AKI Stage Research Articles

Oxygen delivery in pediatric cardiac surgery and its association with acute kidney injury using machine learning

ObjectiveAcute kidney injury (AKI) after pediatric cardiac surgery with cardiopulmonary bypass (CPB) is a frequently reported complication. In this study we aimed to determine the oxygen delivery indexed to body surface area (Do2i) threshold associated with postoperative AKI in pediatric patients during CPB, and whether it remains clinically important in the context of other known independent risk factors. MethodsA single-institution, retrospective study, encompassing 396 pediatric patients, who underwent heart surgery between April 2019 and April 2021 was undertaken. Time spent below Do2i thresholds were compared to determine the critical value for all stages of AKI occurring within 48 hours of surgery. Do2i threshold was then included in a classification analysis with known risk factors including nephrotoxic drug usage, surgical complexity, intraoperative data, comorbidities and ventricular function data, and vasoactive inotrope requirement to determine Do2i predictive importance. ResultsLogistic regression models showed cumulative time spent below a Do2i value of 350 mL/min/m2 was associated with AKI. Random forest models, incorporating established risk factors, showed Do2i threshold still maintained predictive importance. Patients who developed post-CPB AKI were younger, had longer CPB and ischemic times, and required higher inotrope support postsurgery. ConclusionsThe present data support previous findings that Do2i during CPB is an independent risk factor for AKI development in pediatric patients. Furthermore, the data support previous suggestions of a higher threshold value in children compared with that in adults and indicate that adjustments in Do2i management might reduce incidence of postoperative AKI in the pediatric cardiac surgery population.

Estimating baseline kidney function in hospitalized adults with acute kidney injury

AimBaseline serum creatinine values are required to diagnose acute kidney injury but are often unavailable. We evaluated four conventional equations to estimate creatinine. We then developed and validated a new equation corrected by age and gender.MethodsWe retrospectively examined adults who, at first hospital admission, had available baseline creatinine data and developed acute kidney injury ≥24 h after admission. We split the study population: 50% (derivation) to develop a new linear equation and 50% (validation) to compare against conventional equations for bias, precision, and accuracy. We stratified analyses by age and gender.ResultsWe studied 3139 hospitalized adults (58% male, median age 71). Conventional equations performed poorly in bias and accuracy in patients aged <60 or ≥75 (68% of the study population). The new linear equation had less bias and more accuracy. There were no clinically significant differences in precision. The median (95% confidence interval) difference in creatinine values estimated via the new equation minus measured baselines was 0.9 (−3.0, 5.9) and −0.5 (−7.0, 3.7) μmol/L in female patients 18–60 and 75–100, and −1.5 (−4.2, 2.2) and −7.8 (−12.7, −3.6) μmol/L in male patients 18–60 and 75–100, respectively. The new equation improved reclassification of KDIGO AKI stages compared to the MDRD II equation by 5.0%.ConclusionEquations adjusted for age and gender are less biased and more accurate than unadjusted equations. Our new equation performed well in terms of bias, precision, accuracy, and reclassification.

P75 PRELIMINARY FINDINGS OF THE DAVIDS REGISTRY (DYEVERT TO AVOID UNNECESSARY CONTRAST MEDIA DELIVERY DURING PCI SANREMO REGISTRY)

Abstract Background Contrast–induced acute kidney injury (CI–AKI) is a percutaneous coronary intervention’s (PCI) feared complication, linked to increased morbidity and mortality. Many risk factors have been identified. Amongst procedural variables contrast media (CM) volume is one of the most predictive. An easy–to–use and effective CM sparing device would represent a valuable tool in the cath–lab armamentarium. Aim To evaluate the effectiveness of the DyeVert Power XT system in reducing CM delivery during PCI in pts at high risk of CI–AKI, consequently reducing the risk itself. Methods We collected clinical, laboratory, instrumental, procedural and outcome data of 75 consecutive patients (pts) who underwent PCI with the use of the DyeVert system between September 2020 and December 2021. We also compared these data in two groups of patients, divided according to CI–AKI onset. Inclusion criteria were reduced estimated glomerular filtration rate (eGFR) – defined as creatinine clearance (CrCl) &amp;lt;60 mL/min/m2 – and/or need for a complex PCI – chronic total occlusion (CTO), previous coronary artery bypass graft (CABG) or diffuse multivessel disease (MVD) – with the likelihood to receive a high amount of CM. Results Clinical data are shown in Table 1. Lab and instrumental data are shown in Table 2. Procedural data are shown in Table 3. In–hospital events are shown in Table 4. CI–AKI predictors at multivariate analysis are shown in Table 5. Median dose of CM delivered was 255 ml while CM spared with DyeVert was 110 ml (43% volume reduction, median 1 point reduction in Mehran score). Turning to outcomes 11 pts (14.7%) experienced AKI stage I according to Kidney Disease – Improving Global Outcomes (KDIGO) definition, whilst only 3 pts (4%) and 2 pts (2.7%) experienced stage 2 and 3 AKI. At follow–up there were 4 in–hospital deaths, none linked to deteriorating renal function. Conclusions DyeVert use was simple and effective in cutting delivered CM amount, with preserved image quality according to the operators judgement, however the reduction in Mehran score was not sufficient to affect risk class in pts experiencing CI–AKI versus those who did not.

Programmed Cell Death in Sepsis Associated Acute Kidney Injury.

Sepsis-associated acute kidney injury (SA-AKI) is common in patients with severe sepsis, and has a high incidence rate and high mortality rate in ICU patients. Most patients progress to AKI before drug treatment is initiated. Early studies suggest that the main mechanism of SA-AKI is that sepsis leads to vasodilation, hypotension and shock, resulting in insufficient renal blood perfusion, finally leading to renal tubular cell ischemia and necrosis. Research results in recent years have shown that programmed cell death such as apoptosis, necroptosis, pyroptosis and autophagy play important roles. In the early stage of sepsis-related AKI, autophagy bodies form and inhibit various types of programmed cell death. With the progress of disease, programmed cell death begins. Apoptosis promoter represents caspase-8-induced apoptosis and apoptosis effector represents caspase-3-induced apoptosis, however, caspase-11 and caspase-1 regulate gasdermin D-mediated pyroptosis. Caspase-8 and receptor interacting kinase 1 bodies mediate necroptosis. This review focuses on the pathophysiological mechanisms of various programmed cell death in sepsis-related AKI.

MO456: Renal and Major Clinical Outcomes After Nephrectomy in Patients With Pre-Existing Chronic Kidney Disease (ON-CKD Study)

Abstract BACKGROUND AND AIMS Partial nephrectomy (PN) has progressively replaced radical nephrectomy (RN) whenever feasible for renal tumors. However, its effects on renal outcomes are less known in patients with pre-existing chronic kidney disease (CKD) or with solitary kidney (SK). We aimed to assess renal and major clinical outcomes after PN or RN in patients with moderate to severe CKD or SK. METHOD We included all surgical procedures conducted between 2013 and 2018 in the Hospices Civils de Lyon, in patients with last pre-operative estimated glomerular filtration rate (eGFR) &amp;lt;60mL/min/1.73m², or with SK. Exclusion criteria were eGFR &amp;lt; 15mL/min/1.73m² or dialysis, RN on SK, ablative therapy. Demographic, tumors and surgeries characteristics were collected, as well as eGFR 1 month and 1 year after surgery. Main outcome was a composite criterion including CKD progression or major cardio-vascular events or death, assessed 1 year after surgery. Predictors of the main outcome were determined using multivariate analyses. RESULTS We included 173 procedures (67 RN and 79 PN on CKD patients, 27 PN on SK patients). Patients undergoing RN were older, had bigger tumors and higher T stages on TNM classification. Preoperative estimated glomerular filtration rate (eGFR) and CKD stages were not different between the groups. One year after surgery, PN was associated with less occurrence of the main composite outcome compared to RN (42.9% versus 70.7%, P &amp;lt; 0.01). On multivariate analysis, independent risk factors for the main outcome were postoperative AKI (no AKI as reference; AKI stage 1 odds ratio (OR) = 8.68, 95% confidence interval (CI) 3.23–23.33; AKI stage 2 OR = 23.50, 95% CI 2.33–236.51; AKI stage 3 OR = 28.87, 95% CI 4.77–167.61) and bigger tumor size (OR = 1.21/cm, 95% CI 1.02–1.45), while preoperative eGFR was not (Table 1). Compared to pre-operative values, eGFR significantly decreased both after RN or PN 1 month after surgery (eGFR loss -12mL/min 1.73m² after RN P &amp;lt; 0.001, −3mL/min/1.73m² after PN, P &amp;lt; 0.05) and this decrease remained stable 1 year after surgery (eGFR loss -11mL/min/1.73m² after RN, P &amp;lt; 0.001, −3mL/min/1.73m² after PN, P &amp;lt; 0.05), but renal function was better preserved after PN than after RN at 1 month (P &amp;lt; 0.05) or 1 year (P &amp;lt; 0.01) (Figure 1). CONCLUSION In moderate to severe CKD patients, PN was associated with less risk of CKD progression or major cardio-vascular event or death 1 year after surgery, compared to RN. Postoperative AKI was the major determinant of clinical and renal outcomes.

MO315: Risk Factors for CSA-AKI and Performance of Leicester Score in a Spanish Cohort

Abstract BACKGROUND AND AIMS The incidence of acute kidney injury following cardiac surgery (CSA-AKI) is up to 30% and it places patients at an increased risk of death. Leicester score (LS) is a new score designed by Birnie et al. [1] and validated in 2014 in a British Cohort. It predicts CSA-AKI at any stage with better discrimination compared with the Clevaland Clinic Score (CCS) and Euroscore II. The aim of this study was to identify risk factors for CSA-AKI and to assess the performance of LS in a Spanish cohort. METHOD A unicentric retrospective study of patients that required cardiac surgery with cardio-pulmonary bypass (CPB) during 2015 in the Hospital Clinic de Barcelona. The inclusion criteria were patients &amp;gt;18 years old who were operated on for cardiac surgery [valve substitution (VS), coronary artery bypass graft (CABG) or a combination of both procedures] with the need of CPB. CSA-AKI was defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. RESULTS A total of 444 patients were included, of which 171 (38.5%) developed CSA-AKI. The most frequent form of AKI was mild AKI (AKI stage 1), which was present in 105 patients (61.4%). AKI stage 3 was developed in 26 patients, 15 of which required RRT. A total of 66.7% of AKI cases met criteria in the first 24 h and the median duration until total recovery was 3 days. In the multivariate analysis, hypertension (OR 1.883), EGFR &amp;lt; 60 mL/min (OR 2.365) and peripheral vascular disease (OR 4.66) were associated with CSA-AKI. Either discrimination or calibration were better with LS compared with CCS and Euroscore II, with an AUC of 0.721 versus 0.595 and 0.662, respectively (Fig. 1). CONCLUSION Preoperative hypertension in patients with CKD with or without peripheral vasculopathy can identify patients at risk of CSA-AKI. LS has proved to be a valid score that could be used to identify patients at risk who could benefit in intervention studies.

MO250: COVID-19 Associated Collapsing Variant of Focal Segmental Glomerulosclerosis: A Case Series of 7 Patients from a Single UK Centre

BACKGROUND AND AIMSCases of collapsing glomerulopathy in association with COVID-19 infection have been reported worldwide, frequently referred to as COVAN (COVID-19 Associated Nephropathy). Affected patients are almost exclusively of Black ethnicity, likely associated with APOL-1 renal risk variants. There remains a paucity of data on patient outcomes, however, and it is unclear how the natural history of this disease may vary from HIV-associated nephropathy (HIVAN) and other non-viral causes of collapsing FSGS.Here, we present a case series of seven patients with presumed COVAN from a single tertiary UK renal centre; highlighting patient demography, biopsy findings, clinical management and short-term renal outcomes.METHODWe identified all adult patients presenting to our centre with nephrotic syndrome and a renal biopsy demonstrating collapsing glomerulopathy, in association with a positive COVID-19 PCR swab result. Detailed case note reviews were undertaken using electronic health records to extract data relevant to patient demography, co-morbidities, COVID -19 symptoms, renal biopsy findings, treatment and biochemical parameters, both at the time of presentation and during follow-up at 1, 3, 6 and 12 months respectively (where available).RESULTSIn total, we identified seven patients with presumed COVAN. Three of the seven patients were male, median age was 60 years (range 25–80 years). Six of the seven patients were of Black ethnicity and one patient was of South Asian ethnicity (renal transplant recipient with donor ethnicity unknown). All seven patients had a background of hypertension, 5/7 had known chronic kidney disease (CKD), 5/7 had type 2 diabetes mellitus (T2DM) and 4/7 were obese (BMI > 30). In the vast majority of cases, associated COVID-19 symptoms were mild.All patients had profound nephrotic syndrome at the time of renal biopsy, with median urine ACR 1085 mg/mmol (range 682–1380 mg/mmol) and median serum albumin 15 g/L (range 8–20 g/L). Two of seven patients had mild AKI (stage 1) and 5/7 patients had severe AKI (stage 3), with 3 of these patients receiving acute haemodialysis therapy.Management of glomerulopathy was supportive in all cases, including diuresis and anticoagulation (two patients received a short course of oral dexamethasone for their COVID-19 symptoms). ACE inhibitors/angiotensin receptor blockers were re-introduced in two patients and newly commenced in two further patients during follow-up.At 6 months follow-up, one patient remained dialysis dependant and one patient had ongoing decline in renal function (renal transplant recipient); all other patients achieved at least partial remission, with > 50% reduction in urine ACR and some (but not complete) recovery in renal function (Fig. 1).There were no viral particles identified on direct examination of renal biopsy specimens, but 4/7 biopsies exhibited tubulo-reticular inclusions, suggesting an interferon-driven systemic inflammatory process.CONCLUSIONIn this case series of seven COVAN cases from a single tertiary UK centre, we noted that in keeping with reports from North America, Black ethnicity patients were disproportionately affected. Partial remission was achieved in most of our cases with supportive treatment only; however, ongoing monitoring of this cohort is required to better understand longer-term patient outcomes. Testing for APOL-1 gene mutations and molecular testing of biopsy samples for this cohort is also ongoing to facilitate better insights into pathophysiology and risk factors associated with this novel disease.

MO335: Reaching SCR 4.0 mg/dL, the Magical Number for KDIGO-2012 AKI Stage 3. Is it Adequate for Stratifying Severity of Acute on Chronic Kidney Disease?

Abstract BACKGROUND AND AIMS Reaching a SCr ≥ 4 is one criterion of classification for stage 3 in the KDIGO-2012 AKI guidelines. No previous study has challenged this arbitrary cut point by comparing its performance on how patients with pure AKI (pAKI) versus acute on chronic kidney disease (AoCKD) reach that ‘magical number’, and how it affects the prognosis. METHOD Retrospective study of patients with AKI, classified according to the KDIGO-2012 guidelines. We analysed a sub-group of patients that reached a maximum SCr ≥ 4 and divided them in pAKI (basal eGFR ≥ 60) and AoCKD (≥15–≤59). We evaluated epidemiological and clinical variables, and compared the clinical outcomes needed for HD, in-hospital mortality and HD dependence at discharge. As 21 (6%) of AoCKD individuals already had a basal SCr ≥ 4.0, they were excluded in the analysis. RESULTS A total of 492 individuals met the inclusion criteria: 341 (69%) in the AoCKD group. Individuals in this group were older and had a higher Charlson's index. Table 1A summarizes the comparison of clinical characteristics, all patients in the pAKI group reached a four SCr with a rate of SCr increments ≥ 3×. We found no statistically significant difference in in-hospital mortality and the need for HD. The AoCKD group was more dependent on HD at discharge (Table 1B). Figure 1 shows the rate of SCr increments by which individuals reached &amp;gt; 4.0 mg/dL. CONCLUSION We found that individuals in the AoCKD group differ in their basal characteristics from the pAKI group and need lesser increments in SCr to reach the magical number of 4.0 mg/dL to be classified in stage 3. May be, one size does not fit all, and individuals with prior CKD may benefit from a lower rate of SCr increase to stratify AKI severity. We consider that a pitfall in this staging criterion consists in the small portion of patients in the AoCKD group that have a basal SCr ≥ 4.0, with a skew to AKI-KDIGO stage 3.

Acute kidney injury and risk of cardiovascular outcomes: A nationwide cohort study

BackgroundAcute kidney injury (AKI) has been associated with cardiovascular disease, but this is sparsely studied in non-selected populations and with little attention to the effect in age and renal function. Using nationwide administrative data, we investigated the hypothesis of increased one-year risk of cardiovascular event or death associated with AKI. MethodsIn a cohort study, we identified all admissions in Denmark between 2008 and 2018. AKI was defined as ≥1.5 times increase from baseline to peak creatinine during admission, or dialysis. We excluded patients with age <50 years, estimated glomerular filtration rate (eGFR) <15ml/min/1.73m2, renal transplantation, index-admission due to cardiovascular disease or death during index-admission. The primary outcome was cardiovascular risk within one year from discharge, which was a composite of the secondary outcomes ischemic heart disease, heart failure or stroke. To estimate risks, we applied multiple logistic regression fitted by inverse probability of censoring weighting and stratified estimations by eGFR and age. We adjusted for proteinuria in the subcohort with measurements available. ResultsAmong 565,056 hospital admissions, 39,569 (7.0%) cases of AKI were present. In total, 18,642 patients sustained a cardiovascular outcome. AKI was significantly associated with cardiovascular outcome with an adjusted OR [CI] of 1.33 [1.16–1.53], 1.43 [1.33–1.54], 1.23 [1.14–1.34], 1.38 [1.18–1.62] for eGFR ≥90, 60–89, 30–59 and 15–29ml/min/1.73m2, respectively. When omitting the outcome heart failure, these results were 1.24 [1.06–1.45], 1.22 [1.11–1.33], 1.05 [0.95–1.16], 1.25 [1.02–1.54]. Results did not change substantially in strata of age groups, in AKI stages and in the subcohort adjusted for proteinuria. ConclusionNon-selected patients aged 50 years or above with AKI during admission had significantly higher one-year risk of cardiovascular event or death, especially, but not only due to heart failure, independent of age and eGFR.

Procalcitonin, Interleukin-6 and C-reactive Protein Levels Predict Renal Adverse Outcomes and Mortality in Patients with Acute Type A Aortic Dissection.

BackgroundAcute type A aortic coarctation (AAAD) is a highly deadly and serious life-threatening disease. The purpose of this study was to estimate the predictive value of peak procalcitonin, interleukin-6, and C-reactive protein levels on adverse renal outcomes and mortality in patients undergoing surgery for AAAD.MethodsPerioperative peak PCT, CRP, and IL-6 levels were retrospectively collected in 331 patients hospitalized with AAAD from 2009 to 2021. The primary endpoints were AKI stage 2–3 and mortality. The receiver operating characteristic (ROC) curves were used to compare the predictive values of peak PCT, CRP, and IL-6 for different clinical outcomes. Multivariable logistic regression analysis was used to find risk factors for AKI and 30-day mortality.ResultsThe incidence of AKI stage 2–3 following AAAD was 50.8% (168/331). The 30-day and overall mortality were significantly greater in the AKI 2–3 group than in the AKI 0–1 group (P = 0.000). ROC curve analysis showed that peak PCT, with an area under the ROC curve (AUC) of 0.712, was a more accurate predictor of adverse renal outcomes than peak IL-6 and CRP. Multivariable logistic regression analysis revealed that PCT > 0.39 ng/mL was an independent risk factor for AKI stage 2–3. Peak IL-6 > 259 pg/mL was found to be an independent risk factor for 30-day mortality.ConclusionIn patients with surgery for AAAD, peak PCT provides a well-predictive indicator of AKI stage 2–3 and peak IL-6 indicates a favorable predictor of 30-day mortality.

The effect of different consensus definitions on diagnosing acute kidney injury events and their association with in-hospital mortality.

Due to the existence of different AKI definitions, analyzing AKI incidence and associated outcomes is challenging. We investigated the incidence of AKI events defined by 4 different definitions (standard AKIN and KDIGO, and modified AKIN-4 and KDIGO-4) and its association with in-hospital mortality. A total of 7242 adult Greek subjects were investigated. To find the association between AKI stages and in-hospital mortality, we considered both the number of AKI events and the most severe stage of AKI reached by each patient, adjusted for age, sex, and AKI staging, using multivariable logistic regression. To predict mortality in AKI patients, as defined by the four definitions, a classification task with two prediction models (random forest and logistic regression) was also conducted. The incidence of AKI using the KDIGO-4 was 6.72% for stage 1a, 15.71% for stage 1b, 8.06% for stage2, and 2.97% for stage3; however, these percentages for AKIN-4 were 11%, 5.83%, 1.75%, and 0.33% for stage 1a, stage 1b, stage 2, and stage 3, respectively. Results showed KDIGO-4 is more sensitive in detecting AKI events. In-hospital mortality increased as the stage of AKI events increased for both KDIGO-4 and AKIN-4; however, KDIGO-4 (KDIGO) had a higher odds ratio at a higher stage of AKI compared to AKIN-4 (AKIN). Lastly, when using KDIGO, random forest and logistic regression models performed almost equally with a c-statistic of 0.825 and 0.854, respectively. The present study confirms that within the KDIGO AKI stage 1, there are two sub-populations with different clinical outcomes (mortality).

Predictors in-hospital mortality of septic vs non-septic acute kidney injury patients: an observational cohort study

Background: To compare the predictors In-hospital mortality of patients with septic Acute Kidney Injury (S-AKI) and non-septic AKI (NS-AKI). Methods: a cohort study of critically ill patients with AKI admitted to the emergency room at a tertiary hospital from January to June 2019. The primary outcome was hospital mortality. Results: There were 116 patients who met the inclusion criteria. Compared with NS-AKI, patients with S-AKI had significantly lower mean MAP, median eGFR, and urine output. (UO). S-AKI had higher mortality and vasopressor requirements and had a lower renal recovery than NS-AKI (63.2% vs 31.4%, p=0.001; 30.8% vs 13.7%, p=0.031, and 36.9% vs 60.8%, p=0.011, respectively). AKI stage 3 and vasopressor requirements were dependent risk factors for both S-AKI and NS-AKI mortality. Meanwhile, SOFA score &gt; 7 and the need for dialysis are dependent and independent risk factors for mortality in S-AKI. Worsening and/or persistence in UO, serum urea and creatinine levels at 48 h after admission were predictors of mortality in S-AKI and NS-AKI. Improvement in UO in surviving patients was more pronounced in S-AKI than in NS-AKI (50% vs 17.1%, p=0.007). The surviving S-AKI patients had a longer hospital stay than surviving NS-AKI [8 (6-14.5) vs 5 (4 – 8), p=0.004]. S-AKI have higher mortality and vasopressor requirements and have lower renal recovery than NS-AKI. Conclusion: S-AKI have higher mortality and vasopressor requirements and a lower renal recovery than NS-AKI. Independent predictors of mortality in S-AKI were high SOFA scores and the need for dialysis.

Serum IL-17 levels are higher in critically ill patients with AKI and associated with worse outcomes

BackgroundInterleukin-17 (IL-17) antagonism in rats reduces the severity and progression of AKI. IL-17-producing circulating T helper-17 (TH17) cells is increased in critically ill patients with AKI indicating that this pathway is also activated in humans. We aim to compare serum IL-17A levels in critically ill patients with versus without AKI and to examine their relationship with mortality and major adverse kidney events (MAKE).MethodsMulticenter, prospective study of ICU patients with AKI stage 2 or 3 and without AKI. Samples were collected at 24–48 h after AKI diagnosis or ICU admission (in those without AKI) [timepoint 1, T1] and 5–7 days later [timepoint 2, T2]. MAKE was defined as the composite of death, dependence on kidney replacement therapy or a reduction in eGFR of ≥ 30% from baseline up to 90 days following hospital discharge.ResultsA total of 299 patients were evaluated. Patients in the highest IL-17A tertile (versus lower tertiles) at T1 had higher acuity of illness and comorbidity scores. Patients with AKI had higher levels of IL-17A than those without AKI: T1 1918.6 fg/ml (692.0–5860.9) versus 623.1 fg/ml (331.7–1503.4), p < 0.001; T2 2167.7 fg/ml (839.9–4618.9) versus 1193.5 fg/ml (523.8–2198.7), p = 0.006. Every onefold higher serum IL-17A at T1 was independently associated with increased risk of hospital mortality (aOR 1.35, 95% CI: 1.06–1.73) and MAKE (aOR 1.26, 95% CI: 1.02–1.55). The highest tertile of IL-17A (vs. the lowest tertile) was also independently associated with higher risk of MAKE (aOR 3.03, 95% CI: 1.34–6.87). There was no effect modification of these associations by AKI status. IL-17A levels remained significantly elevated at T2 in patients that died or developed MAKE.ConclusionsSerum IL-17A levels measured by the time of AKI diagnosis or ICU admission were differentially elevated in critically ill patients with AKI when compared to those without AKI and were independently associated with hospital mortality and MAKE.

Biomarkers of acute kidney injury

AKI is a common condition with a high risk of death. This condition can be identified easily and treated early with a good outcome. The standard metrics used to define AKI like serum creatinine blood urea nitrogen are insensitive and nonspecific and change significantly only after huge injury which can lead to delay in diagnosis and treatment. The kidney is capable in withstanding injuries for an prolonged period. The lacking of knowledge of biomarkers has led to an increase in morbidity. As children progress to higher stages of AKI the risk and morbidity increase. The urine has yielded promising markers for early detection of AKI and also helps in anticipation. These markers help in the identification of the mechanism of injury, assessment of the site, and severity of the injury. One or more of these biomarkers, singly or in combination will help in diagnosis, intervention, and progression of the disease. The use of creatinine as a marker of AKI has various limitations, like variation in its secretion and extrarenal excretion. Toxin-mediated AKI may be amenable to biomarker detection given the direct tubular injury Imparted by various toxins.

Identification of risk factors for postoperative stage 3 acute kidney injury in patients who received surgical repair for acute type A aortic dissection

BackgroundAcute kidney injury (AKI) is a serious complication that often occurred after acute type A aortic dissection (ATAAD) surgery. Previous studies proved that the Kidney Disease Improving Global Outcomes (KDIGO) defined stage 3 AKI was associated with lower long-term survival rate. However, the risk factors for developing stage 3 AKI had not been identified. The aim of the study was to explore the risk factors for developing KDIGO stage 3 after ATAAD operation.MethodsThis study included 993 patients who received ATAAD operation from 2014 to 2019 at the Nanjing Drum Tower Hospital. Postoperative AKI was diagnosed according to the KDIGO criteria. Multivariate logistic regression analyses were applied to identify risk factors for stage 3 AKI. Kaplan–Meier survival analyses and Cox proportional hazards regression model were conducted to explore the association between different AKI stages and postoperative survival rate.ResultsThe mean age of all enrolled patients was 53.0 ± 13.1 years. A total of 236 (23.8%) patients suffered postoperative stage 3 AKI including 165 patients who required renal replacement therapy. Advanced age (odds ratio [OR] 1.031; 95% confidence interval [CI] 1.005–1.057; P = 0.018), prolonged cardiopulmonary bypass (CPB) duration (OR 1.010; 95% CI 1.002–1.018; P = 0.013), and higher drainage volume 24 h after surgery (OR 1.000; 95% CI 1.000–1.001; P = 0.033) were identified as independent risk factors for developing stage 3 AKI. In addition, our result showed that the mortality rate was correlated significantly with the severity of AKI defined by KDIGO criteria and the Cox regression analysis showed that only stage 3 AKI, but not stage 1 and 2, was an independent risk factor for mortality (Hazard ratio 10.365, 95% CI 4.208 to 25.528; P < 0.001) after adjusting for important confounding factors.ConclusionsOur study suggested that stage 3 postoperative AKI was significantly associated with decreased postoperative survival rate after ATAAD surgery. Advanced age, increased CPB duration and drainage volume 24 h after surgery were identified as risk factors for developing stage 3 AKI.

Evaluation of acute kidney injury by urinary tissue inhibitor metalloproteinases-2 and insulin-like growth factor-binding protein 7 after pediatric cardiac surgery.

With adult patients, the measurement of [TIMP-2]*[IGFBP7] can predict the risk of moderate to severe AKI within 12h of testing. In pediatrics, however, the performance of [TIMP-2]*[IGFBP7] as a predictor of AKI was less studied and yet to be widely utilized in clinical practice. This study was conducted to validate the utility of [TIMP-2]*[IGFBP7] as an earlier biomarker for AKI prediction in Chinese infants and small children. We measured urinary [TIMP-2]*[IGFBP7] using NEPHROCHECK® at eight perioperative time points in 230 patients undergoing complex cardiac surgery and evaluated the performance of [TIMP-2]*[IGFBP7] for predicting severe AKI within 72h of surgery. A total of 50 (22%) of 230 developed AKI stages 2-3 within 72h after CPB initiation. In the AKI stage 2-3 patients, two patterns of serum creatinine (SCr) elevations were observed. The patients with only a transient increase in SCr within 24h (&lt; 24h, early AKI 2-3) did not experience a worse outcome than patients in AKI stage 0-1. AKI stage 2-3 patients with SCr elevation after 24h (24-72h, late AKI 2-3), as well as AKI dialysis patients (together designated severe AKI), did experience worse outcomes. Compared to AKI stages 0-1, significant elevations of [TIMP-2]*[IGFBP7] values were observed in severe AKI patients at hours T2, T4, T12, and T24 following CPB initiation. The AUC for predicting severe AKI with [TIMP-2]*[IGFBP7] at T2 (AUC = 0.76) and maximum T2/T24 (AUC = 0.80) are higher than other time points. The addition of the NEPHROCHECK® test to the postoperative parameters improved the risk assessment of severe AKI. Multiple AKI phenotypes (early versus late AKI) were identified after pediatric complex cardiac surgery according to SCr-based AKI definition. Urinary [TIMP-2]*[IGFBP7] predicts late severe AKI (but not early AKI) as early as 2h following CPB initiation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Derivation and validation of urinary TIMP-1 for the prediction of acute kidney injury and mortality in critically ill children

BackgroundAcute kidney injury (AKI) is associated with high morbidity and mortality. Multiple urinary biomarkers have been identified to be associated with the prediction of AKI and outcomes. However, the accuracy of these urinary biomarkers for AKI and associated outcomes has not been clearly defined, especially in heterogeneous populations. The aims of the study were to compare the ability of 10 existing or potential urinary biomarkers to predict AKI and pediatric intensive care unit (PICU) mortality and validate urinary tissue inhibitor of metalloproteinases-1 (uTIMP-1) as a better biomarker for early prediction in heterogeneous critically ill children.MethodsA derivation-validation approach with separate critically ill cohorts was designed. We first conducted a prospective cohort study to determine the ability of 10 urinary biomarkers serially measured in 123 children during the first 7 days of PICU stay to predict AKI and PICU mortality (derivation study) and further validated the better biomarker of uTIMP-1 in a separate cohort of 357 critically ill children (validation study). AKI diagnosis was based on KDIGO classification with serum creatinine and urine output. PICU mortality was defined as all-cause mortality.ResultsIn the derivation cohort, 17 of 123 (13.8%) children developed AKI stage 3 or died during the PICU stay, and both the initial and peak uTIMP-1 displayed the highest AUCs of 0.87 (0.79–0.94) and 0.90 (0.84–0.96), respectively, for predicting AKI stage 3 or death. In the validation cohort, 78 of 357 (21.8%) developed AKI during the first week after admission, and 38 (10.6%) died during the PICU stay. The initial uTIMP-1 level was validated to be independently associated with AKI (AOR = 2.88, 95% CI 1.97–4.21), severe AKI (AOR = 2.62, 95% CI 1.78–3.88), AKI stage 3 (AOR = 2.94, 95% CI 1.84–4.68) and PICU mortality (AOR = 1.92, 95% CI 1.11–3.30) after adjustment for potential confounders. The predictive values of uTIMP-1 for AKI, severe AKI, AKI stage 3 and PICU mortality were 0.80 (0.74–0.86), 0.83 (0.77–0.89), 0.84 (0.77–0.92) and 0.83 (0.76–0.89), respectively.ConclusionsUrinary TIMP-1 levels have been identified and validated to be independently associated with AKI and PICU mortality in independent prospective cohorts and may be an early potential indicator of AKI and PICU mortality in critically ill children.

POS-849 CHARACTERISTICS AND OUTCOMES OF HOSPITALIZED COVID-19 PATIENTS WITH ACUTE KIDNEY INJURY

Since the breakout of COVID-19 in December 2019, the virus has already affected and taken millions of lives over the past year. There is still much to learn about this disease. It has been postulated that the human kidney is a potential pathway for COVID-19 due to the presence of the ACE2 receptors found in the surfaces of kidney cells. Some studies that demonstrated acute tubular necrosis and lymphocyte infiltration among post mortem COVID-19 patients, concluding that the virus could directly damage the kidney, increasing the risk of the development of Acute Kidney Injury among patients with COVID-19. This study investigated the incidence and severity of Acute Kidney Injury among hospitalized COVID-19 patients and the association of the degree of Acute Kidney Injury with regards to the severity and outcomes of COVID-19 patients. This was a single-center cross-sectional study retrospective chart review of COVID-19 patients who developed Acute Kidney Injury. Descriptive statistics were used to summarize the general and clinical characteristics of the patients. Frequency and proportion were used for categorical variables. Shapiro-Wilk test was used to determine the normality distribution of continuous variables. Continuous quantitative data that met the normality assumption was described using mean and standard deviation, while those that did not were described using median and range. Continuous variables which are normally distributed were compared using the One-way ANOVA, while those variables that are not normally distributed were compared using the Kruskal-Wallis H test. For categorical variables, the Chi-square test was used to compare the outcomes. If the expected percentages in the cells are less than 5%, Fisher's Exact Test was used instead. A total of 1441 COVID-19 in patients from March 1, 2020 to March 1, 2021 were reviewed, 59 of which were excluded. Among the adults with COVID-19 who developed stage I (60%), stage II (10%), or stage III (30%) AKI. The incidence of acute kidney injury among COVID-19 in-patients was 13.10% (95% CI 11.36% to 14.99%). Among the 181 patients, 79 (43.65%) had died (95% CI 36.30-51.20). The mortality rate is 22.02% for Stage I, 50% for Stage II, and 85.19% for Stage III. The median length of hospital stay in days is 12 days, ranging from 1 day up to 181 days. Full renal recovery on discharge was observed only in one-third of the patients. It was observed in 44.95% of Stage I AKI patients, 27.78% of Stage II AKI patients, and 5.56% of Stage III patients. In conclusion, the study demonstrated that the incidence of AKI in hospitalized COVID-19 patients was 13.1% (95% CI 11.36% to 14.99%), which was lower than previously reported. This could be attributed to the longer study period wherein, to date, we have a better understanding of the disease and had already established a standard of care for treatment for the disease attributing to the decreased incidence of AKI among COVID-19 patients than what was initially reported. The development of AKI has a direct correlation with the degree of infection. Among patients who developed AKI, 20% required renal replacement therapy. Overall development of AKI increases the risk of mortality among hospitalized COVID-19 patients. The stage of AKI has a direct correlation with regards to mortality and has an indirect relationship with regards to renal recovery.

Prediction of cardiac surgery associated - acute kidney injury (CSA-AKI) by healthcare professionals and urine cell cycle arrest AKI biomarkers [TIMP-2]*[IGFBP7]: A single center prospective study (the PREDICTAKI trial)

Cardiac surgery associated acute kidney injury (CSA-AKI) is a contributor to adverse outcomes. Preventive measures reduce AKI incidence in high risk patients, identified by biomarkers [TIMP-2]*[IGFBP7] (Nephrocheck®). This study investigate clinical AKI risk assessment by healthcare professionals and the added value of the biomarker result. Adult patients were prospectively included. Healthcare professionals predicted CSA-AKI, with and without biomarker result knowledge. Predicted outcomes were AKI based on creatinine, AKI stage 3 on urine output, anuria and use of kidney replacement therapy (KRT). One-hundred patients were included. Consultant and ICU residents were best in AKI prediction, respectively AUROC 0.769 (95% CI, 0.672-0.850) and 0.702 (95% CI, 0.599-0.791). AUROC of NephroCheck® was 0.541 (95% CI, 0.438-0.642). AKI 3 occurred in only 4 patients; there was no anuria or use of KRT. ICU nurses and ICU residents had an AUROC for prediction of AKI 3 of respectively 0.867 (95% CI, 0.780-0.929) and 0.809 (95% CI, 0.716-0.883); for NephroCheck® this was 0.838 (95% CI, 0.750-0.904). Healthcare professionals performed poor or fair in predicting CSA-AKI and knowledge of Nephrocheck® result did not improved prediction. No conclusions could be made for prediction of severe AKI, due to limited number of events.

The Correlation Between the Types of Initial Bacterial Infection and Clinical Prognosis in Patients With Septic AKI.

BackgroundAcute kidney injury (AKI) is a common complication of sepsis and is an independent risk factor for mortality. It is unclear whether different bacteria play different roles in the occurrence and development of sepsis-associated AKI (S-AKI). We observed the clinical characteristics and outcomes of patients that have types of bacterial infection, and different infections sites before the occurrence of AKI, respectively.MethodsData of patients who were diagnosed with sepsis and later developed AKI from 2008 to 2019 were retrieved from the MIMIC-IV 1.0 database. Patients were first divided into the two groups according to the bacterial culture results obtained prior to AKI occurrence: bacterial cultured positive (N = 1,785) and bacterial cultured negative (N = 8,777). Patients with bacteria culture positive were divided into culture bacteria Gram-positive (CGP, N = 1248) and Gram-negative (CGN, N = 537) groups.ResultsOverall, 1,785 patients were included in the present analysis. The patients in CGN group were older (70 vs. 66, p < 0.001), had lower body mass index (BMI) (27.0 vs. 28.4, p < 0.001), higher acute physiology III (APS III) score (63.0 vs. 58, p = 0.001), shorter time from positive microbial culture to diagnosis of AKI (2.94 vs. 3.16 days, p = 0.013) and longer intensive care unit (ICU) stay time (5.94 vs. 4.77 days, p < 0.001) compared with those in the CGP group (n = 1,248). In the culture gram-negative bacteria in patients with positive blood cultures (CGNb) group, the rate of vasopressors using (73.1 vs. 56.4%, P = 0.007), the Sequential Organ Failure Assessment (SOFA) score (10 vs. 9, p = 0.005), and the level of lactate (3.7 vs. 2.5, p = 0.001) were higher than those in the culture gram-positive bacteria in patients with positive blood cultures (CGPb) group. The time from positive microbial culture to the diagnosis of AKI was shorter (2.23 vs. 3 days, p = 0.001) in the CGNb group. However, there was no significant difference in the continuous renal replacement treatment (CRRT) application or short-term mortality rates between CGN and CGP groups.ConclusionThe Gram types of bacteria cultured prior to S-AKI occurrence was not related to AKI stage, CRRT application, and short-term mortality. Compared with the Gram-positive bacterial infections, Gram-negative bacterial infections take a shorter time to develop into AKI, and had a higher disease severity score.