Effectiveness of Lung Ultrasound Training Utilizing a High-Fidelity Simulator

Background

The usefulness of lung ultrasound (LUS) has been demonstrated. However, it is unclear whether diagnostic techniques using LUS are accepted by all physicians. A simple simulation-based educational program may improve the LUS skills of beginners, but it has not been fully assessed.

Objective

This prospective study was conducted to assess the educational outcomes of LUS training using a high-fidelity simulator.

Methods

A simulator-based program for LUS was conducted. All clerkship students at the Department of Respirology at Chiba University Hospital participated in the program from December 2022 to April 2023. The participants watched a 30 minute teaching video on demand before a hands-on session lasting for 1 hour during the first week of the clinical clerkship. The readiness of the participants to learn LUS and the usefulness of the program were assessed using questionnaires administered before and after the program. The LUS skills were assessed using simulator-based tests during Weeks 1 and 4. Data on the accuracy and time required to answer the questions were collected during the tests.

Results

Forty clerkship students participated in this study. Thirty-three (82.5%) had received other ultrasound education; however, only two (5.0%) had experience with LUS. Based on the questionnaire responses, the participants perceived LUS as useful (preprogram: 4.6 vs. postprogram: 4.8; P = 0.010; a 5-point Likert scale was used [1: not useful to 5: useful]). The simulator-based tests showed comparable accuracies at Weeks 1 and 4 for pneumothorax (Week 1: 47.5% vs. Week 4: 52.5%; P = 0.623), pulmonary edema (Week 1: 100% vs. Week 4: 100%; P = 1.000), and pleural effusion (Week 1: 37.5% vs. Week 4: 40.0%; P = 0.800). The time required for scanning was the same for each question. In addition, the test results did not differ with prior learning, previous knowledge, or experience during clinical clerkships on LUS.

Conclusion

A short educational program consisting of on-demand learning and hands-on sessions with a high-fidelity simulator would be effective in equipping clerkship students with basic LUS skills. However, to increase its educational effectiveness to a practical degree, the program should be improved, and more opportunities for training using simulators should be provided.

Accuracy of lung ultrasound examinations of residual congestion performed by novice residents in patients with acute heart failure

AIMS

The popularity of B-line-guided congestion assessment by lung ultrasound (LUS) has been increasing. However, the ability of novice residents to detect residual congestion with B-line-guided assessment by LUS after decongestion treatment is poorly understood. In this study, we investigated whether novice residents (no prior echocardiography experience) can acquire the skills for B-line-guided residual congestion assessment and whether the range of variation in assessment is acceptable in actual clinical use.

METHODS AND RESULTS

The study included 30 postgraduate first-year novice residents and an expert. The residents underwent training for LUS. At the end of the training session, a set of 15 LUS videos was provided to the residents, and they were asked to estimate the number of B-lines in each video. When the residents' answers greatly differed from the correct answer, we provided feedback to raise awareness of the discrepancies. After the training session, the residents performed residual congestion assessment by LUS after decongestion treatment in patients hospitalized with acute heart failure. The residents identified residual congestion in 57% of the patients. The sensitivity and specificity to identify residual congestion by the residents were 90% and 100%, respectively. The inter-operator agreement between the residents and the expert was substantial (κ = 0.86). The Spearman rank correlation coefficient for the B-lines between the expert and each resident was very high at 0.916 (P < 0.0001).

CONCLUSIONS

After a brief lecture, novice residents can achieve proficiency in quantifying B-lines on LUS and can reliably identify residual congestion on LUS.

Can you teach a hands-on skill online? A scoping review of e-learning for point-of-care ultrasound in medical education

Background

There is an increasing need and interest in teaching point-of-care ultrasound (POCUS) online. The objective of this study was to systematically review the literature regarding e-learning as a method for teaching POCUS in medical education, to assess the benefits and limitations of various styles of e-learning for POCUS, and to identify gaps in the literature that could help guide future research in this field.

Methods

A literature search was conducted on three databases including MEDLINE (Ovid), EMBASE and Cochrane Central Register of Controlled Clinical Trials on October 12, 2021, retrieving a total of 1630 studies. 31 studies met the inclusion and exclusion criteria. These studies were separated into different styles of e-learning and learner outcomes were analyzed based on Kirkpatrick's hierarchy.

Results

The studies were categorized into three styles of e-learning: a) blended learning b) online-only (asynchronous or synchronous) and c) use of handheld machines or telesonography. POCUS knowledge and image interpretation were successfully taught online, however online-only learning for image acquisition was not as consistently effective. Blended learning and telesonography were beneficial for learning image acquisition skills. Generally, novice learners benefited most from e-learning.

Conclusion

E-learning for POCUS is gaining in popularity in recent years. POCUS is a complex technical skill, and depending on the individual task being taught, different styles of e-learning may be more successful. These findings can inform future POCUS educational programs.

Validating a Simplified Lung Ultrasound Protocol for Detection and Quantification of Pulmonary Edema in Patients With Chronic Kidney Disease Receiving Maintenance Hemodialysis

OBJECTIVES

Pulmonary edema is a common clinical problem and lung ultrasound (LUS) presents an efficient method for evaluating this pathology. This study aims to investigate if a clinically efficient LUS protocol can quantify the level of extravascular lung fluid in patients receiving hemodialysis, and to develop a simplified B-line scoring system based on this protocol.

METHODS

A simple 8-area LUS approach was used for the assessment of the extravascular fluid status in patients before, during, and after receiving hemodialysis. The LUS assessments were compared to the amount of removed fluid over time. To determine the best B-line score system, different scorings for each zone were tested in a linear mixed model with pseudo R-square model fit against removed fluid. The B-line score was further validated through correlations with changes in oxygen saturation, grade of dyspnea, and body weight over time.

RESULTS

A total of 53 patients were included and examined on 108 hemodialysis occasions. Median fluid removal was 2.3 L. The B-line score model with best fit was a score of 0 points in a zone with 0 or 1 B-lines, 1 point with 2 or 3 B-lines, 2 points with 3 or more B-lines, and 3 points with any interstitial confluence. Using this B-line score, we found a significant association with amount of removed fluid, oxygen saturation, grade of dyspnea, and change in body weight.

CONCLUSION

A straightforward protocol for LUS and B-line score system was shown valid for quantification of pulmonary edema and fluid removal in hemodialysis patients. The scoring system developed here can be useful also in other patient groups, but this requires further validation.

Can Dialysis Patients Identify and Diagnose Pulmonary Congestion Using Self-Lung Ultrasound?

BACKGROUND

With the recent developments in automated tools, smaller and cheaper machines for lung ultrasound (LUS) are leading us toward the potential to conduct POCUS tele-guidance for the early detection of pulmonary congestion. This study aims to evaluate the feasibility and accuracy of a self-lung ultrasound study conducted by hemodialysis (HD) patients to detect pulmonary congestion, with and without artificial intelligence (AI)-based automatic tools.

METHODS

This prospective pilot study was conducted between November 2020 and September 2021. Nineteen chronic HD patients were enrolled in the Soroka University Medical Center (SUMC) Dialysis Clinic. First, we examined the patient's ability to obtain a self-lung US. Then, we used interrater reliability (IRR) to compare the self-detection results reported by the patients to the observation of POCUS experts and an ultrasound (US) machine with an AI-based automatic B-line counting tool. All the videos were reviewed by a specialist blinded to the performer. We examined their agreement degree using the weighted Cohen's kappa (Kw) index.

RESULTS

A total of 19 patients were included in our analysis. We found moderate to substantial agreement between the POCUS expert review and the automatic counting both when the patient performed the LUS (Kw = 0.49 [95% CI: 0.05-0.93]) and when the researcher performed it (Kw = 0.67 [95% CI: 0.67-0.67]). Patients were able to place the probe in the correct position and present a lung image well even weeks from the teaching session, but did not show good abilities in correctly saving or counting B-lines compared to an expert or an automatic counting tool.

CONCLUSIONS

Our results suggest that LUS self-monitoring for pulmonary congestion can be a reliable option if the patient's count is combined with an AI application for the B-line count. This study provides insight into the possibility of utilizing home US devices to detect pulmonary congestion, enabling patients to have a more active role in their health care.

Long-term lung ultrasound follow-up in patients after COVID-19 pneumonia hospitalization: A prospective comparative study with chest computed tomography

During COVID-19 pandemic, lung ultrasound (LUS) proved to be of great value in the diagnosis and monitoring of patients with pneumonia. However, limited data exist regarding its use to assess aeration changes during follow-up (FU). Our study aims to prospectively evaluate 232 subjects who underwent a 3-month-FU program after hospitalization for COVID-19 at the University Hospital of Pisa. The goals were to assess the usefulness of standardized LUS compared with the gold standard chest computed tomography (CT) to evaluate aeration changes and to verify LUS and CT agreement at FU. Patients underwent in the same day a standardized 16-areas LUS and high-resolution chest CT reported by expert radiologists, assigning interpretative codes. Based on observations distribution, LUS score cut-offs of 3 and 7 were selected, corresponding to the 50th and 75th percentile, respectively. Patients with LUS scores above both these thresholds were older and with longer hospital stay. Patients with a LUS score ≥3 had more comorbidities. LUS and chest CT showed a high agreement in identifying residual pathological findings, using both cut-off scores of 3 (OR 14,7; CL 3,6-64,5, Sensitivity 91%, Specificity 49%) and 7 (OR 5,8; CL 2,3-14,3, Sensitivity 65%, Specificity 79%). Our data suggest that LUS is very sensitive in identifying pathological findings at FU after a hospitalization for COVID-19 pneumonia, compared to CT. Given its low cost and safety, LUS could replace CT in selected cases, such as in contexts with limited resources or it could be used as a gate-keeper examination before more advanced techniques.

Prognostic Role of Sonographic Decongestion in Patients with Acute Heart Failure with Reduced and Preserved Ejection Fraction: A Multicentre Study

BACKGROUND

We investigated the role of the dynamic changes of pulmonary congestion, as assessed by sonographic B-lines, as a tool to stratify prognosis in patients admitted for acute heart failure with reduced and preserved ejection fraction (HFrEF, HFpEF).

METHODS

In this multicenter, prospective study, lung ultrasound was performed at admission and before discharge by trained investigators, blinded to clinical findings.

RESULTS

We enrolled 208 consecutive patients (mean age 76 [95% confidence interval, 70-84] years), 125 with HFrEF, 83 with HFpEF (mean ejection fraction 32% and 57%, respectively). The primary composite endpoint of cardiovascular death or HF re-hospitalization occurred in 18% of patients within 6 months. In the overall population, independent predictors of the occurrence of the primary endpoint were the number of B-lines at discharge, NT-proBNP levels, moderate-to-severe mitral regurgitation, and inferior vena cava diameter on admission. B-lines at discharge were the only independent predictor in both HFrEF and HFpEF subgroups. A cut-off of B-lines > 15 at discharge displayed the highest accuracy in predicting the primary endpoint (AUC = 0.80, p < 0.0001). Halving B-lines during hospitalization further improved event classification (continuous net reclassification improvement = 22.8%, p = 0.04).

CONCLUSIONS

The presence of residual subclinical sonographic pulmonary congestion at discharge predicts 6-month clinical outcomes across the whole spectrum of acute HF patients, independent of conventional biohumoral and echocardiographic parameters. Achieving effective pulmonary decongestion during hospitalization is associated with better outcomes.

Relationship between lung ultrasound and electrical impedance tomography as regional assessment tools during PEEP titration in acute respiratory distress syndrome caused by multi-lobar pneumonia: a pilot study

Acute respiratory distress syndrome (ARDS) caused by multilobar pneumonia (MLP) is markedly different from typical ARDS in pathology, imaging characteristics, and lung mechanics. Regional lung assessment is required. We aimed to analyze the relationship between two regional assessment tools, lung ultrasound (LUS) and electrical impedance tomography (EIT) during positive end-expiratory pressure (PEEP) titration, and determine an appropriate PEEP level. We conducted a prospective study of patients with ARDS caused by MLP with PaO₂/FiO₂ < 150 mmHg. All subjects were equipped with two EIT belts connected with a single EIT machine to measure upper and lower hemithorax impedance change alternatingly at each PEEP level. LUS score was simultaneously determined in chest wall regions corresponding to the EIT regions during PEEP titration. We acquired EIT and LUS data in eight regions of interest at seven PEEP levels in 12 subjects. Therefore, 672 pairs of data were obtained for analysis. There were significant relationships between LUS score and tidal impedance variation and pixel compliance (C_pix). The Spearman's rho between LUS score vs. tidal impedance variation and LUS score vs. the C_pix were - 0.142, P < 0.001, and - 0.195, P < 0.001, respectively. The relationship between the LUS score and C_pix remained the same at every PEEP level but did not reach statistical significance. The individual's mean expected PEEP by LUS was similar to the EIT [10.33(± 1.67) vs. 10.33(± 1.44) cm H₂O, P = 0.15]. Regarding the MLP, the LUS scores were associated with EIT parameters, and LUS scores might proof helpful for finding individual PEEP settings in MLP.

How to Determine Fluid Management Goals during Continuous Kidney Replacement Therapy in Patients with AKI: Focus on POCUS

The utilization of kidney replacement therapies (KRT) for fluid management of patients who are critically ill has significantly increased over the last years. Clinical studies have suggested that both fluid accumulation and high fluid removal rates are associated with adverse outcomes in the critically ill population receiving KRT. Importantly, the ideal indications and/or fluid management strategies that could favorably affect these patients are unknown; however, differentiating clinical scenarios in which effective fluid removal may provide benefit to the patient by avoiding congestive organ injury, compared with other settings in which this intervention may result in harm, is direly needed in the critical care nephrology field. In this review, we describe observational data related to fluid management with KRT, and examine the role of point-of-care ultrasonography as a potential tool that could provide physiologic insights to better individualize decisions related to fluid management through KRT.

The State of Point-of-Care Teleultrasound Use for Educational Purposes: A Scoping Review

Bedside ultrasound has been shown to change and direct patient management in the emergent setting. Demand, use, and diagnostic potential of point-of-care ultrasound (POCUS) has continually increased throughout the years. The ongoing COVID-19 pandemic and physical distancing have necessitated further POCUS innovation. With the advent of affordable portable ultrasound devices, teleultrasound teaching has become a more viable method of POCUS education, especially in resource-limited settings. Here, we provide a scoping review of the current state of teleultrasound, specifically its use for educational purposes.

Lung Congestion Severity in Kidney Transplant Recipients Is Not Affected by Arteriovenous Fistula Function

Lung ultrasound is a bedside technique for the assessment of pulmonary congestion. The study aims to assess the severity of lung congestion in kidney transplant recipients (KTR) in relation to arteriovenous fistula (AVF) patency. One hundred fifty-seven patients at least 12 months after kidney transplantation were recruited to participate in a cross-sectional study. Apart from routine visits, lung ultrasound at 28 typical points was performed. The patients were assigned to either AVF+ or AVF− groups. The mean number of lung ultrasound B-lines (USBLs) was 5.14 ± 4.96 with no differences between groups: 5.5 ± 5.0 in AVF+ and 4.8 ± 4.9 in AVF−, p = 0.35. The number and proportion of patients with no congestion (0–5 USBLs), mild congestion (6–15 USBLs), and moderate congestion (16–30 USBLs) were as follows: 101 (64.7%), 49 (31.4%), and 6 (3.8%), respectively. In multivariate analysis, only symptoms (OR 5.90; CI 2.43,14.3; p = 0.0001), body mass index (BMI) (OR 1.09; CI 1.03,1.17; p = 0.0046), and serum cholesterol level (OR 0.994; CI 0.998,1.000; p = 0.0452) contributed significantly to the severity of lung congestion. Lung ultrasound is a valuable tool for the evaluation of KTR. Functioning AVF in KTR is not the major factor affecting the severity of pulmonary congestion.

Quantitative Lung Ultrasonography for the Nephrologist: Applications in Dialysis and Heart Failure

Volume overload, and its attendant increase in acute care utilization and cardiovascular morbidity and mortality, represents a critical challenge for the practicing nephrologist. This is particularly true among patients with ESKD on HD, where predialysis volume overload and intradialytic and postdialytic hypovolemia account for almost a third of all cost for the Medicare dialysis benefit. Quantitative lung ultrasound is a tool for assessing the extent of extravascular lung water that outperforms physical exam and plain chest radiography. B-lines are vertical hyperechoic artifacts present in patients with increased extravascular lung water. B-lines have been shown to decrease dynamically during the hemodialysis treatment in proportion to ultrafiltration volume. Among patients with chronic heart failure, titration of diuretics on the basis of the extent of pulmonary congestion noted on lung ultrasonography has been shown to decrease recurrent acute care utilization. Early data from randomized controlled trials of lung ultrasound-guided ultrafiltration therapy among patients with ESKD on HD have shown promise for potential reduction in recurrent episodes of decompensated heart failure and cardiovascular events. Ultimately, lung ultrasound may predict those who are ultrafiltration tolerant and could be used to decrease acute care utilization and, thus, cost in this population.

Lung ultrasound B-lines in systemic sclerosis: cut-off values and methodological indications for interstitial lung disease screening

OBJECTIVES

Lung ultrasound (LUS), through assessment of B-lines and pleural line alterations, is able to evaluate interstitial lung disease (ILD), a frequent complication of systemic sclerosis (SSc). Different scanning schemes and counting methods have been proposed, but no clear cut-off values have been indicated for screening. We aimed to evaluate the accuracy of different LUS methodological approaches to detect ILD, compared with high resolution computed tomography (HRCT) as gold standard.

METHODS

Sixty-nine SSc patients underwent LUS and chest HRCT on the same day. Both exams were scored by expert readers. The accuracy of different scanning schemes and counting methods was assessed, and clinical and functional data were compared with imaging findings.

RESULTS

B-lines were more numerous in patients with the diffuse skin subset and Scl70 autoantibody positivity. The number of B-lines correlated with the Scleroderma Lung Study (SLS) I HRCT score (R = 0.754, p< 0.0001). A total number >10 B-lines on the whole chest or > 1 B-line on the postero-basal chest showed 97% sensitivity for detecting even very early ILD signs (corresponding to SLS I score =1). Sensitivity increased to 100% when pleural line alterations were included in the analysis.

CONCLUSIONS

LUS has a very high sensitivity in detecting SSc-related ILD. A cut-off value of > 10 B-lines on the whole chest or > 1 B-line on the postero-basal chest can be used for the screening of SSc-ILD. Assessing only the postero-basal chest seems mostly effective to combine high sensitivity with a less time-consuming approach.

Comprehensive literature review on the radiographic findings, imaging modalities, and the role of radiology in the COVID-19 pandemic

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, over 103214008 cases have been reported, with more than 2231158 deaths as of January 31, 2021. Although the gold standard for diagnosis of this disease remains the reverse-transcription polymerase chain reaction of nasopharyngeal and oropharyngeal swabs, its false-negative rates have ignited the use of medical imaging as an important adjunct or alternative. Medical imaging assists in identifying the pathogenesis, the degree of pulmonary damage, and the characteristic features in each imaging modality. This literature review collates the characteristic radiographic findings of COVID-19 in various imaging modalities while keeping the preliminary focus on chest radiography, computed tomography (CT), and ultrasound scans. Given the higher sensitivity and greater proficiency in detecting characteristic findings during the early stages, CT scans are more reliable in diagnosis and serve as a practical method in following up the disease time course. As research rapidly expands, we have emphasized the CO-RADS classification system as a tool to aid in communicating the likelihood of COVID-19 suspicion among healthcare workers. Additionally, the utilization of other scoring systems such as MuLBSTA, Radiological Assessment of Lung Edema, and Brixia in this pandemic are reviewed as they integrate the radiographic findings into an objective scoring system to risk stratify the patients and predict the severity of disease. Furthermore, current progress in the utilization of artificial intelligence via radiomics is evaluated. Lastly, the lesson from the first wave and preparation for the second wave from the point of view of radiology are summarized.

Cardiac geometry, function, and remodeling patterns in patients under maintenance hemodialysis and peritoneal dialysis treatment

Cardiovascular disease is the leading cause of mortality in patients with end-stage-kidney disease. Evidence on the possible echocardiographic differences between hemodialysis and peritoneal dialysis (PD) is scarce. This study aimed to evaluate differences in left (LA) and right atrial (RA), left (LV) and right ventricular (RV) geometry, systolic and diastolic function in hemodialysis, and PD patients. Thirty-eight hemodialysis and 38 PD patients were matched for age, sex, and dialysis vintage. Two-dimensional and tissue-Doppler echocardiography, and lung ultrasound were performed during an interdialytic day in hemodialysis and before a programmed follow-up visit in PD patients. Vena cava diameter (11.09 ± 4.53 vs. 14.91 ± 4.30 mm; p < 0.001) was significantly lower in hemodialysis patients. Indices of LA, RA, LV, and RV dimensions were similar between the two groups. LVMi (116.91 [38.56] vs. 122.83 [52.33] g/m² ; p = 0.767) was similar, but relative wall thickness was marginally (0.40 [0.14] vs. 0.45 [0.15] cm; p = 0.055) lower in hemodialysis patients. LV hypertrophy prevalence was similar between groups (73.7% vs. 71.1%; p = 0.798), but hemodialysis patients presented eccentric and PD patients concentric LVH. Regarding ventricular systolic function, stroke volume (p = 0.030) and cardiac output (p = 0.036) were higher in hemodialysis, while RV systolic pressure (RVSP) (20.37 [22.54] vs. 27.68 [14.32] mm Hg; p = 0.009) was higher in PD. No significant differences were evidenced in diastolic function indices and lung water excess between the two groups. A moderate association was noted between ultrasound B-lines score and LA volume index (r = 0.465, p < 0.001), RVSP (r = 0.431, p < 0.001), and E/e' ratio (r = 0.304, p = 0.009). Hemodialysis and PD patients present largely similar echocardiographic indices reflecting cardiac geometry, systolic, and diastolic function, but different patterns of abnormal LV remodeling.

Diagnostic and Prognostic Value of Lung Ultrasound B-Lines in Acute Heart Failure With Concomitant Pneumonia

Purpose: To evaluate the potential confounding effect of concomitant pneumonia (PNM) on lung ultrasound (LUS) B-lines in acute heart failure (AHF).

Methods: We enrolled 86 AHF patients with (31 pts, AHF/PNM) and without (55 pts, AHF) concomitant PNM. LUS B-lines were evaluated using a combined antero-lateral (AL) and posterior (POST) approach at admission (T0), after 24 h from T0 (T1), after 48 h from T0 (T2) and before discharge (T3). B-lines score was calculated at each time point on AL and POST chest, dividing the number of B-lines by the number of explorable scanning sites. The decongestion rate (DR) was calculated as the difference between the absolute B-lines number at discharge and admission, divided by the number of days of hospitalization. Patients were followed-up and hospital readmission for AHF was considered as adverse outcome.

Results: At admission, AHF/PNM patients showed no difference in AL B-lines score compared with AHF patients [AHF/PNM: 2.00 (IQR: 1.44–2.94) vs. AHF: 1.65 (IQR: 0.50–2.66), p = 0.072], whereas POST B-lines score was higher [AHF/PNM: 3.76 (IQR: 2.70–4.77) vs. AHF = 2.44 (IQR: 1.20–3.60), p < 0.0001]. At discharge, AL B-lines score [HR: 1.907 (1.097–3.313), p = 0.022] and not POST B-lines score was found to predict adverse events (AHF rehospitalization) after a median follow-up of 96 days (IQR: 30–265) in the overall population.

Conclusions: Assessing AL B-lines alone is adequate for diagnosis, pulmonary congestion (PC) monitoring and prognostic stratification in AHF patients, despite concomitant PNM.

Comprehensive Assessment of Fluid Status by Point-of-Care Ultrasonography

The management of complex fluid and electrolyte disorders is central to the practice of nephrologists. The sensitivity of physical examination alone to determine fluid status is limited, precluding accurate clinical decision making. Point-of-care ultrasonography (POCUS) is emerging as a valuable, noninvasive, bedside diagnostic tool for objective evaluation of physiologic and hemodynamic parameters related to fluid status, tolerance, and responsiveness. Rapid bedside sonographic evaluation can obtain qualitative data on cardiac function and quantitative data on pulmonary congestion. Advanced POCUS, including goal-directed Doppler echocardiography, provides additional quantitative information, including flow velocities and pressures across the cardiac structures. Recently, abnormal Doppler flow patterns in abdominal organs secondary to increased right atrial pressure have been linked to congestive organ damage, adding another component to the hemodynamic assessment. Integrating POCUS findings with clinical and laboratory data can further elucidate a patient's hemodynamic status. This drives decisions regarding crystalloid administration or, conversely, diuresis or ultrafiltration and allows tailored therapy for individual patients. In this article, we provide an overview of the focused assessment of cardiovascular function and pulmonary and venous congestion using POCUS and review relevant literature.

Comprehensive Assessment of Fluid Status by Point-of-Care Ultrasonography

The management of complex fluid and electrolyte disorders is central to the practice of nephrologists. The sensitivity of physical examination alone to determine fluid status is limited, precluding accurate clinical decision making. Point-of-care ultrasonography (POCUS) is emerging as a valuable, noninvasive, bedside diagnostic tool for objective evaluation of physiologic and hemodynamic parameters related to fluid status, tolerance, and responsiveness. Rapid bedside sonographic evaluation can obtain qualitative data on cardiac function and quantitative data on pulmonary congestion. Advanced POCUS, including goal-directed Doppler echocardiography, provides additional quantitative information, including flow velocities and pressures across the cardiac structures. Recently, abnormal Doppler flow patterns in abdominal organs secondary to increased right atrial pressure have been linked to congestive organ damage, adding another component to the hemodynamic assessment. Integrating POCUS findings with clinical and laboratory data can further elucidate a patient's hemodynamic status. This drives decisions regarding crystalloid administration or, conversely, diuresis or ultrafiltration and allows tailored therapy for individual patients. In this article, we provide an overview of the focused assessment of cardiovascular function and pulmonary and venous congestion using POCUS and review relevant literature.

A randomized multicenter trial on a lung ultrasound-guided treatment strategy in patients on chronic hemodialysis with high cardiovascular risk

Lung congestion is a risk factor for all-cause and cardiovascular mortality in patients on chronic hemodialysis, and its estimation by ultrasound may be useful to guide ultrafiltration and drug therapy in this population. In an international, multi-center randomized controlled trial (NCT02310061) we investigated whether a lung ultrasound-guided treatment strategy improved a composite end point (all-cause death, non-fatal myocardial infarction, decompensated heart failure) vs usual care in patients receiving chronic hemodialysis with high cardiovascular risk. Patient-Reported Outcomes (Depression and the Standard Form 36 Quality of Life Questionnaire, SF36) were assessed as secondary outcomes. A total of 367 patients were enrolled: 183 in the active arm and 180 in the control arm. In the active arm, the pre-dialysis lung scan was used to titrate ultrafiltration during dialysis and drug treatment. Three hundred and seven patients completed the study: 152 in the active arm and 155 in the control arm. During a mean follow-up of 1.49 years, lung congestion was significantly more frequently relieved in the active (78%) than in the control (56%) arm and the intervention was safe. The primary composite end point did not significantly differ between the two study arms (Hazard Ratio 0.88; 95% Confidence Interval: 0.63-1.24). The risk for all-cause and cardiovascular hospitalization and the changes of left ventricular mass and function did not differ among the two groups. A post hoc analysis for recurrent episodes of decompensated heart failure (0.37; 0.15-0.93) and cardiovascular events (0.63; 0.41-0.97) showed a risk reduction for these outcomes in the active arm. There were no differences in patient-reported outcomes between groups. Thus, in patients on chronic hemodialysis with high cardiovascular risk, a treatment strategy guided by lung ultrasound effectively relieved lung congestion but was not more effective than usual care in improving the primary or secondary end points of the trial.

Quantitative Lung Ultrasound: Technical Aspects and Clinical Applications

Lung ultrasound is increasingly used in emergency departments, medical wards, and critical care units-adult, pediatric, and neonatal. In vitro and in vivo studies show that the number and type of artifacts visualized change with lung density. This has led to the idea of a quantitative lung ultrasound approach, opening up new prospects for use not only as a diagnostic but also as a monitoring tool. Consequently, the multiple scoring systems proposed in the last few years have different technical approaches and specific clinical indications, adaptable for more or less time-dependent patients. However, multiple scoring systems may generate confusion among physicians aiming at introducing lung ultrasound in their clinical practice. This review describes the various lung ultrasound scoring systems and aims to clarify their use in different settings, focusing on technical aspects, validation with reference techniques, and clinical applications.

Ambulatory blood pressure changes with lung ultrasound-guided dry-weight reduction in hypertensive hemodialysis patients: 12-month results of a randomized controlled trial

OBJECTIVES

Hypertension is highly prevalent and independently associated with adverse outcomes in patients undergoing hemodialysis. Volume overload is the main mechanism of increased blood pressure (BP) in these individuals. This study examines the long-term effects of dry-weight reduction with a standardized lung-ultrasound (US)-guided strategy on ambulatory BP in hypertensive hemodialysis patients.

METHODS

This is the report of the 12-month follow-up of a randomized controlled trial in 71 clinically euvolemic, hemodialysis patients with hypertension. Patients were randomized to dry-weight reduction guided by prehemodialysis lung ultrasound and to standard care. A 48-h ambulatory BP monitoring (ABPM) was performed in all study participants at baseline and after 12 months.

RESULTS

During follow-up, a greater proportion of patients in the active group underwent dry-weight reduction compared with the control group (71.4% vs. 22.2%; P < 0.001). The number of lung US-B lines (a metric of lung water) reduced in the active (-4.83 ± 13.73) and increased in the control arm (+5.53 ± 16.01; P = 0.005) paralleling dry-weight changes (-1.68 ± 2.38 vs. 0.54 ± 2.32 kg; P < 0.001). At 12 months, 48-h systolic BP (136.19 ± 14.78 vs. 130.31 ± 13.57 mmHg; P = 0.034) and diastolic BP (80.72 ± 9.83 vs. 76.82 ± 8.97 mmHg; P = 0.008) were lower compared to baseline in the active but similar in the control group. Changes in 48-h systolic BP (-7.78 ± 13.29 vs. -0.10 ± 14.75 mmHg; P = 0.021) were significantly greater in the active compared to the control group. The proportion of patients experiencing ≥1 episode of intradialytic hypotension was nominally lower in the active group (71.4% vs. 88.9%, P = 0.065).

CONCLUSIONS

Lung-US-guided dry-weight reduction can effectively and safely decrease ambulatory BP levels in the long-term.

Assessment and Management of Volume Overload Among Patients on Chronic Dialysis

Volume overload is the most common complication in end-stage renal disease (ESRD) patients, being directly related to numerous complications including resistant hypertension, cardiac hypertrophy, congestive heart failure or arterial stiffness, among others. Therefore, volume overload is now considered an important risk factor for hard outcomes, like all-cause or cardiovascular mortality. Relying solely on clinical examination for assessing volume overload in ESRD patients lacks sensitivity and specificity. Numerous efforts have been made to identify new methods that could objectively assess volume status; however, each of them has important limitations. This review aims to discuss the most frequently used methods (biomarkers, inferior vena cava assessment, lung ultrasonography, bioimpedance analysis and blood volume monitoring) and to compare the advantage of each method vs. the overall/ clinical strategy.

Ultrasonographic Assessment of Extravascular Lung Water in Hospitalized Patients Requiring Hemodialysis: A Prospective Observational Study

INTRODUCTION

Sonographic technologies can estimate extravascular lung water (EVLW) in hemodialysis (HD) patients. This study investigated the suitability of a handheld scanner in contrast to a portable scanner for quantifying EVLW in hospitalized patients requiring HD.

METHODS

In this prospective study, 54 hospitalized HD patients were enrolled. Bedside lung ultrasound was performed within 30 min before and after dialysis using handheld (phased array transducer, 1.7-3.8 MHz) and portable (curved probe, 5-2 MHz) ultrasound devices. Eight lung zones were scanned for total B-lines number (TBLN). The maximum diameter of inferior vena cava (IVC) was measured. We performed Passing-Bablok regression, Deming regression, Bland-Altman, and logistic regression analysis.

RESULTS

The 2 devices did not differ in measuring TBLN and IVC (p > 0.05), showing a high correlation (r = 0.92 and r = 0.51, respectively). Passing-Bablok regression had a slope of 1.11 and an intercept of 0 for TBLN, and the slope of Deming regression was 1.02 within the CI bands of 0.94 and 1.11 in the full cohort. TBLN was logarithmically transformed for Bland-Altman analysis, showing a bias of 0.06 (TBLN = 1.2) between devices. The slope and intercept of the Deming regression in IVC measurements were 0.77 and 0.46, respectively; Bland-Altman plot showed a bias of -0.07. Compared with predialysis, TBLN significantly (p < 0.001) decreased after dialysis, while IVC was unchanged (p = 0.16). Univariate analysis showed that cardiovascular disease (odds ratio [OR] 8.94 [2.13-61.96], p = 0.002), smoking history (OR 5.75 [1.8-20.46], p = 0.003), and right pleural effusion (OR 5.0 [1.2-25.99], p = 0.03) were strong predictors of EVLW indicated by TBLN ≥ 4.

CONCLUSION

The lung and IVC findings obtained from handheld and portable ultrasound scanners are comparable and concordant. Cardiovascular disease and smoking history were strong predictors of EVLW. The use of TBLN to assess EVLW in hospitalized HD patients is feasible. Further studies are needed to determine if TBLN can help guide volume removal in HD patients.

Lung Ultrasound to Diagnose Pulmonary Congestion Among Patients on Hemodialysis: Comparison of Full Versus Abbreviated Scanning Protocols

RATIONALE & OBJECTIVE

Pulmonary congestion contributes to morbidity and mortality in patients with kidney failure on hemodialysis, but physical assessment is an insensitive approach to its detection. Lung ultrasound is useful for assessing the presence and severity of pulmonary congestion, but the most widely validated 28-zone study is cumbersome. We sought to compare abbreviated 4-, 6-, and 8-zone studies to 28-zone studies.

STUDY DESIGN

Diagnostic test study.

SETTING & PARTICIPANTS

Convenience sample of 98 patients with kidney failure on hemodialysis presenting to an emergency department in the United States.

TESTS COMPARED

4-, 6-, and 8-zone lung ultrasound studies versus a 28-zone lung ultrasound.

OUTCOME

Prediction of pulmonary congestion and 30-day mortality.

RESULTS

All patients completed a 28-zone lung ultrasound. Correlation coefficients (nonparametric Spearman) between each of the studies were high (all values > 0.84). Bland-Altman analysis showed good agreement. Each of the short-form studies discriminated well with area under the receiver-operator characteristic curve > 0.83 for no-to-mild versus moderate-to-severe pulmonary congestion. During a median follow-up period of 778 days, 46 (47%) died. Patients with moderate-to-severe pulmonary congestion on lung ultrasound had a 30-day mortality rate similar to that observed among patients with no-to-mild pulmonary congestion (OR, 0.95 [95% CI, 0.70-1.29]).

LIMITATIONS

Single-center study conducted in an emergency care setting, convenience sample of patients, and lack of long-term follow-up data.

CONCLUSIONS

Among hemodialysis patients presenting to an emergency department, 4-, 6-, or 8-zone lung ultrasounds were comparable to 28-zone studies for the assessment of pulmonary congestion. The mortality rates did not differ between those with no-to-mild and moderate-to-severe pulmonary congestion.

Prognostic value of lung ultrasound in patients hospitalized for heart disease irrespective of symptoms and ejection fraction

Aims

Lung ultrasound B‐lines are the sonographic sign of pulmonary congestion and can be used in the differential diagnosis of dyspnoea to rule in or rule out acute heart failure (AHF). Our aim was to assess the prognostic value of B‐lines, integrated with echocardiography, in patients admitted to a cardiology department, independently of the initial clinical presentation, thus in patients with and without AHF, and in AHF with reduced and preserved ejection fraction (HFrEF and HFpEF).

Methods and results

We enrolled consecutive patients admitted for various cardiac conditions. Patients were classified into three groups: (i) acute HFrEF; (ii) acute HFpEF; and (iii) non‐AHF. All patients underwent an echocardiogram coupled with lung ultrasound at admission, according to standardized protocols. We followed up 1021 consecutive inpatients (69 ± 12 years) for a median of 14.4 months (interquartile range 4.6–24.3) for death and rehospitalization for AHF. During the follow‐up, 126 events occurred. Admission B‐lines > 30, ejection fraction < 50%, tricuspid regurgitation velocity > 2.8 m/s, and tricuspid annular plane systolic excursion < 17 mm were independent predictors at multivariable analysis. B‐lines > 30 had a strong predictive value in HFpEF and non‐AHF, but not in HFrEF.

Conclusions

Ultrasound B‐lines can detect subclinical pulmonary interstitial oedema in patients thought to be free of congestion and provide useful information not only for the diagnosis but also for the prognosis in different cardiac conditions. Their added prognostic value among standard echocardiographic parameters is more robust in patients with HFpEF compared with HFrEF.

Building and Maintaining an Ultrasound Program: It Takes a Village

Building and maintaining a successful point-of-care ultrasound program is a complex process that involves establishing an ecosystem between three unique but overlapping domains: ultrasound equipment, ultrasound users, and the health care system. By highlighting the different areas of focus and each of the key stakeholders and components, a group can ensure adequate attention is paid to all aspects of point-of-care ultrasound program development in nephrology.

Lung Ultrasound: A "Biomarker" for Fluid Overload?

Fluid overload is associated with poor outcomes in patients with acute kidney injury as well as end-stage kidney disease. Lung ultrasound (LUS) has been used in many different settings and specialties including the emergency department, intensive care unit, trauma, cardiology, and nephrology. Although LUS has been a valuable tool in assessing pulmonary congestion, LUS findings may not always be pathognomonic for pulmonary congestion. Furthermore, the feasibility of doing an extensive LUS examination as has been done in research studies may be hard to implement within the clinical setting. This review will go over the use of LUS to evaluate for fluid overload, compare LUS with other markers of fluid overload, review limitations of LUS, and suggest potential future directions in the use of LUS in nephrology.

Lung ultrasound education: simulation and hands-on

COVID-19 can cause damage to the lung, which can result in progressive respiratory failure and potential death. Chest radiography and CT are the imaging tools used to diagnose and monitor patients with COVID-19. Lung ultrasound (LUS) during COVID-19 is being used in some areas to aid decision-making and improve patient care. However, its increased use could help improve existing practice for patients with suspected COVID-19, or other lung disease. A limitation of LUS is that it requires practitioners with sufficient competence to ensure timely, safe, and diagnostic clinical/imaging assessments. This commentary discusses the role and governance of LUS during and beyond the COVID-19 pandemic, and how increased education and training in this discipline can be undertaken given the restrictions in imaging highly infectious patients. The use of simulation, although numerical methods or dedicated scan trainers, and machine learning algorithms could further improve the accuracy of LUS, whilst helping to reduce its learning curve for greater uptake in clinical practice.

Bedside lung ultrasonography by emergency department residents as an aid for identifying heart failure in patients with acute dyspnea after a 2-h training course

BACKGROUND

Ultrasonographic B-lines have recently emerged as a bedside imaging tool for the differential diagnosis of acute dyspnea in the Emergency Department (ED). However, despite its simplicity, LUS has not fully penetrated emergency department. This study aimed to assess the accuracy and reproducibility of ultrasonographic B-lines performed by emergency medicine (EM) residents for the diagnosis of congestive heart failure (CHF) in patients admitted to ED for acute dyspnea.

PATIENTS AND METHODS

This is a cross-sectional prospective study conducted between January 2016 and October 2017 including patients aged over 18 years admitted to ED for acute dyspnea. At admission, two consecutive bedside LUS study were performed by a pair of EM residents who received a 2-h course for recognition of sonographic B-lines to determine independently B-lines score and B-profile pattern. All participating sonographers were blinded to patients' clinical data. B-lines score ≥ 15 or a B-profile pattern was considered as suggestive of CHF. The final leading diagnosis was assessed by two expert sonographers, who were blinded to the residents' interpretations, based on clinical findings, chest X-ray, brain natriuretic peptide, cardiac and lung ultrasound testing. Accuracy and agreement of B-lines score and B-profile pattern were calculated.

RESULTS

We included 700 patients with a mean age of 68 ± 12.6 years and a sex ratio (M/F) of 1.43. The diagnosis of CHF was recorded in 371 patients (53%). The diagnostic performance of B-lines score at a cut-off 15 and B-profile pattern was, respectively, 88% and 82.5% for sensitivity, 75% and 84% for specificity, 80% and 85% for positive predictive value, 84% and 81% for negative predictive value. The area under receiver operating characteristic curve was 0.86 [0.83-0.89] and 0.83 [0.80-0.86], respectively, for B-lines score and B-profile pattern. There was an excellent agreement between residents for the diagnosis of CHF using both scores (kappa = 0.81 and 0.85, respectively, for ordinal scale B-lines score and B-profile pattern).

CONCLUSION

Lung ultrasound B-lines assessment has a good accuracy and an excellent reproducibility in the diagnosis of CHF in the hand of EM residents following a short training program. Trial registration Name of the registry: clinicaltrials.gov; Trial registration number: NCT03717779; Date of registration: October 24, 2018 'Retrospectively registered'; URL of trial registry record: clinicaltrials.gov.

Diagnostic performance of pulmonary ultrasonography and a clinical score for the evaluation of fluid overload in haemodialysis patients

INTRODUCTION

There is no feasible benchmark in daily routine to estimate the hydration status of haemodialysis patients, which is essential to their management.

OBJECTIVE

We performed a study in haemodialysis patients to assess the diagnostic performance of pulmonary ultrasound and clinical examination for the evaluation of fluid overload using transthoracic echocardiography as a gold standard.

METHODS

Thirty-one patients receiving chronic haemodialysis patients were included. Evaluation of hydration status was assessed weekly before haemodialysis sessions using clinical and Echo Comet Score from pulmonary ultrasound and transthoracic echocardiography (reference method).

RESULTS

Five patients had a transthoracic echocardiography overload. Compared with transthoracic echocardiography, the diagnostic performance of the clinical overload score has a sensitivity of 100%, a specificity of 77%, a positive predictive value of 50% and a negative predictive value of 100% with a κ of 0.79. Only orthopnoea (P=0.008), jugular turgor (P=0.005) and hepatic-jugular reflux (P=0.008) were significantly associated with transthoracic echocardiography overload diagnosis. The diagnostic performance of Echo Comet Score by pulmonary ultrasound has a sensitivity of 80%, a specificity of 58%, a positive predictive value of 26% and a negative predictive value of 94%. Ten patients (32.3%) had an increase of extravascular pulmonary water without evidence of transthoracic echocardiography or clinical overload.

CONCLUSIONS

Our clinical score has a convincing diagnostic performance compared to transthoracic echocardiography and could be easily used in daily clinical routine to adjust dry weight. The evaluation of the overload using pulmonary ultrasound seems poorly correlated with the overload evaluated by transthoracic echocardiography. Extravascular pulmonary water undetected by clinical examination and transthoracic echocardiography remains a parameter that requires further investigation.

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).

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Association between extracellular volume control and survival in patients on short daily haemodialysis

Background

Fluid overload (FO) assessed by bioimpedance spectroscopy (BIS) is associated with higher mortality risk in maintenance haemodialysis (HD). The aim was to assess if a better management of FO through short daily haemodialysis (SDHD) could improve survival.

Methods

Retrospective analysis of patients who were on HD 3 sessions/week for at least 3 months and shifted to in-centre SDHD (5 or 6 sessions/week, 2 to 3 h/session) between July 2012 and June 2016 at 23 dialysis units in Brazil. The 12-month risk of death was analysed according to the predialysis hydration status measured before and 6 months after initiation of SDHD. Predialysis hydration status was considered adequate when FO ≤15% of extracellular volume.

Results

A total of 297 patients on SDHD were included in the analysis. Their median age was 57 (IQR 45–67) years, 62% were males, 44% diabetics, 57% on 6 dialysis sessions/week, with a median session duration of 130 (IQR 120–150) minutes. BIS assessment at initiation of the SDHD regimen was performed in 220 patients and FO > 15% was found in 46.4%. Twelve-month survival rates for those with FO ≤15 and > 15% before initiating SDHD were 87.4 and 88.0%, respectively (P = 0.92). BIS analysis when completing 6 months on SDHD were available for 229 patients, 26.6% with FO > 15%. The survival rates for the next 12 months (from the 6th to the 18th month of follow-up) for those with FO ≤15 and > 15% were 91.0 and 72.0%, respectively (P = 0.0006). In a Cox regression model, after adjustment for demographic, clinical and laboratory variables, FO ≤ 15% persisted associated with a lower mortality risk (hazard ratio 0.34, 95%CI 0.13–0.87).

Conclusions

Moving from conventional HD to SDHD was associated with better control of excessive extracellular volume. Patients who reached or maintained predialysis fluid overload ≤15% after initiating SDHD presented a lower risk of death.

Prognostic Value of Lung Ultrasound B-Lines in Systemic Sclerosis

BACKGROUND

A high percentage of systemic sclerosis (SSc) patients experience interstitial lung disease (ILD) during the disease course. Recent data have shown that lung ultrasound (LUS) can assess ILD by the evaluation of B-lines, the sonographic sign of pulmonary interstitial involvement.

RESEARCH QUESTION

To establish the prognostic value of B-lines in a large number of patients with SSc.

STUDY DESIGN AND METHODS

A total of 396 consecutive patients with SSc, who were enrolled at three Rheumatology Departments, underwent a comprehensive LUS examination on the anterolateral and posterior chest for a total of 58 scanning sites. All available clinical, imaging, and functional data were recorded. Patients were followed after enrolment to establish the prognostic role of LUS.

RESULTS

The median number of B-lines was higher in patients with the diffuse cutaneous subset (44 vs 17 B-lines; P < .0001), topoisomerase I autoantibodies (39 vs 16 B-lines; P < .0001), and the presence of ILD at chest high-resolution CT (45 vs 9 B-lines; P < .0001). At multivariable analysis, the number of posterior B-lines ≥5 was associated with new development or worsening ILD (hazard ratio, 3.378; 95% CI, 1.137-9.994; P = .028), with additional value over topoisomerase I positivity. The prognostic value was further confirmed in the subgroup of patients with known ILD at baseline (hazard ratio, 1.010; 95% CI, 1.003-1.018; P = .008).

INTERPRETATION

Lung ultrasound B-lines are associated with worsening or development of pulmonary deterioration. In the near future, LUS might become part of the diagnostic and prognostic armamentarium in patients with SSc, which would allow a more sustainable and user-friendly approach to this very fragile population.

Lung Ultrasound-Guided Dry-Weight Reduction in Hemodialysis Patients Does Not Affect Short-Term Blood Pressure Variability

BACKGROUND

Increased short-term blood pressure (BP) variability (BPV) in hemodialysis is associated with increased cardiovascular and all-cause mortality. Studies on the impact of BP-lowering interventions on BPV are scarce. This study examined the effect of dry-weight reduction with a lung ultrasound-guided strategy on short-term BPV in hemodialysis patients with hypertension.

METHODS

This is a prespecified analysis of a randomized clinical trial in 71 hemodialysis patients with hypertension, assigned in a 1:1 ratio in the active group, following a strategy for dry-weight reduction guided by pre-hemodialysis lung ultrasound and the control group following standard-of-care treatment. All patients underwent 48-hour ambulatory BP monitoring at baseline and after 8 weeks. BPV was calculated with validated formulas for the 48-hour interval and the 2 daytime and nighttime periods.

RESULTS

Dry-weight changes were -0.71 ± 1.39 in active vs. +0.51 ± 0.98 kg in the control group (P < 0.001), generating a between-group difference of 5.9/3.5 mm Hg (P < 0.05) in 48-hour BP at study end. All brachial BPV indices [SD, weighted SD, coefficient of variation, and average real variability (ARV)] did not change significantly from baseline to study end in the active [systolic blood pressure (SBP)-ARV: 12.58 ± 3.37 vs. 11.91 ± 3.13, P = 0.117; diastolic blood pressure (DBP)-ARV: 9.14 ± 1.47 vs. 8.80 ± 1.96, P = 0.190] or control (SBP-ARV: 11.33 ± 2.76 vs. 11.07 ± 2.51, P = 0.544; DBP-ARV: 8.38 ± 1.50 vs. 8.15 ± 1.49, P = 0.295) group (between-group comparison P = 0.211/0.117). Aortic BPV indices followed a similar pattern. Likewise, no significant changes in BPV indices for the daytime and nighttime periods were noted in both groups during follow-up.

CONCLUSIONS

This study is the first to evaluate the effects of a nonpharmacological intervention on short-term BPV in hemodialysis, showing no effect of dry-weight reduction on BPV, despite BP decrease.

Point-of-care ultrasound in end-stage kidney disease: beyond lung ultrasound

PURPOSE OF REVIEW

Following the miniaturization of ultrasound devices, point-of-care ultrasound (POCUS) has been proposed as a tool to enhance the value of physical examination in various clinical settings. The objective of this review is to describe the potential applications of POCUS in end-stage renal disease patients (ESRD).

RECENT FINDINGS

With basic training, the clinician can perform pulmonary, vascular, cardiac, and abdominal POCUS at the bedside of ESRD patients. Pulmonary ultrasound can be used to quantify pulmonary congestion and for the differential diagnosis of dyspnea. Ultrasound of the inferior vena cava combined with simple cardiac ultrasound can be used to promptly investigate the mechanism of hemodynamic instability. Vascular ultrasound can be used for troubleshooting of arteriovenous fistula problems and for catheter installation. Multiple potential applications of POCUS in the ESRD population are reviewed, including areas of future research.

SUMMARY

Acquiring basic skills in POCUS may improve patient care through the rapid identification of threats, improved diagnostic abilities for common symptoms, and safer procedures. The adoption of POCUS in undergraduate, internal medicine and nephrology training curriculums will likely lead to a gradual introduction of this technology in the care of ESRD patients.

Ability of non-physicians to perform and interpret lung ultrasound: A systematic review

BACKGROUND

Lung ultrasound is a useful tool in the assessment of pulmonary congestion in heart failure that is typically performed and interpreted by physicians at the point-of-care.

AIMS

To investigate the ability of nurses, students, and paramedics to accurately identify B-lines and pleural effusions for the detection of pulmonary congestion in heart failure and to examine the training necessary.

METHODS AND RESULTS

We conducted a systematic review and searched online databases for studies that investigated the ability of nurses, students, and paramedics to perform lung ultrasound and detect B-lines and pleural effusions. Of 979 studies identified, 14 met our inclusion criteria: five in nurses, eight in students, and one in paramedics. After 0-12 h of didactic training and 58-62 practice lung ultrasound examinations, nurses were able to identify B-lines and pleural effusions with a sensitivity of 79-98% and a specificity of 70-99%. In image adequacy studies, medical students with 2-9 h of training were able to acquire adequate images for B-lines and pleural effusions in 50-100%. Only one eligible study investigated paramedic-performed lung ultrasound which did not support the ability of paramedics to adequately acquire and interpret lung ultrasound images after 2 h of training.

CONCLUSIONS

Our findings suggest that nurses and students can accurately acquire and interpret lung ultrasound images after a brief training period in a majority of cases. The examination of heart failure patients with lung ultrasound by non-clinicians appears feasible and warrants further investigation.

Competence in thoracic ultrasound

Ultrasound examination is traditionally considered a safe and repeatable exam, but its use is highly operator-dependent. Because of this, lack of sufficient operator skills could lead to diagnostic errors and damage to patient safety related to unnecessary tests or interventional procedures. The indications for lung ultrasound include: diagnosis, quantification, and follow-up of different conditions for which acute respiratory failure or chest pain are the main clinical presentation. Clinicians should have theoretical and practical knowledge on: physics and technology of ultrasound, indications and methodology of ultrasound examination, normal thoracic anatomy identification by echography, and detection of signs of pleuro-pulmonary pathology. Consequently, according to international recommendations, core basic skills and minimum training recommendations for the practice of medical ultrasound and image acquisition are needed to ensure competence of clinicians using ultrasound.

Quality control of B-lines analysis in stress Echo 2020

BACKGROUND

The effectiveness trial "Stress echo (SE) 2020" evaluates novel applications of SE in and beyond coronary artery disease. The core protocol also includes 4-site simplified scan of B-lines by lung ultrasound, useful to assess pulmonary congestion.

PURPOSE

To provide web-based upstream quality control and harmonization of B-lines reading criteria.

METHODS

60 readers (all previously accredited for regional wall motion, 53 B-lines naive) from 52 centers of 16 countries of SE 2020 network read a set of 20 lung ultrasound video-clips selected by the Pisa lab serving as reference standard, after taking an obligatory web-based learning 2-h module ( http://se2020.altervista.org ). Each test clip was scored for B-lines from 0 (black lung, A-lines, no B-lines) to 10 (white lung, coalescing B-lines). The diagnostic gold standard was the concordant assessment of two experienced readers of the Pisa lab. The answer of the reader was considered correct if concordant with reference standard reading ±1 (for instance, reference standard reading of 5 B-lines; correct answer 4, 5, or 6). The a priori determined pass threshold was 18/20 (≥ 90%) with R value (intra-class correlation coefficient) between reference standard and recruiting center) > 0.90. Inter-observer agreement was assessed with intra-class correlation coefficient statistics.

RESULTS

All 60 readers were successfully accredited: 26 (43%) on first, 24 (40%) on second, and 10 (17%) on third attempt. The average diagnostic accuracy of the 60 accredited readers was 95%, with R value of 0.95 compared to reference standard reading. The 53 B-lines naive scored similarly to the 7 B-lines expert on first attempt (90 versus 95%, p = NS). Compared to the step-1 of quality control for regional wall motion abnormalities, the mean reading time per attempt was shorter (17 ± 3 vs 29 ± 12 min, p < .01), the first attempt success rate was higher (43 vs 28%, p < 0.01), and the drop-out of readers smaller (0 vs 28%, p < .01).

CONCLUSIONS

Web-based learning is highly effective for teaching and harmonizing B-lines reading. Echocardiographers without previous experience with B-lines learn quickly.

Lung ultrasound training: a systematic review of published literature in clinical lung ultrasound training

Background

Clinical lung ultrasound examinations are widely used in the primary assessment or monitoring of patients with dyspnoea or respiratory failure. Despite being increasingly implemented, there is no international consensus on education, assessment of competencies, and certification. Today, training is usually based on the concept of mastery learning, but is often unstructured and limited by bustle in a clinical daily life. The aim of the systematic review is to provide an overview of published learning studies in clinical lung ultrasound, and to collect evidence for future recommendations in lung ultrasound education and certification.

Methods

According to PRISMA guidelines, three databases (PubMed, Embase, Cochrane Library) were searched, and two reviewers examined the results for eligibility. Included publications were described and assessed for level of evidence and risk of bias according to guidelines from Oxford Centre for Evidence-Based Medicine and Cochrane Collaboration Tool for Risk of Bias assessment.

Results

Of 7796 studies screened, 16 studies were included. Twelve pre- and post-test studies, three descriptive studies and one randomized controlled trial were identified. Seven studies included web-based or online modalities, while remaining used didactic or classroom-based lectures. Twelve (75%) studies provided hands-on sessions, and of these, 11 assessed participants’ hands-on skills. None of the studies used validated neither written nor practical assessment. The highest level of evidence score was 2 (n = 1), remaining scored 4 (n = 15). Risk of bias was assessed high in 11 of 16 studies (68.75%).

Conclusion

All educational methods proved increased theoretical and practical knowledge obtained at the ultrasound courses, but the included studies were substantial heterogeneous in setup, learning-, and assessment methods, and outcome measures. On behalf of current published studies, it was not possible to construct clear guidelines for the future education and certification in clinical lung ultrasound, but the use of different hands-on training facilities tends to contribute to different aspects of the learning process. This systematic review proves a lack of learning studies within this content, and research with validated theoretical and practical tests for assessment is desired.