Point-of-care ultrasonography in nephrology: Growing applications, misconceptions and future outlook

Abstract

Ultrasound has long been an essential tool in nephrology, traditionally used for procedures like vascular access and kidney biopsies. Point-of-care ultrasonography (POCUS), a rapidly evolving bedside technology, is now gaining momentum in nephrology by providing real-time imaging to enhance physical examination findings. Unlike comprehensive radiology-performed ultrasound, POCUS focuses on specific clinical questions, providing immediate and actionable insights. This narrative review examines the philosophy behind POCUS, its expanding applications in nephrology, and its impact on patient care, including its role in diagnosing obstructive uropathy, guiding fluid management, and evaluating hemodynamics in cardiorenal syndrome. Additionally, the review addresses barriers to widespread adoption, such as the need for structured training, competency validation, and interdisciplinary cooperation. By integrating POCUS into routine practice, nephrologists can refine diagnostic accuracy, improve patient outcomes, and strengthen the role of bedside medicine.

Key Words: Point-of-care ultrasonography; Nephrology; Fluid management; Hemodynamic assessment; Competency assessment; Bedside diagnostics

Core Tip: Point-of-care ultrasonography (POCUS) holds transformative potential in nephrology by enhancing diagnostic accuracy and guiding the management of complex hemodynamic derangements, which often overlap with conditions that nephrologists are consulted for, such as acute kidney injury, renal replacement therapy, and electrolyte disorders. Unlike traditional imaging, POCUS provides real-time, bedside insights that enhance clinical decision-making. However, widespread adoption requires structured training, competency validation, and collaboration with other specialties. Overcoming these barriers will help integrate POCUS into routine nephrology practice, ultimately improving patient care and outcomes.

INTRODUCTION

Ultrasound has been an important imaging tool in nephrology since the specialty’s early days. Traditionally, it has been used to guide procedures such as hemodialysis catheter placement and kidney biopsies, as well as to assess kidney morphology[1]. In certain countries and regions, nephrologists are also responsible for hemodialysis vascular access care, where Doppler ultrasound plays a crucial role in both planning access placement and managing vascular access dysfunction[2]. Point-of-care ultrasonography (POCUS) is an emerging bedside tool in nephrology, intended to complement physical examination findings with real-time ultrasound information. Unlike a comprehensive examination performed by the radiology department, POCUS is used to address focused clinical questions and is typically performed by the physician who is directly taking care of the patient[3,4]. The widespread availability of ultrasound equipment, especially hand-held and portable cart-based machines, along with the pioneering efforts of physicians in emergency medicine, has significantly contributed to the growing popularity of POCUS and the recognition of its clinical value across various specialties, including nephrology[4,5]. This narrative review aims to discuss the philosophy behind POCUS and highlight its applications and benefits in nephrology as well as common misconceptions and challenges for further advancements and mass adoption.

THE PHYSICAL EXAM: AN ART IN NEED OF A MODERN TOUCH

While it’s true that physical exam skills may be diminishing, especially among younger doctors[6,7], clinicians also frequently overestimate the diagnostic accuracy of traditional physical exam findings[8]. Although methodical history-taking and physical exams remain valuable, many of the so-called ‘classic signs’ were identified during a time when effective treatments were unavailable, and 'late-stage' disease presentations were the norm. As a result, most classic signs and symptoms tend to lack sensitivity, though some may be quite specific[6]. Even with Laennec’s revolutionary invention of the stethoscope which went on to become the symbol of the medical profession, many auscultation findings face the same issue: A recent meta-analysis on the diagnostic accuracy of lung auscultation for common acute pulmonary conditions like congestive heart failure, pneumothorax, or obstructive lung disease found an overall sensitivity of just 0.37, although specificity remained high at 0.89[9]. Even seasoned cardiologists often struggle with the low sensitivity of cardiac auscultation for detecting valvular heart disease, a condition usually identified by cardiac murmurs[10].

Physical exam also proves inadequate for hemodynamic assessment, often referred to as ‘volume status assessment’, which is a vital skill for nephrologists. Studies dating back over thirty years have consistently highlighted this issue. For instance, clinical evaluation showed less than 50% accuracy in diagnosing extracellular fluid volume depletion as the cause of hyponatremia in a study involving non-edematous patients[11]. On similar lines, in a population of heart failure patients, where filling pressures were invasively determined, 44% of patients with pulmonary capillary wedge pressures ≥ 22 mmHg did not have evidence of clinical congestion (rales, peripheral edema and/or elevated jugular venous pressure)[12]. Likewise, lung crackles, whether alone or combined with peripheral edema, have been shown to poorly reflect interstitial lung edema in end-stage renal disease patients when compared to lung ultrasound (LUS)[13]. It’s imperative that we need better tools for the hemodynamic evaluation of the increasingly complex patients we encounter in our daily practice.

POCUS: UNDERSTANDING THE RATIONALE AND RECOGNIZING ITS POTENTIAL

POCUS involves the acquisition, interpretation, and immediate clinical integration of ultrasonographic imaging performed by the treating clinician at the patient’s bedside[4]. It is often described as the 5^th pillar of physical examination in addition to inspection, auscultation, percussion, and palpation[14]. Although commonly misunderstood, POCUS is not intended to replace comprehensive diagnostic ultrasounds performed by radiologists or cardiologists, nor is it a substitute for imaging techniques like computed tomography scans. Instead, it enhances the sensitivity of the traditional physical exam, allowing clinicians to answer specific questions at the bedside[4,5]. That said, in certain scenarios, POCUS may reduce the need for additional diagnostic tests, potentially lowering healthcare costs when focused questions are adequately addressed. Indeed, POCUS should NOT be performed without a focused clinical question in mind[15]. Examples of such questions include: “Is obstructive uropathy the cause of acute kidney injury in this patient?”, “Why is my patient hypotensive during dialysis?” or “Is pulmonary edema the cause of the dyspnea of my patient?”.

It has been reported that even medical students with limited POCUS training have better diagnostic accuracy with hand-held ultrasound than physical exam performed by senior cardiologists for common cardiac pathologies[16]. Remarkably, ultrasound has over 90% sensitivity and specificity for the diagnosis of commonly encountered pathologies such as pulmonary edema, pleural effusion, or left ventricular (LV) dysfunction[4,17], a substantial improvement compared to conventional physical exam alone. These findings are very relevant for nephrologists who must use this information for clinical decision-making such as diuretic therapy titration or ultrafiltration orders. It must be emphasized that POCUS’s utility is not limited to diagnosis. This tool is also very useful for evaluating the response to therapeutic interventions such as fluid therapy or ultrafiltration by monitoring dynamic sonographic parameters[18]. Furthermore, POCUS enables clinicians to perform advanced hemodynamic assessments, such as evaluating LV filling pressures or detecting end-organ dysfunction from congestion, provided the user has appropriate training[19].

All of these characteristics facilitate real-time decision-making at the bedside, reducing fragmentation of care, allowing clinicians to order fewer tests, and being more efficient and confident in their management of the patient[20,21]. Indeed, contrary to most technological advances in medicine, POCUS is a tool that puts the clinician back at the bedside and at the same time, improves patient satisfaction[22]. It is important to remember that clinical judgment must always guide decision-making. As the saying goes, ‘a fool with a stethoscope will remain a fool with an ultrasound’. POCUS users should be mindful of the cognitive biases, such as the steep curve of the Dunning-Kruger effect where less experienced users may feel more confident than experts due to their inability to recognize their own limitations[23]. They should also avoid making decisions based on a single finding and instead perform multi-organ assessments to minimize the risk of confounding[19,24]. Additionally, POCUS users must recognize when a more comprehensive evaluation is necessary, for example, a consultative echocardiogram for complex valvular disorders.

CLINICAL APPLICATIONS OF POCUS IN NEPHROLOGY

While it may appear that POCUS is only useful for acute or critical care patients, this couldn’t be further from the truth. POCUS usefulness is ubiquitous across the entire clinical landscape of nephrology (Figure 1). In hemodialysis patients, it can be used to titrate dry weight or evaluate causes of hypotension during dialysis[25,26]. It can also be used to troubleshoot vascular access problems, such as helping dialysis staff with cannulation, assessing fistula maturation, or differentiating hematomas from other causes of tumefaction[27]. Additionally, in peritoneal dialysis patients, POCUS aids in diagnosing and differentiating between types of catheter-related infections (e.g., exit-site vs tunnel infection) and in monitoring the treatment response[28,29]. After a kidney transplant, POCUS can be used to assess graft perfusion and exclude vascular thrombosis, especially in cases of delayed graft function and/or if a comprehensive Doppler ultrasound by radiology is not immediately available[15]. Additionally, hemodynamic assessment is one of the most challenging aspects of nephrology, where POCUS excels. Multi-organ ultrasound, including that of the lungs, kidneys, heart, and Doppler interrogation of systemic veins, is valuable in evaluating “prerenal” (more precisely “hemodynamic”) acute kidney injury and managing cardiorenal patients. We will briefly discuss each component with a focus on practical applications.

Figure 1 Point-of-care ultrasonography use-cases in nephrology. Some examples of nephrology-related clinical questions that can be answered using point-of-care ultrasonography. The asterisk indicates advanced sonographic applications requiring a higher operator skill level/additional training. Reproduced from Koratala et al[58]. COVID-19: Coronavirus disease 2019; LV: Left ventricle; LVH: Left ventricular hypertrophy; IVC: Inferior vena cava; RV: Right ventricle; AKI: Acute kidney injury. Citation: Koratala A, Reisinger N. POCUS for Nephrologists: Basic Principles and a General Approach. Kidney360 2021; 2: 1660-1668. Copyright © 2021 by the American Society of Nephrology. Published by Wolters Kluwer Health, Inc. The authors have obtained the permission for figure using (Supplementary material).

LUS

Traditionally, LUS was considered impossible due to air scattering ultrasound waves, hindering the evaluation of underlying tissues. This notion was challenged in the 1990s by Lichtenstein[30], a French critical care physician, who pioneered point-of-care LUS and demonstrated the clinical value of various ultrasound artifacts generated by air and its interaction with lung water. An intriguing aspect of LUS is that it primarily relies on these artifacts rather than direct anatomical imaging, meaning most images lack a direct clinical-anatomical correlation (except when the lung is consolidated/hepatized). Therefore, the selected imaging preset should have all image-enhancing software, such as harmonics, turned off to ensure that ultrasound artifacts are not reduced or eliminated[25]. LUS is associated with various patterns and signs, with the most clinically relevant ones included in the Bedside LUS in Emergency protocol. This clinical algorithm helps manage critical care patients with dyspnea, demonstrating that common conditions like pneumothorax and pneumonia can be rapidly diagnosed using LUS[31].

For nephrologists, mastering LUS is crucial as it is highly sensitive in detecting tissue congestion, including cardiogenic pulmonary edema and pleural effusion[32]. The learning curve is relatively shallow, images are straightforward to acquire, it is highly reproducible across physicians[33], and it can be performed quickly in any setting with (almost) any ultrasound device[30]. Normal lung ultrasonography is characterized by the presence of pleural sliding, which is the movement of the visceral pleura over the parietal pleura, and horizontal A-lines (Figure 2A). These A-lines are a reverberation artifact originating from the pleural line, indicating a normally aerated lung. Pleural effusion is typically identified in the thoracic posterolateral region of a supine patient by detecting an anechoic (black) effusion in the pleural space[30] (Figure 2B). Additionally, LUS can be used to estimate the volume of the effusion[34].

Figure 2 Basic lung ultrasound findings. A: Normal lung ultrasound demonstrating A-lines (horizontal hyperechoic artifacts); B: Pleural effusion (“a”) appearing as an anechoic area above the liver. Arrow points to atelectatic lung; C: B-lines-vertical hyperechoic artifacts emerging from the pleural line indicative of interstitial thickening (typically from fluid); D: Interstitial pneumonia with confluent B-lines and an irregular pleural line. Arrow points to subpleural consolidation.

Ultrasound B-lines, which appear as vertical hyperechoic lines, are ringdown artifacts originating from the pleural line and move with lung sliding[35]. They occur when the interlobular septa and surrounding tissue thicken or become fluid-filled, making them highly sensitive indicators of interstitial syndrome or pulmonary edema[36]. B-lines correlate semi-quantitatively with the amount of extravascular lung water[32] and are a reliable marker of increased LV filling pressures[37]. Typically, B-lines extend from the pleural line to the end of the screen, erasing A-lines or making them less prominent[38] (Figure 2C). Several LUS protocols have been designed to detect pulmonary edema, varying in the number of scanning zones used. Clinically, the presence of two or more positive zones - defined as three or more B-lines per intercostal space - on both sides is strongly indicative of interstitial syndrome[39]. Of note, B-lines are not exclusive to cardiogenic pulmonary edema; they can also be observed in conditions such as interstitial pneumonia, lung fibrosis, and alveolar hemorrhage. Figure 2D illustrates an image from a patient with COVID-19 pneumonia, showing confluent B-lines (fused together) and an irregular pleural line with subpleural consolidation. In contrast, cardiogenic pulmonary edema in a patient without parenchymal lung disease typically presents with a regular-appearing pleural line. A clinical trial tested a LUS-guided treatment strategy in high cardiovascular-risk hemodialysis patients and found that it effectively relieved lung congestion, reduced the risk of repeated hospitalizations for decompensated heart failure, and resulted in less intradialytic hypotension[37].

FOCUSED CARDIAC ULTRASOUND

The interaction between the heart and kidneys is well established, with nephrologists playing a key role in managing cardiorenal syndrome, given the rising prevalence of both cardiovascular disease and chronic kidney disease (CKD). While hemodynamic factors clearly explain the impact of acute dysfunction in one organ on the other, non-hemodynamic factors like neurohumoral overactivation and inflammatory pathways also contribute to chronic injury in both organs and are integral to the pathophysiology of this syndrome[40]. Cardiovascular disorders, including heart failure, atherosclerotic coronary artery disease, and valvular disorders, are highly prevalent in CKD patients[41,42]. Conversely, patients with heart failure are at increased risk for kidney injury, particularly in acute settings[43]. As such, focused cardiac ultrasound (FoCUS) can be a valuable adjunct for nephrologists in day-to-day practice. It enables bedside evaluation of key morphologic and functional parameters that can significantly impact the management of a patient’s clinical condition.

Basic FoCUS can help answer common focused questions such as: ‘Does the patient have LV systolic dysfunction?’, ‘Is there right ventricular (RV) dysfunction?’, or ‘Is there a pericardial effusion?’. Figure 3 illustrates the basic cardiac views. An LV ejection fraction < 50% is the hallmark of heart failure with reduced ejection fraction, a relatively common comorbidity in CKD patients and the elderly[44,45]. Assessing cardiac pump function can help figure out the potential cause of acute kidney injury in acute decompensated heart failure or intradialytic hypotension in chronic hemodialysis patients. It’s relatively straightforward since it relies on qualitative LV function assessment and not precise measurements. By observing endocardial movement, mitral valve leaflet excursion, and myocardial thickness, LV systolic function can be visually estimated and categorized as hyperdynamic, normal, reduced, or severely reduced[46].

Figure 3 Focused cardiac ultrasound views. A: Parasternal long axis; B: parasternal short axis; C: Apical four-chamber; D: Subxiphoid; E: Inferior vena cava. Green arrows indicate the direction of the transducer orientation marker. Reproduced from Argaiz et al[59]. IVC: Inferior vena cava; LA: Left atrium; LV: Left ventricle; RA: Right atrium; RV: Right ventricle. Citation: Argaiz ER, Koratala A, Reisinger N. Comprehensive Assessment of Fluid Status by Point-of-Care Ultrasonography. Kidney360 2021; 2: 1326-1338. Copyright © 2021 by the American Society of Nephrology. Published by Wolters Kluwer Health, Inc. The authors have obtained the permission for figure using (Supplementary material).

Many heart failure patients have preserved ejection fraction, where the primary issue lies in elevated filling pressures on both sides of the heart. This results in pulmonary and venous congestion, affecting abdominal organs, including the kidneys [see venous excess ultrasound (VExUS) section]. In this context, assessing RV size and function alongside inferior vena cava (IVC) diameter and collapsibility provides valuable insights. Notably, RV dilation and dysfunction are not exclusive to volume overload. For instance, in patients with acute dyspnea, RV dysfunction may signal a massive pulmonary embolism requiring urgent thrombolysis. In such cases, nephrologists performing POCUS can also detect deep vein thrombosis in the lower extremity. For patients with subacute peripheral congestion and RV dysfunction, more aggressive diuresis may be necessary. However, in conditions such as chronic pulmonary hypertension with tricuspid regurgitation, achieving a “normal” RV size or IVC diameter may be neither feasible nor desirable. Multiple views should be utilized to minimize bias, comparing the RV to the LV and assessing septal motion. Similar to LV evaluation, a qualitative approach is effective for estimating RV function[46]. Ultimately, POCUS must always be interpreted in the appropriate clinical context, as the same finding can have different management implications.

The reported prevalence of pericardial effusion in CKD patients varies significantly, ranging from 2% to 62% in the literature. This condition may arise due to the accumulation of uremic toxins or insufficient dialysis leading to generalized fluid overload[47]. While it may cause chest pain, most patients with low-volume or slowly developing effusions are asymptomatic, and physical signs are often insensitive. However, rapid accumulation, such as from hemorrhage, can lead to cardiac tamponade even if the size is small. If a nephrologist can diagnose pericardial effusion early, appropriate interventions can be implemented - patients with advanced CKD can start dialysis, chronic hemodialysis patients can adjust their dialysis prescription to increase ultrafiltration and efficacy, and anticoagulation may be paused to prevent cardiac tamponade[48]. A recent study demonstrated that FoCUS, when performed by non-cardiologists, achieved excellent diagnostic accuracy (> 95%) in detecting left and RV systolic dysfunction, as well as pericardial effusion[49]. Like other aspects of POCUS, FoCUS should be used to answer specific clinical questions, and its findings must be interpreted within the patient’s clinical context, alongside physical exam results, biochemical markers, and other sonographic findings. The goal is not to replace comprehensive echocardiography performed by cardiologists; any significant finding that needs further evaluation or uncertain findings should prompt a referral for a full echocardiogram. Nephrologists with advanced echocardiography training can take FoCUS further, assessing stroke volume, estimating pulmonary artery pressure, and evaluating diastolic dysfunction, all of which can aid in managing complex cases.

VEXUS

Increased cardiac filling pressures are a key pathophysiologic change in heart failure. The backward transmission of this pressure to the systemic and pulmonary venous systems leads to classic signs and symptoms of congestion. When elevated central venous pressure (CVP) extends to abdominal organs and impedes venous outflow, it can cause dysfunction, such as liver and kidney injury. The term ‘congestive nephropathy’ has been suggested to describe this mechanism, which combines increased filling pressures, reduced venous compliance, and renal interstitial edema—leading to a condition akin to tamponade within the encapsulated kidney[50,51]. VExUS has emerged as a tool to assess venous congestion in the abdominal compartment, particularly relevant in right-sided heart failure. It involves measuring IVC diameter and collapsibility, as well as evaluating Doppler waveforms of the hepatic, portal, and renal parenchymal veins.

IVC diameter and respiratory variation are widely used as surrogate markers for CVP. Current guidelines state that an IVC diameter greater than 2.1 cm with less than 50% collapsibility during inspiration indicates elevated right atrial pressure between 10 and 20 mmHg[52]. However, it is crucial to note that IVC dilation can occur due to conditions unrelated to hypervolemia, such as severe tricuspid regurgitation, pulmonary hypertension, pneumothorax, pulmonary embolism, cardiac tamponade, or even in physiologic states like in young athletes. Therefore, using IVC ultrasound alone, without incorporating FoCUS and LUS, is strongly discouraged, as it may lead to inappropriate clinical decisions. Evaluating the IVC is the initial step in assessing venous congestion, as elevated CVP is a key determinant of this condition. Visualizing the IVC in both long and short axis planes can help minimize measurement errors[53-55]. VExUS involves Doppler evaluation of the hepatic, portal, and intrarenal veins to quantify venous congestion as described in Figure 4. Since these waveforms are dynamic, VExUS enables monitoring the effectiveness of decongestive therapy. This is valuable for nephrologists who must make decisions about fluid removal in non-ICU and clinic patients where invasive hemodynamic monitoring is not available. Figure 5 illustrates a case where these waveforms showed improvement with treatment visually guiding the clinician. On the other hand, each Doppler parameter has its limitations. For example, hepatic vein flow may be abnormal at baseline in severe tricuspid regurgitation; the absence of a simultaneous electrocardiogram can lead to significant interpretive errors; portal vein flow may appear more pulsatile in chronic liver disease; and renal venous flow can be abnormal in advanced CKD and technically challenging to assess due to patient breathing[56]. Thus, it is crucial to perform a multiorgan POCUS and integrate all clinical and biochemical information.

Figure 4 Venous excess ultrasound grading score. When inferior vena cava has a diameter > 2 cm, hepatic, portal, and rein vein waveforms should be checked. The abnormalities present in these venous Doppler waveforms correlate with the severity of congestion. Hepatic vein Doppler is considered mildly abnormal when the S wave is smaller than the D wave, but still below the baseline; it is considered severely abnormal when the S wave is reversed. Portal vein Doppler is considered mildly abnormal when the pulsatility is 30%-50%, and severely abnormal when it is ≥ 50%. Intrarenal vein Doppler is mildly abnormal when it is pulsatile with distinct S and D components, and severely abnormal when it is monophasic with a D-only pattern. This figure was adapted from NephroPOCUS.com with permission. The corresponding author Koratala A is the owner of the website and copyright holder[60]. See: https://nephropocus.com/about/.

Figure 5 Doppler venous waveforms showing improvement (from top to bottom) in a patient with acute kidney injury and hyponatremia. In a physiological state, the hepatic vein Doppler resembles the central venous waveform, with a larger S-wave compared to the D-wave. As right atrial pressure (RAP) increases, the S-wave amplitude decreases and eventually reverses, leaving only the D-wave below the baseline. Normally, the portal vein flow is continuous (less than 30% pulsatility), but pulsatility increases with rising RAP, eventually leading to late-systolic flow reversal (below-baseline flow). Increased portal vein pulsatility may indicate gut congestion, potentially affecting diuretic absorption. The renal parenchymal vein, typically continuous (like the portal vein but below the baseline), becomes more pulsatile with increasing RAP, eventually showing distinct S- and D-waves with S-reversal similar to the hepatic vein. Generally, improvements in the portal vein precede those in the hepatic and renal veins, as shown above. Renal interstitial edema may delay recovery of the venous waveform. Reproduced from Koratala et al[61]. AP: Assessment and plan; S-wave: Systolic wave; D-wave: Diastolic wave. Citation: Koratala A, Ronco C, Kazory A. Multi-Organ Point-Of-Care Ultrasound in Acute Kidney Injury. Blood Purif 2022; 51: 967-971. Copyright © 2022 S. Karger AG. Published by Karger Publishers. The authors have obtained the permission for figure using (Supplementary material).

OVERCOMING BARRIERS TO POCUS ADOPTION: CHALLENGES, MISCONCEPTIONS, AND THE PATH FORWARD

Performing POCUS requires access to ultrasound equipment, but this has become less of a hurdle due to the increasing availability of portable and ultra-portable devices, as well as the potential to bill for the studies depending on institutional infrastructure and local regulations. However, the challenge of providing adequate training for nephrologists to perform and interpret POCUS findings remains significant. Currently, the number of nephrologists trained in multi-organ POCUS is very limited, often necessitating reliance on workshops and courses to build skills in image acquisition and interpretation. While these educational opportunities are valuable for beginners, offering real-time feedback, they have limitations, including being resource-intensive and challenging to scale for larger groups. Books, blogs, and social media can also aid in learning and dissemination but lack the hands-on training necessary for proficiency[57]. Inadequate skills and reliance on isolated sonographic parameters, such as IVC or LUS, without comprehensive clinical context, can lead to potential patient harm (Figure 6).

Figure 6 Pitfalls of excessive reliance on individual organ ultrasound and knee-jerk clinical decision-making. Comprehensive bedside hemodynamic evaluation should almost always involve focused cardiac ultrasound, interpreting all these observations in the relevant clinical context. This applies to both initial diagnosis and monitoring selected parameters during follow-up examinations. ^*In intra-abdominal hypertension, inferior vena cava is small irrespective of central venous pressure and typically does not exhibit respiratory variation. Reproduced from Kazory et al[62]. IVC: Inferior vena cava; CVP: Central venous pressure. Citation: Kazory A, Olaoye OA, Koratala A. Nuances of Point-of-Care Ultrasound in Nephrology: A Clarion Call for Deeper Understanding. Blood Purif 2024; 53: 598-602. Copyright © 2024 S. Karger AG. Published by Karger Publishers. The authors have obtained the permission for figure using (Supplementary material).

As medical schools increasingly integrate POCUS into their curricula, more nephrology organizations are advocating for continuous POCUS training during fellowship and objective competency assessment[24,57]. Another barrier to adoption can be the concern about conflicts with radiologists or cardiologists, who may perceive nephrologists as encroaching on their expertise. However, the goal of POCUS is to provide a bedside, clinically oriented examination to address specific questions and guide management, while comprehensive evaluations by radiologists or cardiologists involve a detailed assessment of anatomical regions with predefined parameters and measurements. It is important to engage with these specialists at the institutional level to resolve issues and streamline processes. Additionally, these experts can serve as a quality check until a sufficient number of nephrologists proficient in POCUS are available at each institution. Without proper quality improvements and competency assessments, POCUS risks failing to deliver its full benefits to nephrologists.

Much of the skepticism about POCUS stems from a lack of robust evidence showing that it directly improves hard outcomes like mortality. We believe this perspective is flawed: A diagnostic tool alone cannot alter outcomes unless it is followed by effective treatment, just as a kidney biopsy alone does not improve outcomes in glomerulonephritis without subsequent treatment. POCUS enhances clinical practice by enabling real-time interpretation of pathophysiology at the bedside, allowing for more personalized treatment rather than applying a generic approach. In the modern era, dismissing a tool that improves diagnostic accuracy, accelerates care delivery, and enhances patient satisfaction based on its inability to directly improve mortality is not acceptable. Future research should explore the most effective applications of POCUS in nephrology-specific clinical scenarios and develop optimal management strategies based on its findings. Emphasis should be placed on practical outcomes, such as reducing time to accurate diagnosis, minimizing empiric therapies, decreasing recurrent hospitalizations, and enhancing patient understanding of their condition, rather than solely measuring its impact on mortality.

CONCLUSION

POCUS represents a significant advancement toward personalized medicine, and nephrologists should recognize the limitations of traditional physical examination and integrate POCUS into their practice. Its effectiveness relies not only on the operator’s ability to acquire images but also on their broader clinical expertise, as with any medical tool. To maximize its potential, POCUS should be backed by structured, ongoing training and clearly defined competency standards.