VExUS Nexus: Bedside Assessment of Venous Congestion

Diagnostic value of ultrasonography for post-liver transplant hepatic vein complications

Liver transplantation (LT) is the most effective treatment for patients with end-stage liver disease, and maintaining vascular patency of the transplanted liver is one of the crucial prerequisites for surgical success. Despite hepatic vein complications following LT occurring at a relatively low frequency, ranging between 2% to 11%, delayed diagnosis and treatment may lead to graft dysfunction and even patient mortality. Clinical manifestations of hepatic vein complications are often subtle and nonspecific, posing challenges for early diagnosis. Signs may initially present as mild abnormalities in liver function, delayed recovery of liver function, unexplained ascites, lower limb edema, and perineal edema. Prolonged duration of these complications can lead to hepatic sinusoidal dilatation and eventual liver failure due to prolonged hepatic congestion. Ultrasonography has become the preferred imaging modality for post-liver transplant evaluation due to its convenience and non-invasiveness. Although hepatic vein complications may manifest as disappearance or flattening of the hepatic vein spectrum on routine ultrasound imaging, these findings lack specificity. Contrast-enhanced ultrasound that visualizes the filling of contrast agent in the hepatic veins and dynamically displays blood flow perfusion information in the drainage area can, however, significantly improve diagnostic confidence and provide additional information beyond routine ultrasound examination.

Venous excess ultrasound: A mini-review and practical guide for its application in critically ill patients

Advancements in healthcare technology have improved mortality rates and extended lifespans, resulting in a population with multiple comorbidities that complicate patient care. Traditional assessments often fall short, underscoring the need for integrated care strategies. Among these, fluid management is particularly challenging due to the difficulty in directly assessing volume status especially in critically ill patients who frequently have peripheral oedema. Effective fluid management is essential for optimal tissue oxygen delivery, which is crucial for cellular metabolism. Oxygen transport is dependent on arterial oxygen levels, haemoglobin concentration, and cardiac output, with the latter influenced by preload, afterload, and cardiac contractility. A delicate balance of these factors ensures that the cardiovascular system can respond adequately to varying physiological demands, thereby safeguarding tissue oxygenation and overall organ function during states of stress or illness. The Venous Excess Ultrasound (VExUS) Grading System is instrumental in evaluating fluid intolerance, providing detailed insights into venous congestion and fluid status. It was originally developed to assess the risk of acute kidney injury in postoperative cardiac patients, but its versatility has enabled broader applications in nephrology and critical care settings. This mini review explores VExUS’s application and its impact on fluid management and patient outcomes in critically ill patients.

[Role of ultrasound in critically ill patients with heart failure]

Heart failure (HF) is a clinical syndrome with symptoms and/or signs caused by structural and/or functional cardiac abnormalities. After discharge, patients with acute heart failure (AHF) face a significant risk of rehospitalization and mortality. Detection of residual congestion is crucial to reduce readmissions, improve prognosis, and decrease mortality. Echocardiography provides critical information about the severity of left ventricular dysfunction, elevated filling pressures, valvular dysfunction, and estimation of pulmonary artery systolic pressure. The VExUS approach integrates ultrasound evaluation of the inferior vena cava, hepatic veins, portal vein, and renal veins, providing valuable information about systemic congestion. Lung ultrasound detects pulmonary congestion, facilitating early intervention to prevent progression and hospitalizations. Ultrasound evaluation of the internal jugular vein and femoral vein complements the evaluation of venous congestion. Distension of the internal jugular vein during the Valsalva maneuver or the relationship between the diameter of the internal jugular vein and the femoral vein can predict adverse outcomes in patients with HF. In conclusion, a comprehensive ultrasound approach is crucial in the management of patients with critically ill heart failure. Multiparameter ultrasound evaluation provides vital information, guiding appropriate therapeutic interventions and avoiding potentially harmful measures.

Hepatocardiorenal Syndrome: Integrating Pathophysiology with Clinical Decision-Making via Point-Of-Care Ultrasound

BACKGROUND

Accumulating evidence has challenged the traditional model of the liver-kidney connection in hepatorenal syndrome. Cirrhosis can significantly impact cardiac function, leading to cirrhotic cardiomyopathy. Recent understanding reveals how cardiac dysfunction plays a pivotal role in the development of renal dysfunction in this setting, suggesting that disturbances traditionally categorized under hepatorenal syndrome may actually represent a hepatic form of cardiorenal syndrome - hepatocardiorenal syndrome - where the liver affects the kidney through cardiorenal pathways.

SUMMARY

Effective management of hepatocardiorenal syndrome and acute kidney injury in cirrhosis relies on accurately assessing a patient's hemodynamic and volume status. Point-of-care ultrasound, including lung and focused cardiac ultrasound, is a valuable diagnostic tool that provides crucial data on fluid tolerance, subclinical pulmonary congestion, and left ventricular filling pressures. This objective, bedside approach offers a comprehensive assessment that directly influences patient management and therapeutic decisions.

KEY MESSAGES

Point-of-care ultrasound plays an essential role in evaluating and managing hepatocardiorenal syndrome, providing insights into the underlying pathophysiology. By assessing hemodynamic parameters, it helps guide therapy and monitor patient responses, ensuring more accurate and effective treatment of patients with cirrhosis and acute kidney injury.

Point-of-Care Ultrasound in Nephrology: Beyond Kidney Ultrasound

Point-of-care ultrasound (POCUS) has increasingly become an integral part of clinical practice, particularly in nephrology, where its use extends beyond renal assessment to include multi-organ evaluations. Despite challenges such as limited ultrasound training and equipment access, especially in low- and middle-income countries, the adoption of POCUS is steadily rising. This narrative review explores the growing role of multi-organ POCUS in nephrology, with applications ranging from the assessment of congestion phenotypes, cardiorenal syndrome, and hemodynamic acute kidney injury (AKI) to the evaluation of arteriovenous fistulas and electrolyte disorders. In nephrology, POCUS enhances clinical decision making by enabling rapid, bedside evaluations of fluid status, cardiac function, and arteriovenous access. Studies have demonstrated its utility in diagnosing and managing complications such as heart failure, cirrhosis, and volume overload in end-stage renal disease. Additionally, POCUS has proven valuable in assessing hemodynamic alterations that contribute to AKI, particularly in patients with heart failure, cirrhosis, and systemic congestion. This review highlights how integrating ultrasound techniques, including lung ultrasound, venous Doppler, and focused cardiac ultrasound, can guide fluid management and improve patient outcomes. With advancements in ultrasound technology, particularly affordable handheld devices, and the expansion of targeted training programs, the potential for POCUS to become a global standard tool in nephrology continues to grow, enabling improved care in diverse 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.

Abnormal Venous Flow in Pregnant Women with Mild Right Ventricular Dysfunction in Repaired Tetralogy of Fallot: A Clinical Model for Organ Dysfunction in Preeclampsia

Background: Pregnant women with congenital heart disease carry a high risk of complications, especially when cardiac function is suboptimal. Increasing evidence suggests that impaired right ventricular (RV) function has a negative effect on placental function, possibly through venous congestion. We report a case series of hepatic and renal venous flow patterns in pregnant women with right ventricular dysfunction after repaired Tetralogy of Fallot (ToF), relative to those observed in normal pregnancy and preeclampsia. Methods: At 20-24 weeks pregnancy, RV function was measured by echocardiography and by cardiovascular magnetic resonance in women with repaired ToF. Combined Doppler-ECG of the hepatic and renal interlobular veins were performed in three women with asymptomatic right ventricular dysfunction. Venous impedance index and pulse transit time were measured and classified as abnormal at >75th and <25th reference percentile, respectively. Results: All three women showed dilated RV and mildly impaired RV function. Both hepatic and intrarenal Doppler flow waves were abnormal and very much resembled the patterns seen in preeclampsia. One of the three women had complications including ventricular tachycardia, intrauterine growth restriction, antenatal bleeding, emergency cesarean section and acute heart failure 2 days postpartum. Conclusions: Pregnant women with mild right ventricular dysfunction after repaired ToF show abnormal venous Doppler flow waves in the liver and kidneys, similar to those observed in preeclampsia. These findings are in line with reported observations on the association between impaired RV function, abnormal return of venous blood, venous congestion and organ dysfunction. The parallel with venous Doppler flow observations in preeclampsia suggest that the venous compartment might play an important role in the etiology of preeclampsia-induced organ dysfunction. Whether this phenomenon directly affects the uteroplacental circulation is to be assessed in future research.

Point-of-care ultrasound training in nephrology: a position statement by the International Alliance for POCUS in Nephrology

Point-of-care ultrasonography (POCUS) has rapidly evolved from a niche technology to an indispensable tool across medical specialties, including nephrology. This evolution is driven by advancements in technology and the visionary efforts of clinicians in emergency medicine and beyond. Recognizing its potential, medical schools are increasingly integrating POCUS into training curricula, emphasizing its role in enhancing diagnostic accuracy and patient care. Despite these advancements, barriers such as limited faculty expertise and 'lack of' standardized guidelines hinder widespread adoption and regulation. The International Alliance for POCUS in Nephrology (IAPN), through this position statement, aims to guide nephrologists in harnessing the diagnostic power of POCUS responsibly and effectively. By outlining core competencies, recommending training modalities and advocating for robust quality assurance measures, we envision a future where POCUS enhances nephrology practice globally, ensuring optimal patient outcomes through informed, evidence-based decision-making. International collaboration and education are essential to overcome current challenges and realize the full potential of POCUS in nephrology and beyond.

Portal vein Doppler tracks volume status in patients with severe tricuspid regurgitation: a proof-of-concept study

AIMS

Renal and liver congestion are associated with adverse outcomes in patients with tricuspid regurgitation (TR). Currently, there are no valid sonographic indicators of fluid status in this population. Intra-renal venous Doppler (IRVD) is a novel method for quantifying renal congestion but its interpretation can be challenging in severe TR due to altered haemodynamics. This study explores the potential of portal vein Doppler (PVD) as an alternative marker for decongestion during volume removal in patients with severe TR.

METHODS AND RESULTS

Forty-two patients with severe TR undergoing decongestive therapy were prospectively enrolled. Inferior vena cava diameter, PVD, and IRVD were sequentially assessed during volume removal. Improvement criteria were portal vein pulsatility fraction (PVPF) < 70% and renal venous stasis index (RVSI) < 0.5 for partial improvement, and PVPF < 30% and RVSI < 0.2 for complete improvement. After volume removal, PVPF significantly improved from 130 ± 39% to 47 ± 44% (P < 0.001), while IRVD improved from 0.72 ± 0.08 to 0.54 ± 0.22 (P < 0.001). A higher proportion of patients displayed improvement in PVD compared to IRVD (partial: 38% vs. 29%, complete: 41% vs. 7%) (P < 0.001). Intra-renal venous Doppler only improved in patients with concomitant improvement in severe TR. Portal vein Doppler was the only predictor of achieving ≥5 L of negative fluid balance [area under the ROC curve (AUC) 0.83 P = 0.001].

CONCLUSION

This proof-of-concept study suggests that PVD is the only sonographic marker that can track volume removal in severe TR, offering a potential indicator for decongestion in this population. Further intervention trials are warranted to determine if PVD-guided decongestion improves patient outcomes in severe TR.

Decrease in the Internal Cerebral Vein Pulsation With Improvement of Patent Ductus Arteriosus in Premature Infants at the Risk of Intraventricular Hemorrhage: Two Interesting Case Reports

Recently, augmenting the pulsation of the internal cerebral vein (ICV) has been reported to be a predictor of premature intraventricular hemorrhage (IVH); however, prophylaxis for IVH has not yet been established. Venous pulsation is a marker of central venous pressure elevation and may be improved after heart failure treatment. Herein, we report two cases of low-birth-weight infants (29 weeks and 31 weeks of gestational age), who exhibited improvements in ICV pulsation with relief of hemodynamically significant patent ductus arteriosus (hs-PDA) following indomethacin administration. ICV flow patterns were continuously flat early after birth. Thereafter, both patients demonstrated ICV pulsation augmentation with PDA progression and brain natriuretic peptide (BNP) elevation at 52 h and 39 h after birth (in infants born at 29 and 31 weeks of gestational age, respectively). After relieving PDA with indomethacin administration, both infants exhibited an improvement in ICV pulsation with decreased BNP levels. In both cases, ICV pulsation increased when PDA became hemodynamically significant with BNP elevation, and the pulsation improved by reduction in ductal flow with decreasing BNP when PDA was relieved by indomethacin administration. The association between hs-PDA and elevated ICV pulsation indicates that hs-PDA likely leads to heightened central venous pressure. Additionally, indomethacin treatment was effective in reducing the exacerbated ICV pulsation caused by heart failure due to hs-PDA. These cases suggest that treatment for heart failure might improve the augmented ICV pulsation, which is related to the development of premature IVH. However, further studies are needed to confirm this association.

Reliability and reproducibility of the venous excess ultrasound (VExUS) score, a multi-site prospective study: validating a novel ultrasound technique for comprehensive assessment of venous congestion

Though the novel venous excess ultrasound (VExUS) score is increasingly used as a noninvasive means of venous congestion measurement, the inter-rater reliability (IRR), inter-user reproducibility (IUR), and utility of concurrent ECG have not been evaluated. We conducted a multicenter study of the IRR, IUR, and utility of ECG for VExUS interpretation between four attending physicians of diverse specialties, reporting the Kappa statistic (KS) and Intraclass Correlation Coefficient (ICC) for IRR and IUR for scans with and without ECG. Eighty-four paired VExUS exams from 42 patients, 60 of which had a concurrent ECG tracing, were interpreted. They showed substantial IRR, with a KS of 0.71 and ICC of 0.83 for the overall VExUS grade (p < 0.001), and IUR, with a KS 0.63 and ICC of 0.8. There was greater agreement among images with an ECG tracing. These results suggest that ECG-augmented VExUS may be a reliable and reproducible measure interpretable by clinicians with diverse backgrounds.

Sound waves and solutions: Point-of-care ultrasonography for acute kidney injury in cirrhosis

This article delves into the intricate challenges of acute kidney injury (AKI) in cirrhosis, a condition fraught with high morbidity and mortality. The complexities arise from distinguishing between various causes of AKI, particularly hemodynamic AKI, in cirrhotic patients, who experience hemodynamic changes due to portal hypertension. The term "hepatocardiorenal syndrome" is introduced to encapsulate the intricate interplay among the liver, heart, and kidneys. The narrative emphasizes the often-overlooked aspect of cardiac function in AKI assessments in cirrhosis, unveiling the prevalence of cirrhotic cardiomyopathy marked by impaired diastolic function. The conventional empiric approach involving volume expansion and vasopressors for hepatorenal syndrome is critically analyzed, highlighting potential risks and variable patient responses. We advocate for a nuanced algorithm for AKI evaluation in cirrhosis, prominently featuring point-of-care ultrasonography (POCUS). POCUS applications encompass assessing fluid tolerance, detecting venous congestion, and evaluating cardiac function.

Point-of-care ultrasonography in cirrhosis-related acute kidney injury: How I do it

Discerning the etiology of acute kidney injury (AKI) in cirrhotic patients remains a formidable challenge due to diverse and overlapping causes. The conventional approach of empiric albumin administration for suspected volume depletion may inadvertently lead to fluid overload. In the recent past, point-of-care ultrasonography (POCUS) has emerged as a valuable adjunct to clinical assessment, offering advantages in terms of diagnostic accuracy, rapidity, cost-effectiveness, and patient satisfaction. This review provides insights into the strategic use of POCUS in evaluating cirrhotic patients with AKI. The review distinguishes basic and advanced POCUS, emphasizing a 5-point basic POCUS protocol for efficient assessment. This protocol includes evaluations of the kidneys and urinary bladder for obstructive nephropathy, lung ultrasound for detecting extravascular lung water, inferior vena cava (IVC) ultrasound for estimating right atrial pressure, internal jugular vein ultrasound as an alternative to IVC assessment, and focused cardiac ultrasound for assessing left ventricular (LV) systolic function and identifying potential causes of a plethoric IVC. Advanced POCUS delves into additional Doppler parameters, including stroke volume and cardiac output, LV filling pressures and venous congestion assessment to diagnose or prevent iatrogenic fluid overload. POCUS, when employed judiciously, enhances the diagnostic precision in evaluating AKI in cirrhotic patients, guiding appropriate therapeutic interventions, and minimizing the risk of fluid-related complications.

Exploring congestion endotypes and their distinct clinical outcomes among ICU patients: A post-hoc analysis

BACKGROUND

In the intensive care unit (ICU) patients, fluid overload and congestion are associated with worse outcomes. Because of the heterogeneity of ICU patients, we hypothesized that there may exist different endotypes of congestion. The aim of this study was to identify endotypes of congestion and their association with outcomes.

METHODS

We conducted an unsupervised hierarchical clustering analysis on 145 patients admitted to ICU to identify endotypes. We measured several parameters related to clinical context, volume status, filling pressure, and venous congestion. These parameters included NT-proBNP, central venous pressure (CVP), the mitral E/e' ratio, the systolic/diastolic ratio of hepatic veins' flow velocity, the mean diameter of the inferior vena cava (IVC) and its variations, stroke volume changes following passive leg raising, the portal vein pulsatility index, and the venous renal impedance index.

RESULTS

Three distinct endotypes were identified: (1) "hemodynamic congestion" endotype (n = 75) with moderate alterations of ventricular function, increased CVP and left filling pressure values, and moderate fluid overload; (2) "volume overload congestion" endotype (n = 50); with normal cardiac function and filling pressure despite high positive fluid balance (fluid overload); (3) "systemic congestion" endotype (n = 20) with severe alterations of left and right ventricular functions, increased CVP and left ventricular filling pressure values. These endotypes vary significantly in ICU admission reasons, acute kidney injury rates, mortality, and length of ICU/hospital stay.

CONCLUSIONS

Our analysis revealed three unique congestion endotypes in ICU patients, each with distinct pathophysiological features and outcomes. These endotypes are identifiable through key ultrasonographic characteristics at the bedside.

CLINICAL TRIAL GOV

NCT04680728.

Monitoring the venous circulation: novel techniques and applications

PURPOSE OF REVIEW

Venous pressure is an often-unrecognized cause of patient morbidity. However, bedside assessment of PV is challenging. We review the clinical significance of venous pressure measurement, existing techniques, and introduce the Venous Excess Ultrasound (VExUS) Score as a novel approach using doppler ultrasound to assess venous pressure.

RECENT FINDINGS

Studies show clear associations between elevated venous pressure and adverse outcomes in critically ill patients. Current venous pressure measurement techniques include physical examination, right heart catheterization (RHC), two-dimensional ultrasound, and a variety of labor-intensive research-focused physiological maneuvers. Each of these techniques have specific shortcomings, limiting their clinical utility. To address these gaps, Beaubien-Souligny et al. introduced the VExUS Score, a novel doppler ultrasound-based method that integrates IVC diameter with doppler measurements of the hepatic, portal, and renal veins to generate a venous congestion assesment. Studies show strong correlations between VExUS score and RHC measurements, and well as an association between VExUS score and improvement in cardiorenal acute kidney injury, diuretic response, and fluid status shifts. However, studies in noncardiac populations have been small, heterogenous, and inconclusive.

SUMMARY

Early studies evaluating the use of doppler ultrasound to assess venous congestion show promise, but further research is needed in diverse patient populations and clinical settings.

Acute kidney injury and point-of-care ultrasound in liver cirrhosis: redefining hepatorenal syndrome

Acute kidney injury (AKI) in patients with cirrhosis is a diagnostic challenge due to multiple and sometimes overlapping possible etiologies. Many times, diagnosis cannot be made based on case history, physical examination or laboratory data, especially when the nephrologist is faced with AKI with a hemodynamic basis, such as hepatorenal syndrome. In addition, the guidelines still include generalized recommendations regarding withdrawal of diuretics and plasma volume expansion with albumin for 48 h, which may be ineffective and counterproductive and may have iatrogenic effects, such as fluid overload and acute cardiogenic pulmonary edema. For this reason, the use of new tools, such as hemodynamic point-of-care ultrasound (PoCUS), allows us to phenotype volume status more accurately and ultimately guide medical treatment in a noninvasive, rapid and individualized manner.

Point-of-Care Ultrasound (POCUS)-Guided Management of Cardiogenic Shock in COVID-19 Fulminant Myocarditis With Combined Veno-Arterial Extracorporeal Membrane Oxygenation and Impella (ECPELLA): A Case Report

The COVID-19 pandemic, which has been raging globally, has been reported to cause not only pneumonia but also various cardiovascular diseases. In particular, myocarditis poses a serious risk if it becomes severe. As a characteristic of myocardial damage in this disease, right ventricular dysfunction is frequently reported, and biventricular failure is not uncommon. In cases where cardiogenic shock occurs, ECPELLA, which combines veno-arterial extracorporeal membrane oxygenation and Impella, is used for management. Currently, in Japan, ECPELLA is the central treatment for severe biventricular failure in the acute phase. However, its management method has not been established. Weaning from ECPELLA requires the following three conditions: (1) improvement of left ventricular function; (2) improvement of right ventricular function; and (3) optimization of circulating plasma volume. However, since these conditions change moment by moment, frequent and detailed assessments are necessary. Nevertheless, considering the need for isolation due to COVID-19, there are limitations on the tests that can be performed. In this regard, point-of-care ultrasound (POCUS) allows repeated bedside evaluations while maintaining infection protection. We report that in the case of severe COVID-19-related myocarditis, the use of POCUS enabled the preservation of cardiac function and appropriate timing for weaning from ECPELLA.

Acute heart failure - an EFIM guideline critical appraisal and adaptation for internists

BACKGROUND

Over the past two decades, several studies have been conducted that have tried to answer questions on management of patients with acute heart failure (AHF) in terms of diagnosis and treatment. Updated international clinical practice guidelines (CPGs) have endorsed the findings of these studies. The aim of this document was to adapt recommendations of existing guidelines to help internists make decisions about specific and complex scenarios related to AHF.

METHODS

The adaptation procedure was to identify firstly unresolved clinical problems in patients with AHF in accordance with the PICO (Population, Intervention, Comparison and Outcomes) process, then conduct a critical assessment of existing CPGs and choose recommendations that are most applicable to these specific scenarios.

RESULTS

Seven PICOs were identified and CPGs were assessed. There is no single test that can help clinicians in discriminating patients with acute dyspnoea, congestion or hypoxaemia. Performing of echocardiography and natriuretic peptide evaluation is recommended, and chest X-ray and lung ultrasound may be considered. Treatment strategies to manage arterial hypotension and low cardiac output include short-term continuous intravenous inotropic support, vasopressors, renal replacement therapy, and temporary mechanical circulatory support. The most updated recommendations on how to treat specific patients with AHF and certain comorbidities and for reducing post-discharge rehospitalization and mortality are provided. Overall, 51 recommendations were endorsed and the rationale for the selection is provided in the main text.

CONCLUSION

Through the use of appropriate tailoring process methodology, this document provides a simple and updated guide for internists dealing with AHF patients.

Controlled Mechanical Ventilation in Critically Ill Patients and the Potential Role of Venous Bagging in Acute Kidney Injury

A very low incidence of acute kidney injury (AKI) has been observed in COVID-19 patients purposefully treated with early pressure support ventilation (PSV) compared to those receiving mainly controlled ventilation. The prevention of subdiaphragmatic venous congestion through limited fluid intake and the lowering of intrathoracic pressure is a possible and attractive explanation for this observed phenomenon. Both venous congestion, or "venous bagging", and a positive fluid balance correlate with the occurrence of AKI. The impact of PSV on venous return, in addition to the effects of limiting intravenous fluids, may, at least in part, explain this even more clearly when there is no primary kidney disease or the presence of nephrotoxins. Optimizing the patient-ventilator interaction in PSV is challenging, in part because of the need for the ongoing titration of sedatives and opioids. The known benefits include improved ventilation/perfusion matching and reduced ventilator time. Furthermore, conservative fluid management positively influences cognitive and psychiatric morbidities in ICU patients and survivors. Here, it is hypothesized that cranial lymphatic congestion in relation to a more positive intrathoracic pressure, i.e., in patients predominantly treated with controlled mechanical ventilation (CMV), is a contributing risk factor for ICU delirium. No studies have addressed the question of how PSV can limit AKI, nor are there studies providing high-level evidence relating controlled mechanical ventilation to AKI. For this perspective article, we discuss studies in the literature demonstrating the effects of venous congestion leading to AKI. We aim to shed light on early PSV as a preventive measure, especially for the development of AKI and ICU delirium and emphasize the need for further research in this domain.

Critical Care Echocardiography: Assessing Left and Right Ventricular Function in the Intensive Care Unit

In this review we explore Left Ventricular and Right Ventricular parameters that intensivists can use to evaluate, manage, and monitor the critically ill. Understanding these parameters, their clinical relevance, and potential pitfalls, is crucial for thorough and accurate patient assessment and management. Critical Care Echocardiography encompasses all the advanced cardiac and non-cardiac skillset needed to integrate the findings of Left Ventricular and Right Ventricular size and function. We advocate for a physiologic approach to the critically ill patient, tailoring therapy to reverse the etiology while simultaneously supporting circulation based on a sound understanding of left and right ventricular pressures, volumes, and flow.

Fluid Status Assessment in Critically Ill Patients with COVID-19: A Retrospective Cohort Study

Fluid status (FS) is a diagnostic challenge in critically ill patients with COVID-19. Here, we compared parameters related to FS derived from cumulative fluid balance (CFB), bioelectrical impedance analysis (BIA) and venous congestion assessed by ultrasound (VExUS) to predict mortality. We retrospectively reviewed the medical records of individuals with severe pneumonia due to COVID-19 between July and November 2021 in a single center. Comorbidities, demographic, clinical and laboratory data as well as results from CFB, BIA and VExUS measurements were collected on admission and weekly afterwards for two consecutive evaluations. Seventy-nine patients were included, of which eighteen (14.2%) died. Abnormalities of FS were only identified by BIA. Extracellular water/total body water ratio (ECW/TBW) > 0.394 (overhydrated) by BIA was a good predictor of mortality (AUC = 0.78, 95% CI: 0.067-0.89). Mortality risk was higher in overhydrated patients (OR: 6.2, 95% CI: 1.2-32.6, p = 0.02) and in persistently overhydrated patients (OR: 9.57, 95% CI: 1.18-77.5, p = 0.03) even after adjustment to age, serum albumin and acute kidney injury (AKI) in stages 2-3. Time to death was shorter in overhydrated patients (HR: 2.82, 95% CI: 1.05-7.5, log-rank test p = 0.03). Abnormalities in FS associated with mortality were only identified by BIA in critically ill patients with COVID-19.

Inferior Vena Caval Measures Do Not Correlate with Carotid Artery Corrected Flow Time Change Measured Using a Wireless Doppler Patch in Healthy Volunteers

(1) Background: The inspiratory collapse of the inferior vena cava (IVC), a non-invasive surrogate for right atrial pressure, is often used to predict whether a patient will augment stroke volume (SV) in response to a preload challenge. There is a correlation between changing stroke volume (SV∆) and corrected flow time of the common carotid artery (ccFT∆). (2) Objective: We studied the relationship between IVC collapsibility and ccFT∆ in healthy volunteers during preload challenges. (3) Methods: A prospective, observational, pilot study in euvolemic, healthy volunteers with no cardiovascular history was undertaken in a local physiology lab. Using a tilt-table, we studied two degrees of preload augmentation from (a) supine to 30-degrees head-down and (b) fully-upright to 30-degrees head down. In the supine position, % of IVC collapse with respiration, sphericity index and portal vein pulsatility was calculated. The common carotid artery Doppler pulse was continuously captured using a wireless, wearable ultrasound system. (4) Results: Fourteen subjects were included. IVC % collapse with respiration ranged between 10% and 84% across all subjects. Preload responsiveness was defined as an increase in ccFT∆ of at least 7 milliseconds. A total of 79% (supine baseline) and 100% (head-up baseline) of subjects were preload-responsive. No supine venous measures (including IVC % collapse) were significantly related to ccFT∆. (5) Conclusions: From head-up baseline, 100% of healthy subjects were 'preload-responsive' as per the ccFT∆. Based on the 42% and 25% IVC collapse thresholds in the supine position, only 50% and 71% would have been labeled 'preload-responsive'.

Unifying Fluid Responsiveness and Tolerance With Physiology: A Dynamic Interpretation of the Diamond-Forrester Classification

Point of care ultrasound (POCUS) is a first-line tool to assess hemodynamically unstable patients, however, there is confusion surrounding intertwined concepts such as: "flow," "congestion," "fluid responsiveness (FR)," and "fluid tolerance." We argue that the Frank-Starling relationship is clarifying because it describes the interplay between "congestion" and "flow" on the x-axis and y-axis, respectively. Nevertheless, a single, simultaneous assessment of congestion and flow via POCUS remains a static approach. To expand this, we propose a two-step process. The first step is to place the patient on an ultrasonographic Diamond-Forrester plot. The second step is a dynamic assessment for FR (e.g., passive leg raise), which individualizes therapy across the arc of critical illness.

VExUS Score in the Management of Patients With Acute Kidney Injury in the Intensive Care Unit: AKIVEX Study

OBJECTIVES

Venous congestion is a potential cause of acute kidney injury (AKI) and venous excess ultrasound (VExUS) score is a potentially useful tool in this scenario. The aim of this study is to verify whether the VExUS score can serve as a guide to decongestion in patients with severe AKI and whether the modification of the score can be associated with an increase in the number of renal replacement therapy (RRT)-free days in 28 days.

METHODS

This quasi-experimental study was conducted in patients admitted to the intensive care unit who developed severe AKI. The intervention was to suggest to the attending physician the use of diuretic in patients with VExUS >1. After 48 hours, a new VExUS assessment was performed. Primary outcome was RRT-free days at Day 28.

RESULTS

Ninety patients were included. Patients with a VExUS score >1 (n = 36) at enrollment had a greater use of diuretics in the following 48 hours (75.0%, n = 27) than patients with a VExUS ≤1 (n = 54) at enrollment (38.9%, n = 21), P = .001. Patients who reduced the VExUS score had a significantly greater number of RRT-free days at Day 28 (28.0; 8.0-28.0) when compared with those who did not reduce (15.0; 3.0-27.5), P = .012.

CONCLUSIONS

We found a higher diuretic use in patients with a higher VExUS score, and patients who reduced the VExUS in 48 hours had significantly more RRT-free days in 28 days.

Tricuspid regurgitation, right ventricular function, and renal congestion: a cardiorenal triangle

There is a growing interest in the evaluation of tricuspid regurgitation due to its increasing prevalence and detrimental impact on clinical outcomes. Historically, it has been coined the "forgotten" defect in the field of valvular heart disease due to the lack of effective treatments to improve prognosis. However, the development of percutaneous treatment techniques has led to a new era in its management, with promising results and diminished complication risk. In spite of these advances, a comprehensive exploration of the pathophysiological mechanisms is essential to establish clear indications and optimal timing for medical and percutaneous intervention. This review will address the most important aspects related to the diagnosis, pathophysiology and treatment of tricuspid regurgitation from a cardiorenal perspective, with a special emphasis on the interaction between right ventricular dysfunction and the development of hepatorenal congestion.

Venous excess ultrasound score and acute kidney injury in patients with acute coronary syndrome

AIMS

Systemic venous congestion is associated with an increased risk of acute kidney injury (AKI) in critically ill patients. Venous Excess Ultrasound Score (VExUS) has been proposed as a non-invasive score to assess systemic venous congestion. We aimed to evaluate the association between VExUS and AKI in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

This is a prospective study including patients with the diagnosis of ACS (both ST elevation and non-ST elevation ACS). VExUS was performed during the first 24 h of hospital stay. Patients were classified according to the presence of systemic congestion (VExUS 0/≥1). The primary objective of the study was to determine the occurrence of AKI, defined by KDIGO criteria. A total of 77 patients were included. After ultrasound assessment, 31 (40.2%) patients were categorized as VExUS ≥1. VExUS ≥1 was more frequently found in inferior vs. anterior myocardial infarction/non-ST-segment elevation acute myocardial infarction (48.3 vs. 25.8 and 22.5%, P = 0.031). At each increasing degree of VExUS, a higher proportion of patients developed AKI: VExUS = 0 (10.8%), VExUS = 1 (23.8%), VExUS = 2 (75.0%), and VExUS = 3 (100%; P < 0.001). A significant association between VExUS ≥1 and AKI was found [odds ratio (OR): 6.75, 95% confidence interval (CI): 2.21-23.7, P = 0.001]. After multivariable analysis, only VExUS ≥1 (OR: 6.15; 95% CI: 1.26-29.94, P = 0.02) remained significantly associated with AKI.

CONCLUSION

In patients hospitalized with ACS, VExUS is associated with the occurrence of AKI. Further studies are needed to clarify the role of VExUS assessment in patients with ACS.

The effect of gravity-induced preload change on the venous excess ultrasound (VExUS) score and internal jugular vein Doppler in healthy volunteers

BACKGROUND

The venous excess ultrasound (VExUS) score is a multi-organ Doppler approach to assess venous congestion. Despite growing use of VExUS in research and clinical practice, other veins can be visualized to assess for venous hypertension, which may overcome acquisition barriers of the VExUS exam. In this pilot, observational study, we used a wearable Doppler ultrasound to assess the relationship between jugular venous Doppler and the VExUS score under different preload conditions. We hypothesized that jugular Doppler morphology would accurately distinguish preload conditions, that it would most closely relate to the hepatic venous Doppler morphology in the fully supine position and that the VExUS score would be influenced by preload condition.

RESULTS

We recruited 15 healthy volunteers with no cardiovascular history. Preload change was achieved using a tilt-table with three positions: supine, fully upright, and 30-degree head-down tilt. In each position, a VExUS score was performed; furthermore, inferior vena collapsibility and sphericity index were calculated. At the same time, jugular venous Doppler was captured by a novel, wireless, wearable ultrasound system. A continuous jugular venous Doppler morphology was 96% accurate for detecting the low preload condition. The jugular venous Doppler morphology was highly correlated with the hepatic vein, but only in the supine position. Gravitational position did not significantly affect the sphericity index or the VExUS score.

CONCLUSIONS

The jugular vein Doppler morphology was able to accurately distinguish low from high preload conditions in healthy volunteers. Comparisons between VExUS Doppler morphologies and other veins should occur in the supine position when gravitational pressure gradients are minimized; finally, different preload conditions in healthy subjects did not affect the VExUS score.

Nephrologist-performed point-of-care venous excess Doppler ultrasound (VExUS) in the management of acute kidney injury

Acute kidney injury (AKI) is frequently associated with alterations in fluid balance making accurate assessment of hemodynamics a vital component of patient management. Unfortunately, conventional parameters such as history, physical examination, vital signs, weight, natriuretic peptides have limitations in this regard. Point of care ultrasonography (POCUS) is a clinician-performed limited ultrasound study intended to answer focused clinical questions at the bedside. In the past several years, it has evolved as an extension of physical examination in various medical specialties. Herein, we describe a case of AKI where nephrologist-performed multi-organ POCUS aided in accurate diagnosis of fluid overload state. In addition, we describe how venous Doppler (VExUS) evaluation can be used to monitor the efficacy of decongestive therapy in real-time. Nephrologists should adopt a multi-parametric approach integrating all the pieces of hemodynamic puzzle when evaluating patients with AKI and fluid/electrolyte disorders.

Association between Hepatic Venous Congestion and Adverse Outcomes after Cardiac Surgery

INTRODUCTION

Hepatic venous flow patterns reflect pressure changes in the right ventricle and are also markers of systemic venous congestion. Fluid management is crucial in patients undergoing cardiac surgery.

METHODS

Our goal was to determine which factors are associated with the increased congestion of the liver as measured by Doppler ultrasound in patients undergoing cardiac surgery. This prospective, observational study included 41 patients without preexisting liver disease who underwent cardiac surgery between 1 January 2021 and 30 September 2021 at a tertiary heart center. In addition to routine echocardiographic examination, we recorded the maximal velocity and velocity time integral (VTI) of the standard four waves seen in the common hepatic vein (flow profile) using Doppler ultrasound preoperatively and at the 20-24th hour of the postoperative period. The ratios of the retrograde and anterograde hepatic venous waves were calculated, and the waveforms were compared to the baseline value and expressed as a delta ratio. Demographic data, pre- and postoperative echocardiographic parameters, intraoperative variables (procedure, cardiopulmonary bypass time), postoperative factors (fluid balance, vasoactive medication requirement, ventilation time and parameters) and perioperative laboratory parameters (liver and kidney function tests, albumin) were used in the analysis.

RESULTS

Of the 41 patients, 20 (48.7%) were males, and the median age of the patients was 65.9 years (IQR: 59.8-69.9 years). Retrograde VTI growth showed a correlation with positive fluid balance (0.89 (95% CI 0.785-0.995) c-index. After comparing the postoperative echocardiographic parameters of the two subgroups, right ventricular and atrial diameters were significantly greater in the "retrograde VTI growth" group. The ejection fraction and decrement in ejection fraction to preoperative parameters were significantly different between the two groups. (p = 0.001 and 0.003). Ventilation times were longer in the retrograde VTI group. The postoperative vs. baseline delta VTI ratio of the hepatic vein correlated with positive fluid balance, maximum central venous pressure, and ejection fraction. (B = -0.099, 95% CI = -0.022-0.002, p = 0.022, B = 0.011, 95% CI = 0.001-0.021, p = 0.022, B = 0.091, 95% CI = 0.052-0.213, p = 0.002, respectively.) Conclusion: The increase of the retrograde hepatic flow during the first 24 h following cardiac surgery was associated with positive fluid balance and the decrease of the right ventricular function. Measurement of venous congestion or venous abdominal insufficiency seems to be a useful tool in guiding fluid therapy and hemodynamic management.

Fluid management in acute kidney injury: from evaluating fluid responsiveness towards assessment of fluid tolerance

Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.

[Pathophysiology of septic shock]

Sepsis and septic shock result from an inadequate host response to an infection, which causes organ dysfunction. The progression of this condition is manifested by the occurrence of successive clinical stages, resulting from the systemic inflammatory response secondary to the activation of different inflammatory mediators, leading to organ dysfunction. There is a high burden of evidence on the role of endotoxin in the pathogenesis of sepsis and its crucial role in triggering the inflammatory response in sepsis caused by gram-negative bacteria. The coagulation cascade activation in sepsis patients is part of the host's adaptive immune response to infection. The endothelium is the main target in sepsis, which is metabolically active and can.