Performance and Interpretation of Sonography in the Practice of Nephrology: Core Curriculum 2024.

Ultrasonography is increasingly being performed by clinicians at the point of care, and nephrologists are no exception. This Core Curriculum illustrates how ultrasonography can be incorporated into clinical decision making across the spectrum of kidney disease to optimize the care nephrologists provide to patients. Sonography is valuable in outpatient and inpatient settings for the diagnosis and management of acute and chronic kidney disease, evaluation of cystic disease, urinary obstruction, pain, hematuria, proteinuria, assessment of volume status, and in providing guidance for kidney biopsy. As kidney disease advances, ultrasound is useful in the placement and maintenance of temporary and permanent access for dialysis. After kidney transplantation, ultrasonography is critical for evaluation of allograft dysfunction and for biopsies. Sonography skills expedite patient care and enhance the practice of nephrology and are relatively easily acquired with training. It is our hope that this curriculum will encourage nephrologists to learn and apply this valuable skill.

Point-of-care ultrasound in the practice of nephrology.

Sonography is increasingly being performed by clinicians and has applications throughout the spectrum of nephrology, including acute and chronic renal failure, urinary obstruction, cystic disease, pain, hematuria, transplantation, kidney biopsy, temporary and permanent vascular access, and assessment of fluid status. The skill is relatively easily acquired, expedites patient care, and enhances the practice of nephrology. However, the lack of exposure in most training programs remains a major obstacle.

An integrated pathology and ultrasonography-based simulation for training in performing kidney biopsy
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BACKGROUND: Medical practice trends and limitations in trainees' duty hours have diminished the interest and exposure of nephrology fellows to percutaneous kidney biopsy (PKB). We hypothesized that an integrated nephrology-pathology-led simulation may be an effective educational tool. MATERIALS AND METHODS: A 4-hour PKB simulation workshop (KBSW), led by two ultrasonography (US)-trained nephrologists and two nephropathologists, consisted of 6 stations: 1) diagnostic kidney US with live patients, 2) kidney pathology with plasticine models of embedded torso cross-sections, 3) US-based PKB with mannequin (Blue Phantom™), 4) kidney pathology with dissected cadavers, 5) US-based PKB in lightly-embalmed cadavers, and 6) tissue retrieval adequacy examination by microscope. A 10-question survey assessing knowledge acquisition and procedural confidence gain was administered pre- and post-KBSW. RESULTS: 21 participants attended the KBSW and completed the surveys. The overall percentage of correct answers to knowledge questions increased from 55 to 83% (p = 0.016). The number of "extremely confident" answers increased from 0 - 5% to 19 - 28% in all 4 questions (p = 0.02 - 0.04), and the number of "not at all confident" answers significantly decreased from 14 - 62% to 0 - 5% in 3 out of 4 questions (p = 0.0001 - 0.03). Impact of the imparted training on subsequent practice pattern was not assessed. CONCLUSION: A novel KBSW is an effective educational tool to acquire proficiency in PKB performance and could help regain interest among trainees in performing PKBs.
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Vessel Mapping for Dialysis Access Planning.

The population of patients with end-stage renal disease (ESRD) in the United States is progressively increasing, with hemodialysis (HD) as the major mode of renal replacement therapy. National guidelines recommend increasing the use of arteriovenous fistulae (AVF) in both incident and prevalent hemodialysis patients. Pre-operative vascular mapping prior to the surgical creation of an AVF is now considered standard of care and may be helpful in achieving these goals. This manuscript focuses on the advantages and limitations of the various imaging techniques currently available for vessel mapping including physical examination, ultrasonography, angiography (iodinated contrast vs. CO2 ), and magnetic resonance angiography (MRA), with specific suggestions for clinical use.

Management of vascular access inflow-outflow imbalance: A bimodal approach.

A more accurate descriptive and clinically useful diagnosis based upon pathophysiology for what is commonly referred to as venous outflow stenosis is inflow-outflow imbalance. In these cases, the total outflow capacity of the AV access is inadequate to handle the inflow volume (Qa) without an increase in pressure. The relative inadequacy of the access outflow capacity in comparison to Qa results in increased outflow resistance and a proportional increase in intraluminal pressure. The clinical indicators associated with venous stenosis are the resulting manifestations of this imbalance. The point at which this occurs is dependent upon variations in these two parameters-Qa and outflow resistance. The variations in these two parameters are considerable and reciprocal. Excessive Qa results in or can lead to an entire list of serious problems that adversely affect patient morbidity and mortality. Most studies dealing with AV access Qa reduction have been for the treatment of an existing condition rather than its prevention; however, prevention of disease rather than waiting for its development is an important tenet of medical practice. The resulting clinical picture of inflow-outflow imbalance is taken as an indication for corrective treatment. In the past, in most cases this has meant angioplasty to open the outflow if it is reduced; however, this clinical picture may be associated with an excessive Qa and angioplasty in these cases creates the risk for a further increase in Qa. It is the authors' opinion that access flow measurements should be a part of the evaluation of these cases prior to planning treatment. Using this information, a bimodal approach to primary treatment should be adopted involving either angioplasty for cases with a low or normal Qa or flow reduction in cases with an elevated Qa.

Catheter dysfunction: the role of lock solutions.

Vascular access dysfunction is a major cause of morbidity in hemodialysis (HD) patients. An upper extremity autogenous arteriovenous fistula (AVF) that preferentially involves the cephalic vein is the access of choice for HD patients, followed by autogenous AVF utilizing the basilic vein and the use of prosthetic arteriovenous grafts (AVGs). Despite these recommendations, central venous catheter (CVC) use is widespread among both incident and prevalent HD patients. Long-term use of CVCs for HD is complicated by a high rate of infection and thrombus-related dysfunction. Catheter locking solutions have been used both prophylactically and therapeutically for catheter thrombosis as well as catheter-related infections, with varying degrees of success. This review aims to address the different catheter locking solutions, their advantages and disadvantages, and new directions in this field.

Cannulating the hemodialysis access through a stent graft - is it advisable?

Pseudoaneurysms frequently develop at cannulation sites in arteriovenous grafts. The current treatment options are either open surgical revision or endovascular placement of stents to cover the pseudoaneurysm. The ideal treatment option needs to be individualized based on the clinical assessment and the involved risks with the procedure. The safety of cannulating the dialysis access through a stent graft for hemodialysis has not been conclusively established and needs to be avoided when possible. This case report emphasizes the hazards associated with cannulation of stent grafts, including stent fracture and leakage of blood into the surrounding tissue with recurrence of pseudoaneurysm.

Point-of-care ultrasonography in nephrology comes of age.

The physical exam is changing. Many have argued that the physical exam of the 21st century should include point-of-care ultrasound (POCUS). POCUS is being taught in medical schools and has been endorsed by the major professional societies of internal medicine. In this review we describe the trend toward using POCUS in medicine and describe where the practicing nephrologist fits in. We discuss what a nephrologist's POCUS exam should entail and we give special attention to what nephrologists can gain from learning POCUS. We suggest a 'nephro-centric' approach that includes not only ultrasound of the kidney and bladder, but of the heart, lungs and vascular access. We conclude by reviewing some of the sparse data available to guide training initiatives and give suggested next steps for advancing POCUS in nephrology.

Clinical Aspects of Dialysis Interventions: Physical and Sonographic Findings.

Physical examination (PE) of arteriovenous access remains of high clinical value and continues to be recommended by leading societies and guidelines. PE is easy to learn and perform. Once learned, examiners can provide a comprehensive arteriovenous (AV) access examination in 20 to 30 seconds. Therefore, we continue to advocate that AV access PE should be part of the training for all dialysis care providers. Similarly, ultrasound can provide important AV access evaluation and provide key information. It is relatively cheap and can be readily available at the bed side. Additionally, it is well accepted by patients, as it is not expected to be associated with pain or discomfort during the examination. We present in this review the key components of PE, signs and symptoms of AV access dysfunction, and the role of ultrasound in AV access evaluation as a complementary tool to PE.

Avoiding a cutdown--use of the transcatheter extractor in removal of tunneled dialysis catheters.

The purpose of our study was to evaluate the use of a transcatheter extractor (TCE) device in removing cuffed tunneled dialysis catheters without a surgical cutdown. We report eight cases where a TCE was used to successfully remove cuffed tunneled dialysis catheters through the exit site that would have otherwise required a second incision. The cuff was above the clavicle in all cases and varied 3-5 cm from the exit site. The method included inserting the device over the catheter through the exit site and engaging it over the cuff. A to-and-fro motion was then used in the same plane as the catheter to dissect the cuff from the surrounding tissue. Once the cuff was freed, the catheter was removed easily without resistance. The fibrous cuff was removed intact in all cases. We conclude that the use of this device may help avoid a cutdown and minimize trauma to the patient. It is an effective technique to remove tunneled dialysis catheters and is particularly useful in catheters with ingrown cuffs further from the exit site.

Ultrasound-based simulation for cannulation in outpatient hemodialysis units: An educational protocol.

Portable ultrasounds are often referred to as the "new stethoscope." Their portability and affordability have led to improved diagnostic capabilities at the point of care in virtually every field of medicine, and hemodialysis access is no exception. However, though ultrasonography is increasingly used throughout the spectrum of hemodialysis access, its role in outpatient dialysis units in the United States has been limited so far. This may, in part, be due to limited ultrasound exposure, knowledge, and training of dialysis staff. This article details an educational protocol including hands-on simulation for training dialysis technicians and nurses in ultrasound-guided cannulation techniques.

Lung Ultrasound: A "Biomarker" for Fluid Overload?

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

Implementation of an Electronic Catheter Checklist in Outpatient Hemodialysis Facilities: Results of a Pilot Quality Improvement Project.

Background: Performing catheter-care observations in outpatient hemodialysis facilities are one of the CDC's core interventions, which have been proven to reduce bloodstream infections. However, staff have many competing responsibilities. Efforts to increase and streamline the process of performing observations are needed. We developed an electronic catheter checklist, formatted for easy access with a mobile device, and conducted a pilot project to determine the feasibility of implementing it in outpatient dialysis facilities. Methods: The tool contained the following content: (1) patient education videos; (2) catheter-care checklists (connection, disconnection, and exit-site care); (3) prepilot and postpilot surveys; and (4) a pilot implementation guide. Participating hemodialysis facilities performed catheter-care observations on either a weekly or monthly schedule and provided feedback on implementation of the tool. Results: The pilot data were collected from January 6 through March 12, 2020, at seven participating facilities. A total of 954 individual observations were performed. The catheter-connection, disconnection, and exit-site steps were performed correctly for most individual steps; however, areas for improvement were (1) allowing for appropriate antiseptic dry time, (2) avoiding contact after antisepsis, and (3) applying antibiotic ointment to the exit site. Postpilot feedback from staff was mostly favorable. Use of the electronic checklists facilitated patient engagement with staff and was preferred over paper checklists, because data are easily downloaded and available for use in facility Quality Assurance and Performance Improvement (QAPI) meetings. The educational video content was a unique learning opportunity for both patients and staff. Conclusions: Converting the CDC's existing catheter checklists to electronic forms reduced paperwork and improved the ease of collating data for use during QAPI meetings. An additional benefit was the educational content provided on the tablet, which was readily available for viewing by patients and staff while in the hemodialysis facility.

Ultrasound in dialysis access: Opportunities and challenges.

Sonography is increasingly being used by nephrologists and the field of dialysis access is no exception. Advances in technology have allowed the addition of this universally available, portable, non-invasive tool to the nephrologist's armamentarium, which provides information on both morphology and physiology without the need for contrast or radiation. Ultrasound may be used across the spectrum of dialysis access, including central venous catheter placements, vascular mapping, regional anesthesia, creation, maintenance and assessment of hemodialysis access as well as assessment of the abdominal wall and peritoneal dialysis catheter placements. However, the lack of exposure in most training programs limits incorporation of routine use of ultrasounds in nephrology practice. As our specialty embarks on the ultrasound revolution, a two-pronged approach is essential to provide ample training opportunities while ensuring establishment of basic standards for training and competency.

Interventional Nephrology: Opportunities and Challenges.

The nephrologist has a pivotal role as the leader of multidisciplinary teams to optimize vascular access care of the patient on dialysis and to promote multidisciplinary collaboration in research, training, and education. The continued success of interventional nephrology as an independent discipline depends on harnessing these efforts to advance knowledge and encourage innovation. A comprehensive curriculum that encompasses research from bench to bedside coupled with standardized clinical training protocols are fundamental to this expansion. As we find ourselves on the threshold of a much-awaited revolution in nephrology, there is great opportunity but also formidable challenges in the field - it is up to us to work together to realize the enormous potential of our discipline.

The Nephrologist as an Ultrasonographer.

Ultrasonography is increasingly being used in the practice of nephrology, whether it is for diagnosis or management of acute or chronic kidney dysfunction, until progression to end-stage kidney disease, including preoperative assessment, access placement, and diagnosis and management of dysfunctional hemodialysis access. Point-of-care ultrasounds are also being used by nephrologists to help manage volume status, especially in patients admitted to the intensive care units, and more recently, for guiding fluid removal in the outpatient dialysis units. Fundamental knowledge of sonography has become invaluable to the nephrologist, and performance and interpretation of ultrasound has now become an essential tool for practicing nephrologists to provide patient-centered care, maximize efficiency, and minimize fragmentation of care. This review will address the growing role of ultrasonography in the management of a patient with CKD from the point of initial contact with the nephrologist throughout the spectrum of kidney disease and its consequences.

Patient selection, education, and cannulation of percutaneous arteriovenous fistulae: An ASDIN White Paper.

End-stage kidney disease patients who are candidates for surgical arteriovenous fistula creation commonly experience obstacles to a functional surgical arteriovenous fistula, including protracted wait time for creation, poor maturation, and surgical arteriovenous fistula dysfunction that can result in significant patient morbidity. The recent approval of two endovascular devices designed to create a percutaneous arteriovenous fistula enables arteriovenous fistula creation to be placed in the hands of interventionalists, thereby increasing the number of arteriovenous fistula providers, reducing wait times, and allowing the patient to avoid surgery. Moreover, current studies demonstrate that patients with percutaneous arteriovenous fistula experience improved time to arteriovenous fistula maturation. Yet, in order to realize the potential advantages of percutaneous arteriovenous fistula creation within our hemodialysis patient population, it is critical to select appropriate patients, ensure adequate patient and dialysis unit education, and provide sufficient instruction in percutaneous arteriovenous fistula cannulation and monitoring. In this White Paper by the American Society of Diagnostic and Interventional Nephrology, experts in interventional nephrology, surgery, and interventional radiology convened and provide recommendations on the aforementioned elements that are fundamental to a functional percutaneous arteriovenous fistula.