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.

Point-of-care ultrasonography spotlight: Could venous excess ultrasound serve as a shared language for internists and intensivists?

Point-of-care ultrasonography (POCUS), particularly venous excess ultrasound (VExUS) is emerging as a valuable bedside tool to gain real-time hemodynamic insights. This modality, derived from hepatic vein, portal vein, and intrarenal vessel Doppler patterns, offers a scoring system for dynamic venous congestion assessment. Such an assessment can be crucial in effective management of patients with heart failure exacerbation. It facilitates diagnosis, quantification of congestion, prognostication, and monitoring the efficacy of decongestive therapy. As such, it can effectively help to manage cardiorenal syndromes in various clinical settings. Extended or eVExUS explores additional veins, potentially broadening its applications. While VExUS demonstrates promising outcomes, challenges persist, particularly in cases involving renal and liver parenchymal disease, arrhythmias, and situations of pressure and volume overload overlap. Proficiency in utilizing spectral Doppler is pivotal for clinicians to effectively employ this tool. Hence, the integration of POCUS, especially advanced applications like VExUS, into routine clinical practice necessitates enhanced training across medical specialties.

Unlocking the Potential of VExUS in Assessing Venous Congestion: The Art of Doing It Right.

BACKGROUND: Congestion, marked by elevated cardiac filling pressures and their repercussions, is a contributing factor to morbidity and mortality in heart failure and critical illness. Relying on traditional methods for bedside evaluation often leads to inadequate decongestion and increased hospital readmissions. Point-of-care ultrasound (POCUS), particularly multi-organ POCUS, including the Venous Excess Ultrasound (VExUS) score, offers a promising approach in this scenario. VExUS enables the quantification of systemic venous congestion, aiding in fluid overload states by assessing inferior vena cava and venous Doppler waveforms. SUMMARY: This comprehensive review delves into the latest developments in comprehending and evaluating congestion, shedding light on technical intricacies to enhance the effective application of VExUS. Recent studies emphasize the importance of evaluating signs of hemodynamic congestion before administering intravenous fluids, highlighting the concept of "fluid tolerance." Moreover, VExUS-guided decongestion significantly improves decongestion rates in acute decompensated heart failure patients with acute kidney injury. Newer studies also highlight the prognostic implications of VExUS in the general ICU cohorts not confining to cardiac surgery patients. However, performing VExUS without understanding technical pitfalls may lead to clinical errors. Technical considerations in performing VExUS include nuances related to inferior vena cava and internal jugular vein ultrasound and familiarity with Doppler principles, optimal settings, and artifacts. Additionally, local structural alterations such as those seen in liver and kidney disease impact Doppler waveforms, emphasizing the need for careful interpretation. KEY MESSAGE: Overall, VExUS presents a valuable tool for assessing congestion and guiding management, provided clinicians are familiar with its technical complexities and interpret findings judiciously.

Hepato-Cardio-Renal Syndrome.

Hepatorenal syndrome has conventionally been regarded as a multisystem syndrome in which pathophysiologic pathways that link cirrhosis with impairment in kidney function are followed by dysfunction of several organs such as the heart. The advances in cardiac studies have helped diagnose more subtle cardiac abnormalities that would have otherwise remained unnoticed in a significant subset of patients with advanced liver disease and cirrhosis. Accumulating data suggests that in many instances, the cardiac dysfunction precedes and predicts development of kidney disease in such patients. These observations point to the heart as a key player in hepatorenal syndrome and challenge the notion that the cardiac abnormalities are either the consequence of aberrancies in hepatorenal interactions or have only minor effects. As such, the disturbances traditionally bundled within hepatorenal syndrome may indeed represent a hepatic form of cardiorenal syndrome whereby the liver affects the kidney in part through cardiorenal pathways (that is, hepato-cardio-renal syndrome).

Best Practices for Point of Care Ultrasound: An Interdisciplinary Expert Consensus.

Despite the growing use of point of care ultrasound (POCUS) in contemporary medical practice and the existence of clinical guidelines addressing its specific applications, there remains a lack of standardization and agreement on optimal practices for several areas of POCUS use. The Society of Point of Care Ultrasound (SPOCUS) formed a working group in 2022 to establish a set of recommended best practices for POCUS, applicable to clinicians regardless of their training, specialty, resource setting, or scope of practice. Using a three-round modified Delphi process, a multi-disciplinary panel of 22 POCUS experts based in the United States reached consensus on 57 statements in domains including: (1) The definition and clinical role of POCUS; (2) Training pathways; (3) Credentialing; (4) Cleaning and maintenance of POCUS devices; (5) Consent and education; (6) Security, storage, and sharing of POCUS studies; (7) Uploading, archiving, and reviewing POCUS studies; and (8) Documenting POCUS studies. The consensus statements are provided here. While not intended to establish a standard of care or supersede more targeted guidelines, this document may serve as a useful baseline to guide clinicians, leaders, and systems considering initiation or enhancement of POCUS programs.

Effectiveness of a Brief Point of Care Ultrasound Course at a National Nephrology Conference.

The rising demand for point of care ultrasound (POCUS) instruction during nephrology fellowship has been limited due to a shortage of trained faculty and courses designed specifically for nephrologists. A hands-on POCUS pre-course was organized during the April 2023 National Kidney Foundation (NKF) Spring Clinical Meeting to address this challenge. The course consisted of pre-recorded lectures and a 4-hour hands-on workshop guided by multidisciplinary POCUS experts. The anonymous post-course survey received responses from 25 out of 39 participants, yielding a 64.1% response rate. On a scale of 0-10, confidence levels for acquiring kidney images rose from 2.6 + 2.3 (mean + SD) pre-workshop to 7.8 + 1.5 post-workshop (p<0.001). Similarly, a remarkable improvement in confidence for acquiring lung and cardiac images was seen as scores increased from 1.8 + 2.4 to 7.7 + 1.5 (p<0.001) and from 1.5 + 2.2 to 7.2 + 1.3 (p<0.001), respectively. Additionally, respondents reported a substantial improvement in their confidence to interpret kidney, lung, and cardiac POCUS images, with scores increasing from 4.5 + 2.2 to 7.7 + 1.1 (p<0.001), 2.3 + 2.4 to 7.6 + 1.5 (p<0.001), and 2 + 2 to 7.3 + 1.5 (p<0.001), respectively. Barriers to implementing POCUS use at institutions included a perceived lack of trained faculty, limited protected time for faculty, and insufficient support from division leadership. The NKF POCUS pre-course successfully improved participants' confidence in acquiring and interpreting basic POCUS images.

VExUS to Guide Ultrafiltration in Hemodialysis: Exploring a Novel Dimension of Point of Care Ultrasound.

Venous Excess Ultrasound (VExUS) is a valuable bedside tool for nephrologists within a multi-organ point of care ultrasound (POCUS) framework. VExUS can address limitations of conventional physical examination in identifying hemodynamic congestion and monitoring treatment efficacy. A 53-year-old man with heart failure and end-stage kidney disease on hemodialysis presented with elevated liver function tests. Despite an unremarkable right upper quadrant ultrasound done by radiology, the review of images by the nephrology team uncovered severe venous congestion, evidenced by a dilated inferior vena cava (IVC) and abnormal hepatic and portal vein flow. Follow-up assessments included VExUS scans and daily ultrafiltration that resulted in a notable 8-liter fluid removal. The dynamic changes in IVC shape and improvement in Doppler waveforms underscored successful decongestion. This case demonstrates the clinical utility of VExUS in guiding therapy for fluid overload in complex patients.

Seeing beneath the surface: Harnessing point-of-care ultrasound for internal jugular vein evaluation.

Point-of-care ultrasound (POCUS) of the internal jugular vein (IJV) offers a non-invasive means of estimating right atrial pressure (RAP), especially in cases where the inferior vena cava is inaccessible or unreliable due to conditions such as liver disease or abdominal surgery. While many clinicians are familiar with visually assessing jugular venous pressure through the internal jugular vein, this method lacks sensitivity. The utilization of POCUS significantly enhances the visualization of the vein, leading to a more accurate identification. It has been demonstrated that combining IJV POCUS with physical examination enhances the specificity of RAP estimation. This review aims to provide a comprehensive summary of the various sonographic techniques available for estimating RAP from the internal jugular vein, drawing upon existing data.

Cardiorenal Interactions in Acute Heart Failure: Renal Proximal Tubules in the Spotlight.

BACKGROUND: The maladaptive neurohormonal activation, an integral mechanism in the pathophysiology of heart failure (HF) and cardiorenal syndrome, has a profound impact on renal sodium handling. Congestion is the primary reason for hospitalization of patients with HF and the main target of therapy. As sodium is the main determinant of extracellular volume, the goal is to enhance urinary sodium excretion in order to address excess fluid. The interventions to increase natriuresis have conventionally focused on distal nephron as the primary segment that counterbalances the effects of loop diuretics. SUMMARY: Recent developments in the field of cardiorenal medicine have resulted in a shift of attention to renal proximal tubules (e.g., emerging evidence on proximal tubular dysfunction beyond handling of sodium). Herein, we discuss the three main mechanisms of sodium transport in the proximal tubules with emphasis on their intrinsic links to one another as well as to more distal transporters of sodium. Then, we provide an overview of the findings of the most recent clinical studies that have tried to enhance the conventional decongestive strategies through simultaneous blockade of these mechanisms. KEY MESSAGE: Interventions aiming at renal proximal tubules have the potential to significantly improve our ability to decongest patients with acute HF.