml were considered positive for dyspnea caused by heart failure. A total of 120 patients with an average age of 60.83 ± 16.528 years were studied, 64 (53%) of which were male. In total, 47.5% of patients had a BNP level over 500 pg/ml. Among patients with positive ultrasound, 94.7% were true positive and among those with a negative ultrasound, 61.4% were true negative. Based on the findings, B-line ≥ 10 has the highest specificity and left ventricular ejection fraction (LVEF) < 45% has the highest sensitivity. The combination of LVEF and IVC collapsibility index (IVC-CI), LVEF and BLC, IVC-CI and BLC, and IVC-CI and BBPC had a higher specificity rate and combination of LVEF and BBPC and BLC and BBPC had the highest sensitivity. Sensitivity, specificity, positive predictive value and negative predictive value of all three ultrasounds combined were 31.6%, 98.4%, 94.7% and 61.4%, respectively. In this study, the diagnostic accuracy of double and triple ultrasonography of heart, lung and IVC in the diagnosis of ADHF was very high, among which triple ultrasonography was more preferable.

Basic point-of-care ultrasound framework based on the airway, breathing, and circulation approach for the initial management of shock and dyspnea

Ultrasound (US) carried out and interpreted by clinicians at the bedside is now called point‐of‐care US (POCUS). Clinical studies on POCUS have been carried out based on the ideas of “creation”, “extraction”, and “combination”. “Creation” refers to findings for the upper airway and lung being obtained at the bedside. “Extraction” refers to findings suitable for POCUS being extracted from comprehensive US, including echocardiography, abdominal US, and whole‐leg US. “Combination” refers to these POCUS applications being combined for the comprehensive assessment of patients with trauma, shock, or dyspnea. Emergency and critical care physicians have many opportunities to encounter trauma or non‐trauma patients with shock, dyspnea, or both. Furthermore, the scope of POCUS includes many diseases and injuries that present with both shock and dyspnea. Therefore, we propose a basic POCUS framework based on the systematic airway, breathing, and circulation approach for the initial management of shock and dyspnea in adult patients. In this article, we update and review each application of POCUS and their combination in this framework. Furthermore, we propose the practical usage of the framework based on clinical presentations to improve the management of shock and dyspnea.

Lung Ultrasound for the Cardiologist

For a cardiologist, lung ultrasound is an add-on to transthoracic echocardiography, just as lung auscultation is part of a cardiac physical examination. A cardiac 3.5- to 5.0-MHz transducer is generally suitable because the small footprint makes it ideal for scanning intercostal spaces. The image quality is often adequate, and the lung acoustic window is always patent. The cumulative increase in imaging time is <1 min for the 2 main applications targeted on pleural water (pleural effusion) and lung water (pulmonary congestion as multiple B-lines). In these settings, lung ultrasound outperforms the diagnostic accuracy of the chest radiograph, with a low-cost, portable, real-time, radiation-free method. A "wet lung" detected by lung ultrasound predicts impending acute heart failure decompensation and may trigger lung decongestion therapy. The doctors of tomorrow may still listen with a stethoscope to their patient's lung, but they will certainly be seeing it with ultrasound.

Diagnosis of Acute Heart Failure in the Emergency Department: An Evidence-Based Review

Heart failure is a common presentation to the emergency department (ED), which can be confused with other clinical conditions. This review provides an evidence-based summary of the current ED evaluation of heart failure. Acute heart failure is the gradual or rapid decompensation of heart failure, resulting from either fluid overload or maldistribution. Typical symptoms can include dyspnea, orthopnea, or systemic edema. The physical examination may reveal pulmonary rales, an S3 heart sound, or extremity edema. However, physical examination findings are often not sensitive or specific. ED assessments may include electrocardiogram, complete blood count, basic metabolic profile, liver function tests, troponin, brain natriuretic peptide, and a chest radiograph. While often used, natriuretic peptides do not significantly change ED treatment, mortality, or readmission rates, although they may decrease hospital length of stay and total cost. Chest radiograph findings are not definitive, and several other conditions may mimic radiograph findings. A more reliable modality is point-of-care ultrasound, which can facilitate the diagnosis by assessing for B-lines, cardiac function, and inferior vena cava size. These modalities, combined with clinical assessment and gestalt, are recommended.

Recognising Bias in Studies of Diagnostic Tests Part 1: Patient Selection

In this two-part series on sources of bias in studies of diagnostic test performance, we outline common errors and optimal conditions during three study phases: patient selection, interpretation of the index test and disease verification by a gold standard. Here in part 1, biases associated with suboptimal participant selection are discussed through the lens of partial verification bias and spectrum bias, both of which increase the proportion of participants who are the 'sickest of the sick' or the 'wellest of the well.' Especially through retrospective methodology, partial verification introduces bias by including patients who are test positive by a gold standard, since patients with a positive index test are more likely to go on to further gold standard testing. Spectrum bias is frequently introduced through case-control design, dropping of indeterminate results or convenience sampling. After reading part 1, the informed clinician should be better able to judge the quality of a diagnostic test study, its inherent limitations and whether its results could be generalisable to their practice. Part 2 will describe how interpretation of the index test and disease verification by a gold standard can contribute to diagnostic test bias.

Assessing Extravascular Lung Water With Ultrasound: A Tool to Individualize Fluid Management?

Aggressive fluid resuscitation has become standard of care for hypotensive patients with sepsis. However, sepsis is a syndrome that occurs in patients with diverse underlying physiology and a one-size-fits-all approach to fluid administration seems misguided. To individualize fluid management, several methods to assess fluid responsiveness have been validated, but even in fluid responsive patients, fluid administration may still be harmful and lead to pulmonary edema. Hence, to individualize fluid management, in addition to fluid responsiveness, fluid tolerance needs to be assessed. This article examines whether lung ultrasound can be useful to detect excess extravascular lung water (EVLW) and thus assess fluid tolerance. The physiology of EVLW and the principles of lung ultrasound are briefly described. Articles examining the correlation between EVLW and lung ultrasound findings in various clinical settings are carefully reviewed. Overall, lung ultrasound has been found to be an excellent tool to detect EVLW, but large outcome studies investigating lung ultrasound-guided fluid management are still lacking.

Integration of Ultrasound Into the Physician Assistant Curriculum

PURPOSE

Over the past 10 years, successful ultrasound integration into medical education has resulted in 8 residencies and 52 undergraduate medical schools requiring ultrasound training for graduation. Physician assistants (PAs) are trained in the medical model, yet very little is known about the integration of ultrasound into their curricula. This study examined how ultrasound is used, if at all, in the PA education curricula.

METHODS

Physician assistant program directors (PDs) were sent a survey addressing ultrasound integration into their curricula. Questions focused on the use of ultrasound to teach didactic courses and on inclusion of point-of-care ultrasound (POCUS) scanning skills as an adjunct to the physical examination. The survey also asked about students' feelings toward ultrasound integration into the curricula.

RESULTS

Investigators contacted 201 PDs, and 107 (53.2%) PDs responded. Twenty-five of the respondents (23.4%) reported using ultrasound in the basic sciences. The top 3 reasons for not including ultrasound in preclinical courses were no ultrasound machine, expense, and no faculty trained in ultrasound. Seventy-three of the respondents (68.2%) thought that POCUS scanning skills should be included in the curriculum. More than 83% felt that faculty or adjunct faculty should teach those skills.

CONCLUSION

This survey demonstrated that there is great interest in integrating ultrasound into the PA curriculum but that many challenges inhibit implementation. Lack of access to ultrasound machines and to trained faculty are the biggest challenges to integrating ultrasound into the PA curriculum. Physician assistant programs face content and competency challenges similar to those that medical schools face, as well as several challenges that are unique to PA education. Future research is needed to address these issues.

Comparison between inferior vena cava ultrasound, lung ultrasound, bioelectric impedance analysis, and natriuretic peptides in chronic heart failure

BACKGROUND

Heart failure (HF) is an important healthcare problem. Knowing volume status in outpatients with chronic HF to adjust treatment and to avoid decompensations is a challenge. The aim of this study is comparing the usefulness of inferior vena cava (IVC) ultrasound, lung ultrasound, bioelectrical impedance analysis (BIA), and natriuretic peptides in the follow-up of outpatients with chronic HF.

METHODS

This was a prospective cohort study. Ninety-nine patients with chronic HF were included consecutively as they attended scheduled medical visits. The different techniques were performed on the day of the clinic visit, and the result was hidden from the patients and the responsible medical team. Follow-up time was 1 year. Outcome events checked were a combination of death or hospitalization, due to HF.

RESULTS

Thirty-six patients (36.4%) died or were hospitalized for HF. They had a significantly lower IVC collapse, and a greater number of lung B-lines and higher NTproBNP levels compared to patients who remained stable. There were no differences in the BIA parameters. After multivariable analysis, cut-off points of IVC collapse <30%, number of pulmonary B lines greater than 5, and NTproBNP levels greater than 2000 pg/ml were associated with increased risk of HF death or admission. NTproBNP had the best area under the curve.

CONCLUSION

Evaluation of congestion in outpatients with chronic HF may be based on NTproBNP, IVC ultrasound, or lung ultrasound; they are useful in identifying patients at high risk of hospitalization or death due to HF.

Bedside Ultrasound Versus Chest Radiography for Detection of Pulmonary Edema: A Prospective Cohort Study

OBJECTIVES

Chest radiography has been the preferred imaging study to assess pulmonary congestion. However, chest radiography interpretation is influenced by the level of expertise and high interobserver variability. Lung ultrasound (US) may produce more objective findings through evaluation of vertical comet tail artifacts known as B-lines, which are created by a decrease in the ratio of alveolar air to fluid pulmonary content. Few studies have directly compared chest radiography to bedside US against a reference standard for the diagnosis of pulmonary edema. This study compared the sensitivity and specificity of bedside US and chest radiography in diagnosing pulmonary edema.

METHODS

This prospective observational cohort study involved adult patients presenting to the emergency department of an urban tertiary hospital with dyspnea. The primary outcome was the presence or absence of pulmonary edema, as indicated by B-lines on a bedside lung US examination or radiologist-interpreted chest radiography. Patients underwent a US examination within about 1 hour of chest radiography. The final diagnosis from the discharge summary served as the reference standard.

RESULTS

Ninety-nine patients were enrolled; 32.3% had congestive heart failure, and 40.4% had chronic obstructive pulmonary disease. Bedside US showed significantly higher sensitivity (96%) compared to chest radiography (65%; P < .001). Of 18 patients with negative radiographic findings and a discharge diagnosis of pulmonary edema, 16 (89%) had positive US findings (P < .001).

CONCLUSIONS

Bedside US has the potential to identify pulmonary edema more accurately than chest radiography. As current practice within the United States uses chest radiography, reflecting American College of Cardiology Foundation/American Heart Association guidelines for management of heart failure, the results of this study warrant further evaluation.

Emergency department non-invasive cardiac output study (EDNICO): a feasibility and repeatability study

Background

There is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assessed six non-invasive fluid responsiveness monitoring methods which measure cardiac output directly or indirectly for their feasibility and repeatability of measurements in the ED: (1) left ventricular outflow tract echocardiography derived velocity time integral, (2) common carotid artery blood flow, (3) suprasternal aortic Doppler, (4) bioreactance, (5) plethysmography with digital vascular unloading method, and (6) inferior vena cava collapsibility index.

Methods

This is a prospective observational study of non-invasive methods of assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Feasibility of each method was determined by the proportion of clinically interpretable measurements from the number of measurement attempts. Repeatability was determined by comparing the mean difference of two paired measurements in a fluid steady state (after participants received an intravenous fluid bolus).

Results

76 patients were recruited in the study. A total of 207 fluid responsiveness measurement sets were analysed. Feasibility rates were 97.6% for bioreactance, 91.3% for vascular unloading method with plethysmography, 87.4% for common carotid artery blood flow, 84.1% for inferior vena cava collapsibility index, 78.7% for LVOT VTI, and 76.8% for suprasternal aortic Doppler. The feasibility rates difference between bioreactance and all other methods was statistically significant.

Conclusion

Our study shows that non-invasive fluid responsiveness monitoring in the emergency department may be feasible with selected methods. Higher repeatability of measurements were observed in non-ultrasound methods. These findings have implications for further studies specifically assessing the accuracy of such non-invasive cardiac output methods and their effect on patient outcome in the ED in fluid depleted states such as sepsis.

Electronic supplementary material

The online version of this article (10.1186/s13049-019-0586-6) contains supplementary material, which is available to authorized users.

Pulmonary Ultrasound in Patients with Heart Failure - Systematic Review

Pulmonary congestion is an important clinical finding in patients with heart failure (HF). Physical examination and chest X-ray have limited accuracy in detecting congestion. Pulmonary ultrasound (PU) has been incorporated into clinical practice in the evaluation of pulmonary congestion. This paper aimed to perform a systematic review of the use of PU in patients with HF, in different scenarios. A search was performed in the MEDLINE and LILACS databases in February 2017 involving articles published between 2006 and 2016. We found 26 articles in the present review, 11 of which in the emergency setting and 7 in the outpatient setting, with diagnostic and prognosis defined value and poorly studied therapeutic value. PU increased accuracy by 90% as compared to physical examination and chest X-ray for the diagnosis of congestion, being more sensitive and precocious. The skill of the PU performer did not interfere with diagnostic accuracy. The presence of B-lines ≥ 15 correlated with high BNP values (≥ 500) and E/e' ratio ≥ 15, with prognostic impact in IC patients at hospital discharge and those followed up on an outpatient basis. In conclusion, when assessing pulmonary congestion in HF, PU has an incremental value in the diagnostic and prognostic approach in all scenarios studied.

Anterior vs lateral symmetric interstitial syndrome in the diagnosis of acute heart failure

Acute dyspnea due to acute heart failure (AHF) is one of the most common reasons for admission to the Emergency Department (ED). The importance of lung ultrasound (LUS) examination in the diagnostic workup of AHF has been widely established. Limited anterior LUS examination for the diagnosis of AHF is controversial. This study compares the accuracy of LUS examination limited to the anterior or lateral lung zones for the diagnosis of AHF and their accuracy among patients with different levels of hypoxemia according to PO₂/FiO₂ ratio evaluation. We analyzed 170 patients admitted to the ED for acute dyspnea, who underwent multi-organ ultrasound examination of lung, heart and inferior vena cava for differential diagnosis. The thorax was examined following a simplified protocol that provides two scans at each side (anterior and lateral) to sample upper and lower lobes and the presence or the absence of interstitial syndrome (IS) was evaluated. The presence of anterior symmetric IS exhibited lower accuracy than lateral symmetric IS in the diagnosis of AHF in the whole population, but its diagnostic accuracy improves in sub-groups of patients with severe and critical hypoxemia.

[Emergency lung ultrasound]

Acute and emergency physicians need to make rapid and far-reaching decisions on the basis of little diagnostic information. In patients with symptoms suggestive of a cardiopulmonary diagnosis, point-of-care lung ultrasound (LUS) is becoming increasingly used. In patients with acute dyspnea, chest pain and shock, LUS increases the diagnostic reliability. The BLUE protocol helps to differentiate important diagnoses of acute dyspnea (pulmonary edema, pneumonia, acute respiratory distress syndrome, pulmonary embolism, pleural effusions or pneumothorax). LUS is also used for treatment follow-up. It is clearly superior to other diagnostic measures (auscultation, chest X‑ray). With ever smaller "handheld" ultrasound devices, the use of ultrasound is also being increasingly used in preclinical situations.

Lung Ultrasound for the Emergency Diagnosis of Pneumonia, Acute Heart Failure, and Exacerbations of Chronic Obstructive Pulmonary Disease/Asthma in Adults: A Systematic Review and Meta-analysis

BACKGROUND

Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.

OBJECTIVE

Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.

METHODS

PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).

RESULTS

Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74-0.88) and specificity of 0.94 (95% CI 0.85-0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87-0.93) and specificity of 0.93 (95% CI 0.91-0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72-0.98) and specificity of 0.92 (95% CI 0.79-0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67-0.86) and specificity of 0.94 (95% CI 0.89-0.97) for exacerbations of COPD/asthma.

CONCLUSION

Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma.

Relationship of inferior vena cava collapsibility to ultrafiltration volume achieved in critically ill hemodialysis patients

Background

Ultrasound (US) assessment of intravascular volume may improve volume management of dialysis patients. We investigated the relationship of intravascular volume evaluated by inferior vena cava (IVC) US to net volume changes with intermittent hemodialysis (HD) in critically ill patients.

Methods

A retrospective cohort of 113 intensive care unit patients in 244 encounters had clinical assessment of intravascular volume followed by US of respiratory/ventilatory variation of IVC diameter, and had HD within 24 h. IVC collapsibility index (IVC CI)=(IVCmax–IVCmin)/IVCmax*100%. Volume management was guided by clinical data plus IVC US findings. Intradialytic hypotension (IDH) was categorized by severity from none to inability to tolerate HD.

Results

Linear regression correlating n-weighted proportions of encounters achieving net volume removal of ≥0.5 L, ≥1.0 L, ≥1.5 L, and ≥2.0 L strongly correlated across the range of IVC CI (R²=0.87–0.64). Sensitivity and specificity analysis showed IVC CI was a better predictor than IVCmax of achieving net ultrafiltration (UF) volumes. Mean central venous pressure, pulmonary artery occlusion pressure, and cardiac output were poor predictors by logistic regression and receiver operating curve analyses. IVC CI <20% was the approximate optimal cutoff for achieving ≥0.5 L to ≥2.0 L net UF volumes. Net volume change achieved tended to be less than recommended and may have been limited by the development of IDH. Severity of IDH did not correlate with UF rate in mL/kg/h. χ² analysis showed pre-US clinical intravascular volume assessments had poor concordance with IVC CI categories.

Conclusion

IVC US may be a useful tool for predicting whether critically ill patients will achieve volume removal with HD.

Automated Identification and Localization of the Inferior Vena Cava Using Ultrasound: An Animal Study

Ultrasound measurement of the inferior vena cava (IVC) is widely implemented in the clinic. However, the process is time consuming and labor intensive, because the IVC diameter is continuously changing with respiration. In addition, artificial errors and intra-operator variations are always considerable, making the measurement inconsistent. Research efforts were recently devoted to developing semiautomated methods. But most required an initial identification of the IVC manually. As a first step toward fully automated IVC measurement, in this paper, we present an intelligent technique for automated IVC identification and localization. Forty-eight ultrasound data sets were collected from eight pigs, each of which included two frames in B-mode and color mode (C-mode) collected at the inspiration, and two cine loops in B-mode and C-mode. Static and dynamic automation algorithms were applied to the data sets for identifying and localizing the IVC. The results were evaluated by comparing with the manual measurement of experienced clinicians. The automated approaches successfully identified the IVC in 47 cases (success rate: 97.9%). The automated localization of the IVC is close to the manual counterpart, with the difference within one diameter. The automatically measured diameters are close to those measured manually, with most differences below 15%. It is revealed that the proposed method can automatically identify the IVC with high success rate and localize the IVC with high accuracy. But the study with high accuracy was conducted under good control and without considering difficult cases, which deserve future explorations. The method is a first step toward fully automated IVC measurement, which is suitable for point-of-care applications.

Misconceptions in acute heart failure diagnosis and Management in the Emergency Department

INTRODUCTION

Acute heart failure (AHF) accounts for a significant number of emergency department (ED) visits, and the disease may present along a spectrum with a variety of syndromes.

OBJECTIVE

This review evaluates several misconceptions concerning heart failure evaluation and management in the ED, followed by several pearls.

DISCUSSION

AHF is a heterogeneous syndrome with a variety of presentations. Physicians often rely on natriuretic peptides, but the evidence behind their use is controversial, and these should not be used in isolation. Chest radiograph is often considered the most reliable imaging test, but bedside ultrasound (US) provides a more sensitive and specific evaluation for AHF. Diuretics are a foundation of AHF management, but in pulmonary edema, these medications should only be provided after vasodilator administration, such as nitroglycerin. Nitroglycerin administered in high doses for pulmonary edema is safe and effective in reducing the need for intensive care unit admission. Though classically dopamine is the first vasopressor utilized in patients with hypotensive cardiogenic shock, norepinephrine is associated with improved outcomes and lower mortality. Disposition is complex in patients with AHF, and risk stratification tools in conjunction with other assessments allow physicians to discharge patients safely with follow up.

CONCLUSION

A variety of misconceptions surround the evaluation and management of heart failure including clinical assessment, natriuretic peptide use, chest radiograph and US use, nitroglycerin and diuretics, vasopressor choice, and disposition. This review evaluates these misconceptions while providing physicians with updates in evaluation and management of AHF.