Role of pulmonary ultrasonography in diagnosis of acute heart failure

BACKGROUND

One of the most prevalent causes of emergency room visits is acute dyspnea. Several etiologies, including cardiac, pulmonary, metabolic, psychogenic etc… may be involved. Acute heart failure (AHF) is among the most common causes. This study aims to evaluate, in patients presenting with acute dyspnea to the emergency departement (ED), the accuracy of a diagnostic approach combining Lung ultrasonography (LUS) and clinical assessment as compared to the traditional AHF diagnostic work-up.

METHODS

This is a bi-centric cross-sectional observational study, conducted at the Emergency and Cardiology Department of both the Hedi Chaker Hospital in Sfax and the Habib Thameur Hospital in Tunis for the period extending from 01/07/2022 to 30/09/2023. The diagnostic performance of pulmonary ultrasonography was studied and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were compared with those of clinical examination, chest X-Ray, NT-pro -BNP and the Transthoracic echocardiography (TTE) which was the reference exam.

RESULTS

The most common cause of acute dyspnea is acute heart failure (79.3 %). LUS had a sensitivity of 94,2 % in diagnosing AHF and a specificity of 77,5 %. Its PPV and NPV were respectively 92 % and 81 %. The area under curbe (AUC) of B-Lines required for the diagnosis of interstitial pulmonary syndrome was excellent (92 %). There was a moderate significant positive correlation between the number of B-Lines and NT-Pro-BNP levels r = 0.51, P < 0.001. Also, there was a very strong significant positive relationship between the pulmonary congestion assessed by LUS and Left atrium - pressure r = 0.788, P < 0.001 CONCLUSION: LUS is an excellent test both to confirm and exclude the diagnosis of AHF in patients consulting the emergency room for acute dyspnea and therefore deserves to be performed systematically.

The assessment, interpretation and implementation of lung ultrasound examinations in Heart Failure: Current evidence and gaps in knowledge

Lung ultrasound (LUS) is a simple, fast and non-invasive tool for pulmonary congestion assessment with higher accuracy for the detection of acute heart failure (HF) compared to clinical examination and chest radiography. The integrated assessment with other ultrasound and echocardiographic parameters can lead to a better systemic and pulmonary congestion characterization. Additionally, the combination of echocardiographic and pulmonary features can identify patients at higher risk for adverse outcomes, potentially facilitating both acute and chronic HF management and prognostic stratification. However, the optimal utilization of LUS needs to be better defined both in terms of imaging method and B-line thresholds which may differ based on the clinical scenario and, potentially, the HF phenotype. Despite the extensive potential role of LUS in a wide range of HF scenarios, clinicians may be unaware of the correct technique and exam interpretation. Specifically, the interpretation of LUS findings is influenced by several factors, such as imaging protocol, type of ultrasound transducer, patient positioning, and presence of concomitant pulmonary diseases. The aim of this review is to provide a practical overview of LUS in patients with known or suspected HF with the goal of providing a practical guide for clinicians and nurses in various clinical settings.

Integrative assessment of congestion in heart failure using ultrasound imaging

In heart failure (HF), congestion is a key pathophysiologic hallmark and a major contributor to morbidity and mortality. However, the presence of congestion is often overlooked in both acute and chronic settings, particularly when it is not clinically evident, which can have important clinical consequences. Ultrasound (US) is a widely available, non-invasive, sensitive tool that might enable clinicians to detect and quantify the presence of (subclinical) congestion in different organs and tissues and guide therapeutic strategies. In particular, left ventricular filling pressures and pulmonary pressures can be estimated using transthoracic echocardiography; extravascular lung water accumulation can be evaluated by lung US; finally, systemic venous congestion can be assessed at the level of the inferior vena cava or internal jugular vein. The Doppler evaluation of renal, hepatic and portal venous flow can provide additional valuable information. This review aims to describe US techniques allowing multi-organ evaluation of congestion, underlining their role in detecting, monitoring, and treating volume overload more objectively.

Two- Versus 8-Zone Lung Ultrasound in Heart Failure: Analysis of a Large Data Set Using a Deep Learning Algorithm

OBJECTIVE

Scanning protocols for lung ultrasound often include 8 or more lung zones, which may limit real-world clinical use. We sought to compare a 2-zone, anterior-superior thoracic ultrasound protocol for B-line artifact detection with an 8-zone approach in patients with known or suspected heart failure using a deep learning (DL) algorithm.

METHODS

Adult patients with suspected heart failure and B-lines on initial lung ultrasound were enrolled in a prospective observational study. Subjects received daily ultrasounds with a hand-held ultrasound system using an 8-zone protocol (right and left anterior/lateral and superior/inferior). A previously published deep learning algorithm that rates severity of B-lines on a 0-4 scale was adapted for use on hand-held ultrasound full video loops. Average severities for 8 and 2 zones were calculated utilizing DL ratings. Bland-Altman plot analyses were used to assess agreement and identify bias between 2- and 8-zone scores for both primary (all patients, 5728 videos, 205 subjects) and subgroup (confirmed diagnosis of heart failure or pulmonary edema, 4464 videos, 147 subjects) analyses.

RESULTS

Bland-Altman plot analyses revealed excellent agreement for both primary and subgroup analyses. The absolute difference on the 4-point scale between 8- and 2-zone average scores was not significant for the primary dataset (0.03; 95% CI -0.01 to 0.07) or the subgroup (0.01; 95% CI -0.04 to 0.06).

CONCLUSION

Utilization of a 2-zone, anterior-superior thoracic ultrasound protocol provided similar severity information to an 8-zone approach for a dataset of subjects with known or suspected heart failure.

Thoracic ultrasonographic and clinical findings at 12-month follow-up of patients admitted with COVID-19

Introduction

Thoracic ultrasound (TUS) has proven useful in the diagnosis, risk stratification and monitoring of disease progression in patients with coronavirus disease 2019 (COVID-19). However, utility in follow-up is poorly described. To elucidate this area, we performed TUS as part of a 12-month clinical follow-up in patients previously admitted with COVID-19 and correlated findings with clinical assessment and pulmonary function tests.

Methods

Adult patients discharged from our hospital following admission with COVID-19 during March to May 2020 were invited to a 12-month follow-up. Enrolled patients were interviewed regarding persisting or newly developed symptoms in addition to TUS, spirometry and a 6-min walk test. Patients were referred to high-resolution computed tomography (HRCT) of the lungs if suspicion of pulmonary fibrosis was raised.

Results

Forty patients were enrolled in the study of whom had 13 developed acute respiratory distress syndrome (ARDS) during admission. Patients with ARDS were more prone to experience neurological symptoms at follow-up (p = 0.03) and showed more B-lines on TUS (p = 0.008) but did not otherwise differ significantly in terms of pulmonary function tests. Four patients had pathological findings on TUS where subsequent diagnostics revealed that two had interstitial lung abnormalities and two had heart failure. These four patients presented with a significantly lower diffusing capacity of lung for carbon monoxide (p=0.03) and 6-min walking distance (p=0.006) compared to the remaining 36 patients without ultrasound pathology. No significant difference was observed in spirometry values of % of predicted FEV1 (p=0.49) or FVC (p=0.07). No persisting cardiovascular pathology was observed in patients without ultrasonographic pathology.

Conclusion

At 12-month after admission with COVID-19, a follow-up combining TUS, clinical assessment, and pulmonary function tests may improve the selection of patients requiring further diagnostic investigations such as HRCT or echocardiography.

Exercise-induced B-lines for the diagnosis of heart failure with preserved ejection fraction: a two-centre study

BACKGROUND

Diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging despite the use of scores/algorithms. This study intended to assess the diagnostic value of exercise lung ultrasound (LUS) for HFpEF diagnosis.

METHODS

We studied two independent case-control studies of HFpEF patients and control subjects undergoing different exercise protocols: (i) submaximal exercise stress echocardiography (ESE) with LUS performed by expert cardiologists (N = 116, HFpEF = 65.5%), and (ii) maximal cycle ergometer test (CET) (N = 54, HFpEF = 50%) with LUS performed by unexperienced physicians shortly trained for the study. B-line kinetics (i.e. peak values and their changes from rest) were assessed.

RESULTS

In the ESE cohort, the C-index (95% CI) of peak B-lines for HFpEF diagnosis was 0.985 (0.968-1.000), whereas the C-index of rest and exercise HFA-PEFF scores (i.e. including stress echo findings) were < 0.90 (CI 0.823-0.949), and that of H2FPEF score was < 0.70 (CI 0.558-0.764). The C-index increase of peak B-lines on top of the above-mentioned scores was significant (C-index increase > 0.090 and P-value < 0.001 for all). Similar results were observed for change B-lines. Peak B-lines > 5 (sensitivity = 93.4%, specificity = 97.5%) and change B-lines > 3 (sensitivity = 94.7%, specificity = 87.5%) were the best cutoffs for HFpEF diagnosis. Adding peak or change B-lines on top of HFpEF scores and BNP significantly improved diagnostic accuracy. Peak B-lines showed a good diagnostic accuracy in the LUS beginner-led CET cohort (C-index = 0.713, 0.588-0.838).

CONCLUSIONS

Exercise LUS showed excellent diagnostic value for HFpEF diagnosis regardless of different exercise protocols/level of expertise, with additive diagnostic accuracy on top of available scores and natriuretic peptides.

Induction of Day-Time Periodic Breathing is Associated With Augmented Reflex Response From Peripheral Chemoreceptors in Male Patients With Systolic Heart Failure

Spontaneous day-time periodic breathing (sPB) constitutes a common phenomenon in systolic heart failure (HF). However, it is unclear whether PB during wakefulness could be easily induced and what are the physiological and clinical correlates of patients with HF in whom PB induction is possible. Fifty male HF patients (age 60.8 ± 9.8 years, left ventricle ejection fraction 28.0 ± 7.4%) were prospectively screened and 46 enrolled. After exclusion of patients with sPB the remaining underwent trial of PB induction using mild hypoxia (stepwise addition of nitrogen gas to breathing mixture) which resulted in identification of inducible (iPB) in 51%. All patients underwent assessment of hypoxic ventilatory response (HVR) using transient hypoxia and of hypercapnic ventilatory response (HCVR) employing Read’s rebreathing method. The induction trial did not result in any adverse events and minimal SpO₂ during nitrogen administration was ∼85%. The iPB group (vs. non-inducible PB group, nPB) was characterized by greater HVR (0.90 ± 0.47 vs. 0.50 ± 0.26 L/min/%; p <0.05) but comparable HCVR (0.88 ± 0.54 vs. 0.67 ± 0.68 L/min/mmHg; p = NS) and by worse clinical and neurohormonal profile. Mean SpO₂ which induced first cycle of PB was 88.9 ± 3.7%, while in sPB mean SpO₂ preceding first spontaneous cycle of PB was 96.0 ± 2.5%. There was a reverse relationship between HVR and the relative variation of SpO₂ during induced PB (r = −0.49, p = 0.04). In summary, PB induction is feasible and safe in HF population using simple and standardized protocol employing incremental, mild hypoxia. Pathophysiology of iPB differs from sPB, as it relies mostly on overactive peripheral chemoreceptors. At the same time enhanced HVR might play a protective role against profound hypoxia during iPB.

[Focus ultrasound for cardiology practice. Russian consensus document]

This document is a consensus document of Russian Specialists in Heart Failure, Russian Society of Cardiology, Russian Association of Specialists in Ultrasound Diagnostics in Medicine and Russian Society for the Prevention of Noncommunicable Diseases. In the document a definition of focus ultrasound is stated and discussed when it can be used in cardiology practice in Russian Federation.

Lung Ultrasound-Guided Fluid Management versus Standard Care in Surgical ICU Patients: A Randomised Controlled Trial

The value of lung ultrasound (LU) in assessing extravascular lung water (EVLW) was demonstrated by comparing LU with gold-standard methods for EVLW assessment. However, few studies have analysed the value of B-Line score (BLS) in guiding fluid management during critical illness. The purpose of this trial was to evaluate if a BLS-guided fluid management strategy could improve fluid balance and short-term mortality in surgical intensive care unit (ICU) patients. We conducted a randomised, controlled trial within the ICUs of two university hospitals. Critically ill patients were randomised upon ICU admission in a 1:1 ratio to BLS-guided fluid management (active group) or standard care (control group). In the active group, BLS was monitored daily until ICU discharge or day 28 (whichever came first). On the basis of BLS, different targets for daily fluid balance were set with the aim of avoiding or correcting moderate/severe EVLW increase. The primary outcome was 28-day mortality. Over 24 months, 166 ICU patients were enrolled in the trial and included in the final analysis. Trial results showed that daily BLS monitoring did not lead to a different cumulative fluid balance in surgical ICU patients as compared to standard care. Consecutively, no difference in 28-day mortality between groups was found (10.5% vs. 15.6%, p = 0.34). However, at least 400 patients would have been necessary for conclusive results.

A practical guide to the lung ultrasound for the assessment of congestive heart failure

Dyspnea is one of the major symptoms encountered in the emergency department, and lung ultrasound (LUS) is recommended for the rapid diagnosis of the underlying disease. B-lines, the "comet-tail"-like vertical lines moving with respiration, are an ultrasound finding relevant to the pulmonary congestion. They may be observed in the normal lung, but bilateral, ≥ 3 B-lines are considered pathological. B-lines with lung sliding (B profile) are a specific sign of heart failure, while B-lines with abolished lung sliding (B' profile) are related with the lung diseases such as acute respiratory distress syndrome. B profile is reported to detect pulmonary edema with about 95% sensitivity and 95% specificity in patients with dyspnea. LUS also can assess the severity of pulmonary congestion semi-quantitatively by counting the number of B-lines or that of positive areas. Whereas the original BLUE protocol requires scanning at 12 zones on the chest, more rapid 8- or 6-zone scan is sufficient for the diagnosis of heart failure, and 2- or 4-zone scan may be used for the critical patients. LUS may be used for the evaluation of heart failure treatment, or can be performed as a part of exercise stress test. LUS can be performed easily and rapidly at the bedside using almost any kind of ultrasound apparatus, and it should be performed more widely in the daily practice as well as in the emergent department.

Effects of Lung Ultrasonography-Guided Management on Cumulative Fluid Balance and Other Clinical Outcomes: A Systematic Review

Lung ultrasonography is accurate in detecting pulmonary edema and overcomes most limitations of traditional diagnostic modalities. Whether use of lung ultrasonography-guided management has an effect on cumulative fluid balances and other clinical outcomes remains unclear. In this systematic review, we included 12 studies using ultrasonography guided-management with a total of 2290 patients. Four in-patient studies found a reduced cumulative fluid balance (ranging from -0.3 L to -2.4 L), whereas three out-patient studies found reduction in dialysis dry weight (ranging from -2.6 kg to -0.2 kg) compared with conventionally managed patients. None of the studies found adverse effects related to hypoperfusion. The use of lung ultrasonography-guided management was not associated with other clinical outcomes. This systematic review shows that lung ultrasonography-guided management, exclusively or in concert with other diagnostic modalities, is associated with a reduced cumulative fluid balance. Studies thus far have not shown a consistent effect on clinical outcomes.

The effects of breathing training on dyspnea and anxiety among patients with acute heart failure at emergency department

BACKGROUND

Anxiety-related dyspnea is a compelling symptom among patients with acute heart failure (AHF). Breathing training is a nonpharmacological intervention to relieve dyspnea and anxiety. This study aimed to investigate the effects of breathing training on dyspnea and anxiety among patients with AHF at the emergency department (ED).

METHODS

Two-group pre-post intervention study was conducted at the ED of one university hospital in the northeast of Thailand. Data were collected among 96 patients with AHF, which were equally assigned to breathing training (BT) and control groups. The training group received pursed-lip mindfulness breathing training, whereas the control group received usual care (UC). The pursed-lip mindfulness breathing was delivered from the first 40 min of arrival to the 4th hour in the ED. The breathing training consisted of positioning the patients in Fowler's position with the head of the bed elevated at 60 degrees or higher, supporting both arms with pillows, and breathing in through the nose with breathing out via the mouth with pursed lip while counting. Dyspnea and anxiety scores were measured with Dyspnea Visual Analog Scale and Anxiety Visual Analog Scale, respectively.

RESULTS

The dyspnea and anxiety scores significantly decreased after four hours in both groups. Dyspnea score decreased from 8.85 (SD 1.220) to 3.63 (SD 1.468) after BT (t = 26.111, p < 0.001) in the experimental group whereas in the control group it decreased from 8.98 (SD 1.194) to 6.94 (SD 1.590) after UC (t = 16.181, p < 0.001). Comparing between the groups, dyspnea score reductions were 5.22 (SD 1.468) in the experimental and 2.04 (SD 1.590) in the control (t = 0.101, p < 0.001). Anxiety score decreased from 9.35 (SD 1.000) to 4.44 (SD 1.219) after BT (t = 25.231, p < 0.001) in the experimental while the scores in the control group decreased from 9.48 (SD 1.072) to 8.15 (SD 1.502) after UC (t = 8.131, p < 0.001). The anxiety score reductions were 4.91 (SD 1.219) and 1.33 (SD 1.502) in the experimental and the control groups, respectively (t = 0. 066, p < 0.001). Both the dyspnea and anxiety scores after the intervention were significantly different between the experimental and control groups.

CONCLUSION

Both UC and BT with UC can reduce dyspnea and anxiety in patients admitted to ED with AHF. However, the effect of BT combined with UC was larger comparing to UC only.

Lung ultrasound may be a valuable aid in decision making for patients admitted with COVID-19 disease

INTRODUCTION: COVID-19 is associated with a risk of severe pneumonia and acute respiratory distress syndrome (ARDS), requiring treatment at an intensive care unit (ICU). Since clinical deterioration may occur rapidly, a simple, fast, bedside, non-invasive method for assessment of lung changes is warranted. The primary aim of this study was to investigate whether lung ultrasound (LUS) findings within 72 hours of admission were predictive of clinical deterioration in hospitalized patients with confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

METHODS: Patients admitted to a dedicated COVID-19 unit were subject to daily LUS examinations. Number of present consolidations and pleural effusions were registered and a Mongodi score was calculated. These findings were correlated with initial chest x-ray and clinical deterioration, defined as ICU-admission, ARDS diagnosis, death.

RESULTS: In total, 29 of 83 patients had LUS performed during admission, 18 within 72 h of admission. Of these, four patients died during admission, six were transferred to the ICU and 13 were diagnosed with ARDS.

Initial Mongodi-score did not differ significantly between patients with and without clinical deterioration (p = 0.95). Agreement between initial LUS and chest x-ray findings were fair with Cohen’s Kappa at 0.21.

CONCLUSION: LUS performed within 72 h in patients admitted to a dedicated COVID-19 unit could not predict ARDS, ICU admission or death. However, consecutive investigations may be of value, as sudden substantial changes may herald disease progression, enabling earlier supplementary diagnostics and treatment initiation.

Distinct Mechanical Properties of the Respiratory System Evaluated by Forced Oscillation Technique in Acute Exacerbation of COPD and Acute Decompensated Heart Failure

Discriminating between cardiac and pulmonary dyspnea is essential for patients’ management. We investigated the feasibility and ability of forced oscillation techniques (FOT) in distinguishing between acute exacerbation of COPD (AECOPD), and acute decompensated heart failure (ADHF) in a clinical emergency setting. We enrolled 49 patients admitted to the emergency department (ED) for dyspnea and acute respiratory failure for AECOPD, or ADHF, and 11 healthy subjects. All patients were able to perform bedside FOT measurement. Patients with AECOPD showed a significantly higher inspiratory resistance at 5 Hz, Xrs₅ (179% of predicted, interquartile range, IQR 94–224 vs. 100 IQR 67–149; p = 0.019), and a higher inspiratory reactance at 5 Hz (151%, IQR 74–231 vs. 57 IQR 49–99; p = 0.005) than patients with ADHF. Moreover, AECOPD showed higher heterogeneity of ventilation (respiratory system resistance difference at 5 and 19 Hz, Rrs_5-19: 1.49 cmH₂O/(L/s), IQR 1.03–2.16 vs. 0.44 IQR 0.22–0.76; p = 0.030), and a higher percentage of flow limited breaths compared to ADHF (10%, IQR 0–100 vs. 0 IQR 0–12; p = 0.030). FOT, which resulted in a suitable tool to be used in the ED setting, has the ability to identify distinct mechanical properties of the respiratory system in AECOPD and ADHF.

European Respiratory Society statement on thoracic ultrasound

Thoracic ultrasound is increasingly considered to be an essential tool for the pulmonologist. It is used in diverse clinical scenarios, including as an adjunct to clinical decision making for diagnosis, a real-time guide to procedures and a predictor or measurement of treatment response. The aim of this European Respiratory Society task force was to produce a statement on thoracic ultrasound for pulmonologists using thoracic ultrasound within the field of respiratory medicine. The multidisciplinary panel performed a review of the literature, addressing major areas of thoracic ultrasound practice and application. The selected major areas include equipment and technique, assessment of the chest wall, parietal pleura, pleural effusion, pneumothorax, interstitial syndrome, lung consolidation, diaphragm assessment, intervention guidance, training and the patient perspective. Despite the growing evidence supporting the use of thoracic ultrasound, the published literature still contains a paucity of data in some important fields. Key research questions for each of the major areas were identified, which serve to facilitate future multicentre collaborations and research to further consolidate an evidence-based use of thoracic ultrasound, for the benefit of the many patients being exposed to clinicians using thoracic ultrasound.

Prognostic Value of Lung Ultrasound for Clinical Outcomes in Heart Failure Patients: A Systematic Review and Meta-Analysis

BACKGROUND

There is conflicting information about whether lung ultrasound assessed by B-lines has prognostic value in patients with heart failure (HF).

OBJECTIVES

To evaluate the prognostic value of lung ultrasound assessed by B-lines in HF patients.

METHODS

Four databases (PubMed, EMBASE, Cochrane Library, and Scopus) were systematically searched to identify relevant articles. We pooled the hazard ratio (HR) and 95% confidence interval (CI) from eligible studies and carried out heterogeneity, quality assessment, and publication bias analyses. Data were pooled using a fixed-effects or random-effect model. A p value < 0.05 was considered to indicate statistical significance.

RESULTS

Nine studies involving 1,212 participants were included in the systematic review. B-lines > 15 and > 30 at discharge were significantly associated with increased risk of combined outcomes of all-cause mortality or HF hospitalization (HR, 3.37, 95% CI, 1.52-7.47; p = 0.003; HR, 4.01, 95% CI, 2.29-7.01; p < 0.001, respectively). A B-line > 30 cutoff at discharge was significantly associated with increased risk of HF hospitalization (HR, 9.01, 95% CI, 2.80-28.93; p < 0.001). Moreover, a B-line > 3 cutoff significantly increased the risk for combined outcomes of all-cause mortality or HF hospitalization in HF outpatients (HR, 3.21, 95% CI, 2.09-4.93; I2 = 10%; p < 0.00001).

CONCLUSION

B-lines could predict all-cause mortality and HF hospitalizations in patients with HF. Further large randomized controlled trials are needed to explore whether dealing with B-lines would improve the prognosis in clinical settings.

The association of lung ultrasound images with COVID-19 infection in an emergency room cohort

Lung ultrasound could facilitate the triage of patients with suspected COVID-19 infection admitted to the emergency room. We developed a predictive model for COVID-19 diagnosis based on lung ultrasound and clinical features. We used ultrasound to image the lung bilaterally at two anterior sites, one and two hands below each clavicle, and a posterolateral site that was the posterior transverse continuation from the lower anterior site. We studied 100 patients, 31 of whom had a COVID-19 positive reverse transcriptase polymerase chain reaction. A positive test was independently associated with: quick sequential organ failure assessment score ≥1; ≥3 B-lines at the upper site; consolidation and thickened pleura at the lower site; and thickened pleura line at the posterolateral site. The model discrimination was an area (95%CI) under the receiver operating characteristic curve of 0.82 (0.75-0.90). The characteristics (95%CI) of the model's diagnostic threshold, applied to the population from which it was derived, were: sensitivity, 97% (83-100%); specificity, 62% (50-74%); positive predictive value, 54% (41-98%); and negative predictive value, 98% (88-99%). This model may facilitate triage of patients with suspected COVID-19 infection admitted to the emergency room.

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).

Are pocket sized ultrasound devices sufficient in the evaluation of lung ultrasound patterns and aeration scoring in pulmonary ICU patients?

Lung ultrasound (LUS) is a practical diagnostic tool for several lung pathologies. Pocket sized USG devices (PSUDs) are more affordable, accessible, practical, and learning to use them is easier than standard ultrasound devices (SUDs). Their capability in image quality have been found as comparable with standard USG machines. Studies have been showing that these devices can be useful as much as SUDs in the evaluation of heart, abdomen, vascular structures, diaphragm and optic nerve. The aim of this study is to compare PSUD with a standard ultrasound devices (SUD) in the evaluation of LUS patterns such as alveolar, interstitial syndromes and lung aeration score (LAS). Study performed in an University Hospital Pulmonary ICU. All patients older than 18 years old were included in this study. The sector probe of SUD (Vivid-Q) and PSUD (Vscan) were used for investigation of A lines, interstitial (B lines), alveolar syndromes (consolidation, hepatisation, air bronchograms) and pleural effusion. 33 patients were included in the study. When PSUD was compared with SUD in terms of total B2 count, and LAS in the right, left and both lung, there was an agreement without proportional bias according to Bland Altman test. There was also good inter class correlation coefficient value as greater than 0.8 and 0.7 between two physicians in terms of counting of total B1, B2, total B lines and calculating of total LAS for SUD and PSUD respectively. PSUDs is a reliable and valid method for evaluation of LUS patterns like SUDs.

Point-of-Care Lung Ultrasound for Detecting Severe Presentations of Coronavirus Disease 2019 in the Emergency Department: A Retrospective Analysis

OBJECTIVES

Analyze the diagnostic test characteristics of point-of-care lung ultrasound for patients suspected to have novel coronavirus disease 2019.

DESIGN

Retrospective cohort.

SETTING

Two emergency departments in Detroit, Michigan, United States, during a local coronavirus disease 2019 outbreak (March 2020 to April 2020).

PATIENTS

Emergency department patients receiving lung ultrasound for clinical suspicion of coronavirus disease 2019 during the study period.

INTERVENTIONS

None, observational analysis only.

MEASUREMENTS AND MAIN RESULTS

By a reference standard of serial reverse transcriptase-polymerase chain reactions, 42 patients were coronavirus disease 2019 positive, 16 negative, and eight untested (test results lost, died prior to testing, and/or did not meet hospital guidelines for rationing of reverse transcriptase-polymerase chain reaction tests). Thirty-three percent, 44%, 38%, and 17% had mortality, ICU admission, intubation, and venous or arterial thromboembolism, respectively. Receiver operating characteristics, area under the curve, sensitivity, and specificity with 95% CIs were calculated for five lung ultrasound patterns coded by a blinded reviewer and chest radiograph. Chest radiograph had area under the curve = 0.66 (95% CI, 0.54-0.79), 74% sensitivity (95% CI, 48-93%), and 53% specificity (95% CI, 32-75%). Two lung ultrasound patterns had a statistically significant area under the curve: symmetric bilateral pulmonary edema (area under the curve, 0.57; 95% CI, 0.50-0.64), and a nondependent bilateral pulmonary edema pattern (edema in superior lung ≥ inferior lung and no pleural effusion; area under the curve, 0.73; 95% CI, 0.68-0.90). Chest radiograph plus the nondependent bilateral pulmonary edema pattern showed a statistically improved area under the curve (0.80; 95% CI, 0.68-0.90) compared to either alone, but at the ideal cutoff had sensitivity and specificity equivalent to nondependent bilateral pulmonary edema only (69% and 77%, respectively). The strongest combination of clinical, chest radiograph, and lung ultrasound factors for diagnosis was nondependent bilateral pulmonary edema pattern with temperature and oxygen saturation (area under the curve, 0.86; 95% CI, 0.76-0.94; sensitivity = 77% [58-93%]; specificity = 76% [53-94%] at the ideal cutoff), which was superior to chest radiograph alone.

CONCLUSIONS

Lung ultrasound diagnosed severe presentations of coronavirus disease 2019 with similar sensitivity to chest radiograph, CT, and reverse transcriptase-polymerase chain reaction (on first testing) and improved specificity compared to chest radiograph. Diagnostically useful lung ultrasound patterns differed from those hypothesized by previous, nonanalytical, reports (case series and expert opinion), and should be evaluated in a rigorous prospective study.

Body mass index and B-lines on lung ultrasonography in chronic and acute heart failure

AIMS

Increased body mass index (BMI) is common in heart failure (HF) patients and is associated with lower levels of N-terminal pro-brain natriuretic peptide (NT-proBNP). We evaluated the influence of BMI on lung ultrasonography (LUS) findings indicative of pulmonary congestion (i.e. B-lines) in patients with chronic and acute HF (AHF).

METHODS AND RESULTS

We analysed ambulatory chronic HF (n = 118) and hospitalized AHF (n = 177) patients (mean age 70 years, 64% men, mean BMI 29 kg/m² , mean ejection fraction 42%) undergoing echocardiography and LUS in eight chest zones. B-lines and chest wall thickness (skin to pleura) on ultrasound were quantified offline and blinded to clinical findings. NT-proBNP was available in AHF patients (n = 167). In chronic HF, B-line number decreased by 18% per 5 unit increase in BMI [95% confidence interval (CI) -35% to +5%, P = 0.11]. In AHF, the number of B-lines decreased by 12% per 5 unit increase in BMI (95% CI -19% to -5%, P = 0.001), whereas NT-proBNP concentration decreased by 28% per 5 unit increase in BMI (95% CI -40% to -16%, P < 0.001). For AHF, B-line number declined to a lesser degree than NT-proBNP concentration with increasing BMI (P = 0.020), and >6 B-lines were observed in half of AHF patients with severe obesity. There was an inverse relationship between B-line number and chest wall thickness, and this association varied by chest region.

CONCLUSIONS

Despite an inverse relationship between B-lines and BMI, B-lines declined to a lesser degree than NT-proBNP with increasing BMI. These data suggest that LUS may be useful in patients with HF despite obesity.

Lung Ultrasound for the Diagnosis and Management of Acute Respiratory Failure

For critically ill patients with acute respiratory failure (ARF), lung ultrasound (LUS) has emerged as an indispensable tool to facilitate diagnosis and rapid therapeutic management. In ARF, there is now evidence to support the use of LUS to diagnose pneumothorax, acute respiratory distress syndrome, cardiogenic pulmonary edema, pneumonia, and acute pulmonary embolism. In addition, the utility of LUS has expanded in recent years to aid in the ongoing management of critically ill patients with ARF, providing guidance in volume status and fluid administration, titration of positive end-expiratory pressure, and ventilator liberation. The aims of this review are to examine the basic foundational concepts regarding the performance and interpretation of LUS, and to appraise the current literature supporting the use of this technique in the diagnosis and continued management of patients with ARF.

Accuracy of Several Lung Ultrasound Methods for the Diagnosis of Acute Heart Failure in the ED: A Multicenter Prospective Study

BACKGROUND

Early appropriate diagnosis of acute heart failure (AHF) is recommended by international guidelines. This study assessed the value of several lung ultrasound (LUS) strategies for identifying AHF in the ED.

METHODS

This prospective study, conducted in four EDs, included patients with diagnostic uncertainty based on initial clinical judgment. A clinical diagnosis score for AHF (Brest score) was quantified, followed by an extensive LUS examination performed according to the 4-point (BLUE protocol) and 6-, 8-, and 28-point methods. The primary outcome was AHF discharge diagnosis adjudicated by two senior physicians blinded to LUS measurements. The C-index was used to quantify discrimination.

RESULTS

Among the 117 included patients, AHF (n = 69) was identified in 27.4%, 56.2%, 54.8%, and 76.7% of patients with the 4-point (two bilateral positive points), 6-point, 8-point (≥ 1 bilateral positive point), and 28-point (B-line count ≥ 30) methods, respectively. The C-index (95% CI) of the Brest score was 72.8 (65.3-80.3), whereas the C-index of the 4-, 6-, 8-, and 28-point methods were 63.7 (58.5-68.8), 72.4 (65.0-79.8), 74.0 (67.1-80.9), and 72.4 (63.9-80.9). The highest increase in the C-index on top of the BREST score was observed with the 8-point method in the whole population (6.9; 95% CI, 1.6-12.2; P = .010) and in the population with an intermediate Brest score, followed by the 6-point method.

CONCLUSIONS

In patients with diagnostic uncertainty, the 6-point/8-point LUS method (using the 1 bilateral positive point threshold) improves AHF diagnosis accuracy on top of the BREST score.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03194243; URL: www.clinicaltrials.gov.

Expert consensus document: Reporting checklist for quantification of pulmonary congestion by lung ultrasound in heart failure

Lung ultrasound is a useful tool for the assessment of patients with both acute and chronic heart failure, but the use of different image acquisition methods, inconsistent reporting of the technique employed and variable quantification of 'B-lines,' have all made it difficult to compare published reports. We therefore need to ensure that future studies utilizing lung ultrasound in the assessment of heart failure adopt a standardized approach to reporting the quantification of pulmonary congestion. Strategies to improve patient care by use of lung ultrasound in the assessment of heart failure have been difficult to develop. In the present document, key aspects of standardization are discussed, including equipment used, number of chest zones assessed, the method of quantifying B-lines, the presence and timing of additional investigations (e.g. natriuretic peptides and echocardiography) and the impact of therapy. This consensus report includes a checklist to provide standardization in the preparation, review and analysis of manuscripts. This will serve as a guide for investigators and clinicians and enhance the quality and transparency of lung ultrasound research.

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.

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.

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.

Association between lung ultrasound findings and invasive exercise haemodynamics in patients with undifferentiated dyspnoea

Aims

Dyspnoea is common in heart failure (HF) but non‐specific. Lung ultrasound (LUS) could represent a non‐invasive tool to detect subclinical pulmonary congestion in patients with undifferentiated dyspnoea.

Methods and results

We assessed the feasibility of an abbreviated LUS protocol (eight and two zones) in a prospective pilot study of 25 ambulatory patients with undifferentiated dyspnoea undergoing clinically indicated invasive cardiopulmonary exercise testing (iCPET) at rest (LUS 1) and after peak exercise (LUS 2). We also related LUS findings (B‐lines) to invasive haemodynamics stratified by supine pulmonary capillary wedge pressure (PCWP) (Congestion, >15 mmHg; Control, ≤15 mmHg). All enrolled patients (median age 68, 60% women, 32% prior HF, median ejection fraction 59%) had interpretable LUS 1 images in eight zones, and 20 (80%) had adequate LUS 2 images. LUS images were adequate in two posterior zones in 24 patients (96%) for LUS 1 and 18 (72%) for LUS 2. Although B‐line number was numerically higher in the Congestion group at rest and after peak exercise, this difference did not reach statistical significance. In the entire cohort, there was an association between B‐lines and rest systolic pulmonary artery pressure (r = 0.46, P = 0.02) and PCWP (r = 0.54, P = 0.005). There was an inverse relationship between B‐lines and peak VO₂ (r = −0.65, P = 0.002).

Conclusions

Among ambulatory patients with undifferentiated dyspnoea, an abbreviated LUS protocol before and after iCPET is feasible in the majority of patients. B‐line number at rest was associated with invasively measured markers of haemodynamic congestion and was inversely related with peak VO₂.

Emergency department ultrasound for the detection of B-lines in the early diagnosis of acute decompensated heart failure: a systematic review and meta-analysis

OBJECTIVES

Dyspnea is a common presenting problem that creates a diagnostic challenge for physicians in the emergency department (ED). While the differential diagnosis is broad, acute decompensated heart failure (ADHF) is a frequent cause that can be challenging to differentiate from other etiologies. Recent studies have suggested a potential diagnostic role for emergency lung ultrasound (US). The objective of this systematic review was to assess the accuracy of early bedside lung US in patients presenting to the ED with dyspnea.

METHODS

A systematic search of EMBASE, PubMed, and the Cochrane Library was performed in addition to a grey literature search. We selected prospective studies that reported on the sensitivity and specificity of B-lines from early lung ultrasound in dyspneic patients presenting to the ED. Selected studies underwent quality assessment using the Critical Appraisal and Skills Program (CASP) questionnaire.

DATA EXTRACTION AND SYNTHESIS

The search yielded 3674 articles; seven studies met inclusion criteria and fulfilled CASP requirements for a total of 1861 patients. Summary statistics from the meta-analysis showed that as a diagnostic test for ADHF, bedside lung US had a pooled sensitivity of 82.5% (95% confidence interval [CI]=66.4% to 91.8%) and a pooled specificity of 83.6% (95% CI=72.4% to 90.8%).

CONCLUSIONS

Our results suggest that in patients presenting to the ED with undifferentiated dyspnea, B-lines from early bedside lung US may be reliably used as an adjunct to current diagnostic methods. The incorporation of lung US may lead to more appropriate and timely diagnosis of patients with undifferentiated ADHF.

Modified Lung Ultrasonographic Technique for Evaluation of Idiopathic Pulmonary Fibrosis: Lateral Decubitus Position

OBJECTIVES

To compare lung ultrasonography (US) in the sitting or supine positions and the lateral decubitus position, with regard to the feasibility, duration, patient convenience, and assessment of B-lines, in patients with idiopathic pulmonary fibrosis.

METHODS

Twenty consecutive patients with idiopathic pulmonary fibrosis were prospectively enrolled. Lung US included scanning of 56 intercostal spaces. Each patient was examined twice by 2 protocols. During protocol 1, patients were examined in the supine and sitting positions for the anterior and dorsal chest, respectively. During protocol 2, patients were examined in the left lateral decubitus position for the evaluation of the right hemithorax and the reverse. Total, anterior, and posterior US scores resulted from the sum of B-lines at the whole, anterior, and posterior chest, respectively. High-resolution computed tomography (CT) was considered the reference standard. The duration of each protocol was recorded. Patients were questioned about which protocol they preferred.

RESULTS

There was no difference regarding feasibility between the protocols. A significant correlation was found between total US scores for both protocols and high-resolution CT findings (P < .0001), with protocol 2 showing a slightly higher correlation. A positive correlation was found between the protocols regarding total, anterior, and posterior US scores (P < .0001). The mean duration of protocol 2 was less than that of protocol 1 (P < .005). Nineteen patients (95%) reported a preference for protocol 2.

CONCLUSIONS

Lung US in the lateral decubitus position seems to be faster and more convenient. There appears to be no difference regarding feasibility and the number of B-lines, whereas it shows slightly higher correlation with high-resolution CT, compared with the sitting or supine positions in patients with idiopathic pulmonary fibrosis.

B-lines with Lung Ultrasound: The Optimal Scan Technique at Rest and During Stress

Various lung ultrasound (LUS) scanning modalities have been proposed for the detection of B-lines, also referred to as ultrasound lung comets, which are an important indication of extravascular lung water at rest and after exercise stress echo (ESE). The aim of our study was to assess the lung water spatial distribution (comet map) at rest and after ESE. We performed LUS at rest and immediately after semi-supine ESE in 135 patients (45 women, 90 men; age 62 ± 12 y, resting left ventricular ejection fraction = 41 ± 13%) with known or suspected heart failure or coronary artery disease. B-lines were measured by scanning 28 intercostal spaces (ISs) on the antero-lateral chest, 2nd-5th IS, along with the midaxillary (MA), anterior axillary (AA), mid-clavicular (MC) and parasternal (PS) lines. Complete 28-region, 16-region (3rd and 4th IS), 8-region (3rd IS), 4-region (3rd IS, only AA and MA) and 1-region (left 3rd IS, MA) scans were analyzed. In each space, the B-lines were counted from 0 = black lung to 10 = white lung. Interpretable images were obtained in all spaces (feasibility = 100 %). B-lines (>0 in at least 1 space) were present at ESE in 93 patients (69%) and absent in 42. More B-lines were found in the 3rd IS and along AA and MA lines. The B-line cumulative distribution was symmetric at rest (right/left = 1.10) and asymmetric with left lung predominance during stress (right/left = 0.67). The correlation of per-patient B-line number between 28-S and 16-S (R² = 0.9478), 8-S (R² = 0.9478) and 4-S scan (R² = 0.9146) was excellent, but only good with 1-S (R² = 0.8101). The average imaging and online analysis time were 5 s per space. In conclusion, during ESE, the comet map of lung water accumulation follows a predictable spatial pattern with wet spots preferentially aligned with the third IS and along the AA and MA lines. The time-saving 4-region scan is especially convenient during stress, simply dismissing dry regions and focusing on wet regions alone.

Dynamic changes and prognostic value of pulmonary congestion by lung ultrasound in acute and chronic heart failure: a systematic review

AIMS

Pulmonary congestion is an important finding in patients with heart failure (HF) that can be quantified by lung ultrasound (LUS). We conducted a systematic review to describe dynamic changes in LUS findings of pulmonary congestion (B-lines) in HF and to examine the prognostic utility of B-lines in HF.

METHODS AND RESULTS

We searched online databases for studies conducted in patients with chronic or acute HF that used LUS to assess dynamic changes or the prognostic value of pulmonary congestion. We included studies in adult populations, published in English, and conducted in ≥25 patients. Of 1327 identified studies, 13 (25-290 patients) met the inclusion criteria: six reported on dynamic changes in LUS findings (438 patients) and seven on the prognostic value of B-lines in HF (953 patients). In acute HF, B-line number changed within as few as 3 h of HF treatment. In acute HF, ≥15 B-lines on 28-zone LUS at discharge identified patients at a more than five-fold risk for HF readmission or death. Similarly, in ambulatory patients with chronic HF, ≥3 B-lines on five- or eight-zone LUS marked those at a nearly four-fold risk for 6-month HF hospitalization or death.

CONCLUSIONS

Lung ultrasound findings change rapidly in response to HF therapy. This technique may represent a useful and non-invasive method to track dynamic changes in pulmonary congestion. Furthermore, residual congestion at the time of discharge in acute HF or in ambulatory patients with chronic HF may identify those at high risk for adverse events.

Expert consensus document: Echocardiography and lung ultrasonography for the assessment and management of acute heart failure

Echocardiography is increasingly recommended for the diagnosis and assessment of patients with severe cardiac disease, including acute heart failure. Although previously considered to be within the realm of cardiologists, the development of ultrasonography technology has led to the adoption of echocardiography by acute care clinicians across a range of specialties. Data from echocardiography and lung ultrasonography can be used to improve diagnostic accuracy, guide and monitor the response to interventions, and communicate important prognostic information in patients with acute heart failure. However, without the appropriate skills and a good understanding of ultrasonography, its wider application to the most acutely unwell patients can have substantial pitfalls. This Consensus Statement, prepared by the Acute Heart Failure Study Group of the ESC Acute Cardiovascular Care Association, reviews the existing and potential roles of echocardiography and lung ultrasonography in the assessment and management of patients with acute heart failure, highlighting the differences from established practice where relevant.

Exercise-induced B-lines identify worse functional and prognostic stage in heart failure patients with depressed left ventricular ejection fraction

AIMS

Exercise stress echocardiography (ESE) is recommended by the European Society of Cardiology guidelines for the evaluation of heart failure (HF) patients. Recently, lung ultrasound (LUS) has been proposed for the assessment of extravascular lung water through B-lines. The aim of this study was to assess B-lines during ESE in HF.

METHODS AND RESULTS

Standard transthoracic and LUS evaluation was performed during semi-supine ESE in 103 NYHA class I-III HF patients (76 male; mean age 64 ± 12 years) with depressed left ventricular ejection fraction (35 ± 8%). B-lines were measured by scanning 28 intercostal spaces on antero-lateral chest, both at rest and at peak stress. Resting plasma B-type natriuretic peptide (BNP) levels and exercise capacity during cardiopulmonary testing with peak oxygen uptake (peak VO₂ ) were assessed in all patients. All patients were followed up for a median of 8 months (first quartile, 6; third quartile, 11). LUS was feasible and interpretable in all subjects. The overall number of B-lines increased from rest (median 5, interquartile range 0-10) to peak stress (median 12, interquartile range 0-45) (P < 0.0001). The number of stress B-lines was closely correlated with resting log-BNP (r = 0.88, P < 0.0001) and peak VO₂ (r = -0.90, P < 0.0001). During follow-up, 37 events occurred: 10 deaths, 23 re-hospitalizations for acute HF, and 4 non-fatal myocardial infarctions. Twelve-month event-free survival was 95% in the 36 patients with stress B-lines <30 (best cut-off identified by receiver operating characteristic curve analysis) vs. 7% in patients with ≥30 B-lines (P < 0.0001).

CONCLUSION

B-lines are easy to obtain, frequent in HF patients, and often increase during ESE. Adverse events were more frequent in patients with more B-lines during ESE.

Prehospital lung ultrasound for the diagnosis of cardiogenic pulmonary oedema: a pilot study

BACKGROUND

An improved prehospital diagnostic accuracy of cardiogenic pulmonary oedema could potentially improve initial treatment, triage, and outcome. A pilot study was conducted to assess the feasibility, time-use, and diagnostic accuracy of prehospital lung ultrasound (PLUS) for the diagnosis of cardiogenic pulmonary oedema.

METHODS

A prospective observational study was conducted in a prehospital setting. Patients were included if the physician based prehospital mobile emergency care unit was activated and one or more of the following two were present: respiratory rate >30/min., oxygen saturation <90 %. Exclusion criteria were: age <18 years, permanent mental disability or PLUS causing a delay in life-saving treatment or transportation. Following clinical assessment PLUS was performed and presence or absence of interstitial syndrome was registered. Audit by three physicians using predefined diagnostic criteria for cardiogenic pulmonary oedema was used as gold standard.

RESULTS

A total of 40 patients were included in the study. Feasibility of PLUS was 100 % and median time used was 3 min. The gold standard diagnosed 18 (45.0 %) patients with cardiogenic pulmonary oedema. The diagnostic accuracy of PLUS for the diagnosis of cardiogenic pulmonary oedema was: sensitivity 94.4 % (95 % confidence interval (CI) 72.7-99.9 %), specificity 77.3 % (95 % CI 54.6-92.2 %), positive predictive value 77.3 % (95 % CI 54.6-92.2 %), negative predictive value 94.4 % (95 % CI 72.7-99.9 %).

DISCUSSION

The sensitivity of PLUS is high, making it a potential tool for ruling-out cardiogenic pulmonary. The observed specificity was lower than what has been described in previous studies.

CONCLUSIONS

Performed, as part of a physician based prehospital emergency service, PLUS seems fast and highly feasible in patients with respiratory failure. Due to its diagnostic accuracy, PLUS may have potential as a prehospital tool, especially to rule out cardiogenic pulmonary oedema.

Ultrasound of extravascular lung water: a new standard for pulmonary congestion

Extravascular lung water (EVLW) is a key variable in heart failure management and prognosis, but its objective assessment remains elusive. Lung imaging has been traditionally considered off-limits for ultrasound techniques due to the acoustic barrier of high-impedance air wall. In pulmonary congestion however, the presence of both air and water creates a peculiar echo fingerprint. Lung ultrasound shows B-lines, comet-like signals arising from a hyper-echoic pleural line with a to-and-fro movement synchronized with respiration. Increasing EVLW accumulation changes the normal, no-echo signal (black lung, no EVLW) into a black-and-white pattern (interstitial sub-pleural oedema with multiple B-lines) or a white lung pattern (alveolar pulmonary oedema) with coalescing B-lines. The number and spatial extent of B-lines on the antero-lateral chest allows a semi-quantitative estimation of EVLW (from absent, ≤5, to severe pulmonary oedema, >30 B-lines). Wet B-lines are made by water and decreased by diuretics, which cannot modify dry B-lines made by connective tissue. B-lines can be evaluated anywhere (including extreme environmental conditions with pocket size instruments to detect high-altitude pulmonary oedema), anytime (during dialysis to titrate intervention), by anyone (even a novice sonographer after 1 h training), and on anybody (since the chest acoustic window usually remains patent when echocardiography is not feasible). Cardiologists can achieve much diagnostic gain with little investment of technology, training, and time. B-lines represent 'the shape of lung water'. They allow non-invasive detection, in real time, of even sub-clinical forms of pulmonary oedema with a low cost, radiation-free approach.

Resolution of sonographic B-lines as a measure of pulmonary decongestion in acute heart failure

Objective noninvasive measures of dyspnea in patients with acute heart failure are lacking. In this review, we describe lung ultrasound as a tool to estimate the degree of pulmonary congestion in patients presenting with acute heart failure and to monitor therapeutic efficacy. Serial semiquantitative measures of sonographic B-lines in acute heart failure patients can be converted to pulmonary edema scores obtained at admission and hospital discharge. These scores provide prognostic information for short-term clinical outcomes. Lung ultrasound has the potential to measure changes in pulmonary edema during acute heart failure management and improve risk stratification.

Assessment and prevalence of pulmonary oedema in contemporary acute heart failure trials: a systematic review

AIMS

Pulmonary oedema is a common and important finding in acute heart failure (AHF). We conducted a systematic review to describe the methods used to assess pulmonary oedema in recent randomized AHF trials and report its prevalence in these trials.

METHODS AND RESULTS

Of 23 AHF trials published between 2002 and 2013, six were excluded because they were very small or not randomized, or missing full-length publications. Of the remaining 17 (n = 200-7141) trials, six enrolled patients with HF and reduced ejection fraction (HF-REF) and 11, patients with both HF-REF and HF with preserved ejection fraction (HF-PEF). Pulmonary oedema was an essential inclusion criterion, in most trials, based upon findings on physical examination ('rales'), radiographic criteria ('signs of congestion'), or both. The prevalence of pulmonary oedema in HF-REF trials ranged from 75% to 83% and in combined HF-REF and HF-PEF trials from 51% to 100%. Five trials did not report the prevalence or extent of pulmonary oedema assessed by either clinical examination or chest x-ray. Improvement of pulmonary congestion with treatment was inconsistently reported and commonly grouped with other signs of congestion into a score. One trial suggested that patients with rales over >2/3 of the lung fields on admission were at higher risk of adverse outcomes than those without.

CONCLUSION

Although pulmonary oedema is a common finding in AHF, represents a therapeutic target, and may be of prognostic importance, recent trials used inconsistent criteria to define it, and did not consistently report its severity at baseline or its response to treatment. Consistent and ideally quantitative, methods for the assessment of pulmonary oedema in AHF trials are needed.

Impact of device selection and clip duration on lung ultrasound assessment in patients with heart failure

OBJECTIVES

Pulmonary edema is a common sign of heart failure and can be quantified by counting vertical artifacts (B-lines) on lung ultrasound (LUS). The primary aim of this study was to compare a pocket size ultrasound device to high-end ultrasound systems on the measured number of B-lines. We also compared the impact of different-length ultrasound clips on the measured number of B-lines.

METHODS AND RESULTS

We studied 21 hospitalized patients with heart failure (81% men; median age, 73; 71% Caucasian) who underwent concurrent 8- and 4-zone LUS using both a pocket ultrasound device and a high-end ultrasound system. For the 4-zone scanning method, the median B line number was 2 (interquartile range, 1-4) for the pocket device and 3 (1-5) for the high-end system (P = .67). For the 8-zone method, the median B-line number was 4 (2-7) for the pocket device and 5 (3-7) for the high-end system (P = .18). A higher number of B-lines was identified on the 4- vs 2-second LUS clips (P < .001 for 4 zones, P = .001 for 8 zones), and on the 6- vs 4-second LUS clips (P=0.057 for 4 zones, P=0.018 for 8 zones).

CONCLUSIONS

Our findings suggest significant differences based on LUS clip duration rather than the type of ultrasound device used, with respect to the number of B-lines detectable in patients with heart failure. These factors should be considered in the design and reporting of LUS studies and in longitudinal assessments of heart failure patients.

Lung ultrasound in heart failure: Lessons from re-analysis of Lung Ultrasound 2011 database

Introduction: In the setting of patients presenting with shortness of breath to an Emergency Department a simple lung ultrasound protocol aimed at detecting pulmonary oedema has been shown to have diagnostic accuracy of 85%. This article reviews data from the original study, in an attempt to determine whether adjusting the protocol and/or interpretive criteria would improve results. Method: A large lung ultrasound project provided the dataset. Inter-rater and intertest discrepancies were reviewed. Then original stored images and comments were retrospectively analysed using alternate interpretive criteria. Specific variations included changing the number of B-lines required to define 'wet lung' and assessing other pleural line abnormalities. Where they had been acquired cardiac loops were reviewed in addition to the lung images. Results: The 204 original studies available were reviewed. Some disagreement could be attributed to inexperience and unclear definitions. Adjusting the number of B-lines did not improve diagnostic accuracy. All positive scans, with numerous B-lines were reviewed using more advanced diagnostic criteria (pleural line abnormalities) and the number of false positives was decreased. In cases where cardiac views were available, their inclusion was beneficial. Conclusion: A simple lung ultrasound protocol to assess for 'wet lung' in patients presenting to Emergency Departments provides diagnostic accuracy of around 85% in the hands of relative novices. More advanced interpretation of the same_ultrasound images, and the addition of cardiac views, is likely to further improve diagnostic accuracy.