Portal Vein Doppler is a sensitive marker for evaluating venous congestion in End Stage Kidney Disease.

INTRODUCTION: Determining ultrafiltration volume in patients undergoing intermittent hemodialysis (IHD) is an essential component in the assessment and management of volume status. Venous Excess Ultrasound (VExUS) is a novel tool used to quantify the severity of venous congestion at the bedside. Given the high prevalence of pulmonary hypertension in patients with End Stage Kidney Disease (ESKD), venous Doppler could represent a useful tool to monitor decongestion in these patients. METHODS: This is a prospective observational study conducted in ESKD patients who were admitted to the hospital requiring IHD and Ultrafiltration. Inferior vena cava maximum diameter (IVCd), portal vein Doppler (PVD) and hepatic vein Doppler (HVD) were performed in all patients before and after a single IHD session. RESULTS: Forty-one patients were included. The prevalence of venous congestion was 88% based on IVCd and 63% based on portal vein pulsatility fraction (PVPF). Both mean IVCd and PVPF displayed a significant improvement after ultrafiltration. The percent decrease in PVPF was significantly larger than the percent decrease in IVCd. HVD alterations did not significantly improve after ultrafiltration. CONCLUSIONS: Our study revealed a high prevalence of venous congestion in hospitalized ESKD patients undergoing hemodialysis. After a single IHD session there was a significant improvement in both IVCd and PVPF. HVD showed no significant improvement with one IHD session. PVPF changes were more sensitive than IVCd changes during volume removal. This study suggests that, due to its rapid response to volume removal, PVD, among the various components of the venous excess ultrasound grading system, could be more effective in monitoring real-time decongestion in patients undergoing IHD.

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.

Dynamic changes of hepatic vein Doppler velocities predict preload responsiveness in mechanically ventilated critically ill patients.

BACKGROUND: Assessment of dynamic parameters to guide fluid administration is one of the mainstays of current resuscitation strategies. Each test has its own limitations, but passive leg raising (PLR) has emerged as one of the most versatile preload responsiveness tests. However, it requires real-time cardiac output (CO) measurement either through advanced monitoring devices, which are not routinely available, or echocardiography, which is not always feasible. Analysis of the hepatic vein Doppler waveform change, a simpler ultrasound-based assessment, during a dynamic test such as PLR could be useful in predicting preload responsiveness. The objective of this study was to assess the diagnostic accuracy of hepatic vein Doppler S and D-wave velocities during PLR as a predictor of preload responsiveness. METHODS: Prospective observational study conducted in two medical-surgical ICUs in Chile. Patients in circulatory failure and connected to controlled mechanical ventilation were included from August to December 2023. A baseline ultrasound assessment of cardiac function was performed. Then, simultaneously, ultrasound measurements of hepatic vein Doppler S and D waves and cardiac output by continuous pulse contour analysis device were performed during a PLR maneuver. RESULTS: Thirty-seven patients were analyzed. 63% of the patients were preload responsive defined by a 10% increase in CO after passive leg raising. A 20% increase in the maximum S wave velocity after PLR showed the best diagnostic accuracy with a sensitivity of 69.6% (49.1-84.4) and specificity of 92.8 (68.5-99.6) to detect preload responsiveness, with an area under curve of receiving operator characteristic (AUC-ROC) of 0.82 ± 0.07 (p = 0.001 vs. AUC-ROC of 0.5). D-wave velocities showed worse diagnostic accuracy. CONCLUSIONS: Hepatic vein Doppler assessment emerges as a novel complementary technique with adequate predictive capacity to identify preload responsiveness in patients in mechanical ventilation and circulatory failure. This technique could become valuable in scenarios of basic hemodynamic monitoring and when echocardiography is not feasible. Future studies should confirm these results.

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.

Portal Vein Doppler tracks volume status in patients with severe tricuspid regurgitation: A Proof-of-Concept Study.

BACKGROUND: 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 hemodynamics. 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: 42 patients with severe TR undergoing decongestive therapy were prospectively enrolled. Inferior vena cava diameter (IVCd), 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. RESULTS: 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). IRVD only improved in patients with concomitant improvement in severe TR. PVD was the only predictor of achieving ≥5 litres of negative fluid balance (AUC 0.83 p = 0.001). CONCLUSIONS: 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.

Bedside Ultrasound in the Management of Cardiorenal Syndromes: An Updated Review.

BACKGROUND: Cardiorenal syndromes constitute a spectrum of disorders involving heart and kidney dysfunction modulated by a complex interplay of neurohormonal, inflammatory, and hemodynamic derangements. The management of such patients often poses a diagnostic and therapeutic challenge to physicians owing to gaps in understanding of pathophysiology, paucity of objective bedside diagnostic tools, and individual biases. SUMMARY: In this narrative review, we discuss the role of clinician who performed bedside ultrasound in the management of patients with cardiorenal syndromes. Novel sonographic applications such as venous excess ultrasound score (VExUS) are reviewed in addition to the lung and focused cardiac ultrasound. Further, underrecognized causes of heart failure such as high-flow arteriovenous fistula are discussed. KEY MESSAGE: Bedside ultrasound allows a comprehensive hemodynamic characterization of cardiorenal syndromes.

Correlation of Internal Jugular Vein Collapsibility With Central Venous Pressure in Patients With Liver Cirrhosis.

We aimed to compare internal jugular vein and inferior vena cava ultrasonography as predictors of central venous pressure in cirrhotic patients. We performed ultrasound assessments of the internal jugular vein (IJV) and the inferior vena cava and then invasively measured central venous pressure (CVP). We then compared their correlation with CVP and performed area under the receiver operating characteristic curves to determine which had best sensitivity and specificity. IJV cross-sectional area collapsibility index at 30° correlated better with CVP ( r = -0.56, P < 0.001), and an IJV AP-CI at 30° ≤ 24.8% was better at predicting a CVP ≥8 mm Hg, with 100% sensitivity and 97.1% specificity. Thus, IJV point-of-care ultrasound might be superior than inferior vena cava point-of-care ultrasound as a predictor of CVP in cirrhotic patients.

The burden of chronic kidney disease in Mexico: data analysis based on the Global Burden of Disease 2021 study.

BACKGROUND: Chronic kidney disease (CKD) represents a substantial global burden of disease due to a lack of universal tests and misinterpretation of biomarkers. OBJECTIVE: To analyze CKD epidemiology in Mexico and guide public policies. MATERIAL AND METHODS: Data from the Global Burden of Disease (GBD) 2021 study were used to describe CKD prevalence and mortality in Mexico for the 1990-2021 period, stratifying by gender and age groups. RESULTS: The prevalence of CKD in Mexico in 2021 was 9,184.9 per 100,000 population. Diabetes was the most common cause of CKD, and CKD-related mortality was high, with an increase in 2019 and 2021, possibly as a consequence of the COVID-19 pandemic. CONCLUSIONS: CKD in Mexico entails a high burden of mortality and years of life lost, but it barely contributes to disability. It is essential to improve CKD early detection, access to treatments and coding of the causes of the disease. Moreover, investigating the causes of CKD of unknown etiology, including genetic factors, is crucial in order for specific treatments to be developed in the future.

ANTECEDENTES: La enfermedad renal crónica (ERC) representa una elevada carga global de enfermedad debido a la falta de pruebas universales y a la interpretación errónea de biomarcadores. OBJETIVO: Analizar la epidemiología de la ERC en México y orientar las políticas públicas. MATERIAL Y MÉTODOS: Se utilizaron los datos del estudio Global Burden of Disease (GBD) 2021 para describir la prevalencia y mortalidad de la ERC en México durante el periodo de 1990 a 2021, estratificando por sexo y grupos de edad. RESULTADOS: La prevalencia de la ERC en México en 2021 fue de 9184.9 por 100 000 habitantes. La diabetes constituyó la causa más común de ERC y la mortalidad por ERC fue elevada, se incrementó en 2019 y 2021, posiblemente debido a la pandemia de COVID-19. CONCLUSIONES: La ERC en México presenta una alta carga de mortalidad y años de vida perdidos, pero contribuye poco a la discapacidad. Es esencial mejorar la detección temprana de la ERC, el acceso a tratamientos y la codificación de las causas de la enfermedad. Además, investigar las causas de la ERC de etiología desconocida, incluidos factores genéticos, es crucial para desarrollar tratamientos específicos en el futuro.

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.

Point of care venous Doppler ultrasound: Exploring the missing piece of bedside hemodynamic assessment.

Accurate assessment of the hemodynamic status is vital for appropriate management of patients with critical illness. As such, there has been a constant quest for reliable and non-invasive bedside tools to assess and monitor circulatory status in order to ensure end-organ perfusion. In the recent past, point of care ultrasonography (POCUS) has emerged as a valuable adjunct to physical examination in various specialties, which basically is a clinician-performed bedside ultrasound to answer focused questions. POCUS allows visualization of the internal anatomy and flow dynamics in real time, guiding apt interventions. While both arterial (forward flow) and venous (organ outflow or afterload) limbs of hemodynamic circuit are important for tissue perfusion, the venous side remains relatively under-explored. With recent data underscoring the deleterious consequences of iatrogenic volume overload, objective evaluation of venous congestion is gaining attention. Bedside Doppler ultrasound serves this purpose and aids in diagnosing and monitoring the congestion/venous blood flow pattern. In this article, we summarize the rationale for integrating this technology into routine care of patients with volume-related disorders, discuss the normal and abnormal waveforms, limitations, and future directions.

VExUS Nexus: Bedside Assessment of Venous Congestion.

Organ dysfunction in the setting of heart failure is mainly determined by backward transmission of increased right atrial pressure. Although traditional point-of-care ultrasound applications such as inferior vena cava and lung ultrasound have been increasingly incorporated in the clinical care of congestive heart failure, they do not directly evaluate the hemodynamic consequences of high right atrial pressure on organ blood flow. Congestion induces alterations in the venous flow patterns of abdominal organs that can be readily assessed using Doppler imaging. These alterations have been consistently associated with congestive organ dysfunction and adverse clinical outcomes. In this article, we provide a comprehensive overview of the bedside assessment of venous congestion using Doppler imaging. The review focuses mainly on the normal and abnormal Doppler patterns of the hepatic, portal, and intrarenal veins along with clinical examples of how to incorporate this tool in the management of patients with venous congestion.

Role of KLHL3 and dietary K+ in regulating KS-WNK1 expression.

The physiological role of the shorter isoform of with no lysine kinase (WNK)1 that is exclusively expressed in the kidney (KS-WNK1), with particular abundance in the distal convoluted tubule, remains elusive. KS-WNK1, despite lacking the kinase domain, is nevertheless capable of stimulating the NaCl cotransporter, apparently through activation of WNK4. It has recently been shown that a less severe form of familial hyperkalemic hypertension featuring only hyperkalemia is caused by missense mutations in the WNK1 acidic domain that preferentially affect cullin 3 (CUL3)-Kelch-like protein 3 (KLHL3) E3-induced degradation of KS-WNK1 rather than that of full-length WNK1. Here, we show that full-length WNK1 is indeed less impacted by the CUL3-KLHL3 E3 ligase complex compared with KS-WNK1. We demonstrated that the unique 30-amino acid NH2-terminal fragment of KS-WNK1 is essential for its activating effect on the NaCl cotransporter and recognition by KLHL3. We identified specific amino acid residues in this region critical for the functional effect of KS-WNK1 and KLHL3 sensitivity. To further explore this, we generated KLHL3-R528H knockin mice that mimic human mutations causing familial hyperkalemic hypertension. These mice revealed that the KLHL3 mutation specifically increased expression of KS-WNK1 in the kidney. We also observed that in wild-type mice, the expression of KS-WNK1 was only detectable after exposure to a low-K+ diet. These findings provide new insights into the regulation and function of KS-WNK1 by the CUL3-KLHL3 complex in the distal convoluted tubule and indicate that this pathway is regulated by dietary K+ levels.NEW & NOTEWORTHY In this work, we demonstrated that the kidney-specific isoform of with no lysine kinase 1 (KS-WNK1) in the kidney is modulated by dietary K+ and activity of the ubiquitin ligase protein Kelch-like protein 3. We analyzed the role of different amino acid residues of KS-WNK1 in its activity against the NaCl cotransporter and sensitivity to Kelch-like protein 3.

Dynamic Changes in Portal Vein Flow during Decongestion in Patients with Heart Failure and Cardio-Renal Syndrome: A POCUS Case Series.

INTRODUCTION: Optimal method for noninvasive assessment of venous congestion remains an unresolved issue. Portal vein (PV) and intrarenal venous flow alterations are markers of abdominal venous congestion and have been associated with acute kidney injury (AKI) in cardiac surgery patients. It is currently unknown if portal vein flow (PVF) alterations in heart failure can be reversed with diuretic treatment and track decongestion. OBJECTIVE: The aim of this study is to evaluate PVF alterations in patients with ADHF at arrival and after decongestive treatment. METHODS: Assessment of venous congestion using point-of-care ultrasound was performed in 12 patients with ADHF (6 patients with left-sided heart failure and 6 patients with right-sided heart failure). Evaluation included inferior vena cava (IVC) size and collapsibility in addition to PV Doppler to determine pulsatility fraction (PF). RESULTS: Increased PV PF (81.75 ± 13%) was found on admission. After effective decongestive treatment, it improved to (17.43 ± 2.2%). Improvement in IVC size and collapsibility was seen in most patients with left-sided heart failure and none of the patients with right-sided heart failure. Improvement in PV PF coincided with return to baseline of Serum Cr in patients that presented with AKI. CONCLUSIONS: Evaluation of abdominal venous congestion by point-of-care ultrasound could aid in diagnosis and follow-up of patients with congestive kidney injury.

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.