Renal outcome in multiple myeloma patients with cast nephropathy: a retrospective analysis of potential predictive values on clinical and renal outcome

OBJECTIVE

Cast nephropathy (CN) is the leading cause of acute kidney injury (AKI) in multiple myeloma (MM). Since it is sparsely documented why some patients with CN do achieve a renal response while others do not, we describe a single-center cohort of patients with multiple myeloma and biopsy-confirmed CN to evaluate potential markers of renal response.

METHODS

The data was collected as a retrospective, single-center analysis of CN-patients treated at the Medical University Vienna between 01/01/2004 and 01/01/2022. Baseline parameters and clinical outcome was compared between renal responders and non-responders.

RESULTS

Among 28 patients with CN, n = 23 were assessed for renal response (14 responders; 9 non-responders). Renal responders were younger (median age: 61 years; 77 years, p = 0.039), showed higher overall survival (153months; 58months, p = 0.044) and achieved hematologic response (≥PR) to first-line therapy (p = 0.029), and complete hematologic response (CR) at any time (p = 0.025) significantly more often. Further, we could show that rapid initiation of anti-myeloma therapy after initial presentation correlated significantly with renal response (median 9 days; 27 days, p = 0.016). Analyses of kidney biopsy specimens revealed that patients with a high IF/TA score showed end stage renal disease (dialysis ≥ 3 months) significantly more often (p = <0.001).

DISCUSSION

In summary, our data suggests, that a rapid start with systemic hematologic treatment in patients with MM and CN is crucial and achieving an early hematologic response is important for renal recovery. Moreover, achieving a deep hematologic response and subsequent renal recovery improves clinical outcome as reflected by an overall survival benefit.

Risk factors and renal outcomes of AKI in children with secondary steroid-resistant nephrotic syndrome

BACKGROUND

Acute kidney injury (AKI) is increasingly prevalent in children with nephrotic syndrome (NS). It is associated with adverse outcomes in NS, especially steroid-resistant nephrotic syndrome (SRNS). The incidence, risk factors and outcomes of AKI in secondary SRNS remain undefined. The main objectives of this study were to determine the risk factors and prognosis of AKI in hospitalized children with secondary SRNS.

MATERIAL AND METHODS

This retrospective study was conducted from January 2014 to December 2019, involving 172 hospitalizations with secondary SRNS admitted to the First Affiliated Hospital of Sun Yat-sen University. AKI was defined and classified in accordance with the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines.

RESULTS

AKI was found in 67 (39.0%) of 172 hospitalizations with secondary SRNS. Average age of onset in our group is 4.4 (3.1, 6.7) years with AKI and 3.7 (1.8, 5.6) years without AKI. Urea nitrogen level is 5.9 (4.1, 10.0) mmol/L with AKI and 5.1 (3.7, 7.0) mmol/L. Uric acid level is 446.0 (340.0, 567.0) umol/L with AKI and 401.0 (303.0, 496.0) umol/L. 24-h urinary protein level is 4.14 (2.9, 6.5) g with AKI and 2.5 (1.3, 5.3) without AKI. Multivariate logistic regression revealed that infection (OR = 5.287; 95% confidence interval, 2.349 to 11.899; p < 0.001), age at onset (OR = 1.180; 95% confidence interval, 1.032 to 1.349; p = 0.015) and uric acid level (OR = 1.003; 95% confidence interval, 1.000 to 1.006; p = 0.031) were significantly associated with the development of AKI in children with secondary SRNS. Among 72 children with secondary SRNS, six went to end-stage kidney disease (ESKD). Children in the AKI group were more likely to progress to ESKD compared with children in the non-AKI group (p = 0.017) with a median follow-up of 48.5months.

CONCLUSION

AKI occurred in 39.0% of total hospitalizations associated with secondary SRNS. Risk factors including infection, age of onset, and uric acid level are associated with AKI in children with secondary SRNS. Furthermore, AKI was identified as a risk factor for the progression of secondary SRNS to ESKD.

The combination of kidney function variables with cell cycle arrest biomarkers identifies distinct subphenotypes of sepsis-associated acute kidney injury: a post-hoc analysis (the PHENAKI study)

BACKGROUND

The severity and course of sepsis-associated acute kidney injury (SA-AKI) are correlated with the mortality rate. Early detection of SA-AKI subphenotypes might facilitate the rapid provision of individualized care.

PATIENTS AND METHODS

In this post-hoc analysis of a multicenter prospective study, we combined conventional kidney function variables with serial measurements of urine (tissue inhibitor of metalloproteinase-2 [TIMP-2])* (insulin-like growth factor-binding protein [IGFBP7]) at 0, 6, 12, and 24 h) and then using an unsupervised hierarchical clustering of principal components (HCPC) approach to identify different phenotypes of SA-AKI. We then compared the subphenotypes with regard to a composite outcome of in-hospital death or the initiation of renal replacement therapy (RRT).

RESULTS

We included 184 patients presenting SA-AKI within 6 h of the initiation of catecholamines. Three distinct subphenotypes were identified: subphenotype A (99 patients) was characterized by a normal urine output (UO), a low SCr and a low [TIMP-2]*[IGFBP7] level; subphenotype B (74 patients) was characterized by existing chronic kidney disease (CKD), a higher SCr, a low UO, and an intermediate [TIMP-2]*[IGFBP7] level; and subphenotype C was characterized by very low UO, a very high [TIMP-2]*[IGFBP7] level, and an intermediate SCr level. With subphenotype A as the reference, the adjusted hazard ratio (aHR) [95%CI] for the composite outcome was 3.77 [1.92-7.42] (p < 0.001) for subphenotype B and 4.80 [1.67-13.82] (p = 0.004) for subphenotype C.

CONCLUSIONS

Combining conventional kidney function variables with urine measurements of [TIMP-2]*[IGFBP7] might help to identify distinct SA-AKI subphenotypes with different short-term courses and survival rates.

Machine learning-based prediction of in-hospital mortality for critically ill patients with sepsis-associated acute kidney injury

OBJECTIVES

This study aims to develop and validate a prediction model in-hospital mortality in critically ill patients with sepsis-associated acute kidney injury (SA-AKI) based on machine learning algorithms.

METHODS

Patients who met the criteria for inclusion were identified in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and divided according to the validation (n = 2440) and development (n = 9756, 80%) queues. Ensemble stepwise feature selection method was used to screen for effective features. The prediction models of short-term mortality were developed by seven machine learning algorithms. Ten-fold cross-validation was used to verify the performance of the algorithm in the development queue. The area under the receiver operating characteristic curve (ROC-AUC) was used to evaluate the differentiation accuracy and performance of the prediction model in the validation queue. The best-performing model was interpreted by Shapley additive explanations (SHAP).

RESULTS

A total of 12,196 patients were enrolled in this study. Eleven variables were finally chosen to develop the prediction model. The AUC of the random forest (RF) model was the highest value both in the Ten-fold cross-validation and evaluation (AUC: 0.798, 95% CI: 0.774-0.821). According to the SHAP plots, old age, low Glasgow Coma Scale (GCS) score, high AKI stage, reduced urine output, high Simplified Acute Physiology Score (SAPS II), high respiratory rate, low temperature, low absolute lymphocyte count, high creatinine level, dysnatremia, and low body mass index (BMI) increased the risk of poor prognosis.

CONCLUSIONS

The RF model developed in this study is a good predictor of in-hospital mortality for patients with SA-AKI in the intensive care unit (ICU), which may have potential applications in mortality prediction.

Clinical value of soluble urokinase-type plasminogen activator receptor in predicting sepsis-associated acute kidney injury

BACKGROUND

Sepsis-associated acute kidney injury (S-AKI) is a critical illness and is often associated with high morbidity and mortality rates. The soluble urokinase-type plasminogen activator receptor (suPAR) is an important immune mediator and is involved in kidney injury. However, its diagnostic value in S-AKI patients remains unclear. Therefore, we assessed the early predictive value of suPAR for S-AKI patients.

METHODS

We prospectively enrolled adult patients, immediately after fulfilling the sepsis-3 criteria. Plasma suPAR levels at 0-, 12-, 24-, and 48-h post-sepsis diagnosis were measured. S-AKI development was the primary outcome. S-AKI risk factors were analyzed using logistic regression, and the value of plasma suPAR for early S-AKI diagnosis was assessed using receiver operating characteristic (ROC) curves.

RESULTS

Of 179 sepsis patients, 63 (35.2%) developed AKI during hospitalization. At 12-, 24-, and 48-h post-sepsis diagnosis, plasma suPAR levels were significantly higher in patients with S-AKI than in patients without S-AKI (p < 0.05). The plasma suPAR had the highest area under the ROC curve of 0.700 (95% confidence interval (CI), 0.621-0.779) at 24-h post-sepsis diagnosis, at which the best discrimination ability for S-AKI was achieved with suPAR of ≥6.31 ng/mL (sensitivity 61.9% and specificity 71.6%). Logistic regression analysis showed that suPAR at 24-h post-sepsis diagnosis remained an independent S-AKI risk factor after adjusting for mechanical ventilation, blood urea nitrogen, and pH.

CONCLUSIONS

The findings suggest that plasma suPAR may be a potential biomarker for early S-AKI diagnosis.

TAK-242 improves sepsis-associated acute kidney injury in rats by inhibiting the TLR4/NF-κB signaling pathway

OBJECTIVE

This study was designed to observe the effect of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway activity on sepsis-associated acute kidney injury (SA-AKI), thereby providing new considerations for the prevention and treatment of SA-AKI.

METHODS

The rats were divided into Sham, cecal ligation and puncture (CLP), CLP + vehicle, and CLP + TAK-242 groups. Except the Sham group, a model of CLP-induced sepsis was established in other groups. After 24 h, the indicators related to kidney injury in blood samples were detected. The pathological changes in the kidneys were observed by hematoxylin-eosin staining, and tubular damage was scored. Oxidative stress-related factors, mitochondrial dysfunction-related indicators in each group were measured; the levels of inflammatory factors in serum and kidney tissue of rats were examined. Finally, the expression of proteins related to the TLR4/NF-κB signaling pathway was observed by western blot.

RESULTS

Compared with the CLP + vehicle and CLP + TAK-242 groups, the CLP + TAK-242 group reduced blood urea nitrogen (BUN), creatinine (Cr), cystatin-C (Cys-C), reactive oxygen species (ROS), malondialdehyde (MDA), and inflammatory factors levels (p < 0.01), as well as increased superoxide dismutase (SOD) activity of CLP rats (p < 0.01). Additionally, TAK-242 treatment improved the condition of CLP rats that had glomerular and tubular injuries and mitochondrial disorders (p < 0.01). Further mechanism research revealed that TAK-242 can inhibit the TLR4/NF-κB signaling pathway activated by CLP (p < 0.01). Above indicators after TAK-242 treatment were close to those of the Sham group.

CONCLUSION

TAK-242 can improve oxidative stress, mitochondrial dysfunction, and inflammatory response by inhibiting the activity of TLR4/NF-κB signaling pathway, thereby preventing rats from SA-AKI.

Association between normal saline infusion volume in the emergency department and acute kidney injury in heat stroke patients: a multicenter retrospective study

BACKGROUND

Previous studies have shown that intravenous normal saline (NS) may be associated with the incidence of acute kidney injury (AKI). This study aimed to evaluate the association between the volume of NS infusion and AKI in heat stroke (HS) patients.

METHODS

This multicenter retrospective cohort study included 138 patients with HS. The primary outcome was the incidence of AKI. Secondary outcomes included the need for continuous renal replacement therapy (CRRT), admission to the intensive care unit (ICU), length of stay in the ICU and hospital, and in-hospital mortality. Multivariate regression models, random forest imputation, and genetic and propensity score matching were used to explore the relationship between NS infusion and outcomes.

RESULTS

The mean volume of NS infusion in the emergency department (ED) was 3.02 ± 1.45 L. During hospitalization, 33 patients (23.91%) suffered from AKI. In the multivariate model, as a continuous variable (per 1 L), the volume of NS infusion was associated with the incidence of AKI (OR, 2.51; 95% CI, 1.43-4.40; p = .001), admission to the ICU (OR, 3.46; 95% CI 1.58-7.54; p = .002), and length of stay in the ICU (β, 1.00 days; 95% CI, 0.44-1.56; p < .001) and hospital (β, 1.41 days; 95% CI, 0.37-2.45; p = .008). These relationships also existed in the forest imputation cohort and matching cohort. There were no differences in the use of CRRT or in-hospital mortality.

CONCLUSIONS

The volume of NS infusion was associated with a significant increase in the incidence of AKI, admission to the ICU, and length of stay in the ICU and hospital among patients with HS.

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

Prognostic value of neutrophil-to-lymphocyte ratio dynamics in patients with septic acute kidney injury: a cohort study

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been suggested to be a prognostic marker for various diseases, but whether NLR dynamics (ΔNLR) is related to mortality and disease severity in patients with septic acute kidney injury (AKI) has not been determined.

METHODS

Between August 2013 and August 2021, septic AKI patients at our center were retrospectively enrolled. ΔNLR was defined as the difference between the NLR at septic AKI diagnosis and at hospital admission. The relationship between the ΔNLR and mortality was evaluated by Kaplan-Meier curves, Cox proportional hazards, and cubic spline analyses. The prediction values were compared by area under the receiver-operating characteristic curve (AUROC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) analyses.

RESULTS

Of the 413 participants, the mean age was 63 ± 17 years, and 134 were female (32.4%). According to the median value, patients in the high-ΔNLR group had significantly greater 90-d mortality (74.4% vs. 46.6%, p < 0.001). After adjustment for potential confounders, high ΔNLR remained an independent predictor of 90-d mortality (HR = 2.80; 95% CI = 1.74-4.49, p < 0.001). Furthermore, ΔNLR had the highest AUROC for 90-d mortality (0.685) among the various biomarkers and exhibited an improved NRI (0.314) and IDI (0.027) when incorporated with PCT and CRP. For secondary outcomes, patients with high ΔNLR had increased risk of 30-d mortality (p = 0.004), need for renal replacement therapy (p = 0.011), and developing stage-3 AKI (p = 0.040) according to the adjusted models.

CONCLUSIONS

High ΔNLR is independently associated with increased risk of patient mortality and adverse outcomes. ΔNLR might be utilized to facilitate risk stratification and optimize septic AKI management.

Effects of 24-hour urine-output trajectories on the risk of acute kidney injury in critically ill patients with cirrhosis: a retrospective cohort analysis

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications for critically ill patients with cirrhosis, but it has remained unclear whether urine output fluctuations are associated with the risk of AKI in such patients. Thus, we explored the influence of 24-h urine-output trajectory on AKI in patients with cirrhosis through latent category trajectory modeling.

MATERIALS AND METHODS

This retrospective cohort study examined patients with cirrhosis using the MIMIC-IV database. Changes in the trajectories of urine output within 24 h after admission to the intensive care unit (ICU) were categorized using latent category trajectory modeling. The outcome examined was the occurrence of AKI during ICU hospitalization. The risk of AKI in patients with different trajectory classes was explored using the cumulative incidence function (CIF) and the Fine-Gray model with the sub-distribution hazard ratio (SHR) and the 95% confidence interval (CI) as size effects.

RESULTS

The study included 3,562 critically ill patients with cirrhosis, of which 2,467 (69.26%) developed AKI during ICU hospitalization. The 24-h urine-output trajectories were split into five classes (Classes 1-5). The CIF curves demonstrated that patients with continuously low urine output (Class 2), a rapid decline in urine output after initially high levels (Class 3), and urine output that decreased slowly and then stabilized at a lower level (Class 4) were at higher risk for AKI than those with consistently moderate urine output (Class 1). After fully adjusting for various confounders, Classes 2, 3, and 4 were associated with a higher risk of AKI compared with Class 1, and the respective SHRs (95% CIs) were 2.56 (1.87-3.51), 1.86 (1.34-2.59), and 1.83 1.29-2.59).

CONCLUSIONS

The 24-h urine-output trajectory is significantly associated with the risk of AKI in critically ill patients with cirrhosis. More attention should be paid to the dynamic nature of urine-output changes over time, which may help guide early intervention and improve patients' prognoses.

Factors associated with post-hospitalization dialysis dependence in ECMO patients who required continuous renal replacement therapy

OBJECTIVE

This single center retrospective study aimed to describe the variables associated with outpatient dialysis dependence in extracorporeal membrane oxygenation (ECMO) patients who needed continuous renal replacement therapy (CRRT) for acute kidney injury (AKI) during their hospitalization.

METHODS

Retrospective study of patients who required ECMO-CRRT.

RESULTS

Between the years of 2016 and 2022, 202 patients required ECMO-CRRT. One hundred and six patients (52.5%) survived their hospitalization and were followed up for a median of 391 [133, 1005] days. Eighty-one patients (76.5%) recovered kidney function and were dialysis-free before hospital discharge. Twenty-five patients (23.5%) were hemodialysis-dependent after hospitalization. On multivariate regression analysis, hyperlipidemia (odds ratio, OR 6.08 [1.67-22]) and CRRT duration (OR 1.09 [1.03-1.15]) were associated with the need for dialysis post-hospitalization. In this group, 16 patients eventually became dialysis-free, after a median of 49 [34.7, 78.5] days. These patients had a higher median baseline glomerular filtration rate (GFR) compared to those who never recovered renal function (93 mL/min/1.73 m2 [82.4, 104.3] vs. 63.8 mL/min/1.73 m2 [37.9, 83], p = .009). Their follow-up GFR was lower compared to those who recovered renal function before hospital discharge; (87 mL/min/1.73 m2 [68.2, 98.9] vs. 99 mL/min/1.73 m2 [79, 118], p = .07).

CONCLUSIONS

AKI requiring CRRT was associated with high mortality in patients receiving ECMO. Nonetheless, most ECMO survivors became dialysis-free before hospital discharge. Variables associated with the need for outpatient dialysis included hyperlipidemia and prolonged need for CRRT during hospitalization.

Serum chemokine IL-8 acts as a biomarker for identifying COVID-19-associated persistent severe acute kidney injury

OBJECTIVES

Persistent severe acute kidney injury (PS-AKI) is associated with poor clinical outcomes. Our study attempted to evaluate the diagnostic value of chemokines for early-stage PS-AKI prediction.

METHODS

According to the KDIGO criteria, 115 COVID-19 patients diagnosed with stage 2/3 AKI were recruited from the intensive care unit between December 2022 and February 2023. Primary clinical outcomes included detecting PS-AKI in the first week (≥ KDIGO stage 2 ≥ 72 h). Cytometric Bead Array was used to detect patient plasma levels (interleukin-8 (IL-8), C-C chemokine ligand 5 (CCL5), chemokine (C-X-C Motif) ligand 9 (CXCL9), and interferon-inducible protein 10 (IP-10)) of chemokines within 24 h of enrollment.

RESULTS

Of the 115 COVID-19 patients with stage 2/3 AKI, 27 were diagnosed with PS-AKI. Among the four measured chemokines, only the IL-8 level was significantly elevated in the PS-AKI group than in the Non-PS-AKI group. IL-8 was more effective as a biomarker while predicting PS-AKI with an area under the curve of 0.769 (0.675-0.863). This was superior to other biomarkers related to AKI, including serum creatinine. Moreover, plasma IL-8 levels of >32.2 pg/ml on admission could predict PS-AKI risk (sensitivity = 92.6%, specificity = 51.1%). Additionally, the IL-8 level was associated with total protein and IL-6 levels.

CONCLUSION

Plasma IL-8 is a promising marker for the early identification of PS-AKI among COVID-19 patients. These findings should be validated in further studies with a larger sample size.

Melittin alleviates sepsis-induced acute kidney injury by promoting GPX4 expression to inhibit ferroptosis

OBJECTIVES

Melittin, the main component of bee venom, is a natural anti-inflammatory substance, in addition to its ability to fight cancer, antiviral, and useful in diabetes treatment. This study seeks to determine whether melittin can protect renal tissue from sepsis-induced damage by preventing ferroptosis and explore the protective mechanism.

METHODS

In this study, we investigated the specific protective mechanism of melittin against sepsis-induced renal injury by screening renal injury indicators and ferroptosis -related molecules and markers in animal and cellular models of sepsis.

RESULTS

Our results showed that treatment with melittin attenuated the pathological changes in mice with lipopolysaccharide-induced acute kidney injury. Additionally, we found that melittin attenuated ferroptosis in kidney tissue by enhancing GPX4 expression, which ultimately led to the reduction of kidney tissue injury. Furthermore, we observed that melittin enhanced NRF2 nuclear translocation, which consequently upregulated GPX4 expression. our findings suggest that melittin may be a potential therapeutic agent for the treatment of sepsis-associated acute kidney injury by inhibiting ferroptosis through the GPX4/NRF2 pathway.

CONCLUSIONS

Our study reveals the protective mechanism of melittin in septic kidney injury and provides a new therapeutic direction for Sepsis-AKI.

Complement activation in wasp venom-induced acute kidney injury

Previous studies have highlighted the significant role of complement activation in kidney injuries induced by rhabdomyolysis, intravascular hemolysis, sepsis, and ischemia-reperfusion. Nevertheless, the specific role and mechanism of complement activation in acute kidney injury (AKI) caused by wasp venom remain unclear. The aim of this study was to elucidate the specific complement pathway activated and investigate complement activation in AKI induced by wasp venom. In this study, a complement-depleted mouse model was used to investigate the role of complement in wasp venom-induced AKI. Mice were randomly categorized into control, cobra venom factor (CVF), AKI, and CVF + AKI groups. Compared to the AKI group, the CVF + AKI group showed improved pathological changes in kidneys and reduced blood urea nitrogen (BUN) levels. The expression levels of renal complement 3 (C3), complement 5 (C5), complement 1q (C1q), factor B (FB), mannose-binding lectin (MBL), and C5b-9 in AKI group were upregulated compared with the control group. Conversely, the renal tissue expression levels of C3, C5, C1q, FB, MBL, and C5b-9 were decreased in the CVF + AKI group compared to those in the AKI group. Complement activation occurs through all three pathways in AKI induced by wasp venom. Furthermore, complement depletion by CVF attenuates wasp venom-induced nephrotoxicity, suggesting that complement activation plays a primary role in the pathogenesis of wasp venom-induced AKI.

Mitophagy mediated by HIF-1α/FUNDC1 signaling in tubular cells protects against renal ischemia/reperfusion injury

Acute kidney injury (AKI) is associated with a high mortality rate. Pathologically, renal ischemia/reperfusion injury (RIRI) is one of the primary causes of AKI, and hypoxia-inducible factor (HIF)-1α may play a defensive role in RIRI. This study assessed the role of hypoxia-inducible factor 1α (HIF-1α)-mediated mitophagy in protection against RIRI in vitro and in vivo. The human tubular cell line HK-2 was used to assess hypoxia/reoxygenation (H/R)-induced mitophagy through different in vitro assays, including western blotting, immunofluorescence staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and reactive oxygen species (ROS) measurement. Additionally, a rat RIRI model was established for evaluation by renal histopathology, renal Doppler ultrasound, and transmission electron microscopy to confirm the in vitro data. The selective HIF-1α inhibitor LW6 reduced H/R-induced mitophagy but increased H/R-induced apoptosis and ROS production. Moreover, H/R treatment enhanced expression of the FUN14 domain-containing 1 (FUNDC1) protein. Additionally, FUNDC1 overexpression reversed the effects of LW6 on the altered expression of light chain 3 (LC3) BII and voltage-dependent anion channels as well as blocked the effects of HIF-1α inhibition in cells. Pretreatment of the rat RIRI model with roxadustat, a novel oral HIF-1α inhibitor, led to decreased renal injury and apoptosis in vivo. In conclusion, the HIF-1α/FUNDC1 signaling pathway mediates H/R-promoted renal tubular cell mitophagy, whereas inhibition of this signaling pathway protects cells from mitophagy, thus aggravating apoptosis, and ROS production. Accordingly, roxadustat may protect against RIRI-related AKI.

Kidney damage associated with COVID-19: from the acute to the chronic phase

Severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) infection is well established as a systemic disease including kidney damage. The entry point into the renal cell remains the angiotensin-converting enzyme 2 (ACE-2) receptor and the spectrum of renal lesions is broad, with a clear predominance of structural and functional tubular lesions. The most common form of glomerular injury is collapsing glomerulopathy (CG), which is strongly associated with apolipoprotein L1(APOL-1) risk variants. These acute lesions, which are secondary to the direct or indirect effects of SARS-CoV-2, can progress to chronicity and are specific to long COVID-19 in the absence of any other cause. Residual inflammation associated with SARS-CoV-2 infection, in addition to acute kidney injury (AKI) as a transitional state with or without severe histological lesions, may be responsible for greater kidney function decline in mild-to-moderate COVID-19. This review discusses the evidence for renal histological markers of chronicity in COVID-19 patients and triggers of low-grade inflammation that may explain the decline in kidney function in the post-COVID-19 period.

Diagnostic value of multi-parameter ultrasound evaluation in sepsis complicated by acute kidney injury

BACKGROUND

This study aimed to discuss the diagnostic value of multi-parameter ultrasound evaluation in sepsis complicated with acute kidney injury (AKI).

METHODS

Patients were divided into an AKI group (n = 50) and a non-injury group (n = 50) based on the presence of AKI. The clinical characteristics were collected, and renal function parameters between the two groups were compared, including 24-h urine volume, serum creatinine, urea, serum cystatin C (CysC), renal parenchymal thickness (RPT), renal artery resistance index (RI), and multi-parameter ultrasound scoring (MPUS). Additionally, logistic regression analysis was conducted to determine the influencing factors of sepsis complicated with AKI. The prediction value was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

In the AKI group, creatinine, CysC, urea, MPUS score, RPT, and RI values were significantly higher, while the 24-h urine volume was lower than those in the non-injury group (p < 0.01). Moreover, multivariate logistic analysis indicated that high CysC and RI values were independent risk factors, whereas high 24-h urine volume and low MPUS were independent protective factors for sepsis-induced AKI. The ROC curve demonstrated that RI (AUC = 0.906) was more effective than 24-h urine volume (AUC = 0.797), CysC (AUC = 0.730), and MPUS (AUC = 0.794) in identifying sepsis-induced AKI.

CONCLUSION

High RI values increase the risk of sepsis-induced AKI, whereas low MPUS may reduce it. RI showed high diagnosis values for sepsis complicated with AKI.

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

Analysis of risk factors for acute kidney injury in children with severe wasp stings

BACKGROUND

Acute kidney injury (AKI) is common in children with sepsis, chronic kidney disease, poisoning or other conditions. Wasp stings are recognized as an important etiology. Several retrospective studies have investigated AKI after wasp stings in adults, but research on children remains limited.

METHODS

The study included 48 children with multiple organ dysfunction syndrome after wasp stings. Demographic data, clinical manifestations, laboratory findings, management and clinical outcomes were collected, and analyzed to identify early indicators or risk factors for AKI.

RESULTS

20 children (41.7%) developed AKI, and 28 (58.3%) did not. Serum creatine levels elevated mostly within 24 h from stings in children with AKI (16/20, 80%). Compared with non-AKI group, AKI group exhibited more cases with cola-colored urine, jaundice, and had higher sting numbers/body surface area (BSA) and higher revised sequential organ failure assessment scores (rSOFA) as well as higher levels of C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), lactate dehydrogenase (LDH), troponin (cTnI), creatine kinase (CK), and longer prothrombin time (PT). Both univariable and multivariable logistic regression analysis identified cola-colored urine as a potential early risk factor for AKI.

CONCLUSIONS

The AKI group exhibited higher sting numbers/BSA, higher levels of CRP, ALT, AST, TBIL, LDH, cTnI, and CK, as well as longer PT (p < 0.05). Our findings also suggest that cola-colored urine may serve as an early indicator or potential risk factor for AKI after wasp stings in children, which is very easy to identify for first aiders or pediatricians.

Fifteen-year temporal changes in rates of acute kidney injury among children in Denmark

BACKGROUND

We aimed to examine temporal changes in the annual rate of acute kidney injury (AKI) in Danish children and associated changes in patient characteristics including potential underlying risk factors.

METHODS

In this population-based cohort study, we used plasma creatinine measurements from Danish laboratory databases to identify AKI episodes in children aged 0-17 years from 2007 to 2021. For each child, the first AKI episode per calendar year was included. We estimated the annual crude and sex- and age-standardized AKI rate as the number of children with an AKI episode divided by the total number of children as reported by census numbers. Using Danish medical databases, we assessed patient characteristics including potential risk factors for AKI, such as use of nephrotoxic medication, surgery, sepsis, and perinatal factors.

RESULTS

In total, 14,200 children contributed with 16,345 AKI episodes over 15 years. The mean annual AKI rate was 148 (95% CI: 141-155) per 100,000 children. From 2007 to 2021, the annual AKI rate demonstrated minor year-to-year variability without any discernible overall trend. The highest AKI rate was recorded in 2007 at 174 (95% CI: 161-187) per 100,000 children, while the lowest rate occurred in 2012 at 129 (95% CI: 118-140) per 100,000 children. In 2021, the AKI rate was 148 (95% CI: 141-155) per 100,000 children. Characteristics of children with AKI were similar throughout the study period.

CONCLUSION

The rate of AKI among Danish children was stable from 2007 to 2021 with little variation in patient characteristics over time.

Renoprotective effects of laxative linaclotide: Inhibition of acute kidney injury and fibrosis in a rat model of renal ischemia-reperfusion

Ischemia-reperfusion (I/R) leads to tissue damage in transplanted kidneys, resulting in acute kidney injury (AKI) and chronic graft dysfunction, which critically compromises transplant outcomes, such as graft loss. Linaclotide, a guanylate cyclase C agonist clinically approved as a laxative, has recently been identified to exhibit renoprotective effects in a chronic kidney disease (CKD) model. This study evaluates the therapeutic effects of linaclotide on AKI triggered by I/R in a rat model with an initial comparison with other laxatives. Here, we show that linaclotide administration resulted in substantial reduction in serum creatinine levels, reflective of enhanced renal function. Histological examination revealed diminished tubular damage, and Sirius Red staining confirmed less collagen deposition, collectively indicating preserved structural integrity and mitigation of fibrosis. Further analysis demonstrated lowered expression of TGF-β and associated fibrotic markers, α-SMA, MMP2, and TIMP1, implicating the downregulation of the fibrogenic TGF-β pathway by linaclotide. Furthermore, one day after I/R insult, linaclotide profoundly diminished macrophage infiltration and suppressed critical pro-inflammatory cytokines such as TNF, IL-1β, and IL-6, signifying its potential to disrupt initial inflammatory mechanisms integral to AKI pathology. These findings suggest that linaclotide, with its established safety profile, could extend its benefits beyond gastrointestinal issues and potentially serve as a therapeutic intervention for organ transplantation. Additionally, it could provide immediate and practical insights into selecting laxatives for managing patients with AKI or CKD, regardless of the cause, and for those receiving dialysis or transplant therapy.

A reappraisal of risk factors for hypertension after pediatric acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is common in hospitalized children and increases the risk of chronic kidney disease (CKD) and hypertension, but little is known about the patient level risk factors for pediatric hypertension after AKI. The aims of this study are to evaluate the prevalence and risk factors for new onset hypertension in hospitalized children with AKI and to better understand the role of acute kidney disease (AKD) in the development of hypertension.

METHODS

This study was an observational cohort of all children ≤ 18 years old admitted to a single tertiary care children's hospital from 2015 to 2019 with a diagnosis of AKI. Hypertension was defined as blood pressure > 95th percentile for sex, age, height, diagnosis of hypertension on the problem list, or prescription of antihypertensive medication for > 90 days after AKI.

RESULTS

A total of 410 children were included in the cohort. Of these, 78 (19%) developed hypertension > 90 days after AKI. A multivariable logistic regression model identified AKD, need for kidney replacement therapy, congenital heart disease, and non-kidney solid organ transplantation as risk factors for hypertension after AKI.

CONCLUSIONS

Incident hypertension after 3 months is common among hospitalized children with AKI, and AKD, need for dialysis, congenital heart disease, and non-kidney solid organ transplant are significant risk factors for hypertension after AKI. Monitoring for hypertension development in these high-risk children is critical to mitigate long-term adverse kidney and cardiovascular outcomes.

Persistent acute kidney injury and fluid accumulation with outcomes after the Norwood procedure: report from NEPHRON

BACKGROUND

Cardiac surgery-associated acute kidney injury (CS-AKI) is common, but its impact on clinical outcomes is variable. Parsing AKI into sub-phenotype(s) and integrating pathologic positive cumulative fluid balance (CFB) may better inform prognosis. We sought to determine whether durational sub-phenotyping of CS-AKI with CFB strengthens association with outcomes among neonates undergoing the Norwood procedure.

METHODS

Multicenter, retrospective cohort study from the Neonatal and Pediatric Heart and Renal Outcomes Network. Transient CS-AKI: present only on post-operative day (POD) 1 and/or 2; persistent CS-AKI: continued after POD 2. CFB was evaluated per day and peak CFB during the first 7 postoperative days. Primary and secondary outcomes were mortality, respiratory support-free and hospital-free days (at 28, 60 days, respectively). The primary predictor was persistent CS-AKI, defined by modified neonatal Kidney Disease: Improving Global Outcomes criteria.

RESULTS

CS-AKI occurred in 59% (205/347) neonates: 36.6% (127/347) transient and 22.5% (78/347) persistent; CFB > 10% occurred in 18.7% (65/347). Patients with either persistent CS-AKI or peak CFB > 10% had higher mortality. Combined persistent CS-AKI with peak CFB > 10% (n = 21) associated with increased mortality (aOR: 7.8, 95% CI: 1.4, 45.5; p = 0.02), decreased respiratory support-free (predicted mean 12 vs. 19; p < 0.001) and hospital-free days (17 vs. 29; p = 0.048) compared to those with neither.

CONCLUSIONS

The combination of persistent CS-AKI and peak CFB > 10% after the Norwood procedure is associated with mortality and hospital resource utilization. Prospective studies targeting intra- and postoperative CS-AKI risk factors and reducing CFB have the potential to improve outcomes.

Implication of acute tubular injury in minimal change nephrotic syndrome

While acute tubular injury (ATI) is known to occur in a significant number of minimal change disease (MCD) nephrotic syndrome cases with acute kidney injury (AKI), the clinical significance is not certain, and AKI may also occur without ATI. This study aimed to evaluate whether the severity of AKI defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria correlated with the presence or severity of ATI in a series of adult patients with MCD. We also looked at whether time to remission of nephrotic syndrome (NS) with treatment correlated with the presence of ATI in those with and without AKI. We excluded patients with secondary MCD. Of 61 patients, 20 had AKI (33%). ATI was significantly more likely to occur in those with AKI than in those without AKI (60 vs. 24%). Overall, the severity of AKI did not clearly correspond with the severity of ATI. Remission rates at 4 weeks were lowest (25%) in those with both AKI and ATI, while they were highest (100%) in those with neither AKI nor ATI. Patients with AKI but no ATI and those with no AKI but having ATI were intermediate in remission rates and similar to each other (60 and 62%, respectively). The time to remission in the group of those without AKI was significantly longer in those with ATI than in those without (p = 0.0027), but the numerical difference in remission did not reach statistical significance in the smaller group of AKI patients. Patients with ATI were older and more often male than those without ATI. It appears that having ATI may predict a slower remission rate in MCD though the reason for this is unclear. The different demographics of those with ATI may also play a role.

Clinical role of serum microRNA-155 in early diagnosis and prognosis of septic patients with acute kidney injury

BACKGROUND AND PURPOSE

Acute kidney injury (AKI) is a common complication in patients with sepsis, and early detection and timely treatment are crucial. This article aims to explore the clinical role of microRNA-155 (miR-155) in early diagnosis and prognosis evaluation of septic patients with acute kidney injury.

METHODS

We collected the blood samples of septic patients and measured the relative expression of serum miR-155 by RT-qPCR, and drew the receiver operating characteristic (ROC) curves to evaluate its early diagnosis for septic AKI.

RESULTS

The relative expression of miR-155 in the septic AKI was significantly higher than that in the septic non-AKI, and increased with the aggravation of renal function damage. The ROC curve of miR-155 for the diagnosis of septic AKI was 1.91 (95% CI: 1.61-2.19). When the optimal cut-off value of miR-155 expression was 2.37, its sensitivity for diagnosing septic AKI was 91.12% (95% CI: 80.41-95.07%), and its specificity was 84.52% (95% CI: 71.74-89.36%). Furthermore, the severity of kidney injury, SOFA score, APACHE II score and miR-155 were the risk factors affecting the prognosis of septic patients with AKI.

CONCLUSION

Serum miR-155 can be used as a novel biomarker for the early diagnosis of septic AKI, and also has important clinical value in the prognosis evaluation of septic patients with AKI.

Cytosolic mtDNA-cGAS-STING axis contributes to sepsis-induced acute kidney injury via activating the NLRP3 inflammasome

BACKGROUND

NLRP3 inflammasome activation is significantly associated with sepsis-induced acute kidney injury (S-AKI). Cytosolic DNA derived from damaged mitochondria has been reported to activate NLRP3 inflammasome via upregulating the cyclic GMP-AMP synthase (cGAS)-the stimulator of interferon genes (STING) axis in nucleus pulposus cell and cardiomyocytes. However, the regulatory effect of mitochondria DNA (mtDNA)-cGAS-STING axis on the NLRP3 inflammasome in S-AKI remains unclear.

METHODS

In the current study, we established an in vivo model of S-AKI by intraperitoneally injecting male C57BL/6 J mice with lipopolysaccharide (LPS). Next, selective cGAS inhibitor RU.521, and STING agonist DMXAA were intraperitoneally injected in the mice; then, blood urea nitrogen (BUN), serum creatinine (CRE), urinary kidney injury molecular-1 (KIM-1), pathological changes, and infiltrated neutrophils were detected to assess kidney injury. We also performed western blot and immunofluorescence assays to evaluate STING, cGAS, TBK-1, p-TBK-1, IRF3, p-IRF3, NF-kB, p-NF-kB, NLRP3, cleaved caspase-1, caspase-1, GSDMD-N, and GSDMD expression levels in kidney tissues. IL-18 and IL-1β in renal tissue were identified by ELISA. In vitro, we treated HK-2 cells with LPS to establish a cell model of S-AKI. Furthermore, ethidium bromide (EtBr) was administered to deplete mitochondria DNA (mtDNA). LPS-induced cytotoxicity was evaluated by LDH release assay. Protein expression of cGAS, STING, and NLRP3 in was quantified by western blot. Cytosolic mtDNA was detected by immunofluorescence and q-PCR. Released IL-1β and IL-18 in HK-2 supernatants were detected by ELISA.

RESULTS

LPS injection induced S-AKI in mice, as evidenced by neutrophil infiltration, tubular vacuolation, and increased levels of serum creatinine (CRE), blood urea nitrogen (BUN), and urinary KIM-1. In addition, LPS activated the cGAS-STING axis and NLRP3 inflammasome in vivo, illustrated by increased phosphorylation levels of TBK-1, IRF3, and NF-kB protein, increased ratio of cleaved caspase-1 to caspase-1 and GSDMD-N to GSDMD, and increased IL-1β and IL-18 levels. Moreover, the cGAS inhibitor RU.521 effectively attenuated NLRP3 inflammasome and S-AKI; however, these effects were abolished by treatment with the STING agonist DMXAA. Furthermore, cytosolic release of mtDNA and activation of the cGAS-STING-NLRP3 axis were observed in LPS-treated HK-2 cells. Inhibiting mtDNA replication by Ethidium Bromide (EtBr) treatment reduced cytosolic mtDNA accumulation and downregulated the cGAS-STING-NLRP3 axis, ameliorating the cytotoxicity induced by LPS.

CONCLUSION

This study demonstrated that the cGAS-STING axis was triggered by cytosolic mtDNA and participated in the development of S-AKI by activating NLRP3 inflammasome. Reducing cytosolic mtDNA accumulation or inhibiting the cGAS-STING axis may be potential therapeutic targets for S-AKI.

Parental obesity predisposes offspring to kidney dysfunction and increased susceptibility to ischemia-reperfusion injury in a sex-dependent manner

Although obesity is recognized as a risk factor for cardiorenal and metabolic diseases, the impact of parental obesity on the susceptibility of their offspring to renal injury at adulthood is unknown. We examined the impact of parental obesity on offspring kidney function, morphology, and markers of kidney damage after acute kidney injury (AKI). Offspring from normal (N) diet-fed C57BL/6J parents were fed either N (NN) or a high-fat (H) diet (NH) from weaning until adulthood. Offspring from obese H diet-fed parents were fed N (HN) or H diet (HH) after weaning. All offspring groups were submitted to bilateral AKI by clamping the left and right renal pedicles for 30 min. Compared with male NH and NN offspring from lean parents, male HH and HN offspring from obese parents exhibited higher kidney injury markers such as urinary, renal osteopontin, plasma creatinine, urinary albumin excretion, and neutrophil gelatinase-associated lipocalin (NGAL) levels, and worse histological injury score at 22 wk of age. Only albumin excretion and NGAL were elevated in female HH offspring from obese parents compared with lean and obese offspring from lean parents. We also found an increased mortality rate and worse kidney injury scores after AKI in male offspring from obese parents, regardless of the diet consumed after weaning. Female offspring were protected from major kidney injury after AKI. These results indicate that parental obesity leads to increased kidney injury in their offspring after ischemia-reperfusion in a sex-dependent manner, even when their offspring remain lean.NEW & NOTEWORTHY Offspring from obese parents are more susceptible to kidney injury and worse outcomes following an acute ischemia-reperfusion insult. Male, but not female, offspring from obese parents exhibit increased blood pressure early in life. Female offspring are partially protected against major kidney injury induced by ischemia-reperfusion.

Development and Validation of a Predictive Model for Acute Kidney Injury in Sepsis Patients Based on Recursive Partition Analysis

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is a critical condition with significant clinical implications, yet there is a need for a predictive model that can reliably assess the risk of its development. This study is undertaken to bridge a gap in healthcare by creating a predictive model for SA-AKI with the goal of empowering healthcare providers with a tool that can revolutionize patient care and ultimately lead to improved outcomes.

METHODS

A cohort of 615 patients afflicted with sepsis, who were admitted to the intensive care unit, underwent random stratification into 2 groups: a training set (n = 435) and a validation set (n = 180). Subsequently, a multivariate logistic regression model, imbued with nonzero coefficients via LASSO regression, was meticulously devised for the prognostication of SA-AKI. This model was thoughtfully rendered in the form of a nomogram. The salience of individual risk factors was assessed and ranked employing Shapley Additive Interpretation (SHAP). Recursive partition analysis was performed to stratify the risk of patients with sepsis.

RESULTS

Among the panoply of clinical variables examined, hypertension, diabetes mellitus, C-reactive protein, procalcitonin (PCT), activated partial thromboplastin time, and platelet count emerged as robust and independent determinants of SA-AKI. The receiver operating characteristic curve analysis for SA-AKI risk discrimination in both the training set and validation set yielded an area under the curve estimates of 0.843 (95% CI: 0.805 to 0.882) and 0.834 (95% CI: 0.775 to 0.893), respectively. Notably, PCT exhibited the most conspicuous influence on the model's predictive capacity. Furthermore, statistically significant disparities were observed in the incidence of SA-AKI and the 28-day survival rate across high-risk, medium-risk, and low-risk cohorts (P < .05).

CONCLUSION

The composite predictive model, amalgamating the quintet of SA-AKI predictors, holds significant promise in facilitating the identification of high-risk patient subsets.

Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review

Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.

Determinants of postoperative complications in high-risk noncardiac surgery patients optimized with hemodynamic treatment strategies: A post-hoc analysis of a randomized multicenter clinical trial

STUDY OBJECTIVE

This post-hoc analysis of a randomized controlled trial was undertaken to establish the determinants of postoperative complications and acute kidney injury in high-risk noncardiac surgery patients supported with hemodynamic treatment strategies.

DESIGN

We conducted a post-hoc analysis of patients enrolled in the OPtimization Hemodynamic Individualized by the respiratory QUotiEnt (OPHIQUE) trial.

SETTING

Operating rooms in four university medical centers and one non-university hospital from December 26, 2018, to September 9, 2021.

PATIENTS

We enrolled 350 patients with a high risk of postoperative complications undergoing high-risk noncardiac surgery lasting 2 h or longer under general anesthesia.

INTERVENTIONS

All patients were treated according to hemodynamic treatment strategies which included cardiac output optimization by titration of fluid challenge and targeted systolic blood pressure to remain within ±10% of the reference value.

MEASUREMENTS

We assessed the association between pre-operative and intra-operative exposure of interest with a composite primary outcome of major complications or death within seven days following surgery using a multivariable logistic regression model. We also assessed the association between these exposures of interest and acute kidney injury.

MAIN RESULTS

The data of 341 patients were analyzed. In multivariate analysis, the factors independently associated with the primary outcome were age (OR = 1.04 (1.01-1.06), P = 0.002), preoperative hemoglobin concentration (OR = 0.85 (0.75-0.96), P = 0.012), non-vascular surgery (OR = 0.30 (0.17-0.53), P < 0.0001), and intraoperative surgical complications (OR = 2.08 (1.02-4.24), P = 0.046). The factors independently associated with postoperative acute kidney injury were age (OR = 1.04 (1.01-1.08), P = 0.008), preoperative creatinine concentration (OR = 1.01 (1.00-1.01), P = 0.049), non-vascular surgery (OR = 0.36 (0.20-0.66), P = 0.001), and intraoperative surgical complications (OR = 3.36 (1.50-7.55), P = 0.031).

CONCLUSIONS

Surgical complications, a lower preoperative hemoglobin concentration, age, and vascular surgery were associated with postoperative complications in a high-risk noncardiac surgery population supported with hemodynamic treatment strategies.

Acute Kidney Injury After Heart Transplantation: Risk Factors and Clinical Outcomes

OBJECTIVE

Acute kidney injury (AKI) requiring renal-replacement therapy (RRT) after heart transplantation (OHT) is common and impairs outcomes. This study aimed to identify independent donor and recipient risk factors associated with RRT after OHT.

DESIGN

A retrospective data analysis.

SETTING

Data were collected from clinical routines in a maximum-care university hospital.

PARTICIPANTS

Patients who underwent OHT.

INTERVENTIONS

The authors retrospectively analyzed data from 264 patients who underwent OHT between 2012 and 2021; 189 patients were eligible and included in the final analysis.

MEASUREMENTS AND MAIN RESULTS

The mean age was 48.0 ± 12.3 years, and 71.4% of patients were male. Ninety (47.6%) patients were on long-term mechanical circulatory support (lt-MCS). Posttransplant AKI with RRT occurred in 123 (65.1%) patients. In a multivariate analysis, preoperative body mass index >25 kg/m² (odds ratio [OR] 4.74, p < 0.001), elevated preoperative creatinine levels (OR for each mg/dL increase 3.44, p = 0.004), administration of red blood cell units during transplantation procedure (OR 2.31, p = 0.041) and ischemia time (OR for each hour increase 1.77, p = 0.004) were associated with a higher incidence of RRT. The use of renin-angiotensin-aldosterone system blockers before transplantation was associated with a reduced risk of RRT (OR 0.36, p = 0.013). The risk of mortality was 6.9-fold higher in patients who required RRT (hazard ratio 6.9, 95% CI: 2.1-22.6 p = 0.001). Previous lt-MCS, as well as donor parameters, were not associated with RRT after OHT.

CONCLUSIONS

The implementation of guideline-directed medical therapy, weight reduction, minimizing ischemia time (ie, organ perfusion systems, workflow optimization), and comprehensive patient blood management potentially influences renal function and outcomes after OHT.

Systematic review and meta-analysis of fenestrated or branched devices after previous open surgical aortic aneurysm repair

OBJECTIVE

Despite open surgical repair (OSR) of abdominal aortic aneurysms being considered as a durable solution, disease progression and para-anastomotic aneurysms may require further repair, and fenestrated and branched endovascular aneurysm repair (F/BEVAR) may be applied to address these pathologies. The aim of this systematic review was to assess technical success, mortality, and morbidity (acute kidney injury, spinal cord ischemia) at 30 days, and mortality and reintervention rates during the available follow-up, in patients managed with F/BEVAR after previous OSR.

METHODS

The PRISMA statement was followed, and the study was pre-registered to the PROSPERO (CRD42022363214). The English literature was searched, via Ovid, using MEDLINE, EMBASE, and CENTRAL databases, through November 30, 2022. Observational studies and case series with ≥5 patients (2000-2022), reporting on F/BEVAR outcomes after OSR, were considered eligible. The Newcastle-Ottawa Scale and GRADE were used to assess the risk of bias and quality of evidence. The primary outcome was technical success, mortality, and morbidity at 30 days. Data on the outcomes of interest were synthesized using proportional meta-analysis.

RESULTS

The initial search yielded 1694 articles. Eight retrospective studies (476 patients) were considered eligible. In 78.3% of cases, disease progression set the indication for reintervention. Technical success was estimated at 96% (95% confidence interval [CI], 89%-98%; I2 = 0%; 95% prediction interval [PI], 79%-99%). Thirty-day mortality was 2% (95% CI, 1%-9%; I2 = 0%; 95% PI, 0%-28%). The estimated spinal cord ischemia and acute kidney injury rates were 3% (95% CI, 1%-9%; I2 = 0%; 95% PI, 0%-30%) and 6% (95% CI, 2%-15%; I2 = 0%; 95% PI, 1%-40%), respectively. During follow-up, overall mortality was 5% (95% CI, 2%-12%; I2 = 34%; 95% PI, 0%-45%) and aorta-related mortality was 1% (95% CI, 0%-2%; I2 = 0%; 95% PI, 0%-3%). The rate of reinterventions was 16% (95% CI, 9%-26%; I2 = 22%; 95% PI, 3%-50%).

CONCLUSIONS

According to the available literature, F/BEVAR after OSR may be performed with high technical success and low mortality and morbidity during the perioperative period. Follow-up aortic-related mortality was 1%, whereas the reintervention rates were within the standard range following F/BEVAR.

The impact of tubular dysfunction and its relationship with acute kidney injury in children

BACKGROUND

Tubular dysfunction can cause electrolyte disturbances with potentially serious consequences. We studied the epidemiology and outcomes of electrolyte disturbances and tubular dysfunction among critically ill children and evaluated their relationships with acute kidney injury (AKI).

METHODS

We conducted a prospective cohort study recruiting children aged 1 month to ≤ 18 years old admitted to the pediatric intensive care unit (PICU) from 6/2020 to 6/2021. The serum levels of sodium, potassium, calcium, phosphate, and magnesium were reviewed and simultaneous urinary investigations for tubular function were performed among children with electrolyte disturbances.

RESULTS

Altogether there were 253 episodes of admission. The median (interquartile) age was 4.9 (1.3-11.0) years and 58.1% were male. The median number of electrolyte disorders was 3 (2-4) types. Hypophosphatemia (74.2%), hypocalcemia (70.3%) and hypermagnesemia (52.9%) were the three commonest types of disturbances. Urinary electrolyte wasting was commonly observed among children with hypomagnesemia (70.6%), hypophosphatemia (67.4%) and hypokalemia (28.6%). Tubular dysfunction was detected in 82.6% of patients and urinary β2-microglobulin level significantly correlated with the severity of tubular dysfunction (p < 0.001). The development of tubular dysfunction was independent of AKI status. Tubular dysfunction was associated with mortality (p < 0.001) and was an independent predictor of PICU length of stay (LOS) (p < 0.001). The incorporation of the tubular dysfunction severity into the AKI staging system improved the prediction of PICU LOS.

CONCLUSIONS

Tubular dysfunction was associated with both morbidity and mortality in critically ill children and its assessment may help to capture a more comprehensive picture of acute kidney insult.

Admission proteinuria predicts the incidence of acute kidney injury among patients with acute ST-segment elevation myocardial infarction: a retrospective cohort study

BACKGROUND

Proteinuria indicates renal dysfunction and is associated with the development of acute kidney injury (AKI) in several conditions, but the association between proteinuria and AKI in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear. This research aims to investigate the predictive value of proteinuria for the development of AKI in STEMI patients.

METHODS

A total of 2735 STEMI patients were enrolled. The present study's endpoint was AKI incidence during hospitalization. AKI is defined according to the Kidney Disease: Improving Global Outcomes criteria. We defined proteinuria, measured with a dipstick, as mild (1+) or heavy (2+ to 4+). Multivariate logistic regression and subgroup analyses were used to testify to the association between proteinuria and AKI.

RESULTS

Overall, proteinuria was observed in 634 (23.2%) patients. Multivariate logistic regression analyses revealed that proteinuria [odds ratio (OR), 1.58; 95% confidence interval (CI), 1.25-2.00; P  < 0.001] was the independent predictive factor for AKI. Severe proteinuria was associated with a higher adjusted risk for AKI compared with the nonproteinuria group (mild proteinuria: OR, 1.35; 95% CI, 1.04-1.75; P  = 0.025; severe proteinuria: OR, 2.50; 95% CI, 1.70-3.68; P  < 0.001). The association was highly consistent across all studied subgroups. (all P for interaction >0.05).

CONCLUSION

Admission proteinuria measured using a urine dipstick is an independent risk factor for the development of AKI in STEMI patients.

Arterial Hyperoxemia During Cardiopulmonary Bypass Was Not Associated With Worse Postoperative Pulmonary Function: A Retrospective Cohort Study

BACKGROUND

Arterial hyperoxemia may cause end-organ damage secondary to the increased formation of free oxygen radicals. The clinical evidence on postoperative lung toxicity from arterial hyperoxemia during cardiopulmonary bypass (CPB) is scarce, and the effect of arterial partial pressure of oxygen (Pa o2 ) during cardiac surgery on lung injury has been underinvestigated. Thus, we aimed to examine the relationship between Pa o2 during CPB and postoperative lung injury. Secondarily, we examined the relationship between Pa o2 and global (lactate), and regional tissue malperfusion (acute kidney injury). We further explored the association with regional tissue malperfusion by examining markers of cardiac (troponin) and liver injury (bilirubin).

METHODS

This was a retrospective cohort study including patients who underwent elective cardiac surgeries (coronary artery bypass, valve, aortic, or combined) requiring CPB between April 2015 and December 2021 at a large quaternary medical center. The primary outcome was postoperative lung function defined as the ratio of Pa o2 to fractional inspired oxygen concentration (F io2 ); P/F ratio 6 hours following surgery or before extubation. The association between CPB in-line sample monitor Pa o2 and primary, secondary, and exploratory outcomes was evaluated using linear or logistic regression models adjusting for available baseline confounders.

RESULTS

A total of 9141 patients met inclusion and exclusion criteria, and 8429 (92.2%) patients had complete baseline variables available and were included in the analysis. The mean age of the sample was 64 (SD = 13), and 68% were men (n = 6208). The time-weighted average (TWA) of in-line sample monitor Pa o2 during CPB was weakly positively associated with the postoperative P/F ratio. With a 100-unit increase in Pa o2 , the estimated increase in postoperative P/F ratio was 4.61 (95% CI, 0.71-8.50; P = .02). Our secondary analysis showed no significant association between Pa o2 with peak lactate 6 hours post CPB (geometric mean ratio [GMR], 1.01; 98.3% CI, 0.98-1.03; P = .55), average lactate 6 hours post CPB (GMR, 1.00; 98.3% CI, 0.97-1.03; P = .93), or acute kidney injury by Kidney Disease Improving Global Outcomes (KDIGO) criteria (odds ratio, 0.91; 98.3% CI, 0.75-1.10; P = .23).

CONCLUSIONS

Our investigation found no clinically significant association between Pa o2 during CPB and postoperative lung function. Similarly, there was no association between Pa o2 during CPB and lactate levels, postoperative renal function, or other exploratory outcomes.

Long-term outcome of pediatric renal transplantation with donors younger than 6 years

BACKGROUND

Renal transplantation is currently the best treatment option for patients with end-stage renal disease. However, the use of kidneys from donors under 6 years of age as a possibility to increase the organ pool in pediatric recipients remains a controversial matter. We aimed to investigate whether donor age is associated to the long-term functionality of the renal graft. Likewise, we analyzed the adaptation of the graft to the ascending functional requirements in the pediatric patient.

METHODS

Retrospective study of the results obtained in pediatric recipients transplanted with grafts from donors between 3 and 6 years of age, comparing them with those of grafts from donors older than 6 years. Among the variables compared are cumulative graft survival, renal size, need for antiproteinuric therapy, GFR, incidence of rejection, pyelonephritis, renal failure and surgical or tumor complications.

RESULTS

A total of 43 transplants were performed with donors aged 3-6 years, and 42 transplants with donors older than 6 years. Cumulative graft survival at 5 years was 81% for the younger donor group compared to 98% for the older donor group (p < .05). At 8 years, cumulative graft survival for donors <6 years was 74%. As for the mean estimated graft survival, it was 11.52 years for the younger donor group and 14.51 years for older donors. During follow-up, the younger donor group presented greater renal enlargement and need for antiproteinuric therapy. The older donors group had a higher GFR during the first year of follow-up, which then equalized in both groups. There were no statistically significant differences in the incidence of acute or chronic rejection, acute pyelonephritis, acute renal failure or surgical or tumor complications.

CONCLUSIONS

Renal transplants of grafts equal to or less than 6 years old have good short-term and acceptable long-term results in pediatric patients.

Intraoperative central venous pressure during cardiopulmonary bypass is an alternative indicator for early prediction of acute kidney injury in adult cardiac surgery

BACKGROUND

The relationship between venous congestion in cardiopulmonary bypass (CPB) and acute kidney injury (AKI) in cardiac surgery has not utterly substantiated. This study aimed at investigate the relationship between CVP in CPB and the occurrence of AKI.

METHODS

We retrospectively reviewed 2048 consecutive patients with cardiovascular disease undergoing cardiac procedure with CPB from January 2018 to December 2022. We used the median CVP value obtained during CPB for our analysis and patients were grouped according to this parameter. The primary outcomes were AKI and renal replacement therapy(RRT). Multivariable logistic regression was used to explore the association between CVP and AKI.

RESULTS

A total of 2048 patients were enrolled in our study and divided into high CVP group (CVP ≥ 6.5 mmHg) and low CVP group (CVP < 6.5 mmHg) according to the median CVP value. Patients in high CVP group had the high AKI and RRT rate when compared to the low CVPgroup[(367/912,40.24%)vs.(408/1136,35.92%),P = 0.045;(16/912,1.75%vs.9/1136;0.79%), P = 0.049]. Multivariate logistic regression analysis displayed CVP played an indispensable part in development of renal failure in surgical.

CONCLUSIONS

Elevated CVP(≥ 6.5mmH2OmmHg) in CPB during cardiac operation is associated with an increased risk of AKI in cardiovascular surgery patients. Clinical attention should be paid to the potential role of CVP in predicting the occurrence of AKI.

Perioperative serum syndecan-1 concentrations in patients who underwent cardiovascular surgery with cardiopulmonary bypass and its association with the occurrence of postoperative acute kidney injury: a retrospective observational study

BACKGROUND

Various factors can cause vascular endothelial damage during cardiovascular surgery (CVS) with cardiopulmonary bypass (CPB), which has been suggested to be associated with postoperative complications. However, few studies have specifically investigated the relationship between the degree of vascular endothelial damage and postoperative acute kidney injury (pAKI). The objectives of this study were to measure perioperative serum syndecan-1 concentrations in patients who underwent CVS with CPB, evaluate their trends, and determine their association with pAKI.

METHODS

This was a descriptive and case‒control study conducted at the National University Hospital. Adult patients who underwent CVS with CPB at a national university hospital between March 15, 2016, and August 31, 2020, were included. Patients who were undergoing preoperative dialysis, had preoperative serum creatinine concentrations greater than 2.0 mg dl-1, who were undergoing surgery involving the descending aorta were excluded. The perioperative serum syndecan-1 concentration was measured, and its association with pAKI was investigated.

RESULTS

Fifty-two patients were included. pAKI occurred in 18 (34.6%) of those patients. The serum syndecan-1 concentration increased after CPB initiation and exhibited bimodal peak values. The serum syndecan-1 concentration at all time points was significantly elevated compared to that after the induction of anesthesia. The serum syndecan-1 concentration at 30 min after weaning from CPB and on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.10 [1.01 to 1.21], P = 0.03]; OR = 1.16 [1.01 to 1.34], P = 0.04]; and the cutoff values of the serum syndecan-1 concentration that resulted in pAKI were 101.0 ng ml-1 (sensitivity = 0.71, specificity = 0.62, area under the curve (AUC) = 0.67 (0.51 to 0.83)) and 57.1 ng ml-1 (sensitivity = 0.82, specificity = 0.56, AUC = 0.71 (0.57 to 0.86)). Multivariate logistic regression analysis revealed that the serum syndecan-1 concentration on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.02 [1.00 to 1.03]; P = 0.03).

CONCLUSION

The serum syndecan-1 concentration at all time points was significantly greater than that after the induction of anesthesia. The serum syndecan-1 concentration on postoperative day 1 was significantly associated with the occurrence of pAKI.

TRIAL REGISTRATION

This study is not a clinical trial and is not registered with the registry.

Association between triglyceride glucose and acute kidney injury in patients with acute myocardial infarction: a propensity score‑matched analysis

BACKGROUND

Acute kidney injury (AKI) in patients with acute myocardial infarction (AMI) often indicates a poor prognosis.

OBJECTIVE

This study aimed to investigate the association between the TyG index and the risk of AKI in patients with AMI.

METHODS

Data were taken from the Medical Information Mart for Intensive Care (MIMIC) database. A 1:3 propensity score (PS) was set to match patients in the AKI and non-AKI groups. Multivariate logistic regression analysis, restricted cubic spline (RCS) regression and subgroup analysis were performed to assess the association between TyG index and AKI.

RESULTS

Totally, 1831 AMI patients were included, of which 302 (15.6%) had AKI. The TyG level was higher in AKI patients than in non-AKI patients (9.30 ± 0.71 mg/mL vs. 9.03 ± 0.73 mg/mL, P < 0.001). Compared to the lowest quartile of TyG levels, quartiles 3 or 4 had a higher risk of AKI, respectively (Odds Ratiomodel 4 = 2.139, 95% Confidence Interval: 1.382-3.310, for quartile 4 vs. quartile 1, Ptrend < 0.001). The risk of AKI increased by 34.4% when the TyG level increased by 1 S.D. (OR: 1.344, 95% CI: 1.150-1.570, P < 0.001). The TyG level was non-linearly associated with the risk of AKI in the population within a specified range. After 1:3 propensity score matching, the results were similar and the TyG level remained a risk factor for AKI in patients with AMI.

CONCLUSION

High levels of TyG increase the risk of AKI in AMI patients. The TyG level is a predictor of AKI risk in AMI patients, and can be used for clinical management.

Investigating the role of itaconate in macrophage activation and oxidative stress injury in sepsis-associated acute kidney injury

BACKGROUND

Sepsis may be linked to oxidative stress and can be controlled by itaconate, an activator of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Nevertheless, the itaconate impact on sepsis-associated acute kidney injury (SA-AKI) has yet to be definitively established.

METHODS

We employed SA-AKI mouse model through a cecal ligation and puncture (CLP) procedure for the in vivo investigation of the potential nephroprotective effect of itaconate in this study. A plasmid was transfected into RAW264.7 cells to examine the Nrf2 pathway function after itaconate administration. Finally, the immune-responsive gene 1-knockout (IRG1-/-) mice were used to study the itaconate impacts on oxidative stress-induced SA-AKI.

RESULTS

We have shown that 4-octyl itaconate (OI) significantly reduced CD11b-positive macrophage aggregation and activated the Nrf2 pathway in the bone marrow-derived macrophages (BMDM). The impacts of Nrf2 inhibitor ML385 on the anti-inflammatory and antioxidant properties of itaconate were found to be partial. OI inhibited lipopolysaccharide-induced oxidative stress injury in RAW264.7 macrophages and activated Nrf2 in the nucleus to hinder the expression of nuclear factor kappa B p65, thereby suppressing oxidative stress injury in the macrophages. Additionally, the introduction of the transfected plasmid resulted in a partial inhibition of the anti-inflammatory impact of itaconate. The kidney injury caused by sepsis exhibited greater severity in the IRG1-/- mice than in the wild type mice. Exogenous OI partially attenuated the kidney injury induced by sepsis in the IRG1-/- mice and suppressed the oxidative stress injury in macrophages.

CONCLUSIONS

This investigation offers new proof to support the itaconate function in the development and progression of SA-AKI and shows a new possible therapeutic agent for the SA-AKI treatment.

Personalizing renal replacement therapy initiation in the intensive care unit: a reinforcement learning-based strategy with external validation on the AKIKI randomized controlled trials

OBJECTIVE

The timely initiation of renal replacement therapy (RRT) for acute kidney injury (AKI) requires sequential decision-making tailored to individuals' evolving characteristics. To learn and validate optimal strategies for RRT initiation, we used reinforcement learning on clinical data from routine care and randomized controlled trials.

MATERIALS AND METHODS

We used the MIMIC-III database for development and AKIKI trials for validation. Participants were adult ICU patients with severe AKI receiving mechanical ventilation or catecholamine infusion. We used a doubly robust estimator to learn when to start RRT after the occurrence of severe AKI for three days in a row. We developed a "crude strategy" maximizing the population-level hospital-free days at day 60 (HFD60) and a "stringent strategy" recommending RRT when there is significant evidence of benefit for an individual. For validation, we evaluated the causal effects of implementing our learned strategies versus following current best practices on HFD60.

RESULTS

We included 3748 patients in the development set and 1068 in the validation set. Through external validation, the crude and stringent strategies yielded an average difference of 13.7 [95% CI -5.3 to 35.7] and 14.9 [95% CI -3.2 to 39.2] HFD60, respectively, compared to current best practices. The stringent strategy led to initiating RRT within 3 days in 14% of patients versus 38% under best practices.

DISCUSSION

Implementing our strategies could improve the average number of days that ICU patients spend alive and outside the hospital while sparing RRT for many.

CONCLUSION

We developed and validated a practical and interpretable dynamic decision support system for RRT initiation in the ICU.

Demotion of canonical/non-canonical inflammasome and pyroptosis alleviates ischemia/reperfusion-induced acute kidney injury: Novel role of the D2/D3 receptor agonist ropinirole

Ropinirole used to treat Parkinson's disease highly targets the dopaminergic receptor D3 over the D2 receptor but although both are expressed in the kidneys the ropinirole potential to treat kidney injury provoked by ischemia/reperfusion (I/R) is undraped. We investigated whether ropinirole can alleviate renal I/R by studying its anti-inflammatory, antioxidant, and anti-pyroptotic effects targeting its aptitude to inhibit the High-mobility group box 1/Toll-like receptor 4/Nuclear factor-kappa B (HMGB1/TLR4/NF-κB) cue and the canonical/non-canonical NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome trajectories. Herein, bilateral I/R surgery was induced in animals to be either untreated or treated with ropinirole for three days after the insult. Ropinirole successfully improved the histopathological picture and renal function which was confirmed by reducing cystatin C and the standard parameters creatinine and blood urea nitrogen (BUN). Ropinirole achieved this through its anti-inflammatory capacity mediated by reducing the HMGB1/TLR4 axis and inactivating NF-κB, which are upstream regulators of the NLRP3 pathway. As a result, the injurious inflammasome markers (NLRP3, apoptosis-associated speck-like protein (ASC), active caspase-1) and their target cytokines interleukin-1 beta (IL-1β) and IL-18 were decreased. Ropinirole also reduced the pyroptotic cell death markers caspase-11 and gasdermin-D. Furthermore, ropinirole by replenishing antioxidants and decreasing malondialdehyde helped to reduce oxidative stress in the kidneys. The docking findings confirmed that ropinirole highly binds to the dopaminergic D3 receptor more than to the D2 receptor. In conclusion, ropinirole has the potential to be a reno-therapeutic treatment against I/R insult by abating the inflammatory NLRP3 inflammasome signal, pyroptosis, and oxidative stress.

Machine learning for prediction of acute kidney injury in patients diagnosed with sepsis in critical care

BACKGROUND AND OBJECTIVE

Acute Kidney Injury (AKI) is a common and severe complication in patients diagnosed with sepsis. It is associated with higher mortality rates, prolonged hospital stays, increased utilization of medical resources, and financial burden on patients' families. This study aimed to establish and validate predictive models using machine learning algorithms to accurately predict the occurrence of AKI in patients diagnosed with sepsis.

METHODS

This retrospective study utilized real observational data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. It included patients aged 18 to 90 years diagnosed with sepsis who were admitted to the ICU for the first time and had hospital stays exceeding 48 hours. Predictive models, employing various machine learning algorithms including Light Gradient Boosting Machine (LightGBM), EXtreme Gradient Boosting (XGBoost), Random Forest (RF), Decision Tree (DT), Artificial Neural Network (ANN), Support Vector Machine (SVM), and Logistic Regression (LR), were developed. The dataset was randomly divided into training and test sets at a ratio of 4:1.

RESULTS

A total of 10,575 sepsis patients were included in the analysis, of whom 8,575 (81.1%) developed AKI during hospitalization. A selection of 47 variables was utilized for model construction. The models derived from LightGBM, XGBoost, RF, DT, ANN, SVM, and LR achieved AUCs of 0.801, 0.773, 0.772, 0.737, 0.720, 0.765, and 0.776, respectively. Among these models, LightGBM demonstrated the most superior predictive performance.

CONCLUSIONS

These machine learning models offer valuable predictive capabilities for identifying AKI in patients diagnosed with sepsis. The LightGBM model, with its superior predictive capability, could aid clinicians in early identification of high-risk patients.

Outcomes of coronary artery bypass grafting (CABG) in patients with OSA-COPD overlap syndrome versus COPD alone: an analysis of US Nationwide Inpatient Sample

BACKGROUND

Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are associated with unfavorable outcomes following coronary artery bypass grafting (CABG). The purpose of this study was to compare in-hospital outcomes of patients with COPD alone versus OSA-COPD overlap after CABG.

METHODS

Data of adults ≥ 18 years old with COPD who received elective CABG between 2005 and 2018 were extracted from the US Nationwide Inpatient Sample (NIS). Patients were divided into two groups: with OSA-COPD overlap and COPD alone. Propensity score matching (PSM) was employed to balance the between-group characteristics. Logistic and linear regression analyses determined the associations between study variables and inpatient outcomes.

RESULTS

After PSM, data of 2,439 patients with OSA-COPD overlap and 9,756 with COPD alone were analyzed. After adjustment, OSA-COPD overlap was associated with a significantly increased risk of overall postoperative complications (adjusted odd ratio [aOR] = 1.12, 95% confidence interval [CI]: 95% CI: 1.01-1.24), respiratory failure/prolonged mechanical ventilation (aOR = 1.27, 95%CI: 1.14-1.41), and non-routine discharge (aOR = 1.16, 95%CI: 1.03-1.29), and AKI (aOR = 1.14, 95% CI: 1.00-1.29). Patients with OSA-COPD overlap had a lower risk of in-hospital mortality (adjusted odd ratio [aOR] = 0.53, 95% CI: 0.35-0.81) than those with COPD only. Pneumonia or postoperative atrial fibrillation (AF) risks were not significantly different between the 2 groups. Stratified analyses revealed that, compared to COPD alone, OSA-COPD overlap was associated with increased respiratory failure/prolonged mechanical ventilation risks among patients ≥ 60 years, and both obese and non-obese subgroups. In addition, OSA-COPD overlap was associated with increased risk of AKI among the older and obese subgroups.

CONCLUSION

In US adults who undergo CABG, compared to COPD alone, those with OSA-COPD are at higher risks of non-routine discharge, AKI, and respiratory failure/prolonged mechanical ventilation, but a lower in-hospital mortality. No increased risk of AF was noted.

Sustained acute kidney injury as an independent risk factor for neurodevelopmental and growth outcomes in a single NICU center

PURPOSE

Acute kidney injury (AKI) is commonly seen in neonatal intensive care units (NICUs) and is potentially associated with adverse prognoses in later stages of life. Our study evaluated the impact of sustained AKI (SAKI) on both neurodevelopmental impairment (NDI) and early growth restriction (EGR) in neonates.

METHODS

This case-control study retrospectively analyzed the medical records of neonates diagnosed with SAKI in the NICU of a tertiary medical center during the period from January 2007 to December 2020. Cases without subsequent follow-up and those resulting in death were excluded. We analyzed demographic, biochemical, and clinical outcome data.

RESULTS

Of the 93 neonates with SAKI, 51 cases (54.8%) were included in this study, while 42 cases (45.2%) were excluded due to a lack of follow-up or death. An age-matched control group comprised 103 neonates, who had never experienced AKI or SAKI, were selected at random. In total, 59 (38.3%) cases were identified as NDI and 43 (27.9%) as EGR. Multivariate analysis revealed that patients with SAKI had significantly higher risks of developing NDI (odds ratio, [OR] = 4.013, p = 0.001) and EGR (OR = 4.894, p < 0.001). The AKI interval had an area under the receiver operating characteristic curve of 0.754 for NDI at 9.5 days and 0.772 for EGR at 12.5 days.

CONCLUSIONS

SAKI is an independent risk factor for both NDI and EGR in neonates. Consequently, regular monitoring, neurological development assessments, and appropriate nutritional advice are crucial to these infants who have experienced renal injury.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients

BACKGROUND

Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown.

METHODS

We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support.

RESULTS

We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD.

CONCLUSIONS

In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Acute kidney injury in infants with hypoxic-ischemic encephalopathy

BACKGROUND

This study aimed to investigate the prevalence of acute kidney injury (AKI) in infants with varying degrees of hypoxic-ischemic encephalopathy (HIE) and its associated outcomes, including mortality and length of stay (LOS).

METHODS

The study used the National Inpatient Sample (NIS) dataset from 2010 to 2018. Regression analysis was used to control confounding variables.

RESULTS

Of 31,220,784 infants included in the study, 30,130 (0.1%) had HIE. The prevalence of AKI was significantly higher in infants with HIE (9.0%) compared to those without (0.04%), with an adjusted odds ratio (aOR) of 77.6 (CI:70.1-85.7, p < 0.001), with the highest prevalence of AKI in infants with severe HIE (19.7%), aOR:130 (CI: 107-159), p < 0.001). Infants with AKI had a higher mortality rate compared to those without AKI in those diagnosed with any degree of HIE (28.9% vs. 8.8%), aOR 3.5 (CI: 3.2-3.9, p < 0.001), particularly among those with severe HIE, aOR:1.4 (1.2-1.6, p < 0.001).

CONCLUSIONS

HIE is associated with an increased prevalence of AKI. Infants with severe HIE had the highest prevalence of AKI and associated mortality. The study highlights the need for close monitoring and early detection of AKI in infants with HIE, particularly those with severe HIE, to ameliorate the associated adverse outcomes.

Association between peripheral perfusion index and postoperative acute kidney injury in major noncardiac surgery patients receiving continuous vasopressors: a post hoc exploratory analysis of the VEGA-1 trial

BACKGROUND

The peripheral perfusion index is the ratio of pulsatile to nonpulsatile static blood flow obtained by photoplethysmography and reflects peripheral tissue perfusion. We investigated the association between intraoperative perfusion index and postoperative acute kidney injury in patients undergoing major noncardiac surgery and receiving continuous vasopressor infusions.

METHODS

In this exploratory post hoc analysis of a pragmatic, cluster-randomised, multicentre trial, we obtained areas and cumulative times under various thresholds of perfusion index and investigated their association with acute kidney injury in multivariable logistic regression analyses. In secondary analyses, we investigated the association of time-weighted average perfusion index with acute kidney injury. The 30-day mortality was a secondary outcome.

RESULTS

Of 2534 cases included, 8.9% developed postoperative acute kidney injury. Areas and cumulative times under a perfusion index of 3% and 2% were associated with an increased risk of acute kidney injury; the strongest association was observed for area under a perfusion index of 1% (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 1.00-1.74, P=0.050, per 100%∗min increase). Additionally, time-weighted average perfusion index was associated with acute kidney injury (aOR 0.82, 95% CI 0.74-0.91, P<0.001) and 30-day mortality (aOR 0.68, 95% CI 0.49-0.95, P=0.024).

CONCLUSIONS

Larger areas and longer cumulative times under thresholds of perfusion index and lower time-weighted average perfusion index were associated with postoperative acute kidney injury in patients undergoing major noncardiac surgery and receiving continuous vasopressor infusions.

CLINICAL TRIAL REGISTRATION

NCT04789330.