Assessment of Glomerular Filtration Rate in Patients with Cancer: A Statement from the American Society of Onco-Nephrology.

Accurate assessment of glomerular filtration rate (GFR) is crucial to guiding drug eligibility, dosing of systemic therapy, and minimizing the risks of both undertreatment and toxicity in patients with cancer. Up to 32% of cancer patients have baseline chronic kidney disease (CKD), and both malignancy and treatment may cause kidney injury and subsequent CKD. To date, there has been lack of guidance to standardize approaches to GFR estimation in the cancer population. In this two-part statement from the American Society of Onco-Nephrology, we present key messages for estimation of GFR in patients with cancer, including the choice of GFR estimating equation, use of race and body surface-area (BSA)-adjustment, and anticancer drug dose-adjustment in the setting of CKD. These key messages are based on a systematic review of studies assessing GFR estimating equations using serum creatinine and cystatin C in patients with cancer, against a measured GFR comparator. The preponderance of current data involving validated GFR estimating equations involves the CKD-EPI equations, with 2,508 patients in whom CKD-EPI using serum creatinine and cystatin C was assessed (8 studies) and 15,349 in whom CKD-EPI with serum creatinine was assessed (22 studies). The former may have improved performance metrics and be less susceptible to shortfalls of eGFR using serum creatinine alone. Since included studies were moderate quality or lower, the ASON Position Committee rated the certainty of evidence as low. Additional studies are needed to assess the accuracy of other validated eGFR equations in patients with cancer. Given the importance of accurate and timely eGFR assessment we advocate for the use of validated GFR estimating equations incorporating both serum creatinine and cystatin C in patients with cancer. Measurement of GFR via exogenous filtration markers should be considered in patients with cancer for whom eGFR results in borderline eligibility for therapies or clinical trials.

Cancer therapy in patients with reduced kidney function.

Chronic Kidney Disease (CKD) and cancer constitute two major public health burdens and are on the rise. Moreover, the number of patients affected simultaneously by both conditions is growing. Potential nephrotoxic effect of cancer therapies is particularly important for patients with CKD, as they are also affected by several comorbidities. Therefore, administering the right therapy at the right dose for patients with decreased kidney function can represent a daunting challenge. We review in detail the renal toxicities of anti-cancer therapies i.e. conventional chemotherapy, targeted therapy, immune checkpoint inhibitors, and radioligand therapies, issue recommendations for patient monitoring along with guidance on when to withdraw treatment and suggest dosage guidelines for select agents in advanced stage CKD. Various electrolytes disturbances can occur as the result of the administration of anti-cancer agents in the patient with decreased kidney function. These patients are prone to developing hyponatremia, hyperkalemia, and other metabolic abnormalities because of a decreased GFR. Therefore, all electrolytes, minerals and acid base status should be checked at baseline and before each administration of chemotherapeutic agents. Moreover, studies on patients on kidney replacement therapy (KRT) are very limited and only single cases or small case series are published. Therefore, clinical therapeutical decisions in cancer patients with decreased function should be made by multidisciplinary teams constituted of medical oncologists, nephrologists, and other specialists. Onconephrology is an evolving and expanding subspecialty. It is crucial to consider anticancer drug treatment in these patients and offer them a chance to be treated effectively.

Acute kidney disease beyond day 7 after major surgery: a secondary analysis of the EPIS-AKI trial.

PURPOSE: Acute kidney disease (AKD) is a significant health care burden worldwide. However, little is known about this complication after major surgery. METHODS: We conducted an international prospective, observational, multi-center study among patients undergoing major surgery. The primary study endpoint was the incidence of AKD (defined as new onset of estimated glomerular filtration rate (eCFR) < 60 ml/min/1.73 m2 present on day 7 or later) among survivors. Secondary endpoints included the relationship between early postoperative acute kidney injury (AKI) (within 72 h after major surgery) and subsequent AKD, the identification of risk factors for AKD, and the rate of chronic kidney disease (CKD) progression in patients with pre-existing CKD. RESULTS: We studied 9510 patients without pre-existing CKD. Of these, 940 (9.9%) developed AKD after 7 days of whom 34.1% experiencing an episode of early postoperative-AKI. Rates of AKD after 7 days significantly increased with the severity (19.1% Kidney Disease Improving Global Outcomes [KDIGO] 1, 24.5% KDIGO2, 34.3% KDIGO3; P < 0.001) and duration (15.5% transient vs 38.3% persistent AKI; P < 0.001) of early postoperative-AKI. Independent risk factors for AKD included early postoperative-AKI, exposure to perioperative nephrotoxic agents, and postoperative pneumonia. Early postoperative-AKI carried an independent odds ratio for AKD of 2.64 (95% confidence interval [CI] 2.21-3.15). Of 663 patients with pre-existing CKD, 42 (6.3%) had worsening CKD at day 90. In patients with CKD and an episode of early AKI, CKD progression occurred in 11.6%. CONCLUSION: One in ten major surgery patients developed AKD beyond 7 days after surgery, in most cases without an episode of early postoperative-AKI. However, early postoperative-AKI severity and duration were associated with an increased rate of AKD and early postoperative-AKI was strongly associated with AKD independent of all other potential risk factors.

Effect of Remote and Virtual Technology on Home Dialysis.

In the United States, regulatory changes dictate telehealth activities. Telehealth was available to patients on home dialysis as early as 2019, allowing patients to opt for telehealth with home as the originating site and without geographic restriction. In 2020, coronavirus disease 2019 was an unexpected accelerant for telehealth use in the United States. Within nephrology, remote patient monitoring has most often been applied to the care of patients on home dialysis modalities. The effect that remote and virtual technologies have on home dialysis patients, telehealth and health care disparities, and health care providers' workflow changes are discussed here. Moreover, the future use of remote and virtual technologies to include artificial intelligence and artificial neural network model to optimize and personalize treatments will be highlighted. Despite these advances in technology challenges continue to exist, leaving room for future innovation to improve patient health outcome and equity. Prospective studies are needed to further understand the effect of using virtual technologies and remote monitoring on home dialysis outcomes, cost, and patient engagement.

Optimizing peritoneal dialysis catheter placement.

Long-term success of peritoneal dialysis as a kidney replacement therapy requires a well-functioning peritoneal dialysis catheter. With ongoing reductions in infectious complications, there is an increased emphasis on the impact of catheter-related and mechanical complications. There is currently a marked variation in the utilization of various types of catheters (double cuff vs single cuff, coiled tip vs straight tip), methods of catheter insertion (advanced laparoscopic, open surgical dissection, image guided percutaneous, blind percutaneous), timing of catheter insertion, location of catheter placement (pre-sternal v. abdominal) and peri-operative practices. Specialized approaches to catheter placement in clinical practice include use of extended catheters and embedded catheters. Marked variations in patient lifestyle preferences and comorbidities, specifically in high acuity patient populations (polycystic kidney disease, obesity, cirrhosis) necessitate individualized approaches to catheter placement and care. Current consensus guidelines recommend local procedural expertise, consideration of patient characteristics and appropriate resources to support catheter placement and long-term functioning. This review focuses on an overview of approaches to catheter placement with emphasis on a patient-centered approach.

Standardization of Nomenclature for the Mechanisms and Materials Utilized for Extracorporeal Blood Purification.

In order to develop a standardized nomenclature for the mechanisms and materials utilized during extracorporeal blood purification, a consensus expert conference was convened in November 2022. Standardized nomenclature serves as a common language for reporting research findings, new device development, and education. It is also critically important to support patient safety, allow comparisons between techniques, materials, and devices, and be essential for defining and naming innovative technologies and classifying devices for regulatory approval. The multidisciplinary conference developed detailed descriptions of the performance characteristics of devices (membranes, filters, and sorbents), solute and fluid transport mechanisms, flow parameters, and methods of treatment evaluation. In addition, nomenclature for adsorptive blood purification techniques was proposed. This report summarizes these activities and highlights the need for standardization of nomenclature in the future to harmonize research, education, and innovation in extracorporeal blood purification therapies.

Acute kidney injury in neurocritical care.

Approximately 20% of patients with acute brain injury (ABI) also experience acute kidney injury (AKI), which worsens their outcomes. The metabolic and inflammatory changes associated with AKI likely contribute to prolonged brain injury and edema. As a result, recognizing its presence is important for effectively managing ABI and its sequelae. This review discusses the occurrence and effects of AKI in critically ill adults with neurological conditions, outlines potential mechanisms connecting AKI and ABI progression, and highlights AKI management principles. Tailored approaches include optimizing blood pressure, managing intracranial pressure, adjusting medication dosages, and assessing the type of administered fluids. Preventive measures include avoiding nephrotoxic drugs, improving hemodynamic and fluid balance, and addressing coexisting AKI syndromes. ABI patients undergoing renal replacement therapy (RRT) are more susceptible to neurological complications. RRT can negatively impact cerebral blood flow, intracranial pressure, and brain tissue oxygenation, with effects tied to specific RRT methods. Continuous RRT is favored for better hemodynamic stability and lower risk of dialysis disequilibrium syndrome. Potential RRT modifications for ABI patients include adjusted dialysate and blood flow rates, osmotherapy, and alternate anticoagulation methods. Future research should explore whether these strategies enhance outcomes and if using novel AKI biomarkers can mitigate AKI-related complications in ABI patients.

Digital health and acute kidney injury: consensus report of the 27th Acute Disease Quality Initiative workgroup.

Acute kidney injury (AKI), which is a common complication of acute illnesses, affects the health of individuals in community, acute care and post-acute care settings. Although the recognition, prevention and management of AKI has advanced over the past decades, its incidence and related morbidity, mortality and health care burden remain overwhelming. The rapid growth of digital technologies has provided a new platform to improve patient care, and reports show demonstrable benefits in care processes and, in some instances, in patient outcomes. However, despite great progress, the potential benefits of using digital technology to manage AKI has not yet been fully explored or implemented in clinical practice. Digital health studies in AKI have shown variable evidence of benefits, and the digital divide means that access to digital technologies is not equitable. Upstream research and development costs, limited stakeholder participation and acceptance, and poor scalability of digital health solutions have hindered their widespread implementation and use. Here, we provide recommendations from the Acute Disease Quality Initiative consensus meeting, which involved experts in adult and paediatric nephrology, critical care, pharmacy and data science, at which the use of digital health for risk prediction, prevention, identification and management of AKI and its consequences was discussed.

Changes in Doppler-Derived Kidney Venous Flow and Adverse Cardiorenal Outcomes in Patients With Heart Failure.

Background The impact of changes in Doppler-derived kidney venous flow in heart failure (HF) is not well studied. We aimed to investigate the association of Doppler-derived kidney venous stasis index (KVSI) and intrakidney venous-flow (IKVF) patterns with adverse cardiorenal outcomes in patients with HF. Methods and Results In this observational cohort study, consecutive inpatients with HF referred to a nephrologist because of a history of diuretic resistance and abnormal kidney function (n=216) underwent spectral kidney assessments after admission (Doppler 1) and 25 to 35 days later (Doppler 2) to identify IKVF patterns (continuous/pulsatile/biphasic/monophasic) and KVSI levels. Cox proportional hazard regression models were used to evaluate the associations between KVSI/IKVF patterns at Doppler 1 as well as changes from Doppler 1 to Doppler 2 and risk of cardiorenal events up to 18 months after admission. Worsening HF or death occurred in 126 patients. Both baseline KVSI (hazard ratio [HR], 1.49 [95% CI, 1.37-1.61] per 0.1-unit increase) and baseline IKVF pattern (HR, 2.47 [95% CI, 2.01-3.04] per 1 pattern severity increase) were significantly associated with worsening HF/death. Increases in both KVSI and IKVF pattern severity from Doppler 1 to 2 were also associated with an increased risk of worsening HF/death (HR, 3.00 [95% CI, 2.08-4.32] per 0.1-unit increase change; and HR, 6.73 [95% CI, 3.27-13.86] per 1 pattern increase in severity change, respectively). Similar results were observed for kidney outcomes. Conclusions Baseline kidney venous flow predicted adverse cardiorenal events, and inclusion of serial kidney venous flow in cardiorenal risk stratification could facilitate clinical decision-making for patients with HF. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03039959.

Treatment Guidelines for Hyponatremia: Stay the Course.

International guidelines designed to minimize the risk of complications that can occur when correcting severe hyponatremia have been widely accepted for a decade. On the basis of the results of a recent large retrospective study of patients hospitalized with hyponatremia, it has been suggested that hyponatremia guidelines have gone too far in limiting the rate of rise of the serum sodium concentration; the need for therapeutic caution and frequent monitoring of the serum sodium concentration has been questioned. These assertions are reminiscent of a controversy that began many years ago. After reviewing the history of that controversy, the evidence supporting the guidelines, and the validity of data challenging them, we conclude that current safeguards should not be abandoned. To do so would be akin to discarding your umbrella because you remained dry in a rainstorm. The authors of this review, who represent 20 medical centers in nine countries, have all contributed significantly to the literature on the subject. We urge clinicians to continue to treat severe hyponatremia cautiously and to wait for better evidence before adopting less stringent therapeutic limits.

Acquired Disorders of Hypomagnesemia.

Magnesium disorders are common in clinical practice and when present can manifest clinically as cardiovascular, neuromuscular, or other organ dysfunction. Hypomagnesemia is far more common than hypermagnesemia, which is largely seen in patients with reduced glomerular filtration rates receiving magnesium-containing medications. In addition to inherited disorders of magnesium handling, hypomagnesemia is also seen with excessive gastrointestinal or renal losses and due to medications such as amphotericin B, aminoglycosides, and cisplatin. Laboratory assessment of body magnesium stores largely relies on the measurement of serum magnesium levels that are a poor proxy for total body stores but does correlate with the development of symptoms. Replacement of magnesium can be challenging, with oral replacement strategies being generally more effective at slowly replacing body stores but intravenous replacement being more effective at treating the more life-threatening and severe cases of hypomagnesemia. We conducted a thorough review of the literature using PubMed (1970-2022) and the search terms magnesium, hypomagnesemia, drugs, medications, treatment, and therapy. In the absence of clear data on optimal management of hypomagnesemia, we have made recommendations on magnesium replacement based on our clinical experience.

Rationale for a New Classification of Solutes of Interest in Chronic Kidney Disease and Hemodialysis.

A hallmark of chronic kidney disease is the retention of solutes that normally are eliminated by the kidneys. The current classification defines uremic toxins based on molecular weight and protein affinity. The retention of solutes is already detected in the early stages of the disease when patients are pauci-symptomatic or asymptomatic but the role of therapies to retard the loss of kidney function in patients with chronic kidney disease (e.g., modulators of the renin-angiotensin-aldosterone system, sodium-glucose cotransporter inhibitors) in reducing uremic toxins is poorly understood. Most of the research evaluating the impact of therapies to lower serum concentrations of those toxic compounds is carried out in patients with kidney failure already undergoing kidney replacement therapy. The removal of those molecules relies in physicochemical mass transfer phenomena, i.e., adsorption, diffusion, and convection. In the past 2 decades, the rise and broad adoption of blood purification strategies with enhanced convective properties, such as high-volume online hemodiafiltration and expanded hemodialysis, considerably amplified the ability to mechanically extract middle molecules (molecular weight >0.5 kDa) from the blood compartment. Nonetheless, the classification of uremic toxins has not evolved in parallel with dialysis advancements. Mounting evidence demonstrates the link between middle molecules with uremic symptoms, cardiovascular and mortality risks. An urgent need for updating the classification exists. Defining the causative relationship between specific solutes and specific clinical outcomes will promote the development of targeted therapies. In parallel, the inclusion of new pertinent dimensions to the classification like the influence of new dialysis membranes, sorbents, and intestinal chelators in the concentration of uremic toxins would improve the understanding of the pathogenesis of chronic kidney disease, setting the pace for future research in nephrology.

Outcomes associated with acute kidney disease: A systematic review and meta-analysis.

Background: Acute kidney disease (AKD) defines the period after kidney damage and it is a critical period of both repair and fibrotic pathways. However, the outcomes of patients with AKD have not been well-defined. Methods: In this meta-analysis, PubMed, Embase, Cochrane and China National Knowledge Infrastructure were searched on July 31,2022. We excluded studies including patients undergoing kidney replacement therapy at enrollment. The data was used to conduct a random-effects model for pool outcomes between patients with AKD and non-AKD (NKD). This study is registered with PROSPERO, CRD 42021271773. Findings: The search generated 739 studies of which 21 studies were included involving 1,114,012 patients. The incidence rate of community-acquired AKD was 4.60%, 2.11% in hospital-acquired AKD without a prior AKI episode, and 26.11% in hospital-acquired AKD with a prior AKI episode. The all-cause mortality rate was higher in the AKD group (26.54%) than in the NKD group (7.78%) (odds ratio [OR]: 3.62, 95% confidence interval [CI]: 2.64 to 4.95, p < 0.001, I2 = 99.11%). The rate of progression to end-stage kidney disease (ESKD) was higher in the AKD group (1.3%) than in the NKD group (0.14%) (OR: 6.58, p < 0.001, I2 = 94.95%). The incident rate of CKD and progressive CKD was higher in the AKD group (37.2%) than in the NKD group (7.45%) (OR:4.22, p < 0.001, I2 = 96.67%). Compared to the NKD group, patients with AKD without prior AKI had a higher mortality rate (OR: 3.00, p < 0.001, I2 = 99.31%) and new-onset ESKD (OR:4.96, 95% CI, p = 0.002, I2 = 97.37%). Interpretation: AKD is common in community and hospitalized patients who suffer from AKI and also occurs in patients without prior AKI. The patients with AKD, also in those without prior AKI had a higher risk of mortality, and new-onset ESKD than the NKD group. Funding: This study was supported by Ministry of Science and Technology (MOST) of the Republic of China (Taiwan) [grant number, MOST 107-2314-B-002-026-MY3, 108-2314-B-002-058, 110-2314-B-002-241, 110-2314-B-002-239], National Science and Technology Council (NSTC) [grant number, NSTC 109-2314-B-002-174-MY3, 110-2314-B-002-124-MY3, 111-2314-B-002-046, 111-2314-B-002-058], National Health Research Institutes [PH-102-SP-09], National Taiwan University Hospital [109-S4634, PC-1246, PC-1309, VN109-09, UN109-041, UN110-030, 111-FTN0011] Grant MOHW110-TDU-B-212-124005, Mrs. Hsiu-Chin Lee Kidney Research Fund and Chi-mei medical center CMFHR11136. JAN is supported, in part, by grants from the National Institute of Health, NIDDK (R01 DK128208 and P30 DK079337) and NHLBI (R01 HL148448-01).

Critical Appraisal of Limitations in the Current Definition/Classification of Uremic Toxins.

Progress in the identification and characterization of uremic retention solutes has refined our understanding of the pathophysiology of the uremic syndrome. Furthermore, the evolution of dialysis and other techniques designed to remove uremic retention solutes offers opportunities to provide a more personalized and targeted treatment for patients with chronic kidney disease (CKD) with an aim to improve outcomes. Considering these developments, a consensus report was recently published that readdressed the 2003 definition and classification of uremic toxins and formulated recommendations for future research to enhance the understanding of uremic retention solutes. In the present work, the authors of a work group that contributed to the consensus report provide a more detailed rationale for the recommendations related to their theme "Critical appraisal of limitations in the current definition/classification of uremic toxins." In summary, the authors propose that the current definition of uremic toxins should remain organized on hemodialysis strategies, membranes, and removal patterns since hemodialysis is the most frequently applied therapeutic strategy to reduce their concentration in advanced CKD. Nevertheless, the work group also acknowledges that any classification based on cutoff values and/or molecular spatial configurations is arbitrary and will likely need to be changed with therapeutic advancements. Furthermore, the current physicochemical classification might be extended to reflect the degree of toxicity of a specific toxin that is likely to support more personalized and targeted dialysis prescriptions and improve the outcomes for patients with CKD.