Acute Kidney Injury Classification Research Articles

Improving awareness of kidney function through electronic urine output monitoring: a comparative study

BackgroundThe current classification for acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria integrates both serum creatinine (SCr) and urine output (UO). Most reports on AKI claim to use KDIGO guidelines but fail to include the UO criterion. It has been shown that patients who had intensive UO monitoring, with or without AKI, had significantly less cumulative fluid volume and fluid overload, reduced vasopressor use, and improved 30-day mortality. We examined whether real-time monitoring of this simple, sensitive, and easy-to-use biomarker in the ICU led to more appropriate intervention by healthcare providers and better outcomes. MethodsRenalSense Clarity RMS Consoles were installed in the General ICU at the Hadassah Medical Center, Israel, from December 2019 to November 2020. The Clarity RMS system continuously and electronically monitors UO in real-time. 100 patients were randomly selected from this period as the study group (UOelec) and compared to a matched control group (UOmanual) from the same period two years earlier. To test whether there was an association between oliguric hours and fluid treatment in each group, the correlation was calculated and analyzed for each of the different UO monitoring methods.ResultsTherapeutic intervention: The correlation of the sum of all oliguric hours on Day 1 and 2 with the sum of any therapeutic intervention (fluid bolus or furosemide) showed a significant correlation for the study group UOelec (P = 0.017). The matched control group UOmanual showed no such correlation (P = 0.932). Length of Stay (LOS): Median LOS [IQR] in the ICU of UOelec versus UOmanual was 69.46 [44.7, 125.9] hours and 116.5 [62.46, 281.3] hours, respectively (P = 0.0002).ConclusionsThe results of our study strongly suggest that ICU patients had more meaningful and better medical intervention, and improved outcomes, with electronic UO monitoring than with manual monitoring.

Assessment of Renal Function in Head and Neck Cancer Patients Treated with Cisplatin: Different Biomarkers and Acute Kidney Injury Classifications.

Cisplatin is associated with dose-limiting nephrotoxicity, and the timely detection of acute kidney injury (AKI) can affect morbimortality. Therefore, this study aimed to investigate the tools for monitoring renal function in AKI. This was a retrospective, cohort study. Cisplatin-treated patients with head and neck cancer were included. Nephrotoxicity was assessed using serum creatinine, estimated creatinine clearance, serum electrolytic alterations, and plasma kidney injury molecule-1 (KIM-1). The toxicity severity was classified according to Common Terminology Criteria for Adverse Events (CTCAE), and AKI was classified by Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) and Acute Kidney Injury Network (AKIN). A total of 81 participants were included, of whom only 32 did not have AKI. Almost 90% of participants had a decreased estimated glomerular filtration rate five (D5) days after chemotherapy. The AKI estimate differs between AKIN and RIFLE; more participants were diagnosed by the RIFLE at D5, 19.5% versus 2.4% by AKIN, and fifteen had a discordance between these classifications. All laboratory markers showed significant changes on D5. KIM-1 appeared a possible biomarker when considering CTCAE or AKIN classifications (p < 0.05 on D5), but not when RIFLE classification was used (p = 0.0780). Further studies may seek to understand the profiles of different biomarkers together.

Update on prognosis driven classification of pediatric AKI.

Acute kidney injury (AKI) affects a large proportion of hospitalized children and increases morbidity and mortality in this population. Initially thought to be a self-limiting condition with uniformly good prognosis, we now know that AKI can persist and progress to acute kidney disease (AKD) and chronic kidney disease (CKD). AKI is presently categorized by stage of injury defined by increase in creatinine, decrease in eGFR, or decrease in urine output. These commonly used biomarkers of acute kidney injury do not change until the injury is well established and are unable to detect early stage of the disease when intervention is likely to reverse injury. The kidneys have the ability to compensate and return serum creatinine to a normal or baseline level despite nephron loss in the setting of AKI possibly masking persistent dysfunction. Though these definitions are important, classifying children by their propensity for progression to AKD and CKD and defining these risk strata by other factors besides creatinine may allow for better prognosis driven discussion, expectation setting, and care for our patients. In order to develop a classification strategy, we must first be able to recognize children who are at risk for AKD and CKD based on modifiable and non-modifiable factors as well as early biomarkers that identify their risk of persistent injury. Prevention of initial injury, prompt evaluation and treatment if injury occurs, and mitigating further injury during the recovery period may be important factors in decreasing risk of AKD and CKD after AKI. This review will cover presently used definitions of AKI, AKD, and CKD, recent findings in epidemiology and risk factors for AKI to AKD to CKD progression, novel biomarkers for early identification of AKI and AKI that may progress to CKD and future directions for improving outcome in children with AKI.

Diagnostic Performance of Height-Estimated Baseline Creatinine in Diagnosing Acute Kidney Injury in Children with Type 1 Diabetes Mellitus Onset.

At type 1 diabetes mellitus (T1DM) onset, acute kidney injury (AKI) is very common. To diagnose AKI, the availability of a baseline serum creatinine (bSCr) is pivotal. However, in most hospitalized children the bSCr is unknown. We aimed to test whether the bSCr estimated on the basis of height (ebSCr) could be a reliable surrogate for AKI diagnosis compared with the measured bSCr (mbSCr). As the mbSCr, we considered the creatinine measured 14 days after T1DM onset while ebSCr (mg/dL) = (k × height [cm])/120 mL/min/1.73 m2, where k = 0.55 for children and adolescent girls and k = 0.7 for adolescent boys. AKI was defined as serum creatinine values >1.5 times the baseline creatinine. Kappa statistics and the percentage of agreement in AKI classification by ebSCr–AKI versus mbSCr–AKI definition methods were calculated. Bland–Altman plots were used to show the agreement between the creatinine ratio (highest/baseline creatinine; HC/BC) calculated with mbSCr and ebSCr. The number of 163 patients with T1DM onset were included. On the basis of mbSCr, 66/163 (40.5%) presented AKI while, on the basis of ebSCr, 50/163 (30.7%) accomplished AKI definition. ebSCr showed good correlation with mbSCr using both the Spearman test (rho = 0.67; p < 0.001) and regression analysis (r = 0.68; p < 0.001). Moreover, at the Bland–Altman plots, the bias of the highest/baseline creatinine ratio calculated on the basis of the mbSCr compared to ebSCr was minimal (bias = −0.08 mg/dL; 95% limits of agreement = −0.23/0.39). AKI determined using ebSCr showed 90% agreement with AKI determined using mbSCr (kappa = 0.66; p < 0.001). Finally, we compared the area under a receiver–operating characteristic curve (AUROC) of HC/BC ratio calculated on the basis of ebSCr with AUROC of the gold standard HC/BC ratio calculated on the basis of mbSCr. As expected, the gold standard had an AUROC = 1.00 with a 95% confidence interval (CI) between 0.98 and 1.00, p < 0.001. The HC/BC ratio calculated on the basis of ebSCr also had significant AUROC (AUROC = 0.94; 95% CI: 0.90–0.97; p < 0.001). The comparison of the two ROC curves showed a p < 0.001. In conclusion, when mbSCr is unknown in patients with T1DM onset, the ebSCr calculated on the basis of height could be an alternative to orientate clinicians toward AKI diagnosis.

Advances in laboratory detection of acute kidney injury

Recent advances have improved our understanding of the epidemiology and pathophysiology of acute kidney injury (AKI). So far, the Kidney Disease: Improving Global Outcome guidelines define and stratify kidney injury based on increases in serum creatinine level and/or decreases in urine output. Although the term AKI acknowledges the existence of cellular injury, its diagnosis is still only defined by the reduced excretory function of the kidney. New biomarkers that aid a better understanding of the relationship between acute tubular injury and kidney dysfunction have been identified, reflecting the advances in molecular biology. The expression of some of these novel biomarkers precedes changes in conventional biomarkers or can increase their predictive power. Therefore, they might enhance the clinical accuracy of the definition of AKI. This review summarizes the limitations of the current AKI classification and a panel of candidate biomarkers for augmenting AKI classification and recognition of AKI subphenotypes. We expect that the integration of appropriately selected biomarkers in routine clinical practice can improve AKI care.

Clinical profile of patients with acute kidney injury admitted in intensive care unit

Background: Acute kidney injury (AKI) is a frequent complication in critically sick patients admitted to the intensive care unit (ICU). The objective of this study was to assess the risk factors and clinical outcomes of AKI in patients admitted to a teaching hospital's intensive care unit.Methods: This prospective observational study was conducted in the department of internal medicine, Janaki Medical College, Janakpur, Nepal from June 2018 till May 2019. Adults (aged 18 years or more) diagnosed with AKI using RIFLE criteria and were either admitted in ICU with diagnosis of AKI or developed AKI after admission to ICU. AKI patients were classified as those who satisfied any of the RIFLE categorization criteria.Results: The most common presenting complaint was fever (77%). The most common etiology of AKI was sepsis (71%). Other causes of AKI were post-operative cases (16%) and alcoholic liver disease (13%). When classified as per RIFLE criteria, we classified 38 cases (31.9%) as ‘risk’, 53 (44.54%) as ‘injury’ and 28 (23.53%) as ‘failure’. The etiological classification of our patients to be significantly associated with RIFLE classification (p&lt;0.01). However, we found the mortality not to be significantly associated with RIFLE classification (p=0.74). Conclusions: AKI classification should be used as a risk assessment tool towards the AKI's influence on the prognosis of ICU patients. Further study should investigate determining the death rate according to the RIFLE criteria in this region of Nepal.

COVID-19 and kidney disease: insights from epidemiology to inform clinical practice.

Over the course of the COVID-19 pandemic, numerous studies have aimed to address the challenges faced by patients with kidney disease and their caregivers. These studies addressed areas of concern such as the high infection and mortality risk of patients on in-centre haemodialysis and transplant recipients. However, the ability to draw meaningful conclusions from these studies has in some instances been challenging, owing to barriers in aspects of usual care, data limitations and problematic methodological practices. In many settings, access to SARS-CoV-2 testing differed substantially between patient groups, whereas the incidence of SARS-CoV-2 infection varied over time and place because of differences in viral prevalence, targeted public health policies and vaccination rates. The absence of baseline kidney function data posed problems in the classification of chronic kidney disease and acute kidney injury in some studies, potentially compromising the generalizability of findings. Study findings also require attentive appraisal in terms of the effects of confounding, collider bias and chance. As this pandemic continues and in the future, the implementation of sustainable and integrated research infrastructure is needed in settings across the world to minimize infection transmission and both prevent and plan for the short-term and long-term complications of infectious diseases. Registries can support the real-world evaluation of vaccines and therapies in patients with advanced kidney disease while enabling monitoring of rare complications.

Association of latent class analysis-derived subphenotypes of acute kidney injury with mortality in critically ill patients with cardiovascular disease: a retrospective cohort study

BackgroundTo explore the potential heterogeneity of acute kidney injury (AKI) and evaluate the prognostic differences among AKI subphenotypes in critically ill patients with cardiovascular diseases.MethodsData were extracted from the Medical Information Mart for Intensive Care (MIMIC)-III database. Latent class analysis (LCA) was used to explore the potential subphenotypes of AKI in critically ill patients with cardiovascular diseases. The number of classes was identified by the Bayesian information criterion and entropy. The differences in prognostic ability among the AKI subphenotypes were evaluated by logistic regression analysis.ResultA total of 7738 AKI patients were enrolled in this study. Using LCA, AKI patients were divided into 4 heterogeneous subphenotypes, which were obviously different from the Kidney Disease: Improving Global Outcomes (KDIGO) stages. Interestingly, class 3 classified by LCA was dominated by stage 2, while the mortality rate in class 3 was significantly different from that in class 1 (15.2% vs. 1.6%, p < 0.05). After further adjustment, the mortality rate in class 3 remained higher than that in class 1, with an odds ratio of 12.31 (95% confidence interval, 8.96–16.89).ConclusionsLCA was feasible for AKI classification in critically ill patients with cardiovascular disease, and 4 distinct subphenotypes of AKI patients with different prognoses were identified. Our results highlighted the potential heterogeneity of AKI patients, which is worthy of further investigation.

Assessment of knowledge of acute kidney injury among non-nephrology healthcare workers in North-Kivu Province, Democratic Republic of the Congo

Background: Assessment of knowledge of acute kidney injury (AKI) among healthcare workers (HCWs) is necessary to identify areas of deficiency and key topics to focus on while organizing educational programs to improve AKI care. The objective of this study was to assess AKI knowledge and practice among health care providers in North Kivu province, the eastern Democratic Republic of the Congo. Material and methods: This was a cross-sectional study conducted in six public hospitals in North Kivu province using a self-administered questionnaire. Results: A total of 158 HCWs completed the survey, among them 66 (41.78%) were physicians. The mean age of respondents was 36.07 ± 10.16 years and the male gender was 56.33%. Only 12 (7.59%) of the respondents had a good knowledge of the definition and classification of AKI. The respondents’ mean scores were 6.76 out of a total of 18 about risk factors for AKI and 6.29 out of a total of 11 with regard to nephrotoxic drugs. Regarding practices, 28.48% of the respondents assess the risk of AKI in their patients in their daily practices; 31.65% report AKI in the patients’ medical history, and 33.54% call on a nephrologist specialist to get specialized advice. Conclusion: This study found considerable gaps in knowledge and practice regarding AKI among most of HCWs in North Kivu province.

Epidemiology and Causes of Acute Renal Failure and Transition to Chronic Kidney Disease

Acute kidney injury (AKI) refers to an acute functional deterioration of the kidneys, which leads to retention of urinary substances, dysregulation of the electrolyte and acid-base balance, and disturbance of fluids. Although didactically helpful, the oversimplified AKI classification of prerenal/renal/postrenal is currently considered obsolete. Indeed, the boundaries blur quite quickly, particularly between prerenal and renal causes. Based on the AKI pathophysiology, it can be etiologically divided into decreased renal perfusion, postrenal obstruction and kidney specific injury or unspecific injury. AKI is a common event in hospitalized patients and associates strongly with mortality and chronic kidney disease (CKD). Today it is accepted that AKI and CKD are rather an individually variable continuum, than 2 distinct entities. If AKI has not regressed after 7 days, it is referred to as acute kidney disease (AKD). Persisting AKD for > 90days is classified as CKD. The transition from AKD to CKD is the result of an incomplete and maladaptive repair process. Although follow-up of post-AKI patients is essential, optimal concepts still need to be developed.

The attributable mortality of new-onset acute kidney injury among critically ill patients: a propensity-matched analysis based on a multicentre prospective cohort study

PurposeThis study aimed to evaluate the attributable mortality of new-onset acute kidney injury (AKI).MethodsThe data in the present study were derived from a multi-center, prospective cohort study in China that was performed at 18 Chinese ICUs. A propensity-matched analysis was performed between matched patients with and without AKI selected from all eligible patients to estimate the attributable mortality of new-onset AKI.ResultsA total of 2872 critically ill adult patients were eligible. The incidence of new-onset AKI was 29.1% (n = 837). After propensity score matching, 788 patients with AKI were matched 1:1 with 788 controls (patients without AKI). Thirty-day mortality was significantly higher among the patients with AKI than among their matched controls (25.5% versus 17.4%, p < 0.001). Subgroup analysis in terms of AKI classification showed that there was no significant difference (p = 0.509) in 30-day mortality between patients with stage 1 AKI and their matched controls. The attributable mortality values of stage 2 and stage 3 AKI were 12.4% [95% confidence interval (CI) 2.6–21.8%, p = 0.013] and 16.1% (95% CI 8.2–23.8%, p < 0.001), respectively. The attributable mortality of persistent AKI was 15.7% (95% CI 8.8–22.4%, p = 0.001), while no observable difference in 30-day mortality was identified between transient AKI patients and their matched non-AKI controls (p = 0.229).ConclusionThe absolute excess 30-day mortality that is statistically attributable to new-onset AKI is substantial (8.1%) among general ICU patients. However, neither stage 1 AKI nor transient AKI increases 30-day mortality.

The comparison of three different acute kidney injury classification systems after congenital heart surgery.

We aimed to compare the frequency of acute kidney injury (AKI) and its effects on mortality and morbidity with different classification systems in pediatric patients who had surgery under cardiopulmonary bypass for congenital heart disease. This study included children younger than 18 years old who were followed up in the pediatric cardiac intensive care unit between September 1 and December 1, 2020, after congenital heart surgery with cardiopulmonary bypass. Each case was categorized postoperatively in terms of AKI using Pediatric-Modified Risk, Injury, Failure, Loss, and End-Stage (pRIFLE), Acute Kidney Injury Network (AKIN), and Kidney Disease: Improving Global Outcomes (KDIGO). Hospital mortality (developed within the first 30 days postoperatively) and morbidity (longer than 7 days intensive care unit stay) were compared by three model classes. Results were evaluated statistically. One hundred patients were included in the study. The median age was 3 months (1 day-180 months). Acute kidney injury was diagnosed in 49% of the cases according to the pRIFLE classification. It was diagnosed in 31% of the patients by AKIN classification. It was diagnosed in 41% of the patients with the KDIGO criteria. Morbidity was observed in 25% (n = 25) of all cases. The morbidity predictor was 0.800 for pRIFLE, 0.747 for AKIN and 0.853 for KDIGO by receiver operating characteristics analysis. All three categories predicted morbidity significantly (P < 0.001). Mortality was 10% (n = 10) for all groups. The mortality predictor was 0.783 for pRIFLE, 0.717 for AKIN and 0.794 for KDIGO by receiver operating characteristics analysis, and all three categories predicted mortality significantly (P < 0.001). Regardless of the three methods used, AKI was commonly detected in pediatric patients undergoing congenital heart surgery. pRIFLE classification diagnosed more patients with AKI than AKIN and KDIGO. The KDIGO and pRIFLE classifications were better in predicting hospital mortality.

Associated Biochemical Changes and Outcome of Acute Kidney Injury in ICU Patients and Impact on Rifle Classes

Background: Acute Kidney Injury (AKI) has an independent impact on outcome, even after correction of all other variables in critically ill patients . AKI in ICU is often associated with different biochemical metabolic derrangements as a result of sepsis and non-renal organ system failure. Adequate informations are essential to develop effective measures to prevent and control morbidity and mortality. This study was done to detect AKI with their associated biochemical abnormalities and outcome among admitted patients in intensive care unit of BSMMU.&#x0D; Materials and methods: This prospective observational study was carried out in the Department of Nephrology, Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka, during the period of September 2015 to October 2016. A total of 105 patients who were admitted in the Department of Anesthesia, Analgesia and intensive care medicine, BSMMU were included in this study. Patients who had pre-existing CKD, those on maintenance dialysis, with history of renal transplantation, Feature suggestive of chronic kidney disease were excluded. Baseline data were recorded accordingly. The study population was divided initially into two group (No AKI and AKI) then sub groups into risk, injury, failure and followed up till discharge or death.&#x0D; Results: Incidence of AKI was 37.14%. Mean increase in Serum creatinine was 64.53%, 132.87% and 375.01% from baseline for risk, injury and failure respectively. Subgroup analysis revealed risk (20%) injury (6.67%) and failure (10.47%). Associated acid base disorder, electrolytes imbalance, hepatic dysfunction, haemotogical disorder and hypoalbuminemia were found statistically significant between two groups. Logistic regression analysis showed that associated haematological abnormalities were positively correlated to the development of AKI. But among these no variables showed significant effect on RIFLE class population. Our study revealed overall morality is (53.8%). Mortality was highest in Failure class and most patients from risk class achieved renal recovery.&#x0D; Conclusion: The incidence of AKI in critically ill patient is high. Associated biochemical changes should be addressed properly to minimize fatality. RIFLE classification for AKI might help in recruitment of patients for predicting prognosis.&#x0D; JCMCTA 2021 ; 32 (2) : 53-58

Acute kidney injury in paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) is not associated with progression to chronic kidney disease

BackgroundPaediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) is a rare complication of SARS-CoV-2 associated with single or multiorgan dysfunction.ObjectiveWe aimed to evaluate the incidence of acute kidney injury...

Abstract 9592: Acute Kidney Injury Subphenotypes in Critically Ill Patients with Cardiovascular Diseases by Latent Class Analysis: A Retrospective Cohort Study

Introduction: According to the potential heterogeneity of acute kidney injury (AKI) in critically ill patients with cardiovascular diseases, we explored the subphenotypes of AKI and evaluated the prognostic differences among AKI subphenotypes. Hypothesis: We hypothesized that patients with different AKI subphenotypes would suffer different prognosis. Methods: Clinical information from the Medical Information Mart for Intensive Care (MIMIC)-III database was enrolled. Latent class analysis (LCA) was used to explore the potential subphenotypes of AKI in critically ill patients with cardiovascular diseases. The number of classes was identified using the Bayesian information criterion and entropy. The differences in prognostic ability among the AKI subphenotypes were evaluated by logistic regression analysis. Results: In this study, a total of 7738 AKI patients were enrolled and divided into 4 heterogeneous subphenotypes by using LCA. The subphenotypes showed remarkable dofference from kidney disease classified by improving Global Outcomes (KDIGO) stages. Notedly, though both dominated by stage 2, the mortality between class 4 and class 1 classified by LCA were significantly different (15.2% vs. 1.6%, p &lt;0.05). The trend remained the same after further adjustment, with an odds ratio of 12.31 (95% confidence interval, 8.96-16.89). Conclusions: LCA was feasible for AKI classification and different subphenotypes prognosis prediction in critically ill patients with cardiovascular disease. Our study revealed the potential heterogeneity of AKI patients, which is worthy of further investigation.

Definitions of acute renal dysfunction: an evolving clinical and biomarker paradigm.

The current definition and classification of acute kidney injury (AKI) has limitations and shortcomings, which impact clinical management. The aim of this review is to highlight recent advances in our understanding of the pathophysiology and epidemiology of AKI, which impacts management and offers opportunities. Kidney damage varies according to the type of primary insult, secondary effects and mitigating responses and leads to distinct molecular, cellular and functional changes. Different sub-types of AKI with varying clinical phenotypes, recovery patterns and responses to therapeutic interventions have been identified. New tools to identify and characterize these AKI sub-types are available with the potential opportunity for individualized timely aetiology-based management of AKI. The identification of different sub-phenotypes of AKI based on genetic, molecular, cellular and functional pathophysiological changes following potential nephrotoxic exposures is possible with new technologies. This offers opportunities for personalized management of AKI and supports the call for a refinement of the existing AKI criteria.

НЕОНАТАЛЬНОЕ ОСТРОЕ ПОВРЕЖДЕНИЕ ПОЧЕК: ИНФОРМИРОВАННОСТЬ ВРАЧЕЙ ОТДЕЛЕНИЙ РЕАНИМАЦИИ НОВОРОЖДЕННЫХ И ВРАЧЕЙ ДРУГОГО ПЕДИАТРИЧЕСКОГО ПРОФИЛЯ

Neonatal acute kidney injury (AKI) is common in newborns in critical condition in the intensive care units and significantly reduces the chances of recovery. The analysis of attitudes to this problem and the practical experience of pediatric doctors working with newborns regarding the risks of development and outcomes of AKI is an important step in improving the prognosis of the disease. Objective of the study: determination of awareness of the problem of neonatal AKI. Materials and methods of research: the study was carried out in the form of a sociological survey (questionnaire) of doctors (n=63) working in neonatal intensive care units (NICU) (n=34, 54%), and pediatricians not associated with work in the NICU (n=29, 46%). The questionnaire contained 34 questions. 51% of the respondents (n=32) were under 40 years old, 49% – over 40 years old (n=31). Results: there is a lack of awareness of specialists regarding definitions, diagnostics, treatment tactics, prognosis of the disease, as well as insufficient availability of treatment facilities for access to nephrological and dialysis care. 29% (95% CI 14–44%, n=10) NICU doctors and 21% (95% CI 6–36%, n=6) doctors from other departments were unaware of the existing AKI classifications in newborns (p=0,615). 62% (95% CI 46–78%, n=21) of NICU staff and 55% (95% CI 37–73%, n=16) by doctors of other specialties (p=0,785) reported that nephrology counseling was available. The availability of renal replacement therapy was reported by 27% (95% CI 12–42%, n=9) by NICU doctors and 35% (95% CI 18–52%, n=10) by doctors from other departments (p=0,678). Only 52 (83%) (95% CI 74–92%) doctors believe that the child should be examined by a nephrologist. Conclusion: it is necessary to raise awareness among doctors about neonatal AKI.

Urinary actin, as a potential marker of sepsis-related acute kidney injury: A pilot study.

A major complication of sepsis is the development of acute kidney injury (AKI). Recently, it was shown that intracellular actin released from damaged tissues appears in the urine of patients with multiple organ dysfunction syndrome. Our aims were to measure urinary actin (u-actin) concentrations of septic and control patients and to test if u-actin levels could predict AKI and mortality. Blood and urine samples were collected from septic and sepsis-related AKI patients at three time points (T1-3): T1: within 24 hours after admission; T2: second day morning; T3: third day morning of follow-up. Patients with malignancies needing palliative care, end-stage renal disease or kidney transplantation were excluded. Serum and u-actin levels were determined by quantitative Western blot. Patients were categorized by the Sepsis-3 and KDIGO AKI classifications. In our study, 17 septic, 43 sepsis-induced AKI and 24 control patients were enrolled. U-actin levels were higher in septic patients compared with controls during follow-up (p<0.001). At T1, the septic and sepsis-related AKI groups also showed differences (p<0.001), yet this increase was not statistically significant at T2 and T3. We also detected significantly elevated u-actin concentrations in AKI-2 and AKI-3 septic patients compared with AKI-1 septic patients (p<0.05) at T1 and T3, along with a significant increase in AKI-2 septic patients compared with AKI-1 septic patients at T2 (p<0.01). This tendency remained the same when referring u-actin to urine creatinine. Parameters of first-day septic patient samples could discriminate AKI from non-AKI state (AUC ROC, p<0.001): u-actin: 0.876; se-creatinine: 0.875. Derived cut-off value for u-actin was 2.63 μg/L (sensitivity: 86.0%, specificity: 82.4%). U-actin may be a complementary diagnostic biomarker to se-creatinine in sepsis-related AKI while higher u-actin levels also seem to reflect the severity of AKI. Further investigations may elucidate the importance of u-actin release in sepsis-related AKI.

Pathogenetic mechanisms, epidemiology and classification of acute kidney injury in heart transplant recipients

Kidney injury in heart transplant recipients is of a complex nature and bears the features of all types of cardiorenal interaction impairment. Pre-transplant renal dysfunction, perioperative acute kidney injury, as well as factors associated with graft and immunosuppression, determine the prevalence and severity of kidney pathology in this group of patients. This review examines the pathophysiology of kidney dysfunction in heart failure, the epidemiology, and criteria for acute kidney injury.

Acute kidney injury: epidemiology and course in critically ill children.

Acute kidney injury (AKI) is a major cause of morbidity and mortality in critically ill children. The aim of this paper wasto describe the prevalence and course of AKI in critically ill children and to compare different AKI classification criteria. We conducted a retrospective observational study in our multi-disciplinary Pediatric Intensive Care Unit (ICU) from January 2015 to December 2018. All patients from birth to 16years of age who were admitted to the pediatric ICU were included. The Kidney Disease Improving Global Outcomes (KDIGO) definition was considered as the reference standard. We compared the incidence data assessed by KDIGO, pediatric risk, injury, failure, loss of kidney function and end- stage renal disease (pRIFLE) and pediatric reference change value optimised for AKI (pROCK). Out of 7505 patients, 9.2% developed AKI by KDIGO criteria. The majority (59.8%) presented with stage 1 AKI. Recovery from AKI was observed in 70.4% of patients within 7days from diagnosis. Both pRIFLE and pROCK were less sensitive compared to KDIGO criteria for the classification of AKI. Patients who met all three-KDIGO, pRIFLE and pROCK criteria had a high mortality rate (35.0%). Close to one in ten patients admitted to the pediatric ICU met AKI criteria according to KDIGO. In about 30% of patients, AKI persisted beyond 7 days. Follow-up of patients with persistent kidney function reduction at hospital discharge is needed to reveal the long-term morbidity due to AKI in the pediatric ICU.