International Criteria for Acute Kidney Injury: Advantages and Remaining Challenges

Impact of Non-Dialysis-Requiring Acute Kidney Injury on Survival Outcomes in Non-critically Ill Hospitalized Medical Patients in a Resource-Limited Setting: A Retrospective Cohort Study

Introduction The severe consequences of acute kidney injury (AKI) have been well-documented in high-risk patient populations. However, the effects of milder forms in non-critically ill patients remain understudied, particularly in resource-limited settings. While the risk of mortality associated with these cases is considered low, it can still lead to various complications including prolonged hospitalization, which may influence long-term renal and patient survival. Hence, the objective of this study was to study the impact of non-dialysis-requiring AKI (NDR-AKI) on survival outcomes of non-critically ill medical patients admitted to St. Paul's Hospital Millennium Medical College in Ethiopia during the period from July 2019 to January 2022. Methods A retrospective cohort study was conducted among 300 non-critically ill medical patients, 93 with NDR-AKI and 207 without AKI. Descriptive statistics, including frequency distributions and median survival times, were employed to summarize the data. Kaplan-Meier curves and the log-rank test were utilized to compare survival experiences of groups. A Cox proportional hazards survival model was fitted to estimate the impact of NDR-AKI on time to recovery. Adjusted hazard ratio (AHR) with 95% confidence interval (CI) was used to report findings. Results Two hundred four (68.0%) were discharged after improvement and the median recovery time was 16 days (95%CI: 13.5-18.5 days). Having NDR-AKI was associated with a 43% lower rate of achieving recovery (AHR=0.57, 95%CI=0.38, 0.84, p-value=0.004). Females were found to have a 1.41 times higher rate of recovery (AHR=1.41, 95%CI=1.03,1.94, p-value=0.033). Additionally, having tuberculosis (AHR=0.41, 95%CI=0.23,0.72, p-value=0.002) and being on anticoagulant (AHR=0.67, 95%CI=0.47,0.95, p-value=0.027) were associated with a 59% and 33% lower rate of recovery, respectively. Conclusion NDR-AKI significantly delays recovery compared to patients without AKI suggesting that even milder forms of AKI in non-critically ill patients can negatively impact patient outcomes. Early identification, prompt management, and addressing underlying causes are key to improving recovery and reducing long-term morbidity and mortality. Strict screening and monitoring of high-risk groups such as men, patients with tuberculosis, and those on anticoagulants is also crucial.

Advancements in Trauma-Induced Acute Kidney Injury: Diagnostic and Therapeutic Innovations

Acute kidney injury following trauma impacts patient recovery critically, necessitating an integrated approach to emergency care and nephrology. This review aims to provide a comprehensive understanding of trauma-induced nephropathy, highlighting recent advancements in pathophysiological insights, diagnostic techniques, and strategic interventions. Our key findings emphasize the role of biomarkers, like Neutrophil Gelatinase-Associated Lipocalin and Liver Fatty Acid-Binding Protein, and imaging techniques, such as contrast-enhanced ultrasound, in early AKI detection. Preventive strategies, including aggressive fluid resuscitation, avoidance of nephrotoxic agents, and hemodynamic optimization, are essential for mitigating AKI progression. Integrating these approaches into trauma care frameworks aims to enhance patient outcomes and set a foundation for future research and clinical improvements.

Hospital-Acquired Acute Kidney Injury in Non-Critical Medical Patients in a Developing Country Tertiary Hospital: Incidence and Predictors

Background

Acute kidney injury (AKI) is a frequent complication in critical patients, leading to a worse prognosis. Although its consequences are worse among critical patients, AKI is also associated with less favorable outcomes in non-critical patients. Therefore, understanding the magnitude of the problem in these patients is crucial, yet there is a scarcity of evidence in non-critical settings, especially in resource limited countries. Hence, the study aimed at determining the incidence and predictors of hospital acquired acute kidney injury (HAAKI) in non-critical medical patients who were admitted at a large tertiary hospital in Ethiopia.

Methods

A retrospective chart review study was conducted from September 25, 2022 to January 20, 2023 among 232 hospitalized non-critical medical patients admitted to St. Paul's Hospital Millennium Medical College between January 2020 and January 2022. The incidence of HAAKI was estimated using incidence density per total person day (PD) observation of the study participants. To identify predictors of HAAKI, a log binomial regression model was fitted at a p value of ≤0.05. The magnitude of association was measured using adjusted relative risk (ARR) with its 95% CI.

Results

During the median follow-up duration of 11 days (IQR, 6-19 days), the incidence of HAAKI was estimated to be 6.0 per 100 PD (95% CI = 5.5 to 7.2). Significant predictors of HAAKI were found to be having type 2 diabetes mellitus (ARR = 2.36, 95% CI = 1.03, 5.39, p-value=0.042), and taking vancomycin (ARR = 3.04, 95% CI = 1.38, 6.72, p-value=0.006) and proton pump inhibitors (ARR = 3.80, 95% CI = 1.34,10.82, p-value=0.012).

Conclusion

HAAKI is a common complication in hospitalized non-critical medical patients, and is associated with a common medical condition and commonly prescribed medications. Therefore, it is important to remain vigilant in the prevention and timely identification of these cases and to establish a system of rational prescribing habits.

A National audit of the care of patients with acute kidney injury in England and Wales in 2019 and the association with patient outcomes

BACKGROUND

Acute kidney injury (AKI) is a common complication of hospitalisations. This national audit assessed the care received by patients with AKI in hospital Trusts in England and Wales.

METHODS

Twenty four hospital Trusts across England and Wales took part. Patients with AKI stage2/3 were identified using the UK Renal Registry AKI master patient index. Data was returned through a secure portal with linkage to hospital episode statistic mortality and hospitalisation data. Completion rates of AKI care standards and regional variations in care were established.

RESULTS

989 AKI episodes were included in the analyses. In-hospital 30-day mortality was 31-33.1% (AKI 2/3). Standard AKI interventions were completed in >80% of episodes. Significant inter-hospital variation remained in attainment of AKI care standards after adjustment for age and sex. Recording of urinalysis (41.9%) and timely imaging (37.2%) were low. Information on discharge summaries relating to medication changes/re-commencement and follow-up blood tests associated with reduced mortality. No quality indicators relating to clinical management associated with mortality. Better communication on discharge summaries associated with reduced mortality.

CONCLUSIONS

Outcomes for patients with AKI in hospital remain poor. Regional variation in care exists. Work is needed to assess whether improving and standardising care improves patient outcomes.

Blood urea nitrogen to serum albumin ratio is associated with all-cause mortality in patients with AKI: a cohort study

Background

This study aims to investigate the relationship between blood urea nitrogen to serum albumin ratio (BAR) and all-cause mortality in patients with acute kidney injury (AKI) and evaluate the effect of BAR on the prognosis of AKI.

Methods

Adult patients with AKI admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) were selected in a retrospective cohort study. BAR (mg/g) was calculated using initial blood urea nitrogen (mg/dl)/serum albumin (g/dl). According to the BAR, these patients were divided into quartiles (Q1-Q4). Kaplan-Meier analysis was used to compare the mortality of the above four groups. Multivariate Cox regression analysis was used to evaluate the association between BAR and 28-day mortality and 365-day mortality. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated, and the subgroup analysis was finally stratified by relevant covariates.

Results

A total of 12,125 patients with AKI were included in this study. The 28-day and 365-day mortality rates were 23.89 and 39.07%, respectively. Kaplan-Meier analysis showed a significant increase in all-cause mortality in patients with high BAR (Log-rank p < 0.001). Multivariate Cox regression analysis showed that BAR was an independent risk factor for 28-day mortality (4.32 < BAR≤7.14: HR 1.12, 95% CI 0.97-1.30, p = 0.114; 7.14 < BAR≤13.03: HR 1.51, 95% CI 1.31-1.75, p < 0.001; BAR>13.03: HR 2.07, 95% CI 1.74-2.47, p < 0.001; Reference BAR≤4.32) and 365-day mortality (4.32 < BAR≤7.14: HR 1.22, 95% CI 1.09-1.36, p < 0.001; 7.14 < BAR≤13.03: HR 1.63, 95% CI 1.46-1.82, p < 0.001; BAR>13.03: HR 2.22, 95% CI 1.93-2.54, p < 0.001; Reference BAR ≤ 4.32) in patients with AKI. The AUC of BAR for predicting 28-day mortality and 365-day mortality was 0.649 and 0.662, respectively, which is better than that of blood urea nitrogen and sequential organ failure assessment. In addition, subgroup analysis showed a stable relationship between BAR and adverse outcomes in patients with AKI.

Conclusion

BAR is significantly associated with increased all-cause mortality in patients with AKI. This finding suggests that BAR may help identify people with AKI at high risk of mortality.

Ferroptosis: A new mechanism of traditional Chinese medicine compounds for treating acute kidney injury

Acute kidney injury (AKI) is a major health concern owing to its high morbidity and mortality rates, to which there are no drugs or treatment methods, except for renal replacement therapy. Therefore, identifying novel therapeutic targets and drugs for treating AKI is urgent. Ferroptosis is an iron-dependent and lipid-peroxidation-driven regulatory form of cell death and is closely associated with the occurrence and development of AKI. Traditional Chinese medicine (TCM) has unique advantages in treating AKI due to its natural origin and efficacy. In this review, we summarize the mechanisms underlying ferroptosis and its role in AKI, and TCM compounds that play essential roles in the prevention and treatment of AKI by inhibiting ferroptosis. This review suggests ferroptosis as a potential therapeutic target for AKI, and that TCM compounds show broad prospects in the treatment of AKI by targeting ferroptosis.

Efficacy of orally administered montmorillonite in myoglobinuric acute renal failure model in male rats

Objectives

Acute kidney injury can be associated with serious consequences and therefore early treatment is critical to decreasing mortality and morbidity rate. We evaluated the effect of montmorillonite, the clay with strong cation exchange capacity, on the AKI model in rats.

Materials and Methods

Glycerol (50% solution, 10 ml/kg) was injected in the rat hind limbs to induce AKI. 24 hr after induction of acute kidney injury, the rats received oral doses of montmorillonite (0.5 g/kg or 1 g/kg), or sodium polystyrene sulfonate (1 g/kg) for three consecutive days.

Results

Glycine induced acute kidney injury in rats with high levels of urea (336.60± 28.19 mg/dl), creatinine (4.10± 0.21 mg/dl), potassium (6.15 ± 0.28 mEq/L), and calcium (11.52 ± 0.19 mg/dl). Both doses of montmorillonite (0.5 and 1 g/kg) improved the serum urea (222.66± 10.02 and 170.20±8.06, P<0.05), creatinine (1.86±0.1, 2.05± 0.11, P<0.05), potassium (4.68 ± 0.4, 4.73 ± 0.34, P<0.001) and calcium (11.15 ± 0.17, 10.75 ± 0.25, P<0.01) levels. Treatment with montmorillonite especially at a high dose reduced the kidney pathological findings including, tubular necrosis, amorphous protein aggregation, and cell shedding into the distal and proximal tubule lumen. However, administration of SPS could not significantly decrease the severity of damages.

Conclusion

According to the results of this study, as well as the physicochemical properties of montmorillonite, such as high ion exchange capacity and low side effects, montmorillonite can be a low-cost and effective treatment option to reduce and improve the complications of acute kidney injury. However, the efficacy of this compound in human and clinical studies needs to be investigated.

Association between uric acid level and contrast-induced acute kidney injury in patients with type 2 diabetes mellitus after coronary angiography: a retrospective cohort study

BACKGROUND

This study assessed the predictive value of uric acid (UA) for contrast-induced acute kidney injury (CI-AKI) in patients with type 2 diabetes mellitus (T2DM) who underwent coronary angiography (CAG). A nomogram to aid in the prediction of CI-AKI was also developed and validated, and the construction of a prognostic nomogram combined with clinical features was attempted.

METHODS

This study retrospectively enrolled T2DM patients who underwent CAG between December 2019 and December 2020 at the Affiliated Zhongda Hospital of Southeast University. Multivariable logistic regression analysis was used for the analysis of clinical outcomes. Receiver operating characteristic (ROC) analyses were performed to determine the area under the ROC curve (AUC) and the cut-off points for continuous clinical data. The prediction accuracies of models for CI-AKI were estimated through Harrell's concordance indices (C-index). Nomograms of the prognostic models were plotted for individualized evaluations of CI-AKI in T2DM patients after CAG.

RESULTS

A total of 542 patients with T2DM who underwent CAG were included in this study. We found that a high UA level (≥ 425.5 µmol/L; OR = 6.303), BUN level (≥ 5.98 mmol/L; OR = 3.633), Scr level (≥ 88.5 µmol/L; OR = 2.926) and HbA1C level (≥ 7.05%; OR = 5.509) were independent factors for CI-AKI in T2DM patients after CAG. The nomogram model based on UA, BUN, Scr and HbA1C levels presented outstanding performance for CI-AKI prediction (C-index: 0.878). Decision curve analysis (DCA) showed good clinical applicability in predicting the incidence of CI-AKI in T2DM patients who underwent CAG.

CONCLUSION

High UA levels are associated with an increased incidence of CI-AKI in T2DM patients after CAG. The developed nomogram model has potential predictive value for CI-AKI and might serve as an economic and efficient prognostic tool in clinical practice.

Regulator of calcineurin 1 deletion attenuates mitochondrial dysfunction and apoptosis in acute kidney injury through JNK/Mff signaling pathway

Ischemia-reperfusion (I/R) induced acute kidney injury (AKI), characterized by excessive mitochondrial damage and cell apoptosis, remains a clinical challenge. Recent studies suggest that regulator of calcineurin 1 (RCAN1) regulates mitochondrial function in different cell types, but the underlying mechanisms require further investigation. Herein, we aim to explore whether RCAN1 involves in mitochondrial dysfunction in AKI and the exact mechanism. In present study, AKI was induced by I/R and cisplatin in RCAN1^flox/flox mice and mice with renal tubular epithelial cells (TECs)-specific deletion of RCAN1. The role of RCAN1 in hypoxia-reoxygenation (HR) and cisplatin-induced injury in human renal proximal tubule epithelial cell line HK-2 was also examined by overexpression and knockdown of RCAN1. Mitochondrial function was assessed by transmission electron microscopy, JC-1 staining, MitoSOX staining, ATP production, mitochondrial fission and mitophagy. Apoptosis was detected by TUNEL assay, Annexin V-FITC staining and Western blotting analysis of apoptosis-related proteins. It was found that protein expression of RCAN1 was markedly upregulated in I/R- or cisplatin-induced AKI mouse models, as well as in HR models in HK-2 cells. RCAN1 deficiency significantly reduced kidney damage, mitochondrial dysfunction, and cell apoptosis, whereas RCAN1 overexpression led to the opposite phenotypes. Our in-depth mechanistic exploration demonstrated that RCAN1 increases the phosphorylation of mitochondrial fission factor (Mff) by binding to downstream c-Jun N-terminal kinase (JNK), then promotes dynamin related protein 1 (Drp1) migration to mitochondria, ultimately leads to excessive mitochondrial fission of renal TECs. In conclusion, our study suggests that RCAN1 could induce mitochondrial dysfunction and apoptosis by activating the downstream JNK/Mff signaling pathway. RCAN1 may be a potential therapeutic target for conferring protection against I/R- or cisplatin-AKI.

Identifying and managing acute kidney injury

Acute kidney injury, previously referred to as acute renal failure, is a common and often preventable condition that is seen in patients in acute and primary care settings. Nurses in both settings should be able to identify and assess patients at risk of acute kidney injury, and those with developing acute kidney injury, and understand the principles of clinical management. Early identification can assist in prevention of acute kidney injury, while supportive management and interventions can prevent further deterioration in patients diagnosed with the condition. This article describes acute kidney injury and outlines the pathophysiology, staging, and signs and symptoms. The author also describes the clinical management of patients with acute kidney injury and the long-term effects of the condition.

Loop Diuretics Are Associated with Increased Risk of Hospital-Acquired Acute Kidney Injury in Adult Patients: A Retrospective Study

Background: The association between loop diuretics and acute kidney injury (AKI) remains unclear. Methods: The population studied was selected from the Epidemiology of AKI in Chinese Hospitalized patients (EACH) study. Exposure to loop diuretics was defined as any filled prescription prior to the date when AKI was detected in patients with HA-AKI, and prior to the last date of SCr testing in those without AKI. The outcome was AKI, defined by the Kidney Disease Improving Global Outcomes criteria. Associations between loop diuretics and HA-AKI were examined by Cox proportional hazards models adjusted for baseline and time-dependent covariates. Results: Of the 150,020 patients, 16,437 (11.0%) were prescribed loop diuretics, and 5717 (3.8%) experienced HA-AKI events. The crude rates of HA-AKI in patients who were and were not prescribed loop diuretics were 1632 (9.9%) and 3262 (2.8%), respectively. A multivariate cox proportional hazards analysis showed that exposure to loop diuretics was associated with significantly increased risks of HA-AKI compared with non-users (hazard ratio (HR), 1.61; 95% CI (confidence interval), 1.55–1.67), other diuretics (HR, 1.09; 95% CI, 1.03–1.15), and osmotic diuretics (HR, 1.30; 95% CI, 1.20–1.42). Compared with other diuretics, the use of loop diuretics was associated with higher risks of HA-AKI in women, in patients without hypertension, in patients without heart failure, in patients without liver cirrhosis, and in patients not requiring surgery. Conclusions: Loop diuretics are widely used and are associated with increased risks of HA-AKI in hospitalized adults. Renal function should be more closely monitored during the use of loop diuretics.

Use of an extended KDIGO definition to diagnose acute kidney injury in patients with COVID-19: A multinational study using the ISARIC-WHO clinical characterisation protocol

BACKGROUND

Acute kidney injury (AKI) is one of the most common and significant problems in patients with Coronavirus Disease 2019 (COVID-19). However, little is known about the incidence and impact of AKI occurring in the community or early in the hospital admission. The traditional Kidney Disease Improving Global Outcomes (KDIGO) definition can fail to identify patients for whom hospitalisation coincides with recovery of AKI as manifested by a decrease in serum creatinine (sCr). We hypothesised that an extended KDIGO (eKDIGO) definition, adapted from the International Society of Nephrology (ISN) 0by25 studies, would identify more cases of AKI in patients with COVID-19 and that these may correspond to community-acquired AKI (CA-AKI) with similarly poor outcomes as previously reported in this population.

METHODS AND FINDINGS

All individuals recruited using the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC)-World Health Organization (WHO) Clinical Characterisation Protocol (CCP) and admitted to 1,609 hospitals in 54 countries with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection from February 15, 2020 to February 1, 2021 were included in the study. Data were collected and analysed for the duration of a patient's admission. Incidence, staging, and timing of AKI were evaluated using a traditional and eKDIGO definition, which incorporated a commensurate decrease in sCr. Patients within eKDIGO diagnosed with AKI by a decrease in sCr were labelled as deKDIGO. Clinical characteristics and outcomes-intensive care unit (ICU) admission, invasive mechanical ventilation, and in-hospital death-were compared for all 3 groups of patients. The relationship between eKDIGO AKI and in-hospital death was assessed using survival curves and logistic regression, adjusting for disease severity and AKI susceptibility. A total of 75,670 patients were included in the final analysis cohort. Median length of admission was 12 days (interquartile range [IQR] 7, 20). There were twice as many patients with AKI identified by eKDIGO than KDIGO (31.7% versus 16.8%). Those in the eKDIGO group had a greater proportion of stage 1 AKI (58% versus 36% in KDIGO patients). Peak AKI occurred early in the admission more frequently among eKDIGO than KDIGO patients. Compared to those without AKI, patients in the eKDIGO group had worse renal function on admission, more in-hospital complications, higher rates of ICU admission (54% versus 23%) invasive ventilation (45% versus 15%), and increased mortality (38% versus 19%). Patients in the eKDIGO group had a higher risk of in-hospital death than those without AKI (adjusted odds ratio: 1.78, 95% confidence interval: 1.71 to 1.80, p-value < 0.001). Mortality and rate of ICU admission were lower among deKDIGO than KDIGO patients (25% versus 50% death and 35% versus 70% ICU admission) but significantly higher when compared to patients with no AKI (25% versus 19% death and 35% versus 23% ICU admission) (all p-values <5 × 10-5). Limitations include ad hoc sCr sampling, exclusion of patients with less than two sCr measurements, and limited availability of sCr measurements prior to initiation of acute dialysis.

CONCLUSIONS

An extended KDIGO definition of AKI resulted in a significantly higher detection rate in this population. These additional cases of AKI occurred early in the hospital admission and were associated with worse outcomes compared to patients without AKI.

Acute Kidney Injury and Acute Respiratory Distress Syndrome

Acute kidney injury (AKI) complicates approximately a third of all acute respiratory distress syndrome (ARDS) cases, and the combination of the two drastically worsens prognosis. Recent advances in ARDS supportive care have led to improved outcomes; however, much less is known on how to prevent and support patients with AKI and ARDS together. Understanding the dynamic relationship between the kidneys and lungs is crucial for the practicing intensivist to prevent injury. This article summarizes key concepts for the critical care physician managing a patient with ARDS complicated by AKI. Also provided is a discussion of AKI in the COVID-19 era.

Developing an Agnostic Risk Prediction Model for Early AKI Detection in Cancer Patients

Acute kidney injury (AKI) is a common complication among oncology patients associated with lower remission rates and higher mortality. To reduce the impact of this condition, we aimed to predict AKI earlier than existing tools, to allow clinical intervention before occurrence. We trained a random forest model on 597,403 routinely collected blood test results from 48,865 patients undergoing cancer treatment at The Christie NHS Foundation Trust between January 2017 and May 2020, to identify AKI events upcoming in the next 30 days. AKI risk levels were assigned to upcoming AKI events and tested through a prospective analysis between June and August 2020. The trained model gave an AUROC of 0.881 (95% CI 0.878-0.883), when assessing predictions per blood test for AKI occurrences within 30 days. Assigning risk levels and testing the model through prospective validation from the 1st June to the 31st August identified 73.8% of patients with an AKI event before at least one AKI occurrence, 61.2% of AKI occurrences. Our results suggest that around 60% of AKI occurrences experienced by patients undergoing cancer treatment could be identified using routinely collected blood results, allowing clinical remedial action to be taken and disruption to treatment by AKI to be minimised.

Comparison of Static and Dynamic Baseline Creatinine Surrogates for Defining Acute Kidney Injury

BACKGROUND

"Dynamic" baseline serum creatinine (sCr), based on a rolling 48-h window, and a static baseline sCr (previous outpatient sCr) were used to define acute kidney injury (AKI).

METHODS

Retrospective cohort study of adult admissions to the University of Alabama (UAB) Health System hospitals for years 2016-2018. Included admissions had >1- and <180-day length of stay, >2 inpatient sCr measurements, and an averaged estimated glomerular filtration rate >15 mL/min/1.73 m2. The final cohort of 62,380 patients included 100,570 admissions, 3,509 inpatient deaths, and 1,916 admissions with inpatient dialysis. AKI was defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria and a static or dynamic baseline sCr. Discrimination was evaluated with area under receiver operator curves (AUC), logistic regression, and net reclassification improvement (NRI).

RESULTS

Preadmission outpatient "static" sCr values were available for 43,433 admissions. The lowest sCr value during a rolling 48-h window before each inpatient sCr defined a "dynamic" baseline sCr. Using point-wise comparisons, the dynamic baseline sCr performed better than static baseline sCr for inpatient mortality (AUC [0.819 vs. 0.741; p < 0.001] and NRI ≥0.306 [p < 0.001]) and inpatient dialysis (AUC [0.903 vs. 0.864; p < 0.001] and NRI ≥0.317 [p < 0.001]).

CONCLUSIONS

The dynamic baseline sCr is available without reference to preadmission sCr values and avoids confounding associated with missing outpatient sCr values. AKI defined with the dynamic baseline sCr significantly improved discrimination of risk for inpatient mortality and dialysis compared to static baseline sCr.

Mortality and predictors of acute kidney injury in adults: a hospital-based prospective observational study

Acute kidney injury (AKI) is a major global public health problem. It is expensive to manage and associated with a high rate of prolonged hospitalization and in-hospital mortality. Little is known about the burden of acute kidney injury in moderate to low-income countries. We aim to assess predictors of in-hospital mortality among AKI patients admitted to the medical ward. We prospectively identified patients meeting kidney disease improving global outcomes (KIDGO) AKI definitions from April to August 2019. Patients with underlying CKD and patients hospitalized for less than 48 h were excluded. The Cox regression model was fitted to identify predictors of mortality and statistical significance was considered at the p-value of less than 0.05. A total of 203 patients were enrolled over 5 months. Out of this, 121(59.6%) were males, 58(28.6%) were aged greater than 60 years, and 141(69.5%) had community-acquired acute kidney injury. The most common causes of AKI were Hypovolemia 99(48.77%), Glomerulonephritis 51(25.11%), and sepsis 32(15.79%). The overall in-hospital mortality rate was 12.8%. Stage 3 AKI (AHR = 9.61, 95% CI 1.17-28.52, p = 0.035), duration of AKI (AHR = 7.04, 95% CI 1.37-36.08, p = 0.019), length of hospital stay (AHR = 0.19, 95% CI 0.05-0.73, p = 0.012), and hyperkalemia (AHR = 3.61, 95% CI 1.12-11.71, p = 0.032) were significantly associated with in-hospital mortality. There is a high rate of acute kidney injury-related in-hospital mortality in adult patients admitted to the medical ward. The severity of AKI, hyperkalemia duration of AKI, and a short length of hospital stay were predictors of 30-days in-hospital mortality. Most of the causes of AKI are preventable and patients may benefit from early identification and treatment of these reversible causes.

Predictors and Outcomes of Dengue-Associated Acute Kidney Injury

Dengue viral infections present with a wide clinical spectrum ranging from asymptomatic to severe manifestations with organ involvement. The term "expanded dengue syndrome" has been commonly used to illustrate the unusual or atypical manifestations; acute kidney injury (AKI) is one of the atypical manifestations of this syndrome. The use of heterogeneous criteria to determine the presence of AKI in dengue patients due to the vast diversity in populations led to difficulties in assessing the true incidence of dengue-associated AKI. This review presents a variable, but often high, frequency of dengue-associated AKI among vastly diverse populations with various disease severities. Dengue-associated AKI is not an uncommon complication, and its importance has often been neglected during the management of dengue patients. The risk factors and certain clinical and laboratory findings commonly reported among dengue patients with AKI should be considered to support a timely diagnosis and case management. This review highlights the need for clinicians to be aware of dengue-associated AKI to reduce the morbidity and mortality associated with this common and important tropical disease.

Long-term Renal Outcomes in Adults With Sepsis-Induced Acute Kidney Injury: A Systematic Review

BACKGROUND

Despite advances in medical technologies and intervention occurrences, acute kidney injury (AKI) incidence continues to rise. Early interventions after sepsis are essential to prevent AKI and its long-term consequences. Acute kidney injury is the leading cause of organ failure in sepsis; therefore, more research is needed on its long-term consequences and progression to kidney injury.

OBJECTIVES

The aim of this study was to review the state of the science on long-term renal outcomes after sepsis-induced AKI and long-term renal consequences.

METHODS

We identified research articles from PubMed and CINAHL databases using relevant key words for sepsis-induced AKI within 5 years delimited to full-text articles in English.

RESULTS

Among 1280 abstracts identified, we ultimately analyzed 12 full-text articles, identifying four common themes in the literature: (1) AKI determination criteria, (2) severity/prognosis-related factors, (3) time frame for long-term outcome measures, and (4) chronic kidney disease (CKD) and renal related exclusions. Researchers primarily used KDIGO (Kidney Disease: Improving Global Outcomes) guidelines to define AKI. All of these studies excluded patients with CKD. The range of time for long-term renal outcomes was 28 days to 3 years, with the majority being 1 year. Renal outcomes ranged from recovery to renal replacement therapy to death.

CONCLUSIONS

To better understand the long-term renal outcomes after sepsis-induced AKI, more consistent measures are needed across all studies regarding the time frame and specific renal outcomes. Because all of these articles excluded patients with CKD, a gap exists on long-term renal outcome in acute on CKD.

An epidemiologic overview of acute kidney injury in intensive care units

SUMMARY INTRODUCTION Acute kidney injury (AKI) is a frequent event among critically ill patients hospitalized in intensive care units (ICU) and represents a global public health problem, being imperative an interdisciplinary approach. OBJECTIV To investigate, through literature review, the AKI epidemiology in ICUs. METHODS: Online research in Medline, Scientific Electronic Library Online, and Latin American and Caribbean Literature in Health Sciences databases, with analysis of the most relevant 47 studies published between 2010 and 2017. RESULTS Data of the 67,033 patients from more than 300 ICUs from different regions of the world were analyzed. The overall incidence of AKI ranged from 2.5% to 92.2%, and the mortality from 5% to 80%. The length of ICU stay ranged from five to twenty-one days, and the need for renal replacement therapy from 0.8% to 59.2%. AKI patients had substantially higher mortality rates and longer hospital stays than patients without AKI. CONCLUSION AKI incidence presented high variability among the studies. One of the reasons for that were the different criteria used to define the cases. Availability of local resources, renal replacement therapy needs, serum creatinine at ICU admission, volume overload, and sepsis, among others, influence mortality rates in AKI patients.

An Organizational-Level Program of Intervention for AKI: A Pragmatic Stepped Wedge Cluster Randomized Trial

BACKGROUND

Variable standards of care may contribute to poor outcomes associated with AKI. We evaluated whether a multifaceted intervention (AKI e-alerts, an AKI care bundle, and an education program) would improve delivery of care and patient outcomes at an organizational level.

METHODS

A multicenter, pragmatic, stepped-wedge cluster randomized trial was performed in five UK hospitals, involving patients with AKI aged ≥18 years. The intervention was introduced sequentially across fixed three-month periods according to a randomly determined schedule until all hospitals were exposed. The primary outcome was 30-day mortality, with pre-specified secondary endpoints and a nested evaluation of care process delivery. The nature of the intervention precluded blinding, but data collection and analysis were independent of project delivery teams.

RESULTS

We studied 24,059 AKI episodes, finding an overall 30-day mortality of 24.5%, with no difference between control and intervention periods. Hospital length of stay was reduced with the intervention (decreases of 0.7, 1.1, and 1.3 days at the 0.5, 0.6, and 0.7 quantiles, respectively). AKI incidence increased and was mirrored by an increase in the proportion of patients with a coded diagnosis of AKI. Our assessment of process measures in 1048 patients showed improvements in several metrics including AKI recognition, medication optimization, and fluid assessment.

CONCLUSIONS

A complex, hospital-wide intervention to reduce harm associated with AKI did not reduce 30-day AKI mortality but did result in reductions in hospital length of stay, accompanied by improvements in in quality of care. An increase in AKI incidence likely reflected improved recognition.

[Expression and significance of tight junction proteins in the kidney in a mouse model of renal ischemia-reperfusion injury]

OBJECTIVE

To study the expression and significance of tight junction proteins (claudin-2, claudin-10, and claudin-17) in a mouse model of renal ischemia-reperfusion injury.

METHODS

A total of 152 male C57BL/6 mice were randomly assigned to control group (n=8), sham-operation group (n=72), and model group (n=72). The renal pedicles at both sides were clamped for 30 minutes to establish a mouse model of renal ischemia-reperfusion injury. According to the time points of reperfusion (0, 3, 6, 12, 24, 48, and 72 hours and 5 and 7 days), the sham-operation group and the model group were further divided into 9 subgroups, with 8 mice in each subgroup. RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue.

RESULTS

The control and sham-operation groups had no significant changes in the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue over the time of reperfusion (P>0.05). Compared with the control and sham-operation groups, the model group had decreased mRNA and protein expression of claudin-2 and claudin-10 after reperfusion, and the expression decreased gradually over the time of reperfusion, with the lowest levels at 24 hours of reperfusion (P<0.05). Compared with the control and sham-operation groups, the model group had increased mRNA and protein expression of claudin-17 after reperfusion, and the expression increased gradually over the time of reperfusion, with the highest mRNA level at 12 hours and the highest protein level at 24 hours of reperfusion (P<0.05).

CONCLUSIONS

Renal ischemia-reperfusion injury is closely associated with abnormal expression of tight junction proteins claudin-2, claudin-10, and claudin-17.

[Expression and significance of tight junction proteins in the kidney in a mouse model of renal ischemia-reperfusion injury]

OBJECTIVE

To study the expression and significance of tight junction proteins (claudin-2, claudin-10, and claudin-17) in a mouse model of renal ischemia-reperfusion injury.

METHODS

A total of 152 male C57BL/6 mice were randomly assigned to control group (n=8), sham-operation group (n=72), and model group (n=72). The renal pedicles at both sides were clamped for 30 minutes to establish a mouse model of renal ischemia-reperfusion injury. According to the time points of reperfusion (0, 3, 6, 12, 24, 48, and 72 hours and 5 and 7 days), the sham-operation group and the model group were further divided into 9 subgroups, with 8 mice in each subgroup. RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue.

RESULTS

The control and sham-operation groups had no significant changes in the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue over the time of reperfusion (P>0.05). Compared with the control and sham-operation groups, the model group had decreased mRNA and protein expression of claudin-2 and claudin-10 after reperfusion, and the expression decreased gradually over the time of reperfusion, with the lowest levels at 24 hours of reperfusion (P<0.05). Compared with the control and sham-operation groups, the model group had increased mRNA and protein expression of claudin-17 after reperfusion, and the expression increased gradually over the time of reperfusion, with the highest mRNA level at 12 hours and the highest protein level at 24 hours of reperfusion (P<0.05).

CONCLUSIONS

Renal ischemia-reperfusion injury is closely associated with abnormal expression of tight junction proteins claudin-2, claudin-10, and claudin-17.

Definition, Management, and Outcomes of Acute Kidney Injury: An International Survey of Nephrologists

Background

Acute kidney injury (AKI) is a complex disease burdened by uncertainties of definition, management strategies, and prognosis. This study explores the relationship between demographic characteristics of nephrologists and their perceptions about the definition, management, and follow-up of AKI.

Methods

We developed a Web-based survey, the International Survey on Acute Kidney Injury (ISAKI), consisting of 29 items in 4 categories: (1) demographic and practice characteristics, (2) definition of AKI, (3) management of renal replacement therapy (RRT) in AKI, and (4) sequelae of AKI. A multivariable stepwise logistic regression model was used to examine relationships between the dependent variables and the demographic characteristics of the respondents.

Results

Responses from 743 nephrologists from 90 countries were analyzed. The majority (60%) of respondents reported using RIFLE and/or AKIN criteria regularly to define AKI, although US nephrologists were less likely to do so (OR: 0.58; 95% CI: 0.42-0.85). The most common initial RRT modality was intermittent hemodialysis (63.5%), followed by continuous RRT (23.8%). Faculty affiliation was associated with a higher likelihood of using a dialysis schedule of ≥4 times a week (OR: 1.75; 95% CI: 1.20-2.55). The respondents believed that a single episode of AKI increases the likelihood of development of chronic kidney disease (CKD) (55%), subsequent AKI (36%), and rapid progression of preexisting CKD (87%). US nephrologists were less likely to recommend follow-up after resolution of AKI (OR: 0.15; 95% CI: 0.07-0.33).

Conclusions

Our findings highlight the need for a widely accepted consensus definition of AKI, a uniform approach to management, and improved follow-up after resolution of AKI episodes.

Serelaxin as a potential treatment for renal dysfunction in cirrhosis: Preclinical evaluation and results of a randomized phase 2 trial

BACKGROUND

Chronic liver scarring from any cause leads to cirrhosis, portal hypertension, and a progressive decline in renal blood flow and renal function. Extreme renal vasoconstriction characterizes hepatorenal syndrome, a functional and potentially reversible form of acute kidney injury in patients with advanced cirrhosis, but current therapy with systemic vasoconstrictors is ineffective in a substantial proportion of patients and is limited by ischemic adverse events. Serelaxin (recombinant human relaxin-2) is a peptide molecule with anti-fibrotic and vasoprotective properties that binds to relaxin family peptide receptor-1 (RXFP1) and has been shown to increase renal perfusion in healthy human volunteers. We hypothesized that serelaxin could ameliorate renal vasoconstriction and renal dysfunction in patients with cirrhosis and portal hypertension.

METHODS AND FINDINGS

To establish preclinical proof of concept, we developed two independent rat models of cirrhosis that were characterized by progressive reduction in renal blood flow and glomerular filtration rate and showed evidence of renal endothelial dysfunction. We then set out to further explore and validate our hypothesis in a phase 2 randomized open-label parallel-group study in male and female patients with alcohol-related cirrhosis and portal hypertension. Forty patients were randomized 1:1 to treatment with serelaxin intravenous (i.v.) infusion (for 60 min at 80 μg/kg/d and then 60 min at 30 μg/kg/d) or terlipressin (single 2-mg i.v. bolus), and the regional hemodynamic effects were quantified by phase contrast magnetic resonance angiography at baseline and after 120 min. The primary endpoint was the change from baseline in total renal artery blood flow. Therapeutic targeting of renal vasoconstriction with serelaxin in the rat models increased kidney perfusion, oxygenation, and function through reduction in renal vascular resistance, reversal of endothelial dysfunction, and increased activation of the AKT/eNOS/NO signaling pathway in the kidney. In the randomized clinical study, infusion of serelaxin for 120 min increased total renal arterial blood flow by 65% (95% CI 40%, 95%; p < 0.001) from baseline. Administration of serelaxin was safe and well tolerated, with no detrimental effect on systemic blood pressure or hepatic perfusion. The clinical study's main limitations were the relatively small sample size and stable, well-compensated population.

CONCLUSIONS

Our mechanistic findings in rat models and exploratory study in human cirrhosis suggest the therapeutic potential of selective renal vasodilation using serelaxin as a new treatment for renal dysfunction in cirrhosis, although further validation in patients with more advanced cirrhosis and renal dysfunction is required.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01640964.