Acute kidney disease and renal recovery: consensus report of the Acute Disease Quality Initiative (ADQI) 16 Workgroup. Nat Rev Nephrol. 2017;13:241-257. [PMID: 28239173 DOI: 10.1038/nrneph.2017.2]

Performance of urinary C-C motif chemokine ligand 14 and the renal resistive index in predicting persistent AKI

OBJECTIVES

The purpose of this study was to evaluate the performance of urinary C-C motif chemokine ligand 14 (CCL14) and the renal resistive index (RI) in predicting persistent AKI in unselected critically ill patients.

METHODS

This prospective observational study was conducted in a tertiary hospital's general intensive care unit (ICU). Consecutive adults who were admitted to the ICU were enrolled, with a primary endpoint of AKI lasting 48 h or longer. Urinary CCL14 was evaluated upon inclusion, and the renal RI was determined within 12 h of ICU admission. The individual discriminative ability of urinary CCL14 and the renal RI to predict persistent AKI was evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

Overall, 166 patients were included, of whom 56 had persistent AKI. Urinary CCL14 showed good ability to predict persistent AKI, with an AUC of 0.817. However, the overall performance of the renal RI was fair, with an AUC of 0.739. Forty-nine patients presented with mild AKI at inclusion, and the values of CCL14 were significantly lower than those of patients with moderate or severe AKI (0.205 [0.125-0.300] vs. 0.302 [0.157-0.501]; p = 0.034). In the subgroup analysis, although the diagnostic performance of CCL14 was excellent in patients with moderate or severe AKI, it was fair in patients with mild AKI [AUC = 0. 738; 95% confidence interval (CI) 0.593-0.853].

CONCLUSION

Urinary CCL14 was an excellent predictor of persistent AKI in patients with moderate or severe AKI, but its performance was not good in patients with mild AKI. The renal RI cannot discriminate between transient and persistent AKI.

Acute kidney disease in hospitalized pediatric patients: risk prediction based on an artificial intelligence approach

BACKGROUND

Acute kidney injury (AKI) and acute kidney disease (AKD) are prevalent among pediatric patients, both linked to increased mortality and extended hospital stays. Early detection of kidney injury is crucial for improving outcomes. This study presents a machine learning-based risk prediction model for AKI and AKD in pediatric patients, enabling personalized risk predictions.

METHODS

Data from 2,346 hospitalized pediatric patients, collected between January 2020 and January 2023, were divided into an 85% training set and a 15% test set. Predictive models were constructed using eight machine learning algorithms and two ensemble algorithms, with the optimal model identified through AUROC. SHAP was used to interpret the model, and an online prediction tool was developed with Streamlit to predict AKI and AKD.

RESULTS

The incidence of AKI and AKD were 14.90% and 16.26%, respectively. Patients with AKD combined with AKI had the highest mortality rate, at 6.94%, when analyzed by renal function trajectories. The LightGBM algorithm showed superior predictive performance for both AKI and AKD (AUROC: 0.813, 0.744). SHAP identified top predictors for AKI as serum creatinine, white blood cell count, neutrophil count, and lactate dehydrogenase, while key predictors for AKD included proton pump inhibitor, blood glucose, hemoglobin, and AKI grade.

CONCLUSION

The high incidence of AKI and AKD among hospitalized children warrants attention. Renal function trajectories are strongly associated with prognosis. Supported by a web-based tool, machine learning models can effectively predict AKI and AKD, facilitating early identification of high-risk pediatric patients and potentially improving outcomes.

Clinical impact of Wnt5a expression on persistence of acute kidney injury in patients with urosepsis

Abnormal Wnt5a expression is associated with dysregulated inflammation and organ dysfunction. However, the effect of Wnt5a activation on the duration of organ dysfunction remains unclear. This prospective study investigated the association between Wnt5a levels and persistent acute kidney injury (AKI) in patients with urosepsis. Serum creatinine and Wnt5a levels were measured on days 1 and 5 and at discharge in 87 patients diagnosed with urosepsis. Patients with urosepsis were classified into an improving acute kidney injury (AKI) group and a persistent or worsening AKI group according to the AKI stage on days 1 and 5. AKI recovery was defined as a discharge-to-baseline serum creatinine ratio of <1.5. Twenty-eight patients with urosepsis (32.2%) had persistent or worsening AKI, and their Wnt5a levels were higher on days 1 and 5 and at discharge than those with improving AKI. The association between Wnt5a levels and persistent or worsening AKI was maintained after adjusting for age, sex, baseline serum creatinine levels, and disease severity. Moreover, elevated Wnt5a levels were associated with an increased risk of major adverse kidney events. High Wnt5a levels at discharge were associated with unrecovered AKI and participants with AKI recovery had a steeper Wnt5a slope over time than those without recovery, irrespective of age, sex, baseline serum creatinine level, or disease severity. Assessment of Wnt5a expression was helpful in predicting AKI persistence and adverse outcomes in patients with urosepsis. Therefore, Wnt5a may serve as a valuable bio-marker for identifying the risk of persistence of AKI.

Novel dysregulated long non-coding RNAs in the acute kidney injury-to-chronic kidney diseases transition unraveled by transcriptomic analysis

Acute kidney injury (AKI)-to-chronic kidney disease (CKD) transition involves a complex pathomechanism, including inflammation, apoptosis, and fibrosis where long non-coding RNAs (lncRNAs) play a crucial role in their regulation. However, to date, only a few lncRNAs have been discovered to be involved in the AKI-to-CKD transition. Therefore, this study aims to investigate the dysregulated lncRNAs in the AKI-to-CKD transition in vitro and in vivo. To mimic AKI-to-CKD transition both in vivo and in vitro, bilateral ischemia-reperfusion (IR) kidney injury was performed in Wistar rats (male), and normal rat kidney epithelial cell (NRK52E) cells were treated with exogenous transforming growth factor-β1 (TGF-β1). Further processing and analysis of samples collected from these studies (e.g., biochemical, histopathology, immunofluorescence, and RNA isolation) were also performed, and transcriptomic analysis was performed to identify the dysregulated lncRNAs. Rats subjected to IR showed a significant increase in kidney injury markers (creatinine, blood urea nitrogen (BUN), kidney injury molecule-1(KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) along with altered cell morphology). Apoptosis, inflammation, and fibrosis markers were markedly increased during the AKI-to-CKD transition. Furthermore, transcriptomic analysis revealed 62 and 84 unregulated and 95 and 92 downregulated lncRNAs in vivo and in vitro, respectively. Additionally, functional enrichment analysis revealed their involvement in various pathways, including the tumor necrosis factor (TNF), wingless-related integration site (Wnt), and hypoxia-inducible factor-1 (HIF-1) signaling pathways. These identified dysregulated lncRNAs significantly contribute to AKI-to-CKD transition, and their knockin/out can aid in developing targeted therapeutic interventions against AKI-to-CKD transition.

Acute kidney injury in patients treated with immune checkpoint inhibitors: a single-center retrospective study

BACKGROUND

Immune checkpoint inhibitor-associated acute kidney injury (ICI-AKI) is the most common renal complication and has attracted increasing amounts of attention. However, studies on this topic in Chinese cancer patients are very limited. Therefore, we conducted a retrospective study on the incidence, risk factors, clinical features and renal recovery of ICI-AKI in all patients with malignancies treated with ICIs in Shandong Provincial Hospital Affiliated to Shandong First Medical University.

METHODS

In this single-center retrospective cohort study, the data of 904 patients who received immune checkpoint inhibitors (ICIs) treatment were retrospectively analyzed. Multivariable logistic regression was used to identify the predictors of ICI-AKI.

RESULTS

A total of 46 of 904 patients receiving ICIs developed ICI-AKI, and the incidence of ICI-AKI was 5.1%. Patients developed ICI-AKI at a median of 9 weeks (IQR 3-23) after ICIs initiation. A lower baseline estimated glomerular filtration rate (eGFR) and use of antibiotics were associated with a higher risk of ICI-AKI. Renal recovery occurred in 17 patients (46%) at a median of 4 weeks (IQR 2-8) after ICI-AKI, including 16 (43%) with complete recovery and 1 (3%) with partial recovery. Of the 14 rechallenged patients, only one developed recurrent ICI-AKI.

CONCLUSIONS

Patients with ICI-AKI were more likely to have impaired renal function at baseline and after treatment with antibiotics. Approximately half of the patients achieved renal recovery.

Incidence, risk factors, and outcomes of acute liver injury in hospitalized adults with acute kidney injury: a large multicenter study

BACKGROUND

Acute kidney injury (AKI) and acute liver injury (ALI) were associated with poor outcomes during hospitalization, respectively. However, the clinical outcome of AKI combined with ALI (AKI-ALI) remains unknown. The current study aimed to describe AKI-ALI's incidences, risk factors, and outcomes.

METHODS

The study population included patients aged 18-99 years with enough serum creatinine and liver testing hospitalized at 19 medical centers throughout China between 2000 and 2021. AKI was defined by Kidney Disease Improving Global Outcomes and ALI was defined by the change of liver enzymes based on Asia Pacific Association of Study of Liver consensus guidelines. Cox proportional hazard model was used to identify risk factors for AKI-ALI, and a time-dependent Cox proportional hazard regression model was used to estimate the association between AKI-ALI and in-hospital mortality.

RESULTS

Among the 18,461 patients with AKI, 1689 (9.1%) combined with ALI. Male patients or those who have used nonsteroidal anti-inflammatory drugs or vasopressors, and who have heart failure or shock, with higher AST or GGT values, were associated with an increased risk of AKI-ALI. Compared with AKI-nonALI, patients with AKI-ALI were at higher risk of in-hospitalized mortality (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.54, 2.00). In addition, a stronger association between AKI-ALI and in-hospital mortality was found in those with lower AKI grades (p for interaction = 0.037).

CONCLUSIONS

ALI was not uncommon among patients with AKI, especially in patients who used vasopressors and had shock. This study highlights the association between AKI-ALI and a significantly increased risk of mortality. It suggests that dynamic monitoring of liver function is essential, particularly in patients with AST and GGT exceeding the normal upper limit, to improve the in-hospital prognosis of AKI patients.

Renal dysfunction in surgical patients

PURPOSE OF REVIEW

To provide an overview of the current diagnostic criteria for acute kidney injury (AKI) including their limitations and to discuss prevention and treatment approaches in the perioperative setting.

RECENT FINDINGS

AKI is common in the perioperative period and is associated with worse short- and long-term outcomes. Current definitions of AKI have several limitations and lead to delayed recognition of kidney dysfunction which is why novel diagnostic approaches by using renal biomarkers may be helpful. In general, prevention of the development and progression of AKI is vital as a causal treatment for AKI is currently not available. Optimization of kidney perfusion and avoidance of nephrotoxic drugs reduce the occurrence of AKI in surgical patients. Angiotensin II as a new vasopressor, the use of remote ischemic preconditioning, and amino acids may be approaches with a positive effect on the kidneys.

SUMMARY

Evidence suggests that the implementation of supportive measures in patients at high risk for AKI might reduce the occurrence of AKI. Novel biomarkers can help allocating resources by detecting patients at high risk for AKI.

Outcomes of acute kidney injury continuum in children

BACKGROUND

Acute kidney injury (AKI) is associated with high morbidity and mortality. The continuum of kidney damage after an AKI episode is poorly explored in the paediatric population.

METHODS

We performed a retrospective cohort study on 2346 children with AKI from a tertiary care hospital in Romania over a 9-year period. The main objective was to evaluate the impact of AKI duration on mortality and the risk of new-onset chronic kidney disease (CKD).

RESULTS

Out of 2346 AKI patients, transient AKI was present in 655 patients (27.9%), persistent AKI in 1009 children (43%) and acute kidney disease in 682 patients (29.1%). In contrast to transient AKI, children who developed acute kidney disease were younger, with a higher degree of anaemia, lower number of platelets, higher procalcitonin, higher LDH, higher GGT, higher urea and higher serum creatinine levels. The pre-renal cause of AKI was the leading cause regardless of AKI duration. As kidney injury progressed over time, there was an increasing incidence of the intrinsic causes of AKI (11.1% in transient AKI, 13.2% in persistent AKI and 22.6% in acute kidney disease). Acute kidney disease patients had the highest mortality rate (16.42%), followed by transient AKI (14.66%) and persistent AKI (9.81%). Overall mortality increased in the presence of renal microvascular alterations, acute tubular necrosis, lower haemoglobin, serum proteins and platelets, and higher procalcitonin levels.

CONCLUSIONS

The continuum of AKI expressed as acute kidney disease resulted in an increased risk of new-onset CKD. CKD was influenced by the intrinsic cause of AKI and not by AKI severity.

Predictive models of sepsis-associated acute kidney injury based on machine learning: a scoping review

BACKGROUND

With the development of artificial intelligence, the application of machine learning to develop predictive models for sepsis-associated acute kidney injury has made potential breakthroughs in early identification, grading, diagnosis, and prognosis determination.

METHODS

Here, we conducted a systematic search of the PubMed, Cochrane Library, Embase (Ovid), Web of Science, and Scopus databases on April 28, 2023, and screened relevant literature. Then, we comprehensively extracted relevant data related to machine learning algorithms, predictors, and predicted objectives. We subsequently performed a critical evaluation of research quality, data aggregation, and analyses.

RESULTS

We screened 25 studies on predictive models for sepsis-associated acute kidney injury from a total of originally identified 2898 studies. The most commonly used machine learning algorithm is traditional logistic regression, followed by eXtreme gradient boosting. We categorized these predictive models into early identification models (60%), prognostic prediction models (32%), and subtype identification models (8%) according to their predictive purpose. The five most commonly used predictors were serum creatinine levels, lactate levels, age, blood urea nitrogen concentration, and diabetes mellitus. In addition, a single data source, insufficient assessment of clinical utility, lack of model bias assessment, and hyperparameter adjustment may be the main reasons for the low quality of the current research.

CONCLUSIONS

However, studies on the nondeath prognostic outcomes, the long-term clinical outcomes, and the subtype identification models are insufficient. Additionally, the poor quality of the research and the insufficient practicality of the model are problems that need to be addressed urgently.

Carfilzomib-associated thrombotic microangiopathy: clinical features and outcomes

BACKGROUND

Carfilzomib, a new proteasome inhibitor indicated for patients with relapsed/refractory myeloma, has been associated with cases of thrombotic microangiopathy (CFZ-TMA). The role of variants in the complement alternative pathway and therapeutic potential of complement blockade with eculizumab remain to be determined.

METHODS

We report 37 cases of CFZ-TMA recorded in the French reference center for TMA with their clinical characteristics, genetic analysis and outcome according to treatments.

RESULTS

A trigger was identified in more than half of cases, including eight influenza and five severe acute respiratory syndrome coronavirus-2 cases. All patients presented with acute kidney injury (AKI) [KDIGO stage 3 in 31 (84%) patients] while neurological (n = 13, 36%) and cardiac (n = 7, 19%) damage were less frequent. ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type I repeats-13) and complement activity were normal (n = 28 and 18 patients tested) and no pathogenic variant in the alternative complement pathway was found in 7 patients tested. TMA resolved in most (n = 34, 94%) patients but 12 (44%) still displayed stage 3 AKI at discharge. Nineteen (51%) patients were treated with therapeutic plasma exchange, 14 (38%) patients received corticosteroids and 18 (50%) were treated with eculizumab. However, none of these treatments demonstrated a significant impact on outcomes.

CONCLUSION

This study is the largest case series of CFZ-TMA since its approval in 2012. Patients present with severe AKI and experience frequent sequelae. Complement variants and blockade therapy do not seem to play a role in the pathophysiology and prognosis of the disease.

Hemoadsorption: consensus report of the 30th Acute Disease Quality Initiative workgroup

Adsorption-based extracorporeal therapies have been subject to technical developments and clinical application for close to five decades. More recently, new technological developments in membrane and sorbent manipulation have made it possible to deliver more biocompatible extracorporeal adsorption therapies to patients with a variety of conditions. There are several key rationales based on physicochemical principles and clinical considerations that justify the application and investigation of such therapies as evidenced by multiple ex vivo, experimental and clinical observations. Accordingly, unspecific adsorptive extracorporeal therapies have now been applied to the treatment of a wide array of conditions from poisoning to drug overdoses, to inflammatory states and sepsis, and acute or chronic liver and kidney failure. In response to the rapidly expanding knowledge base and increased clinical evidence, we convened an Acute Disease Quality Initiative consensus conference dedicated to such treatment. The data show that hemoadsorption has clinically acceptable short-term biocompatibility and safety, technical feasibility and experimental demonstration of specified target molecule removal. Pilot studies demonstrate potentially beneficial effects on physiology and larger studies of endotoxin-based hemoadsorption have identified possible target phenotypes for larger randomized controlled trials. Moreover, in a variety of endogenous and exogenous intoxications, removal of target molecules has been confirmed in vivo. However, some studies have raised concerns about harm, or failed to deliver benefits. Thus, despite many achievements, modern hemoadsorption remains a novel and experimental intervention with limited data, and a large research agenda.

Prognostic Scores for Acute Kidney Injury in Critically Ill Patients

BACKGROUND

Numerous prognostic scores have been developed and used in intensive care; however, the applicability and effectiveness of these scores in critically ill patients with acute kidney injury may vary due to the characteristics of this population.

OBJECTIVE

To assess the predictive capacity of the Simplified Acute Physiology Score III (SAPS III), Sequential Sepsis-related Organ Failure Assessment (SOFA) and Nursing Activities Score (NAS) prognostic scoring systems for acute kidney injury in critically ill patients.

METHODS

Cohort, prospective and quantitative study with follow-up of 141 critical patients in intensive care. A questionnaire was used to collect information about the capacity of prognostic scoring systems to predict AKI. Mann-Whitney, Kruskal-Wallis and Bonferroni-corrected Mann-Whitney tests were used and the statistical significance was considered to be at two-sided p < 0.05.

RESULTS

It was revealed that 41.85% of patients developed acute kidney injury during their stay in the Intensive Care Unit and indicated greater severity assessed by the medians of prognostic scoring systems-SAPS III [55 (42-65 vs. 38 (32-52), p < 0.001], SOFA [3.3 (2.26-5.00) vs. 0.66 (0.06-2.29), p < 0.001] and NAS [90 (75-95) vs. 97 (91-103), p < 0.001]-when compared to patients without kidney damage.

CONCLUSIONS

The SAPS III, SOFA and NAS prognostic scoring systems showed good predictive capacity for acute kidney injury in critically ill patients. This study was not registered.

Exploring the role of Artificial Intelligence in Acute Kidney Injury management: a comprehensive review and future research agenda

This study reviews the studies utilizing Artificial Intelligence (AI) and AI-driven tools and methods in managing Acute Kidney Injury (AKI). It categorizes the studies according to medical specialties, analyses the gaps in the existing research, and identifies opportunities for future research directions. PRISMA guidelines were adopted using the three most common databases (PubMed, Scopus, and EBSCO), which resulted in 27 eligible studies, published between 2012 and 2023. The study showed significant heterogeneity in the design of the models, with variations in clinical settings, patient characteristics, cohort regions, and statistical methods. Most models were developed for AKI in hospitalized patients, particularly those undergoing surgery or in intensive care units. Compact models with a subset of significant predictors were deemed more clinically applicable than full models with all predictors. The findings suggest that AI tools, such as machine learning (ML) algorithms, have high prediction capabilities despite the dynamic and complex association among the influencing factors and AKI. Based on these findings and the recognized need for broader inclusivity, future studies should consider adopting a more inclusive approach by incorporating diverse healthcare settings, including resource-limited or developing countries. This inclusivity will lead to a more holistic understanding of AKI management challenges and facilitate the development of adaptable and universally applicable AI-driven solutions. Additionally, further investigations should focus on refining AI models to enhance their accuracy and interpretability, promoting seamless integration and implementation of AI-based tools in real-world clinical practice. Addressing these key aspects will elevate the effectiveness and impact of AI-driven approaches in managing AKI.

Quantitative proteomics analysis reveals the protective role of S14G-humanin in septic acute kidney injury using 4D-label-free and PRM Approaches

Mitochondrial dysfunction contributes to septic acute kidney injury (S-AKI), making mitochondrial protection a potential therapeutic strategy. This study investigates the effects of S14G-humanin (HNG) in S-AKI, utilizing 4D-label-free and parallel reaction monitoring (PRM) techniques for proteomic analysis. An S-AKI model was created in male C57BL/6 mice using lipopolysaccharide (LPS) injection, followed by HNG administration. After 24 h, kidney tissues were analyzed for histology, biochemistry, mitochondrial function, and proteomics. HNG treatment improved renal function, reduced tubular injury, and decreased pro-inflammatory cytokines and oxidative stress markers. Proteomic analysis identified 5900 proteins, with 5111 quantifiable. HNG altered the expression of 132 proteins, with 18 selected for PRM validation. Ten of these proteins were linked to key pathways, including fatty acid degradation and PPAR signaling. This study is the first to show HNG's protective effects in S-AKI, providing insights into its mechanisms through advanced proteomic techniques.

Study protocol for a consortium linking health medical records, biospecimens, and biosignals in Korean patients with acute kidney injury (LINKA cohort)

Background

Acute kidney injury (AKI) may transition into acute kidney disease (AKD) or chronic kidney disease (CKD), leading to subacute and chronic deterioration, respectively. Despite extensive research on AKI, a significant gap exists in understanding the specific biomarkers and development of individualized treatments prior to progression to AKD and CKD.

Methods

As a consortium linking health medical records, biospecimens, and biosignals, eight Korean tertiary hospitals participated in the establishment of a retrospective and prospective cohort, each comprising approximately 1,500 patients with AKI receiving continuous kidney replacement therapy (CKRT). Other information included AKI-related information, CKRT prescriptions, and patient outcomes. Follow-up timeframes were set at baseline, 1 week, 3 months, and 1 year after the initiation of CKRT. Human biospecimens will be collected from the prospective cohort. An artificial intelligence model was developed using the retrospective cohort to predict the prognosis of AKD and its subsequent sequelae and to formulate patient-individualized treatments, with validation planned in a prospective cohort. Follow-up studies are scheduled to identify biomarkers related to outcomes using biospecimens. Finally, based on the results and literature review, decision-making on the prevention and management of diseases, as well as the development of treatment guidelines, are being planned.

Conclusion

This study will provide scientific evidence on clinical insights and appropriate management targets for AKI and AKD, which will form the basis for relevant treatment guidelines. Additionally, these findings may facilitate a more personalized approach to patient care, enabling clinicians to tailor treatments based on individual biomarker profiles and predictive models.

Recent advances of photoresponsive nanomaterials for diagnosis and treatment of acute kidney injury

Non-invasive imaging in the near-infrared region (NIR) offers enhanced tissue penetration, reduced spontaneous fluorescence of biological tissues, and improved signal-to-noise ratio (SNR), rendering it more suitable for in vivo deep tissue imaging. In recent years, a plethora of NIR photoresponsive materials have been employed for disease diagnosis, particularly acute kidney injury (AKI). These encompass inorganic nonmetallic materials such as carbon (C), silicon (Si), phosphorus (P), and upconversion nanoparticles (UCNPs); precious metal nanoparticles like gold and silver; as well as small molecule and organic semiconductor polymer nanoparticles with near infrared responsiveness. These materials enable effective therapy triggered by NIR light and serve as valuable tools for monitoring AKI in living systems. The review provides a concise overview of the current state and pathological characteristics of AKI, followed by an exploration of the application of nanomaterials and photoresponsive nanomaterials in AKI. Finally, it presents the design challenges and prospects associated with NIR photoresponsive materials in AKI.

Impact of Different Angiotensin-Converting Enzyme Inhibitors or Angiotensin Receptor Blocker Resumption Timing on Post Acute Kidney Injury Outcomes

Introduction

Evidence suggests a survival benefit from resuming angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) post acute kidney injury (AKI) compared to nonuse; however, the optimal timing and its impact on outcomes are unclear. The risks of earlier resumption, such as recurrent AKI or hyperkalemia, remain unexplored.

Methods

Using multiinstitutional electronic health records, we analyzed the relationship between 3 ACEI or ARB (ACEI/ARB) resumption timelines post-AKI (prior to discharge, 0-3 months, and 4-6 months postdischarge) and outcomes including all-cause mortality, major adverse cardiac and cerebrovascular events (MACCEs), dialysis initiation or end-stage renal disease (ESRD), severe hyperkalemia, and recurrent AKI with hospitalization. Cox proportional models estimated hazard ratios (HRs) for outcomes across different resumption timings, following a target trial design.

Results

Among 5392 AKI survivors resuming ACEI/ARB within 6 months post-AKI, earlier resumption was associated with lower mortality, MACCE, MACCE-related mortality, new dialysis initiation or ESRD (P < 0.001 in trend tests), without increased risks of severe hyperkalemia and re-AKI admissions. Early resumption has a lower mortality compared to 4 to 6 months postdischarge (before discharge, HR: 0.88, 95% confidence interval [CI]: 0.83-0.93; 0-3 months, HR: 0.89, 95% CI: 0.85-0.94). Subgroup analysis showed a lower mortality HR from earlier resumption among AKI survivors with prior ACEI/ARB comorbidity indications (P < 0.001 in trend tests; before discharge, HR: 0.85, 95% CI: 0.80-0.90; 0-3 months, HR: 0.88, 95% CI: 0.83-0.93).

Conclusion

Our cohort demonstrates lower risks for mortality, cardiovascular events, and ESRD with early ACEI/ARB resumption, without heightened risks of severe hyperkalemia or rehospitalization for AKI. Early resumption should be considered for patients with indications for ACEI/ARB.

Clustering based on renal and inflammatory admission parameters in critically ill patients admitted to the ICU

INTRODUCTION

The COVID-19 pandemic has been associated with significant variability in acute kidney injury (AKI) incidence, leading to concerns regarding patient heterogeneity. The study's primary objective was a cluster analysis, to identify homogeneous subgroups of patients (clusters) using baseline characteristics, including inflammatory biomarkers. The secondary objectives were the comparisons of MAKE-90 and mortality between the different clusters at three months.

METHODS

This retrospective single-center study was conducted in the Medical Intensive Care Unit of the University Hospital of Clermont-Ferrand, France. Baseline data, clinical and biological characteristics on ICU admission, and outcomes at day 90 were recorded. The primary outcome was the risk of major adverse kidney events at 90 days (MAKE-90). Clusters were determined using hierarchical clustering on principal components approach based on admission characteristics, biomarkers and serum values of immune dysfunction and kidney function.

RESULTS

It included consecutive adult patients admitted between March 20, 2020 and February 28, 2021 for severe COVID-19. A total of 149 patients were included in the study. Three clusters were identified of which two were fully described (cluster 3 comprising 2 patients). Cluster 1 comprised 122 patients with fewer organ dysfunctions, moderate immune dysfunction, and was associated with reduced mortality and a lower incidence of MAKE-90. Cluster 2 comprised 25 patients with greater disease severity, immune dysfunction, higher levels of suPAR and L-FABP/U Creat, and greater organ support requirement, incidence of AKI, day-90 mortality and MAKE-90.

CONCLUSIONS

This study identified two clusters of severe COVID-19 patients with distinct biological characteristics and renal event risks. Such clusters may help facilitate the identification of targeted populations for future clinical trials. Also, it may help to understand the significant variability in AKI incidence observed in COVID-19 patients.

Identification and outcomes of acute kidney disease in patients presenting in Bolivia, Brazil, South Africa, and Nepal

BACKGROUND

The International Society of Nephrology proposes an acute kidney disease (AKD) management strategy that includes a risk score to aid AKD identification in low- and low-middle-income countries (LLMICs). We investigated the performance of the risk score and determined kidney and patient outcomes from AKD at multiple LLMIC sites.

METHODS AND FINDINGS

Adult patients presenting to healthcare facilities in Bolivia, Brazil, South Africa, and Nepal were screened using a symptom-based risk score and clinical judgment. Those at AKD risk underwent serum creatinine testing, predominantly with a point-of-care (POC) device. Clinical data were collected prospectively between September 2018 and November 2020. We analyzed risk score performance and determined AKD outcomes at discharge and over follow-up of 90 days. A total of 4,311 patients were at increased risk of AKD, and 2,922 (67.8%) had AKD confirmed. AKD prevalence was 80.2% in patients enrolled based on the risk score and 32.5% when enrolled on clinical judgment alone (p < 0.0001). The area under the receiver operating characteristic curve was 0.73 for the risk score to detect AKD. Death during admission occurred in 84 (2.9%) patients with AKD and 3 (0.2%) patients without kidney disease (p < 0.0001). Death after discharge occurred in 206 (9.7%) AKD patients, and 1865 AKD patients underwent reassessment of kidney function after discharge; 902 (48.4%) patients had persistent kidney disease including 740 (39.7%) patients reclassified with de novo or previously undiagnosed chronic kidney disease (CKD). The study was pragmatically designed to assess outcomes as part of routine healthcare, and there was heterogeneity in clinical practice and outcomes between sites, in addition to selection bias during cohort identification.

CONCLUSIONS

The use of a risk score can aid AKD identification in LLMICs. High rates of persistent kidney disease and mortality after discharge highlight the importance of AKD follow-up in low-resource settings.

Diagnostic Validation of the Updated Pediatric Sepsis Biomarker Risk II for Acute Kidney Injury Prediction Model in Pediatric Septic Shock

OBJECTIVES

We previously derived the updated Pediatric Sepsis Biomarker Risk for Acute Kidney Injury (PERSEVERE-II AKI) prediction model, which had robust diagnostic test characteristics for severe AKI on day 3 (D3 severe AKI) of septic shock. We now sought to validate this model in an independent cohort of children to the one in which the model was developed.

DESIGN

A secondary analysis of a multicenter, prospective, observational study carried out from January 2019 to December 2022.

SETTING

Ten PICUs in the United States.

PATIENTS

Children with septic shock 1 week to 18 years old admitted to the PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Seventy-nine of 363 patients (22%) had D3 severe AKI, defined as Kidney Disease Improving Global Outcomes stage 2 or higher. Patients were assigned a probability of D3 severe AKI using the PERSEVERE-II AKI model. The model predicted D3 severe AKI with an area under the receiver operating characteristic curve of 0.89 (95% CI, 0.85-0.93), sensitivity of 77% (95% CI, 66-86%), specificity of 88% (95% CI, 84-92%), positive predictive value of 65% (95% CI, 54-74%), and negative predictive value of 93% (95% CI, 89-96%). These data represent an increase in post-test probability of D3 severe AKI with a positive test from 22% to 65%, and a prevalence threshold of 28%. On multivariable regression, the PERSEVERE-II AKI prediction model demonstrated greater adjusted odds ratio (aOR) for D3 severe AKI (aOR, 11.2; 95% CI, 4.9-25.3) and lesser aOR for failure of D3 renal recovery from early AKI (aOR, 0.31; 95% CI, 0.13-0.69).

CONCLUSIONS

The PERSEVERE-II AKI model demonstrates consistently robust performance for prediction of new or persistent D3 severe AKI in children with septic shock. A major limitation is that actual D3 severe AKI prevalence is below the prevalence threshold for the test, and thus future work should focus on evaluating use in enriched populations.

Acute Kidney Injury Survivor Remote Patient Monitoring: A Single Center's Experience and an Effectiveness Evaluation

Rationale & Objective

Remote patient monitoring (RPM) could improve the quality and efficiency of acute kidney injury (AKI) survivor care. This study described our experience with AKI RPM and characterized its effectiveness.

Study Design

A cohort study matched 1:3 to historical controls.

Setting & Participants

Patients hospitalized with an episode of AKI who were discharged home and were not treated with dialysis.

Exposure

Participation in an AKI RPM program, which included use of a home vital sign and symptom monitoring technology and weekly in-center laboratory assessments.

Outcomes

Risk of unplanned hospital readmission or emergency department (ED) visit within 6 months.

Analytic Approach

Endpoints were assessed using Cox proportional hazards models.

Results

Forty of the 49 patients enrolled in AKI RPM (82%) participated in the program after hospital discharge. Seventy three percent of patients experienced one AKI RPM alert, most commonly related to fluid status. Among those with stage 3 AKI, the risk of unplanned readmission or ED visit within 6 months of discharge was not different between AKI RPM patients (n = 34) and matched controls (n = 102) (HR 1.33 [95% CI, 0.81-2.18]; P = 0.27). The incidence of an ED visit without hospitalization was significantly higher in the AKI RPM group (HR 1.95, [95% CI, 1.05-3.62]; P = 0.035). The risk of an unplanned readmission or ED visit was higher in those with baseline eGFR < 45 mL/min/1.73 m2 exposed to AKI RPM (HR 2.24 [95% CI, 1.19-4.20]; P = 0.012) when compared with those with baseline eGFR ≥45 mL/min/1.73 m2 (HR 0.69 [95% CI, 0.29-1.67]; P = 0.41) (test of interaction P = 0.04).

Limitations

Small sample size that may have been underpowered for the effectiveness endpoints.

Conclusions

AKI RPM, when used after hospital discharge, led to alerts and interventions directed at optimizing kidney health and AKI complications but did not reduce the risk for rehospitalization.

Association between Changes in Preoperative Serum Creatinine and Acute Kidney Injury after Cardiac Surgery: A Retrospective Cohort Study

INTRODUCTION

Limited information exists regarding the impact of preoperative serum creatinine changes on cardiac surgery-associated acute kidney injury (CSA-AKI). This study aimed to investigate the development of AKI in patients with a baseline estimated glomerular filtration rate of ≥60 mL/min/1.73 m2 who present with an elevation in preoperative serum creatinine.

METHODS

This retrospective cohort study assessed patients who underwent open-heart surgery. Preoperative serum creatinine change was calculated as the ratio of the maximum preoperative serum creatinine value to the baseline creatinine (MCR). Patients were categorized into three groups based on MCR: non-elevation (≤1.0), mild elevation (1.0 to 1.5), and pronounced elevation (≥1.5). Multivariable logistic regression was used to estimate the risk of AKI, severe AKI, and non-recovery from AKI.

RESULTS

There were significant increases in the odds of AKI (adjusted odds ratio [OR], 1.42; 95% confidence interval [CI], 1.29-1.57; per 0.1 increase in MCR), severe AKI (adjusted OR, 1.28; 95% CI, 1.15-1.41), and AKI non-recovery (adjusted OR, 1.29; 95% CI, 1.16-1.43). Pronounced elevation in preoperative serum creatinine was associated with a higher risk of AKI (adjusted OR, 15.45; 95% CI, 6.63-36.00), severe AKI (adjusted OR, 3.62; 95% CI, 1.20-10.87), and AKI non-recovery (adjusted OR, 4.74; 95% CI, 1.63-13.89) than non-elevation. Mild elevation in preoperative serum creatinine was also significantly associated with AKI (adjusted OR, 3.76; 95% CI, 1.92-7.37).

CONCLUSIONS

Elevation in preoperative serum creatinine from baseline was associated with an increased risk of AKI; even mild elevation significantly increased the risk of AKI.

Incidence of Acute Kidney Injury and Associated Mortality among Individuals with Drug-Susceptible Tuberculosis in Uganda

Key Points

AKI is thought to be a rare complication in patients with tuberculosis (TB) infection and is mostly attributed to TB drugs. Our findings show AKI occurs more often than previously thought and approximately 33% of patients with drug-susceptible TB may have kidney dysfunction. According to our study findings, monitoring kidney function should be routine among patients diagnosed with TB even before treatment initiation.

Background

Although tuberculosis (TB) is associated with significant mortality and morbidity, its impact on kidney function is not well understood and is often attributed to anti-TB drugs. We aimed to assess the incidence of AKI in the immediate post-TB diagnosis period in Uganda, a TB/HIV-endemic country in sub-Saharan Africa.

Methods

We included patients enrolled in an observational cohort study of adults diagnosed with drug-susceptible TB followed longitudinally. Adults (≥18 years) without known kidney disease were enrolled between August 2022 and July 2023 at three regional hospitals serving 12.5% of the Ugandan population. Our primary outcome was incidence of Kidney Disease Improving Global Outcomes-defined AKI within 2 weeks of TB diagnosis. Other outcomes included predictors of AKI and its association with 30-day survival.

Results

A total of 156 adults were included. The median age was 39 (interquartile range, 28–53) years, most patients were male (68.6%), and 49.4% had HIV. People with HIV had shorter time to TB diagnosis from symptom onset (21 days; interquartile range, 7–30) compared with HIV-negative participants (60 days; interquartile range, 23–90), P < 0.001. The incidence of AKI was 33.3% (52/156) and was similar between people with and without HIV. Proteinuria or hematuria at enrollment was associated with higher odds of AKI (odds ratio, 2.68; 95% confidence interval, 1.09 to 6.70; P approximately 0.033). AKI was associated with a significant risk of mortality (adjusted hazard ratio, 8.22; 95% confidence interval, 1.94 to 34.72; P approximately 0.004) independent of HIV status.

Conclusions

The overall incidence of AKI in the immediate post-TB diagnosis period is high and associated with increased mortality risk. Our findings suggest that monitoring kidney function should be routine for patients with TB, including before treatment initiation.

Outcomes after acute kidney injury and critical illness

PURPOSE OF REVIEW

Acute kidney injury (AKI) in critical illness is common, and survivors are faced with a host of adverse outcomes. In this article, we review the current landscape of outcomes and care in survivors of AKI and critical illness.

RECENT FINDINGS

Follow-up care of survivors of AKI and critical illness is prudent to monitor for and mitigate the risk of adverse outcomes. Observational data have suggested improvement in outcomes with nephrology-based follow-up care, and recent interventional studies demonstrate similar findings. However, current post-AKI care is suboptimal with various challenges, such as breakdowns in the transition of care during hospital episodes and into the community, barriers for patients in follow-up, and lack of identification of high-risk patients for nephrology-based follow-up. Tools predictive of renal nonrecovery and long-term outcomes may help to identify high-risk patients who may benefit the most from nephrology-based care post-AKI.

SUMMARY

Follow-up care of survivors of AKI and critical illness may improve outcomes and there is a need to prioritize transitions of care into the community. Further research is needed to elucidate the best ways to risk-stratify and manage post-AKI survivors to improve outcomes.

Ammonia and urea metabolism in acute liver failure: A multicentre cohort study

BACKGROUND & AIMS

Ammonia is metabolized into urea in the liver. In acute liver failure (ALF), ammonia has been associated with survival. However, urea variation has been poorly studied.

METHODS

Observational cohort including ALF patients from Curry Cabral Hospital (Lisbon, Portugal) and Clinic Hospital (Barcelona, Spain) between 10/2010 and 01/2023. The United States ALF Study Group cohort was used for external validation. Primary exposures were serum ammonia and urea on ICU admission. Primary endpoint was 30-day transplant-free survival (TFS). Secondary endpoint was explanted liver weight.

RESULTS

Among 191 ALF patients, median (IQR) age was 46 (32; 57) years and 85 (44.5%) were males. Overall, 86 (45.0%) patients were transplanted and 75 (39.3%) died. Among all ALF patients, following adjustment for age, sex, body weight, and aetiology, higher ammonia or lower urea was independently associated with higher INR on ICU admission (p < .009). Among all ALF patients, following adjustment for sex, aetiology, and lactate, higher ammonia was independently associated with lower TFS (adjusted odds ratio (95% confidence interval [CI]) = 0.991 (0.985; 0.997); p = .004). This model predicted TFS with good discrimination (area under receiver operating curve [95% CI] = 0.78 [0.75; 0.82]) and reasonable calibration (R2 of 0.43 and Brier score of 0.20) after external validation. Among transplanted patients, following adjustment for age, sex, actual body weight, and aetiology, higher ammonia (p = .024) or lower (p < .001) urea was independently associated with lower explanted liver weight.

CONCLUSIONS

Among ALF patients, serum ammonia and urea were associated with ALF severity. A score incorporating serum ammonia predicted TFS reasonably well.

Early Acute Kidney Injury Recovery in Elderly Patients Undergoing Valve Replacement Surgery

OBJECTIVES

This study was designed to determine the incidence, contributing factors, and prognostic implications of acute kidney injury (AKI) recovery patterns in patients who experienced AKI after valve replacement surgery (VRS).

DESIGN

A retrospective cohort study was conducted.

SETTING

The work took place in a postoperative care center in a single large-volume cardiovascular center.

PARTICIPANTS

Patients undergoing VRS between January 2010 and December 2019 were enrolled.

INTERVENTION

Patients were categorized into three groups based on their postoperative AKI status: non-AKI, AKI with early recovery (less than 48 hours), and persistent AKI.

MEASUREMENT AND MAIN RESULTS

The primary outcome was in-hospital major adverse clinical events. The secondary outcomes included in-hospital and 1-year mortality. A total of 4,161 patients who developed AKI following VRS were included. Of these, 1,513 (36.4%) did not develop postoperative AKI, 1,875 (45.1%) experienced AKI with early recovery, and 773 (18.6%) had persistent AKI. Advanced age, diabetes, New York Heart Association III-IV heart failure, moderate-to-severe renal dysfunction, anemia, and AKI stages 2 and 3 were identified as independent risk factors for persistent AKI. In-hospital major adverse clinical events occurred in 59 (3.9%) patients without AKI, 88 (4.7%) with early AKI recovery, and 159 (20.6%) with persistent AKI (p < 0.001). Persistent AKI was independently associated with an increased risk of in-hospital adverse events and 1-year mortality. In contrast, AKI with early recovery did not pose additional risk compared with non-AKI patients.

CONCLUSIONS

In patients who develop AKI following VRS, early AKI recovery does not pose additional risk compared with non-AKI. However, AKI lasting more than 48 hours is associated with an increased risk of in-hospital and long-term adverse outcomes.

Potential Nephroprotective Effect of Kaempferol: Biosynthesis, Mechanisms of Action, and Clinical Prospects

Kidney is an essential organ that is highly susceptible to cellular injury caused by various toxic substances in the blood. Several studies have shown that untreated injuries to this organ can cause glomerulosclerosis, tubulointerstitial fibrosis, and tubular cell apoptosis, leading to kidney failure. Despite significant advancements in modern treatment, there is no fully effective drug for repairing its function, providing complete protection, and assisting in cell regeneration. Furthermore, some available medications have been reported to exacerbate injuries, showing the need to explore alternative treatments. Natural drugs are currently being explored as a new therapeutic strategy for managing kidney diseases. Kaempferol, a polyphenol found in plants, including vegetables, legumes, and fruits, has been extensively studied in various nephrotoxicity protocols. The compound has been reported to have potential as a nephroprotective agent with beneficial effects on various physiological pathways, such as CPL-induced kidney injury, DOX, LPO, ROS, RCC, and diabetic nephropathy. Therefore, this study aims to provide a brief overview of the current nephroprotective effects of kaempferol, as well as its molecular mechanisms of action, biosynthesis pathways, and clinical prospects.

High-dose colistin pharmacokinetics in critically ill patients receiving continuous renal replacement therapy

BACKGROUND

Colistin, administered as intravenous colistimethate (CMS), is still used in the critical care setting and current guidelines recommend high dosage CMS in patients undergoing continuous renal replacement therapy (CRRT). Due to the paucity of real-life data, we aimed to describe colistin pharmacokinetic/pharmacodynamic (PK/PD) profile in a cohort of critically ill patients with infections due to carbapenem-resistant (CR) bacteria undergoing CRRT.

RESULTS

All consecutive patients admitted to three Intensive Care Units (ICUs) of a large metropolitan University Hospital, treated with colistin for at least 48 h at the dosage of 6.75 MUI q12, after 9 MIU loading dose, and undergoing CRRT were included. After the seventh dose, patients underwent blood serial sampling during a time frame of 24 h. We included 20 patients, who had CR-Acinetobacter baumannii ventilator-associated pneumonia and were characterized by a median SAPS II and SOFA score of 41 [34.5-59.3] and 9 [6.7-11], respectively. Fifteen patients died during ICU stay and six recovered renal function. Median peak and trough colistin concentrations were 16.6 mcg/mL [14.8-20.6] and 3.9 mcg/mL [3.3-4.4], respectively. Median area under the time-concentration curve (AUC0 - 24) and average steady-state concentration (Css, avg) were 193.9 mcg h/mL [170.6-208.6] and 8.07 mcg/mL [7.1-8.7]. Probability of target attainment of colistin pharmacodynamics according to the fAUC0 - 24/MIC target ≥ 12 was 100% for MIC ≤ 2 mcg/mL and 85% for MIC = 4 mcg/ML, although exceeding the toxicity limit of Css, avg 3-4 mcg/mL.

CONCLUSIONS

In critically ill patients with CR infections undergoing CRRT, recommended CMS dosage resulted in colistin plasmatic levels above bacterial MIC90, but exceeding the safety Css, avg. limit.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov on 23/07/2021 with the ID NCT04995133 (https//clinicaltrials.gov/study/NCT04995133).

Personalized Prediction of Long-Term Renal Function Prognosis Following Nephrectomy Using Interpretable Machine Learning Algorithms: Case-Control Study

BACKGROUND

Acute kidney injury (AKI) is a common adverse outcome following nephrectomy. The progression from AKI to acute kidney disease (AKD) and subsequently to chronic kidney disease (CKD) remains a concern; yet, the predictive mechanisms for these transitions are not fully understood. Interpretable machine learning (ML) models offer insights into how clinical features influence long-term renal function outcomes after nephrectomy, providing a more precise framework for identifying patients at risk and supporting improved clinical decision-making processes.

OBJECTIVE

This study aimed to (1) evaluate postnephrectomy rates of AKI, AKD, and CKD, analyzing long-term renal outcomes along different trajectories; (2) interpret AKD and CKD models using Shapley Additive Explanations values and Local Interpretable Model-Agnostic Explanations algorithm; and (3) develop a web-based tool for estimating AKD or CKD risk after nephrectomy.

METHODS

We conducted a retrospective cohort study involving patients who underwent nephrectomy between July 2012 and June 2019. Patient data were randomly split into training, validation, and test sets, maintaining a ratio of 76.5:8.5:15. Eight ML algorithms were used to construct predictive models for postoperative AKD and CKD. The performance of the best-performing models was assessed using various metrics. We used various Shapley Additive Explanations plots and Local Interpretable Model-Agnostic Explanations bar plots to interpret the model and generated directed acyclic graphs to explore the potential causal relationships between features. Additionally, we developed a web-based prediction tool using the top 10 features for AKD prediction and the top 5 features for CKD prediction.

RESULTS

The study cohort comprised 1559 patients. Incidence rates for AKI, AKD, and CKD were 21.7% (n=330), 15.3% (n=238), and 10.6% (n=165), respectively. Among the evaluated ML models, the Light Gradient-Boosting Machine (LightGBM) model demonstrated superior performance, with an area under the receiver operating characteristic curve of 0.97 for AKD prediction and 0.96 for CKD prediction. Performance metrics and plots highlighted the model's competence in discrimination, calibration, and clinical applicability. Operative duration, hemoglobin, blood loss, urine protein, and hematocrit were identified as the top 5 features associated with predicted AKD. Baseline estimated glomerular filtration rate, pathology, trajectories of renal function, age, and total bilirubin were the top 5 features associated with predicted CKD. Additionally, we developed a web application using the LightGBM model to estimate AKD and CKD risks.

CONCLUSIONS

An interpretable ML model effectively elucidated its decision-making process in identifying patients at risk of AKD and CKD following nephrectomy by enumerating critical features. The web-based calculator, found on the LightGBM model, can assist in formulating more personalized and evidence-based clinical strategies.

Nanoparticles constructed from natural polyphenols are used in acute kidney injury

Acute kidney injury (AKI) is a severe clinical syndrome characterized by rapid deterioration of renal function caused by a variety of pathogeneses. Natural polyphenols have been considered to have potential in the treatment of AKI due to their powerful antioxidant and anti-inflammatory activities, but their low bioavailability in vivo limits their efficacy. Polyphenol nanoparticles based on a nano-delivery system show good effects in reducing kidney injury, improving renal function and promoting renal tissue repair, and brings new hope and possibility for the treatment of AKI. This review provides an overview of the common characteristics, treatments, and associated adverse effects of AKI. The classification and bioavailability of polyphenols as well as their therapeutic role in AKI and potential possible effects are outlined. The potential therapeutic effects of polyphenol-based nanoparticles on AKI and the underlying mechanisms are discussed.

Complex Pathophysiology of Acute Kidney Injury (AKI) in Aging: Epigenetic Regulation, Matrix Remodeling, and the Healing Effects of H2S

The kidney is an essential excretory organ that works as a filter of toxins and metabolic by-products of the human body and maintains osmotic pressure throughout life. The kidney undergoes several physiological, morphological, and structural changes with age. As life expectancy in humans increases, cell senescence in renal aging is a growing challenge. Identifying age-related kidney disorders and their cause is one of the contemporary public health challenges. While the structural abnormalities to the extracellular matrix (ECM) occur, in part, due to changes in MMPs, EMMPRIN, and Meprin-A, a variety of epigenetic modifiers, such as DNA methylation, histone alterations, changes in small non-coding RNA, and microRNA (miRNA) expressions are proven to play pivotal roles in renal pathology. An aged kidney is vulnerable to acute injury due to ischemia-reperfusion, toxic medications, altered matrix proteins, systemic hemodynamics, etc., non-coding RNA and miRNAs play an important role in renal homeostasis, and alterations of their expressions can be considered as a good marker for AKI. Other epigenetic changes, such as histone modifications and DNA methylation, are also evident in AKI pathophysiology. The endogenous production of gaseous molecule hydrogen sulfide (H2S) was documented in the early 1980s, but its ameliorative effects, especially on kidney injury, still need further research to understand its molecular mode of action in detail. H2S donors heal fibrotic kidney tissues, attenuate oxidative stress, apoptosis, inflammation, and GFR, and also modulate the renin-angiotensin-aldosterone system (RAAS). In this review, we discuss the complex pathophysiological interplay in AKI and its available treatments along with future perspectives. The basic role of H2S in the kidney has been summarized, and recent references and knowledge gaps are also addressed. Finally, the healing effects of H2S in AKI are described with special emphasis on epigenetic regulation and matrix remodeling.

Biomarkers in acute kidney injury

Acute kidney injury (AKI) is a multifactorial syndrome with a high risk of short- and long-term complications as well as increased health care costs. The traditional biomarkers of AKI, serum creatinine and urine output, have important limitations. The discovery of new functional and damage/stress biomarkers has enabled a more precise delineation of the aetiology, pathophysiology, site, mechanisms, and severity of injury. This has allowed earlier diagnosis, better prognostication, and the identification of AKI sub-phenotypes. In this review, we summarize the roles and challenges of these new biomarkers in clinical practice and research.

Association between Proton Pump Inhibitors, Immune Checkpoint Inhibitors, and Acute Kidney Injury: A Nested Case-Control Study

Key Points

This is the first study to use a large database of patients with cancer to examine the association between the studied drugs and AKI. The use of either proton pump inhibitors or immune checkpoint inhibitors was associated with an increased risk of AKI. However, their additive interaction was not identified.

Background

An association between proton pump inhibitor (PPI) use and an increased risk of AKI has been confirmed. This study aimed to evaluate the effects of PPI use on the risk of AKI in patients with cancer who were administered immune checkpoint inhibitors (ICIs), a class of drugs used in cancer treatment, and in those who were not.

Methods

We used a database provided by the Health, Clinic, and Education Information Evaluation Institute, which included demographic data, diagnoses, prescriptions, and laboratory results. We conducted a nested case–control study of 38,930 patients with cancer who were new PPI or ICI users and had no history of AKI before cohort entry. The odds ratio (OR) for AKI was estimated using conditional logistic regression models.

Results

During a mean follow-up of 8.3 months, 5870 cases of AKI were identified (incidence rate, 21.9/100 person-years). Compared with never or past PPI use without ICI use, the adjusted ORs of AKI for current PPI use without ICI use, past or never PPI use with prior ICI use, current PPI use with prior ICI use were 2.20 (95% confidence interval [CI], 2.01 to 2.40), 1.72 (95% CI, 1.37 to 2.17), or 2.62 (95% CI, 1.75 to 3.93), respectively. The risk of AKI in patients treated with both PPIs and ICIs was not higher than the additional or multiplication of the risks in those who were treated with PPIs or ICIs alone.

Conclusions

This study reinforces the association between PPI and ICI use and the increased risk of AKI. Although the interaction between the two drug classes was not detected, these findings highlight the need for careful monitoring and evaluation of kidney function in patients treated with PPIs and ICIs.

Risk Factors and Outcomes Associated With the Development of Persistent Acute Kidney Injury in Non-Renal Solid Organ Transplant Recipients: Systematic Review and Meta-Analysis

Persistent acute kidney injury (pAKI), compared with acute kidney injury (AKI) that resolves in <72 h, is associated with worse prognosis in critically ill patients. Definitions and prognosis of pAKI are not well characterized in solid organ transplant patients. Our aims were to investigate (a) definitions and incidence of pAKI; (b) association with clinical outcomes; and (c) risk factors for pAKI among heart, lung, and liver transplant recipients. We systematically reviewed the literature including PubMed, Embase, Web of Science, and Cochrane from inception to 8/1/2023 for human prospective and retrospective studies reporting on the development of pAKI in heart, lung, or liver transplant recipients. We assessed heterogeneity using Cochran's Q and I2. We identified 25 studies including 6330 patients. AKI (8%-71.6%) and pAKI (2.7%-55.1%) varied widely. Definitions of pAKI included 48-72 h (six studies), 7 days (three studies), 14 days (four studies), or more (12 studies). Risk factors included age, body mass index (BMI), diabetes, preoperative chronic kidney disease (CKD), intraoperative vasopressor use, and intraoperative circulatory support. pAKI was associated with new onset of CKD (odds ratio [OR] 1.41-11.2), graft dysfunction (OR 1.81-8.51), and long-term mortality (OR 3.01-13.96), although significant heterogeneity limited certainty of CKD and graft dysfunction outcome analyses. pAKI is common and is associated with worse mortality among liver and lung transplant recipients. Standardization of the nomenclature of AKI will be important in future studies (PROSPERO CRD42022371952).

Clinical Impact of Malnutrition According to the Global Leadership Initiative on Malnutrition Criteria Combined With Kidney Dysfunction to Determine Mortality in Inpatients

OBJECTIVE

The clinical impact of malnutrition based on the Global Leadership Initiative on Malnutrition (GLIM) criteria in patients with kidney dysfunction remains poorly understood. This study investigated the usefulness of GLIM criteria for malnutrition in predicting mortality in patients with kidney dysfunction and different clinical renal states, including no kidney disease (NKD), acute kidney injury (AKI), and chronic kidney disease (CKD).

METHODS

This single-center retrospective cohort study included 6,712 patients aged ≥18 admitted between 2018 and 2019. The relationship between the estimated glomerular filtration rate (eGFR) groups, nutritional status based on the GLIM criteria, and the incidence of all-cause mortality was evaluated using a multivariate Cox proportional hazards model. Malnutrition was defined as at least one phenotype (weight loss, low body mass index, or reduced muscle mass) and one etiological criterion (reduced intake/assimilation or disease burden/inflammation).

RESULTS

Multivariate Cox proportional hazards model showed that eGFR ≤29 (vs. eGFR: 60-89, adjusted hazard ratio [HR] = 1.84, 95% confidence interval [CI]: 1.52-2.22), 30-59 (vs. eGFR: 60-89, adjusted HR = 1.40, 95% CI: 1.20-1.64), and ≥90 (vs. eGFR: 60-89, adjusted HR = 1.40, 95% CI: 1.14-1.71), moderate and severe malnutrition (vs. without malnutrition, adjusted HR = 1.38 [1.18-1.62] and 2.18 [1.86-2.54], respectively) were independently associated with the incidence of death. The all-cause mortality rate was higher in patients with malnutrition or eGFR ≤29 (adjusted HR, 3.31; 95% CI: 2.51-4.35) than in patients without malnutrition or eGFR 60-89. Furthermore, moderate and severe malnutrition (vs. no malnutrition) was independently associated with death in patients with NKD, AKI, and CKD.

CONCLUSION

Malnutrition based on the GLIM criteria was associated with increased all-cause mortality in inpatients, and malnutrition combined with kidney dysfunction was associated with a higher risk of mortality. Furthermore, patients with NKD, AKI, and CKD showed an association between malnutrition based on GLIM criteria and mortality.

Distribution of Acute and Chronic Kidney Disease Across Clinical Phenotypes for Sepsis

BACKGROUND

Sepsis is the most common cause of acute kidney injury (AKI) in critically ill patients. Four phenotypes (α, β, γ, δ) for sepsis, which have different outcomes and responses to treatment, were described using routine clinical data in the electronic health record.

RESEARCH QUESTION

Do the frequencies of AKI, acute kidney disease (AKD), chronic kidney disease (CKD), and AKI on CKD differ by sepsis phenotype?

STUDY DESIGN AND METHODS

This was a secondary analysis of a randomized clinical trial of early resuscitation, including patients with septic shock at 31 sites. After excluding patients with end-stage kidney disease and missing data, we determined frequencies of the following clinical outcomes: AKI (defined within 24 h as Kidney Disease: Improving Global Outcomes stages 2 or 3 or stage 1 with tissue inhibitor of metalloproteinases-2 × insulin-like growth factor binding protein 7 value of > 2.0), CKD, and AKD (persistence of AKI at any stage on day 7 after enrollment) across four phenotypes. We performed multivariable logistic regression to assess the risk-adjusted association between development of AKI and AKD and phenotype.

RESULTS

Among 1,090 eligible patients, 543 patients (50%) had AKI. Across phenotypes, the frequencies of AKI varied, being highest in the δ and β phenotypes (78% and 71%, respectively) and the lowest in the α phenotype (26%; P < .001). AKD occurred most often in the δ phenotype (41%) and least often in the α phenotype (8%; P < .001). The highest frequencies of CKD and of AKI on CKD were found in the β phenotype (53% and 38% respectively; P < .001 for both). In the multivariable logistic regression models (α phenotype as reference), δ phenotype showed the strongest association with AKI (OR, 12.33; 95% CI, 7.81-19.47; P < .001) and AKD (OR, 9.18; 95% CI, 5.44-15.51; P < .001).

INTERPRETATION

The rates of AKI and AKD differed across clinical sepsis phenotypes and are more common among patients with phenotypes β and δ. Phenotype β showed a higher level of underlying CKD that predisposed patients to new AKI. The α and γ phenotypes showed lower frequencies of AKI and less progression to AKD.

Transitions and Long-Term Clinical Outcomes in Patients Admitted in Intensive Care Units Receiving Continuous Renal Replacement Therapy

Introduction: Acute kidney injury (AKI) significantly disrupts vital renal functions and is a common and serious condition in intensive care units (ICUs). AKI leads to extended hospital stays, increases mortality rates, and often necessitates nephrology consultations. Continuous renal replacement therapy (CRRT) plays a central role in managing AKI, requiring a multidisciplinary approach involving nephrologists, intensivists, and anesthesiologists. This study examines the clinical profile and progression of AKI in ICU patients requiring CRRT, with a focus on CRRT indications and modalities. Materials and Methods: We conducted a single-center retrospective observational study on ICU patients with AKI requiring CRRT from January to December 2019. AKI diagnosis followed the RIFLE criteria, and patients who received CRRT for less than 36 h were excluded. Data collected included demographics, hemodynamic parameters, and renal function parameters, with follow-ups at 1 week, 1 month, 6 months, and 12 months. Statistical analyses evaluated outcomes and transitions between CRRT and other renal replacement therapies. Results: Among 123 evaluated patients, 95 met inclusion criteria. Fifteen patients received CRRT for less than 36 h, with an early mortality rate of 80%. The final cohort comprised 80 patients who underwent CRRT for over 36 h, with a mean age of 65.3 years (SD = 13.6) and a Charlson index of 6.4. Patients were categorized based on primary diagnosis into heart failure, cardiac surgery, sepsis, other surgeries, and miscellanea groups. Mortality rates were highest in the heart failure and miscellanea groups. Significant variability was observed in therapy transitions and long-term outcomes. Continuous venovenous hemodiafiltration (CVVHDF) was the most frequently used CRRT modality. Conclusions: This study highlights the variability in CRRT practices and the poor prognosis for critically ill patients with AKI requiring CRRT. Timely nephrology consultation and tailored treatment plans may improve patient outcomes and optimize CRRT utilization. Future research should focus on refining CRRT protocols and exploring preventive strategies for AKI.

Chemokine (C-C Motif) Ligand 14 to Predict Persistent Severe Acute Kidney Injury: A Systematic Review and Meta-Analysis

INTRODUCTION

In this systematic review and meta-analysis, we aimed to review available data and provide pooled estimates of the predictive performance of urinary chemokine (C-C motif) ligand (uCCL14) for persistent (≥48 h) severe acute kidney injury (PS-AKI).

METHODS

We searched MEDLINE, PubMed, Cochrane Library, and EMBASE for studies published up to April 11, 2023. We considered all studies including adults and reporting on the ability of uCCL14 to predict PS-AKI as defined by AKI persisting for 48 or 72 h. Data extraction was performed by one investigator using a standardized form. It was checked for adequacy and completeness by another investigator.

RESULTS

After screening, we identified 13 relevant studies. Among those, four (561 patients) provided sufficient data regarding the outcome of interest and were included. Considering each study cutoff value, pooled sensitivity and specificity were 0.85 (95% CI: 0.77-0.90, I2 = 34.1%) and 0.96 (95% CI: 0.94-0.98, I2 = 53.7%), respectively. Pooled positive likelihood ratio (LR), negative LR, and diagnostic odds ratio were 8.98 (95% CI: 4.92-16.37, I2 = 23%), 0.25 (95% CI: 0.17-0.37, I2 = 0%), and 14.98 (95% CI: 3.55-63.27, I2 = 72.9%), respectively. The area under the curve estimated by summary receiver operating characteristics was 0.86 (95% CI: 0.70-0.95). Heterogeneity induced by the threshold effect was low (Spearman's correlation coefficient: -0.30, p value = 0.62) but significant for non-threshold effect. Risk of bias and concern for applicability according to the QUADAS-2 criteria was generally low. High risk in the index test due to the absence of prespecified thresholds was a concern for most studies.

CONCLUSION

Based on current evidence, uCCL14 appears to have a good predictive performance for the occurrence of PS-AKI. Interventional trials to study a biomarker-guided application of AKI care bundles and RRT are indicated.

Acute Kidney Disease in Oncology: A New Concept to Enhance the Understanding of the Impact of Kidney Injury in Patients with Cancer

BACKGROUND

Cancer patients are prone to developing acute kidney disease (AKD), yet this phenomenon remains understudied compared to acute kidney injury (AKI). AKD, which often develops insidiously, can cause treatment interruptions, extended hospital stays, and increased mortality.

SUMMARY

This perspective article explores the intricate relationship between AKD and cancer, focusing on prevalence, risk factors, implications for anticancer therapy, and long-term outcomes, including chronic kidney disease progression.

KEY MESSAGES

To emphasize the importance of early detection and intervention, this work advocates for increased research and awareness among clinicians to improve patient outcomes and manage healthcare burdens associated with AKD in cancer patients.

Machine learning-based risk prediction of acute kidney disease and hospital mortality in older patients

Introduction

Acute kidney injury (AKI) is a prevalent complication in older people, elevating the risks of acute kidney disease (AKD) and mortality. AKD reflects the adverse events developing after AKI. We aimed to develop and validate machine learning models for predicting the occurrence of AKD, AKI and mortality in older patients.

Methods

We retrospectively reviewed the medical records of older patients (aged 65 years and above). To explore the trajectory of kidney dysfunction, patients were categorized into four groups: no kidney disease, AKI recovery, AKD without AKI, or AKD with AKI. We developed eight machine learning models to predict AKD, AKI, and mortality. The best-performing model was identified based on the area under the receiver operating characteristic curve (AUC) and interpreted using the Shapley additive explanations (SHAP) method.

Results

A total of 22,005 patients were finally included in our study. Among them, 4,434 patients (20.15%) developed AKD, 4,000 (18.18%) occurred AKI, and 866 (3.94%) patients deceased. Light gradient boosting machine (LGBM) outperformed in predicting AKD, AKI, and mortality, and the final lite models with 15 features had AUC values of 0.760, 0.767, and 0.927, respectively. The SHAP method revealed that AKI stage, albumin, lactate dehydrogenase, aspirin and coronary heart disease were the top 5 predictors of AKD. An online prediction website for AKD and mortality was developed based on the final models.

Discussion

The LGBM models provide a valuable tool for early prediction of AKD, AKI, and mortality in older patients, facilitating timely interventions. This study highlights the potential of machine learning in improving older adult care, with the developed online tool offering practical utility for healthcare professionals. Further research should aim at external validation and integration of these models into clinical practice.

Extracellular Vesicle Transplantation Is Beneficial for Acute Kidney Injury

Under vasculogenic conditioning, certain pro-inflammatory subsets within peripheral blood mononuclear cells (PBMCs) undergo phenotypic transformation into pro-regenerative types, such as vasculogenic endothelial progenitor cells, M2 macrophages, and regulatory T cells. These transformed cells are collectively termed regeneration-associated cells (RACs). In this study, we aimed to investigate the therapeutic efficacy of RAC-derived extracellular vesicles (RACev) compared with a vehicle-treated group in the context of renal ischemia-reperfusion injury (R-IRI). Human PBMCs were cultured with defined growth factor cocktails for seven days to harvest RACs. EV quantity and size were characterized by nanoparticle tracking analysis. Notably, the systemic injection of RACev significantly decreased serum creatinine and blood urine nitrogen at day three compared to the control group. Histologically, the treatment group showed less fibrosis in the cortex and medullary areas (p < 0.04 and p < 0.01) compared to the control group. The CD31 staining confirmed enhanced capillary densities in the treatment group compared to the control group (p < 0.003). These beneficial effects were accompanied by angiogenesis, anti-fibrosis, anti-inflammation, and anti-apoptosis RACev miR delivery to ischemic injury to control inflammatory, endothelial mesenchymal transition, and hypoxia pathways. In vivo bioluminescence analysis demonstrated a preferential accumulation of RACev in the IR-injured kidney. The systemic transplantation of RACev beneficially restored kidney function by protecting from tissue fibrosis and through anti-inflammation, angiogenesis, and anti-apoptosis miR delivery to the ischemic tissue.

Prevalent and new use of common drugs for the incidence of community-acquired acute kidney injury: cohort and case-crossover study

Although community-acquired acute kidney injury (CA-AKI) represents a significant subset of all AKI incidence, evidence is limited due to the lack of comprehensive data prior to diagnosis. Here, we examined the risk of drug use for CA-AKI by using exhaustive pre-diagnostic prescription data. We included 78,754 working-age healthy individuals who underwent an annual health checkup program. We conducted a cohort study to assess the association between prevalent drug use and subsequent CA-AKI incidence using the Cox proportional hazard model. Subsequently, we conducted a case-crossover study to compare the new drug use in the case period directly before the CA-AKI incidence (- 3 to 0 months) with that in the control period far before the CA-AKI incidence (- 15 to - 12 months and - 9 to - 6 months) using the conditional Poisson regression model. The prevalent use of renin-angiotensin-aldosterone system (RAAS) inhibitors was associated with an increased CA-AKI incidence, but the new use was not. The new use of diuretics, anti-infectious drugs, and contrast medium was also associated with an increased CA-AKI incidence. These results suggest we need to pay attention for the incidence of AKI among the general population taking those common drugs.

Assessing Functional Outcomes of Partial Versus Radical Nephrectomy for T1b-T2 Renal Masses: Results from a Multi-institutional Collaboration

BACKGROUND

Deterioration of renal function is associated with increased all-cause mortality. In renal masses larger than 4 cm, whether partial versus radical nephrectomy (PN vs. RN) might affect long-term functional outcomes is unknown. This study tested the association between PN versus RN and postoperative acute kidney injury (AKI), recovery of at least 90% of the preoperative estimated glomerular filtration rate (eGFR) at 1 year, upstaging of chronic kidney disease (CKD) one stage or more at 1 year, and eGFR decline of 45 ml/min/1.73 m2 or less at 1 year.

METHODS

Data from 23 high-volume institutions were used. The study included only surgically treated patients with single, unilateral, localized, clinical T1b-2 renal masses. Multivariable logistic regression analyses were performed.

RESULTS

Overall, 968 PN patients and 325 RN patients were identified. The rate of AKI was lower in the PN versus the RN patients (17% vs. 58%; p < 0.001). At 1 year after surgery, for the PN versus the RN patients, the rate for recovery of at least 90% of baseline eGFR was 51% versus 16%, the rate of CKD progression of ≥ 1 stage was 38% versus 65%, and the rate of eGFR decline of 45 ml/min/1.73 m2 or less was 10% versus 23% (all p < 0.001). Radical nephrectomy independently predicted AKI (odds ratio [OR], 7.61), 1-year ≥ 90% eGFR recovery (OR, 0.30), 1-year CKD upstaging (OR, 1.78), and 1-year eGFR decline of 45 ml/min/1.73 m2 or less (OR, 2.36) (all p ≤ 0.002).

CONCLUSIONS

For cT1b-2 masses, RN portends worse immediate and 1-year functional outcomes. When technically feasible and oncologically safe, efforts should be made to spare the kidney in case of large renal masses to avoid the hazard of glomerular function loss-related mortality.

Biomarkers of acute kidney injury: From discovery to the future of clinical practice

Purpose of this review Acute kidney injury (AKI) is a complex syndrome whose development is associated with an increased morbidity and mortality. Recent studies show that this syndrome is a common complication in critically ill and surgical patients the trajectory of which may differ. As AKI can be induced by different triggers, it is complex and therefore challenging to manage patients with AKI. This review strives to provide a brief historical perspective on AKI, elucidate recent developments in diagnosing and managing AKI, and show the current usage of novel biomarkers in both clinical routine and research. In addition, we provide a perspective on potential future developments and their impact of AKI understanding and management. Recent findings/developments Recent studies show the merits of stress and damage biomarkers, highlighting limitations of the current KDIGO definition that only uses the functional biomarkers serum creatinine and urine output. The use of novel biomarkers led to the introduction of the concept of "subclinical AKI". This new classification may allow a more distinct management of affected or at risk patients. Ongoing studies, such as BigpAK-2 and PrevProgAKI, investigate the implementation of biomarker-guided interventions in clinical practice and may demonstrate an improvement in patients' outcome. Summary The ongoing scientific efforts surrounding AKI have deepened our understanding of the syndrome prompting an expansion of existing concepts. A future integration of stress and damage biomarkers in AKI management, may lead to an individualized therapy in this area.

Prevalence, Associated Factors, and Outcomes of Severe Acute Kidney Injury in Pediatric Acute Liver Failure: Single-Center Retrospective Study, 2003-2017

OBJECTIVES

Our aim was to determine the prevalence and explanatory factors associated with outcomes in children with acute liver failure (ALF) admitted to the PICU, who also develop severe acute kidney injury (AKI).

DESIGN

Retrospective cohort, 2003 to 2017.

SETTING

Sixteen-bed PICU in a university-affiliated tertiary care hospital.

PATIENTS

Admissions to the PICU with ALF underwent data review of the first week and at least 90-day follow-up. Patients with stages 2-3 AKI using the British Association of pediatric Nephrology definitions, or receiving continuous renal replacement therapy (CRRT) for renal indications, were defined as severe AKI. We excluded ALF cases on CRRT for hepatic-only indications.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics, proportion with severe AKI, illness severity and interventions, and outcomes (i.e., transplant, survival with native liver, overall survival, duration of PICU stay, and mechanical ventilation). Ninety-four children with ALF admitted to the PICU were included. Over the first week, 29 had severe AKI, and another eight received CRRT for renal/mixed reno-hepatic indications; hence, the total severe AKI cohort was 37 of 94 (39.4%). In a multivariable logistic regression model, peak aspartate aminotransferase (AST) and requirement for inotropes on arrival were associated with severe AKI. Severe AKI was associated with longer PICU stay and duration of ventilation, and lower spontaneous survival with native liver. In another model, severe AKI was associated with greater odds of mortality (odds ratio 7.34 [95% CI, 1.90-28.28], p = 0.004). After 90 days, 3 of 17 survivors of severe AKI had serum creatinine greater than the upper limit of normal for age.

CONCLUSIONS

Many children with ALF in the PICU develop severe AKI. Severe AKI is associated with the timecourse of PICU admission and outcome, including survival with native liver. Future work should look at ALF goal directed renoprotective strategies at the time of presentation.

Assessment of Plasma Cystatin C as a Marker of Acute Renal Injury in Patients Undergoing Extracorporeal Shock Wave Lithotripsy for Renal Stone Disease

Introduction This study aimed to assess plasma cystatin C (CysC) as a marker of acute kidney injury (AKI) in patients undergoing extracorporeal shock wave lithotripsy (ESWL). We compared serum levels of CysC, C-reactive protein (CRP), and creatinine before and after ESWL. The study results may have implications for early detection of AKI and prevention of progression to chronic kidney disease. Methodology This prospective observational study included 105 adult participants and was conducted from August 2022 to July 2024. ESWL was the only modality of treatment. Results Forty-eight (46%) patients developed AKI after ESWL. Patients with AKI had significantly higher post-ESWL mean plasma CysC levels than patients without AKI (121 ± 0.25 vs. 0.94 ± 0.22 mg/dL, respectively; P = 0.001). The mean serum CRP levels after ESWL were significantly higher in patients who developed AKI compared with those who did not (4.36 ± 1.63 vs. 2.64 ± 0.95 mg/dL, respectively; P = 0.001). Conclusions In patients with renal stone disease, serum creatinine, serum CRP, and plasma CysC can be used as markers of acute renal injury after ESWL.

Incidence of acute kidney injury and attributive mortality in acute respiratory distress syndrome randomized trials

PURPOSE

The development of acute kidney injury (AKI) after the acute respiratory distress syndrome (ARDS) reduces the chance of organ recovery and survival. The purpose of this study was to examine the AKI rate and attributable mortality in ARDS patients.

METHODS

We performed an individual patient-data analysis including 10 multicenter randomized controlled trials conducted over 20 years. We employed a Super Learner ensemble technique, including a time-dependent analysis, to estimate the adjusted risk of AKI. We calculated the mortality attributable to AKI using an inverse probability of treatment weighting estimator integrated with the Super Learner.

RESULTS

There were 5148 patients included in this study. The overall incidence of AKI was 43.7% (n = 2251). The adjusted risk of AKI ranged from 38.8% (95% confidence interval [CI], 35.7 to 41.9%) in ARMA, to 55.8% in ROSE (95% CI, 51.9 to 59.6%). 37.1% recovered rapidly from AKI, with a significantly lower recovery rate in recent trials (P < 0.001). The 90-day excess in mortality attributable to AKI was 15.4% (95% CI, 12.8 to 17.9%). It decreased from 25.4% in ARMA (95% CI, 18.7 to 32%), to 11.8% in FACTT (95% CI, 5.5 to 18%) and then remained rather stable over time. The 90-day overall excess in mortality attributable to acute kidney disease was 28.4% (95% CI, 25.3 to 31.5%).

CONCLUSIONS

The incidence of AKI appears to be stable over time in patients with ARDS enrolled in randomized trials. The development of AKI remains a significant contributing factor to mortality. These estimates are essential for designing future clinical trials for AKI prevention or treatment.