3-5 year longitudinal follow-up of pediatric patients after acute renal failure

The incidence and outcome of acute kidney injury during pediatric kidney tumor treatment-a national cohort study

BACKGROUND

Acute kidney injury (AKI) is a serious complication of pediatric cancer treatment that is suggested to increase the risk of chronic kidney disease (CKD). Children with a kidney tumor may be at particular risk. This study aimed to determine the incidence and risk factors of AKI and its association with CKD during pediatric kidney tumor treatment.

METHODS

We analyzed data from a prospective national cohort of patients ≤ 18 years old diagnosed with a kidney tumor between 2015 and 2021 in the Princess Máxima Center for Pediatric Oncology in the Netherlands. AKI was defined according to KDIGO criteria. CKD was assessed 1 year post-treatment based on proteinuria and/or decreased estimated glomerular filtration rate (eGFR).

RESULTS

Of 147 patients, we observed AKI in 104 patients (71%) during therapy. AKI occurred most often within 48 h after tumor nephrectomy (88/104), while the rest had non-nephrectomy-related AKI from multifactorial causes. Sixteen patients experienced more than one AKI episode, and 92/104 episodes were reversible. Patients who developed AKI had a higher eGFR prior to surgery compared to those who did not develop AKI. CKD was observed in 16/120 patients (13%). Risk factors for developing CKD included the occurrence of at least 1 AKI event, the use of a > 3-drug regimen, and a lower eGFR at the start of treatment.

CONCLUSION

The high incidence of AKI and its association with early CKD highlights the need for early detection, prevention, and intervention strategies during pediatric kidney tumor treatment.

Diagnostic Accuracy of Furosemide Stress Test and Cystatin-C for Predicting Acute Kidney Injury Progression in Children: A Prospective Cohort Study

OBJECTIVES

To evaluate the predictive ability of furosemide stress test (FST), serum and urine cystatin-C in identifying progressive acute kidney injury (AKI) and the need for kidney replacement therapy (KRT).

METHODS

Children aged one month to 18 y admitted in the pediatric intensive care unit (PICU) with Kidney Diseases Improving Global Outcomes (KDIGO) stage-1/2 AKI were enrolled. FST and serum and urine cystatin-C levels were performed and analyzed. The primary outcome was progression to stage-3 AKI. Secondary outcomes included comparing predictive ability of FST vs. cystatin-C for stage-3 AKI and need for KRT, adverse effects, length of hospital stay and mortality.

RESULTS

Of the 41 children enrolled, seven (17.07%) progressed to KDIGO stage-3 AKI. Four children were furosemide non-responders at 2 h and five at 6 h post-FST. The sensitivity, specificity and area under the receiver operating characteristic curve (AUROC) of FST at 2 h were 57.14%, 100% and 0.84 (p = 0.01), and at 6 h were 71.43%, 100% and 0.87 (p < 0.001), respectively. Urine cystatin-C was positive in 20 (48.78%) children, of which seven progressed to stage-3 AKI [sensitivity- 100%, specificity- 61.76%, AUROC- 0.91 (p = 0.003)]. Five of nine children with positive serum cystatin-C progressed to stage-3 AKI [sensitivity- 71.43%, specificity- 88.24%, AUROC- 0.75 (p = 0.08)]. All FST non-responders progressed to undergo KRT showing sensitivity and specificity of 66.67% and 100% at 2 h (AUROC- 0.87) and 85% and 100% at 6 h (AUROC- 0.89) respectively.

CONCLUSIONS

FST is a simple bedside tool with robust predictive value in detecting kidney impairment progression in children and can be utilized in PICU for assessing tubular dysfunction. The diagnostic accuracy of FST was comparable to that of urine and serum cystatin-C. Further studies can be done on a larger cohort for better generalizability.

Progression of acute kidney injury to chronic kidney disease: a prospective cohort study

BACKGROUND

Prospective studies on kidney outcomes in critically ill children with acute kidney injury (AKI) are scarce from low- and middle-income countries (LMIC). We conducted a pilot study to evaluate the continuum of transient AKI-persistent AKI-acute kidney disease (AKD) and chronic kidney disease (CKD).

METHODS

Children (1-18 years) admitted to our tertiary Pediatric Intensive Care Unit (PICU) and developing AKI with no known pre-existing kidney co-morbidities from January 2021 to June 2022 were included with follow up visits at 1 and 3 months after AKI onset. AKI and CKD were defined as per KDIGO 2012. At risk of CKD was defined by albuminuria, hypertension, estimated glomerular filtration rate (eGFR) 60-90 ml/kg/1.73 m2 or hyperfiltration (eGFR ≥ 150 ml/kg/1.73 m2).

RESULTS

Of 390 children, 15% (n = 57) developed AKI. 75% (n = 43) with AKI had underlying primarily non-kidney systemic etiology. Fourteen (25%) died at median 5 days (IQR 4-7) after admission, and three were lost to follow up after discharge. For the 40 AKI survivors with three months data, incidence of transient AKI was 40% (n = 16), persistent AKI 20% (n = 8), AKD 32% (n = 13), and CKD 8% (n = 3). In addition, 18% (n = 7) were at risk of CKD. 38% with AKI for > 48 h vs. 6% with AKI < 48 h developed CKD or were at risk of CKD (p = 0.025). All three AKI survivors who progressed to CKD had an underlying primarily kidney etiology and progressed from AKD to CKD.

CONCLUSIONS

In this LMIC study, kidney sequelae were high at 3 months among PICU AKI survivors. This pilot supports the need and feasibility of larger prospective trials in LMIC settings to understand outcomes for all children with AKI.

Growth after pediatric and neonatal acute kidney injury: a meta-analysis

BACKGROUND

Acute kidney injury (AKI) occurs commonly in critically ill children. The impact of AKI on pediatric growth outcomes has been sparsely described.

OBJECTIVE

To compare growth in children with a history of AKI compared to those without AKI. We hypothesized that children with AKI would have worse growth compared to those without AKI.

DATA SOURCES

A convenience sample of existing prospective and retrospective cohorts of children with AKI who had already collected or were able to collect data on growth parameters before and after an episode of AKI.

STUDY ELIGIBILITY CRITERIA

There are < 5 studies in the published literature on growth in children with AKI. These investigators were contacted, and additional studies were added by contacting primary investigators of studies of childhood AKI in which data on growth parameters was able to be collected.

PARTICIPANTS AND INTERVENTIONS

Children from existing cohorts evaluating AKI (exposure) during childhood. Each included cohort had previously received local IRB approval per institutional guidelines. As our study was a meta-analysis and only used cohort-level data, no IRB approval was required for this report.

STUDY APPRAISAL AND SYNTHESIS METHODS

Growth parameters (length and weight z-scores) before and after an episode of AKI were compared using a meta-means analysis. MOOSE guidelines were used. Data were pooled using a random-effects model. Hedges g was calculated, and Higgins I2 statistic was used to define variability due to between-cohort heterogeneity.

RESULTS

We included 3,586 children from 17 existing cohorts of AKI in various populations, including infants, children with cardiac disease, solid organ transplant and critically ill children without cardiac disease with follow-up from 12 months to 11 years after AKI. At most distant follow-up, those with AKI had lower length z-score than those without AKI (mean difference -0.37 [95%CI -0.52, -0.22, p < 0.001]) and lower weight z-score (mean difference of -0.29 [95%CI -0.43, -0.15, p < 0.001]). This difference was most striking in infants, as those with AKI had impaired growth (both length z-score and weight z-score) after AKI compared to those without AKI.

LIMITATIONS

The analysis included only a convenience sample of observational cohorts of children, study selection could have been biased, and we did not evaluate the relationship between decreased kidney function (e.g., chronic kidney disease) after AKI in these cohorts and its relationship to poor growth.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This meta-analysis found that children with AKI have impaired growth after AKI. These findings were most striking in infants. We suggest focusing on growth outcomes in both clinical care and research investigating the impacts of AKI.

SYSTEMATIC REVIEW REGISTRATION NUMBER

NA.

Nanoparticle-mediated Klotho gene therapy prevents acute kidney injury to chronic kidney disease transition through regulating PPARα signaling in renal tubular epithelial cells

Klotho is an anti-aging protein produced primarily by tubular epithelial cells (TECs). Down-regulated expression of Klotho in injured TECs plays a key pathogenic role in promoting acute kidney injury (AKI) to chronic kidney disease (CKD) transition, yet therapeutic approaches targeting the restoration of renal Klotho levels remain challenging for clinical application. Here, we synthesize polydopamine-polyethylenimine-l-serine-Klotho plasmid nanoparticles (PPSK NPs), which can safely and selectively deliver the Klotho gene to the injured TECs through binding kidney injury molecule-1 and maintain the expression of Klotho protein. In vitro, PPSK NPs effectively reduce the hypoxia-reoxygenation-induced reactive oxygen species production and fibrotic gene expression. In the unilateral ischemia-reperfusion injury- and folic acid-induced AKI-CKD transition mouse models, a single low-dose injection of PPSK NPs is sufficient to preserve the normal kidney architecture and prevent renal fibrosis. Mechanismly, the protective effect of PPSK NPs relies on upregulating a key molecule peroxisome proliferator-activated receptor alpha (PPARα) via the inhibition of p38 and JNK phosphorylation, which in turn improves tubular fatty acid beta-oxidation and reduces renal lipid accumulation, thereby protecting against kidney fibrosis. In conclusion, our results highlight the translational potential of nanoparticle-based Klotho gene therapy in preventing the AKI-CKD transition.

Kidney and blood pressure outcomes 11 years after pediatric critical illness and longitudinal impact of AKI: a prospective cohort study

BACKGROUND

Acute kidney injury (AKI) is common in critically ill children and associated with adverse short-term outcomes; however, long-term outcomes are not well described.

METHODS

This longitudinal prospective cohort study examined the prevalence of chronic kidney disease (CKD) and hypertension (HTN) 11 vs. 6 years after pediatric intensive care unit (PICU) admission and association with AKI. We examined children (age < 19 years) without pre-existing kidney disease 11 ± 1.5 years after PICU admission at a single center. AKI was defined using serum creatinine criteria. The primary outcome was a composite of CKD or HTN. CKD was defined as estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m2 or albuminuria. Multivariable analyses compared outcomes at 11- vs. 6-year follow-up and association with AKI during PICU admission.

RESULTS

Of 96 children evaluated 11 years after PICU admission, 16% had evidence of CKD or HTN (vs. 28% at 6 years, p < 0.05). Multivariable analysis did not show improvement in outcomes from 6- to 11-year follow-up. eGFR decreased from 6- to 11-year follow-up (adjusted coefficient - 11.7, 95% CI - 17.6 to - 5.9) and systolic and diastolic blood pressures improved. AKI was associated with composite outcome at 6-year (adjusted odds ratio (aOR) 12.7, 95% CI 3.2-51.2, p < 0.001), but not 11-year follow-up (p = 0.31). AKI was associated with CKD (aOR 10.4, 95% CI 3.1-34.7) at 11 years.

CONCLUSIONS

This study provides novel data showing that adverse kidney and blood pressure outcomes remain highly prevalent 10 years after critical illness in childhood. The association with AKI wanes over time.

Pediatric Considerations in Post Acute Kidney Injury Care

Acute kidney injury in children is associated with adverse outcomes. These include longer hospital stays, increased mortality, and nonrecovery of kidney function in the short term and increased health care utilization, new onset hypertension, and chronic kidney disease in the long term. Systematic post acute kidney injury care may help mitigate some of the complications that follow acute kidney injury. Patient, family, and health care team education is a key aspect of post acute kidney injury care. This includes individualized education to the patient and family, ideally prior to hospital discharge, provision of a discharge summary with details of the acute kidney injury episode and follow-up plan, and communication with the primary care provider. Given that severe acute kidney injury may often be seen in patients with other underlying medical conditions, partnership between the primary care provider, non-nephrology specialist and the nephrologist, and the use of telehealth may facilitate follow-up without increasing caregiver burden. Ongoing surveillance includes monitoring kidney function, proteinuria, and hypertension. There are no guidelines on the frequency of this evaluation or the duration of follow-up. These decisions should be individualized based on the characteristics of the index acute kidney injury episode and underlying risk factors for chronic kidney disease.

Acute Kidney Injury in Critically Ill Children: Prevalence, Progression, Recovery Mortality, and Impact of Severity

Introduction: Acute kidney injury (AKI) among the pediatric population is considered a risk factor for mortality and morbidities during pediatric intensive care unit (PICU) admission. The association between AKI and increased mortality risk and length of stay (LOS) is still inconclusive. This retrospective cohort study aimed to evaluate the impact of AKI severity upon critical management and clinical parameters with an evaluation of severity progression among AKI patients admitted to the PICU at a tertiary care hospital. Methods: AKI, defined with the Kidney Disease Improving Global Outcomes (KDIGO) classification, was determined based on serum creatinine and urine output with respect to the patient's baseline value. The following outcomes were examined: mortality, mechanical ventilation use, use of non-invasive ventilation, recovery at discharge, and LOS in the hospital and PICU stratified by type of AKI upon admission. Medical records of the 165 included patients were reviewed for clinical data and study outcomes. Results: The median age of the patients was 7 years (IQR 1.5-10 years), and 58% were boys; 78 (47.2%) had stage 1 AKI, 49 (29.71%) had stage 2 AKI, and 38 (23%) had stage 3 AKI at admission. The mortality rate was 26%. The median LOS in the PICU was statistically significant between AKI stages, with a higher median LOS among patients with AKI stage 3 at admission. Using the maximum KDIGO stage, there was no association between AKI and mortality (adjusted OR 1.91, 95% CI 0.05), whereas for the mechanical ventilation outcome, the adjusted OR was 1.84 (95% CI 0.42-8.1). Conclusions: The severity of AKI is not associated solely with mortality and clinical outcomes as the numbers of comorbidities and organ failures contribute to mortality. However, improving awareness of AKI and understanding the disease progression course would reduce acute and long-term morbidity and mortality.

ID Consultant: Laboratory Monitoring During Long-Term Use of Oral Antimicrobials in Pediatric Patients

Oral antimicrobials remain the mainstay of long-term treatment for many infections. Meanwhile, the use of oral agents is becoming commonplace for the treatment of several pediatric infections once managed exclusively with parenteral therapies. Unfortunately, antimicrobials are associated with several laboratory toxicities, particularly when high doses or combination therapies are used, but there is a paucity of data on optimal laboratory monitoring strategies. In this ID Consultant article, we offer a summary of the 3 most common laboratory-based toxicities seen with long-term use of oral antimicrobials-drug-induced kidney injury, liver injury, and hematological toxicities-and we provide our recommended approach to monitoring.

Long-Term Kidney Outcomes after Pediatric Acute Kidney Injury

Key Points

Among 4173 children with AKI, 18% had major adverse kidney events (death, kidney failure, or CKD) during a median 10-year follow-up. AKI survivors were at 2–4 times higher risk of major adverse kidney events, hypertension, and subsequent AKI versus matched hospitalized comparators. This justifies improved surveillance after pediatric AKI to detect CKD and hypertension early and improve long-term kidney health.

Background

AKI is common in hospitalized children. Pediatric AKI receiving acute KRT is associated with long-term CKD, hypertension, and death. We aim to determine the outcomes after AKI in children who did not receive acute KRT because these remain uncertain.

Methods

Retrospective cohort study of all hospitalized children (0–18 years) surviving AKI without acute KRT between 1996 and 2020 in Ontario, Canada, identified by validated diagnostic codes in provincial administrative health databases. Children with prior KRT, CKD, or AKI were excluded. Cases were matched with up to four hospitalized comparators without AKI by age, neonatal status, sex, intensive care unit admission, cardiac surgery, malignancy, hypertension, hospitalization era, and a propensity score for AKI. Patients were followed until death, provincial emigration, or censoring in March 2021. The primary outcome was long-term major adverse kidney events (a composite of all-cause mortality, long-term KRT, or incident CKD).

Results

We matched 4173 pediatric AKI survivors with 16,337 hospitalized comparators. Baseline covariates were well-balanced following propensity score matching. During a median 9.7-year follow-up, 18% of AKI survivors developed long-term major adverse kidney event versus 5% of hospitalized comparators (hazard ratio [HR], 4.0; 95% confidence interval [CI], 3.6 to 4.4). AKI survivors had higher rates of long-term KRT (2% versus <1%; HR, 11.7; 95% CI, 7.5 to 18.4), incident CKD (16% versus 2%; HR, 7.9; 95% CI, 6.9 to 9.1), incident hypertension (17% versus 8%; HR, 2.3; 95% CI, 2.1 to 2.6), and AKI during subsequent hospitalization (6% versus 2%; HR, 3.7; 95% CI, 3.1 to 4.5), but no difference in all-cause mortality (3% versus 3%; HR, 0.9; 95% CI, 0.7 to 1.1).

Conclusions

Children surviving AKI without acute KRT were at higher long-term risk of CKD, long-term KRT, hypertension, and subsequent AKI versus hospitalized comparators.

Epidemiology of Vancomycin in Combination With Piperacillin/Tazobactam-Associated Acute Kidney Injury in Children: A Systematic Review and Meta-analysis

BACKGROUND

Several studies have shown that vancomycin combined with piperacillin/tazobactam (VPT) increased the risk of acute kidney injury (AKI) compared with other antibiotics in children. However, the epidemiology of VPT-associated AKI in children is unknown.

OBJECTIVE

To evaluate the incidence and risk factors of VPT-associated AKI in children.

DATA SOURCES

Literature databases of PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Database, WanFang Database, and China Biology Medicine Disc were searched from inception to November 2023. References of included studies were also manually checked.

STUDY SELECTION AND DATA EXTRACTION

Two independent reviewers selected studies, extracted data, and quality assessment. Meta-analyses were performed to quantify the incidence and risk factors of VPT-associated AKI in children.

DATA SYNTHESIS

Sixteen cohort studies were identified. Overall, the incidence of VPT-associated AKI in children was 24.3% (95% CI: 17.9%-30.6%). The incidence of VPT-associated AKI in critically ill children (26.6%) was higher than that in noncritically ill children (10.9%). Moreover, higher serum vancomycin trough concentration (>15 mg/L), use of vasopressors, combination of nephrotoxins and intensive care unit admission were risk factors for VPT-associated AKI in children (P < 0.05).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Identifying high-risk groups and determining safer treatments is critical to reducing the incidence of VPT-associated AKI in children.

CONCLUSIONS

The incidence of VPT-associated AKI in children is high, especially in critically ill children. Medication regimens should be personalized based on the presence of individual risk factors. Moreover, renal function was regularly assessed throughout treatment with VPT.

Perinatal asphyxia leads to acute kidney damage and increased renal susceptibility in adulthood

Perinatal asphyxia (PA) poses a significant threat to multiple organs, particularly the kidneys. Diagnosing PA-associated kidney injury remains challenging, and treatment options are inadequate. Furthermore, there is a lack of long-term follow-up data regarding the renal implications of PA. In this study, 7-day-old male Wistar rats were exposed to PA using a gas mixture (4% O2; 20% CO2 in N2 for 15 min) to investigate molecular pathways linked to renal tubular damage, hypoxia, angiogenesis, heat shock response, inflammation, and fibrosis in the kidney. In a second experiment, adult rats with a history of PA were subjected to moderate renal ischemia-reperfusion (IR) injury to test the hypothesis that PA exacerbates renal susceptibility. Our results revealed an increased gene expression of renal injury markers (kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin), hypoxic and heat shock factors (hypoxia-inducible factor-1α, heat shock factor-1, and heat shock protein-27), proinflammatory cytokines (interleukin-1β, interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1), and fibrotic markers (transforming growth factor-β, connective tissue growth factor, and fibronectin) promptly after PA. Moreover, a machine learning model was identified through random forest analysis, demonstrating an impressive classification accuracy (95.5%) for PA. Post-PA rats showed exacerbated functional decline and tubular injury and more intense hypoxic, heat shock, proinflammatory, and profibrotic response after renal IR injury compared with controls. In conclusion, PA leads to subclinical kidney injury, which may increase the susceptibility to subsequent renal damage later in life. In addition, the parameters identified through random forest analysis provide a robust foundation for future biomarker research in the context of PA.NEW & NOTEWORTHY This article demonstrates that perinatal asphyxia leads to subclinical kidney injury that permanently increases renal susceptibility to subsequent ischemic injury. We identified major molecular pathways involved in perinatal asphyxia-induced renal complications, highlighting potential targets of therapeutic approaches. In addition, random forest analysis revealed a model that classifies perinatal asphyxia with 95.5% accuracy that may provide a strong foundation for further biomarker research. These findings underscore the importance of multiorgan follow-up for perinatal asphyxia-affected patients.

Acute kidney injury: the experience of a tertiary center of Pediatric Nephrology

INTRODUCTION

Acute kidney injury (AKI) is an abrupt deterioration of kidney function. The incidence of pediatric AKI is increasing worldwide, both in critically and non-critically ill settings. We aimed to characterize the presentation, etiology, evolution, and outcome of AKI in pediatric patients admitted to a tertiary care center.

METHODS

We performed a retrospective observational single-center study of patients aged 29 days to 17 years and 365 days admitted to our Pediatric Nephrology Unit from January 2012 to December 2021, with the diagnosis of AKI. AKI severity was categorized according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The outcomes considered were death or sequelae (proteinuria, hypertension, or changes in renal function at 3 to 6 months follow-up assessments).

RESULTS

Forty-six patients with a median age of 13.0 (3.5-15.5) years were included. About half of the patients (n = 24, 52.2%) had an identifiable risk factor for the development of AKI. Thirteen patients (28.3%) were anuric, and all of those were categorized as AKI KDIGO stage 3 (p < 0.001). Almost one quarter (n = 10, 21.7%) of patients required renal replacement therapy. Approximately 60% of patients (n = 26) had at least one sequelae, with proteinuria being the most common (n = 15, 38.5%; median (P25-75) urinary protein-to-creatinine ratio 0.30 (0.27-0.44) mg/mg), followed by reduced glomerular filtration rate (GFR) (n = 11, 27.5%; median (P25-75) GFR 75 (62-83) mL/min/1.73 m2).

CONCLUSIONS

Pediatric AKI is associated with substantial morbidity, with potential for proteinuria development and renal function impairment and a relevant impact on long-term prognosis.

Programs and processes for advancing pediatric acute kidney support therapy in hospitalized and critically ill children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

Pediatric acute kidney support therapy (paKST) programs aim to reliably provide safe, effective, and timely extracorporeal supportive care for acutely and critically ill pediatric patients with acute kidney injury (AKI), fluid and electrolyte derangements, and/or toxin accumulation with a goal of improving both hospital-based and lifelong outcomes. Little is known about optimal ways to configure paKST teams and programs, pediatric-specific aspects of delivering high-quality paKST, strategies for transitioning from acute continuous modes of paKST to facilitate rehabilitation, or providing effective short- and long-term follow-up. As part of the 26th Acute Disease Quality Initiative Conference, the first to focus on a pediatric population, we summarize here the current state of knowledge in paKST programs and technology, identify key knowledge gaps in the field, and propose a framework for current best practices and future research in paKST.

Risk factors for acute kidney injury in pediatric patients after hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Risk factors for acute kidney injury (AKI) in pediatric patients after hematopoietic stem cell transplantation (HSCT) remain controversial.

OBJECTIVES

This study aimed to identify risk factors for AKI following HSCT in the pediatric population.

DATA SOURCES

PubMed, Embase, Web of Science, Cochrane Library, and Scopus databases were searched from inception to February 8, 2023.

STUDY ELIGIBILITY CRITERIA

Studies meeting the following criteria were included: (1) The study was a case-control, cohort study, or cross-sectional design, (2) the study was performed among pediatric and young patients aged 21 years or younger undergoing HSCT, (3) the study measured at least one related factor for AKI after pediatric HSCT, (4) the study included a sample of at least ten patients, and (5) original articles published in English in peer-reviewed scientific journals.

PARTICIPANTS AND INTERVENTIONS

Children who were undergoing pediatric HSCT.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed the quality of the included studies and analyzed them with a random-effect model.

RESULTS

Fifteen studies with a total of 2,093 patients were included. All were cohort studies of high quality. The overall pooled incidence of AKI was 47.4% (95%CI 0.35, 0.60). We found significant associations between post-transplant AKI in pediatric patients and unrelated donor [odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.09-2.79], cord blood stem cell transplantation (OR = 3.14, 95%CI 2.14-4.60), and veno-occlusive disease (VOD)/sinusoidal obstruction syndrome (SOS) (OR = 6.02, 95%CI 1.40-25.88). Other controversial factors such as myeloablative conditioning (MAC), acute graft vs. host disease (aGVHD), and the use of calcineurin inhibitors (CNI) were not found to be related to AKI after pediatric HSCT.

LIMITATIONS

Results were limited mainly by heterogeneity in the characteristics of patients and transplantation.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Posttransplant AKI in children is a common complication. Unrelated donors, cord blood stem cell transplantation, and VOD/SOS might be risk factors for AKI after pediatric HSCT. Further large-scale studies are still needed to draw firm conclusions.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42022382361 A higher resolution version of the Graphical abstract is available as Supplementary information.

Profile of Acute Kidney Injury in the Pediatric Age Group in a Tertiary Care Hospital: A Prospective Observational Study

BACKGROUND AND OBJECTIVES

Acute kidney injury (AKI) is a menace in the pediatric intensive care unit (PICU) and is responsible for significant morbidity and mortality all over the world. There are limited data available on pediatric AKI in central India. Our primary objective is to determine the clinical, etiological, and outcome profile of AKI in the pediatric age group of 3 months to 15 years admitted to the All India Institute of Medical Sciences (AIIMS), Raipur. The secondary objective(s) is to predict the association of mortality in children diagnosed with AKI and to estimate the number of patients developing chronic kidney disease (CKD) at three-month follow-up.

MATERIALS AND METHODS

This observational study was conducted in the Department of Pediatrics at AIIMS Raipur, Chhattisgarh, from September 2021 to February 2023. All patients aged 3 months to 15 years of age satisfying the Kidney Disease: Improving Global Outcomes (KDIGO) criteria for AKI and presenting to the hospital were included, and those refusing consent or having CKD stage ≥3 were excluded. A total of 66 children were assessed for eligibility. Out of these 66 patients, 2 were excluded as they had AKI on CKD, and a total of 64 patients were included. For all included patients, details of their demography, clinical features, etiology workup, and hospital stay were collected. Their outcome was observed and categorized into complete response, partial response, no response, left against medical advice (LAMA), or death. Patients who were discharged were followed up for three months and observed for the recovery or development of CKD.

RESULTS

The incidence of AKI in the PICU was 15.48% (64/413). Ventricular septal defect with pneumonia and pneumonia (12.5%, 8/64 each) were the most common diagnoses at presentation, resulting in AKI. The most common clinical presentations were fever (54.7%, 35/64) and respiratory distress (43.8%, 28/64). Out of them, 73.4% (47/64) had sepsis, and 62.5% (40/64) had shock. About 56.2% (36/64) of children had non-oliguric AKI as compared to 43.8% (28/64) who had oliguric AKI. Among total children with AKI, 54.7% (35/64) of patients had prerenal AKI, 43.8% (28/64) had renal AKI, and 1.6% (1/64) had postrenal AKI. Of all the children included, 32.8% (21/64) experienced complete resolution of AKI, while 18.8% (12/64) showed partial resolution, and 1.6% (1/64) remained unresolved. Among them, 3.1% (2/64) LAMA, and 43.8% (28/64) died. The median duration of the hospital stay in our study was 16.5 days. Out of them, 59.4% (38/64) of patients required renal replacement therapy (60.5% required peritoneal dialysis (PD), 36.8% required hemodialysis (HD), and 2.6% required both). Among survivors, 19.35% (6/31) developed CKD on a three-month follow-up.

CONCLUSION

The incidence of AKI was seen in critically ill children in the PICU, and it was associated with high mortality.

A Machine Learning Algorithm Predicting Acute Kidney Injury in Intensive Care Unit Patients (NAVOY Acute Kidney Injury): Proof-of-Concept Study

BACKGROUND

Acute kidney injury (AKI) represents a significant global health challenge, leading to increased patient distress and financial health care burdens. The development of AKI in intensive care unit (ICU) settings is linked to prolonged ICU stays, a heightened risk of long-term renal dysfunction, and elevated short- and long-term mortality rates. The current diagnostic approach for AKI is based on late indicators, such as elevated serum creatinine and decreased urine output, which can only detect AKI after renal injury has transpired. There are no treatments to reverse or restore renal function once AKI has developed, other than supportive care. Early prediction of AKI enables proactive management and may improve patient outcomes.

OBJECTIVE

The primary aim was to develop a machine learning algorithm, NAVOY Acute Kidney Injury, capable of predicting the onset of AKI in ICU patients using data routinely collected in ICU electronic health records. The ultimate goal was to create a clinical decision support tool that empowers ICU clinicians to proactively manage AKI and, consequently, enhance patient outcomes.

METHODS

We developed the NAVOY Acute Kidney Injury algorithm using a hybrid ensemble model, which combines the strengths of both a Random Forest (Leo Breiman and Adele Cutler) and an XGBoost model (Tianqi Chen). To ensure the accuracy of predictions, the algorithm used 22 clinical variables for hourly predictions of AKI as defined by the Kidney Disease: Improving Global Outcomes guidelines. Data for algorithm development were sourced from the Massachusetts Institute of Technology Lab for Computational Physiology Medical Information Mart for Intensive Care IV clinical database, focusing on ICU patients aged 18 years or older.

RESULTS

The developed algorithm, NAVOY Acute Kidney Injury, uses 4 hours of input and can, with high accuracy, predict patients with a high risk of developing AKI 12 hours before onset. The prediction performance compares well with previously published prediction algorithms designed to predict AKI onset in accordance with Kidney Disease: Improving Global Outcomes diagnosis criteria, with an impressive area under the receiver operating characteristics curve (AUROC) of 0.91 and an area under the precision-recall curve (AUPRC) of 0.75. The algorithm's predictive performance was externally validated on an independent hold-out test data set, confirming its ability to predict AKI with exceptional accuracy.

CONCLUSIONS

NAVOY Acute Kidney Injury is an important development in the field of critical care medicine. It offers the ability to predict the onset of AKI with high accuracy using only 4 hours of data routinely collected in ICU electronic health records. This early detection capability has the potential to strengthen patient monitoring and management, ultimately leading to improved patient outcomes. Furthermore, NAVOY Acute Kidney Injury has been granted Conformite Europeenne (CE)-marking, marking a significant milestone as the first CE-marked AKI prediction algorithm for commercial use in European ICUs.

Angiotensin II type 1 receptor antibodies and native kidney function in pediatric liver and intestinal transplant recipients

BACKGROUND

Angiotensin II type-1 receptor antibody (AT1R-Ab) has been associated with vascular injury and kidney dysfunction in pediatric kidney transplant recipients. The role of AT1R-Ab in the development of chronic kidney disease in pediatric liver and intestinal transplant recipients has not been explored.

METHODS

Twenty-five pediatric intestinal transplant recipients and 79 pediatric liver transplant recipients had AT1R-Ab levels measured at varying time points in the post-transplant period. Estimated glomerular filtration rate (eGFR) was determined using creatinine based CKiD U25 equation and measured at time of AT1R-Ab measurement, at 1 year post-AT1R-Ab measurement, at 5 years post-AT1R-Ab measurement, and at the most recent routine clinic visit. The prevalence of hypertension and antihypertensive medication use were also evaluated.

RESULTS

Younger age at time of AT1R-Ab measurement was associated with AT1R-Ab positivity in liver transplant recipients. There was no association between AT1R-Ab status and change in eGFR, prevalence of hypertension, or use of antihypertensive medications at the described time points.

CONCLUSIONS

AT1R-Ab positivity was not associated with a decline in eGFR or hypertension in pediatric liver and intestinal transplant recipients. Further studies are needed using other markers of kidney function, such as cystatin C, to validate this finding. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical Review of Risk of Nephrotoxicity with Acyclovir Use for Treatment of Herpes Simplex Virus Infections in Neonates and Children

OBJECTIVE

This study aims to clarify the risk of nephrotoxicity with intravenous use of acyclovir (ACV) for the treatment of neonates (ages <3 months) and children (ages ≥3 months to <12 years) with herpes simplex virus (HSV) infections and to identify gaps in knowledge that could be further investigated.

METHODS

Multiple databases were searched to identify studies on risk of nephrotoxicity with ACV use for treatment of invasive HSV infections, defined as any neonatal infection or HSV encephalitis (HSE) in children.

RESULTS

There were 5 and 14 studies that evaluated the risk of ACV-associated nephrotoxicity in neonates and children, respectively. The US Food and Drug Administration (FDA) delayed the approval of high (HD; 60 mg/kg/day) ACV in neonates secondary to risk of toxicity. Based on our review, the risk of ACV-associated nephrotoxicity was lower in the neonatal compared with the pediatric population. Acyclovir dose >1500 mg/m2, older age, and concomitant use of nephrotoxic drugs were identified as variables that increased the risk of ACV nephrotoxicity in children. Although the FDA has approved the use of HD ACV for the treatment of HSE in children, the American Academy of Pediatrics recommends a lower dose to minimize the risk of toxicity. The efficacy and safety of high vs lower doses of ACV for the management of HSE in children has yet to be evaluated.

CONCLUSIONS

The risk of ACV-associated nephrotoxicity was lower among neonates compared with older children. Future studies are needed to identify the optimal dosage that minimizes toxicities and maximizes the efficacy of ACV in children with HSE.

Epidemiology data on the cost and outcomes associated with pediatric acute kidney injury

BACKGROUND

Hospitalized children with acute kidney injury (AKI) have not been extensively studied for clinical outcomes including hospital stay, the need for mechanical ventilation, mortality rates, and healthcare utilization. We hypothesize significant financial costs and increased morbidity and mortality associated with pediatric AKI.

METHODS

This is a retrospective study of pediatric patients (age ≤18 years) included in the Kids' Inpatient Database (KID) between January 1, 2016, and December 31, 2021. The results of the data analysis were utilized for comparative testing between the AKI and non-AKI cohorts.

RESULTS

The study included 4842 children [with AKI (n = 2424) and without AKI (n = 2418)]. The odds of mortality (p = 0.004) and mechanical ventilation (p < 0.001) were observed to be significantly higher among those with AKI as compared to those without AKI. Additionally, the median (IQR) duration of stay in the hospital (p < 0.001) and total cost (p < 0.001) were significantly higher among those with AKI vs. those without AKI.

CONCLUSIONS

AKI in children was associated with higher odds of mortality, longer duration of hospital stay, increased requirement of mechanical ventilation, and increased hospital expenditure. The scientific community can utilize this information to better understand the outcomes associated with this disease process in this patient population.

IMPACT

This article has thoroughly evaluated epidemiologic data associated with pediatric acute kidney injury (AKI) in hospitalized patients This study assesses mortality, hospital expenditure, and other factors to strengthen single-center and few multi-center studies and provides novel data regarding insurance and cost associated with pediatric AKI With increased knowledge of current epidemiology and risk factors, the scientific community can better understand prevention and outcomes in hospitalized children with AKI.

Anemia and Hypoxia Impact on Chronic Kidney Disease Onset and Progression: Review and Updates

Chronic kidney disease (CKD) is caused by hypoxia in the renal tissue, leading to inflammation and increased migration of pathogenic cells. Studies showed that leukocytes directly sense hypoxia and respond by initiating gene transcription, encoding the 2-integrin adhesion molecules. Moreover, other mechanisms participate in hypoxia, including anemia. CKD-associated anemia is common, which induces and worsens hypoxia, contributing to CKD progression. Anemia correction can slow CKD progression, but it should be cautiously approached. In this comprehensive review, the underlying pathophysiology mechanisms and the impact of renal tissue hypoxia and anemia in CKD onset and progression will be reviewed and discussed in detail. Searching for the latest updates in PubMed Central, Medline, PubMed database, Google Scholar, and Google search engines were conducted for original studies, including cross-sectional studies, cohort studies, clinical trials, and review articles using different keywords, phrases, and texts such as "CKD progression, anemia in CKD, CKD, anemia effect on CKD progression, anemia effect on CKD progression, and hypoxia and CKD progression". Kidney tissue hypoxia and anemia have an impact on CKD onset and progression. Hypoxia causes nephron cell death, enhancing fibrosis by increasing interstitium protein deposition, inflammatory cell activation, and apoptosis. Severe anemia correction improves life quality and may delay CKD progression. Detection and avoidance of the risk factors of hypoxia prevent recurrent acute kidney injury (AKI) and reduce the CKD rate. A better understanding of kidney hypoxia would prevent AKI and CKD and lead to new therapeutic strategies.

Tubulovascular protection from protease-activated receptor-1 depletion during AKI-to-CKD transition

BACKGROUND

Thromboembolic events are prevalent in chronic kidney disease (CKD) patients due to increased thrombin generation leading to a hypercoagulable state. We previously demonstrated that inhibition of protease-activated receptor-1 (PAR-1) by vorapaxar reduces kidney fibrosis.

METHODS

We used an animal model of unilateral ischemia-reperfusion injury-induced CKD to explore the tubulovascular crosstalk mechanisms of PAR-1 in acute kidney injury (AKI)-to-CKD transition.

RESULTS

During the early phase of AKI, PAR-1-deficient mice exhibited reduced kidney inflammation, vascular injury, and preserved endothelial integrity and capillary permeability. During the transition phase to CKD, PAR-1 deficiency preserved kidney function and diminished tubulointerstitial fibrosis via downregulated transforming growth factor-β/Smad signaling. Maladaptive repair in the microvasculature after AKI further exacerbated focal hypoxia with capillary rarefaction, which was rescued by stabilization of hypoxia-inducible factor and increased tubular vascular endothelial growth factor A in PAR-1-deficient mice. Chronic inflammation was also prevented with reduced kidney infiltration by both M1- and M2-polarized macrophages. In thrombin-induced human dermal microvascular endothelial cells (HDMECs), PAR-1 mediated vascular injury through activation of NF-κB and ERK MAPK pathways. Gene silencing of PAR-1 exerted microvascular protection via a tubulovascular crosstalk mechanism during hypoxia in HDMECs. Finally, pharmacologic blockade of PAR-1 with vorapaxar improved kidney morphology, promoted vascular regenerative capacity, and reduced inflammation and fibrosis depending on the time of initiation.

CONCLUSIONS

Our findings elucidate a detrimental role of PAR-1 in vascular dysfunction and profibrotic responses upon tissue injury during AKI-to-CKD transition and provide an attractive therapeutic strategy for post-injury repair in AKI.

NSAID-associated acute kidney injury in hospitalized children - a prospective Pediatric Nephrology Research Consortium study

BACKGROUND

Acute kidney injury (AKI) in children has serious short-term and long-term consequences. We sought 1) to prospectively describe NSAID-associated AKI in hospitalized children; 2) to determine if NSAID-associated AKI was more severe in younger children < 5 years; and 3) to follow outcomes after hospitalization for NSAID-associated AKI.

METHODS

This was a prospective, multi-center study in hospitalized children 1 month to 18 years. Parents/guardians were given a brief questionnaire to determine the dosing, duration, and type of NSAIDs given. Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria were used to stage AKI severity. Patients with other causes of AKI were excluded (e.g., other nephrotoxins, sepsis, malignancy, etc.).

RESULTS

We identified 25 patients with NSAID-associated AKI, accounting for 3.1% of AKI. All 25 had AKI upon hospital presentation. The median age was 15.5 years, and 20/25 (80%) had volume depletion. Median duration of NSAID use was 2 days, and 63% of patients took the normal recommended NSAID dose. Median hospital length of stay was 4 days, and none required dialysis. At the most recent estimated glomerular filtration rate (eGFR) after discharge (available in 17/25 patients), only 4/17 (24%) had eGFR ≥ 90 ml/min/1.73 m2, and 13/17 (76%) had eGFR 60 to < 90 ml/min/1.73 m2, indicative of abnormal kidney function.

CONCLUSIONS

NSAID-associated AKI usually occurs with recommended NSAID dosing in the setting of dehydration. Follow-up after AKI showed a substantial rate of CKD. Therefore, we recommend that NSAIDs should not be used in dehydrated children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Epidemiology of childhood acute kidney injury in England using e-alerts

Background

Few studies describe the epidemiology of childhood acute kidney injury (AKI) nationally. Laboratories in England are required to issue electronic (e-)alerts for AKI based on serum creatinine changes. This study describes a national cohort of children who received an AKI alert and their clinical course.

Methods

A cross-section of AKI episodes from 2017 are described. Hospital record linkage enabled description of AKI-associated hospitalizations including length of stay (LOS) and critical care requirement. Risk associations with critical care (hospitalized cohort) and 30-day mortality (total cohort) were examined using multivariable logistic regression.

Results

In 2017, 7788 children (52% male, median age 4.4 years, interquartile range 0.9-11.5 years) experienced 8927 AKI episodes; 8% occurred during birth admissions. Of 5582 children with hospitalized AKI, 25% required critical care. In children experiencing an AKI episode unrelated to their birth admission, Asian ethnicity, young (<1 year) or old (16-<18 years) age (reference 1-<5 years), and high peak AKI stage had higher odds of critical care. LOS was higher with peak AKI stage, irrespective of critical care admission. Overall, 30-day mortality rate was 3% (n = 251); youngest and oldest age groups, hospital-acquired AKI, higher peak stage and critical care requirement had higher odds of death. For children experiencing AKI alerts during their birth admission, no association was seen between higher peak AKI stage and critical care admission.

Conclusions

Risk associations for adverse AKI outcomes differed among children according to AKI type and whether hospitalization was related to birth. Understanding the factors driving AKI development and progression may help inform interventions to minimize morbidity.

Acute Kidney Injury Defined by Fluid-Corrected Creatinine in Premature Neonates: A Secondary Analysis of the PENUT Randomized Clinical Trial

Importance

Acute kidney injury (AKI) and disordered fluid balance are common in premature neonates; a positive fluid balance dilutes serum creatinine, and a negative fluid balance concentrates serum creatinine, both of which complicate AKI diagnosis. Correcting serum creatinine for fluid balance may improve diagnosis and increase diagnostic accuracy for AKI.

Objective

To determine whether correcting serum creatinine for fluid balance would identify additional neonates with AKI and alter the association of AKI with short-term and long-term outcomes.

Design, Setting, and Participants

This study was a post hoc cohort analysis of the Preterm Erythropoietin Neuroprotection Trial (PENUT), a phase 3, randomized clinical trial of erythropoietin, conducted at 19 academic centers and 30 neonatal intensive care units in the US from December 2013 to September 2016. Participants included extremely premature neonates born at less than 28 weeks of gestation. Data analysis was conducted in December 2022.

Exposure

Diagnosis of fluid-corrected AKI during the first 14 postnatal days, calculated using fluid-corrected serum creatinine (defined as serum creatinine multiplied by fluid balance [calculated as percentage change from birth weight] divided by total body water [estimated 80% of birth weight]).

Main Outcomes and Measures

The primary outcome was invasive mechanical ventilation on postnatal day 14. Secondary outcomes included death, hospital length of stay, and severe bronchopulmonary dysplasia (BPD). Categorical variables were analyzed by proportional differences with the χ2 test or Fisher exact test. The t test and Wilcoxon rank sums test were used to compare continuous and ordinal variables, respectively. Odds ratios (ORs) and 95% CIs for the association of exposure with outcomes of interest were estimated using unconditional logistic regression models.

Results

A total of 923 premature neonates (479 boys [51.9%]; median [IQR] birth weight, 801 [668-940] g) were included, of whom 215 (23.3%) received a diagnosis of AKI using uncorrected serum creatinine. After fluid balance correction, 13 neonates with AKI were reclassified as not having fluid-corrected AKI, and 111 neonates previously without AKI were reclassified as having fluid-corrected AKI (ie, unveiled AKI). Therefore, fluid-corrected AKI was diagnosed in 313 neonates (33.9%). Neonates with unveiled AKI were similar in clinical characteristics to those with AKI whose diagnoses were made with uncorrected serum creatinine. Compared with those without AKI, neonates with unveiled AKI were more likely to require ventilation (81 neonates [75.0%] vs 254 neonates [44.3%] and have longer hospital stays (median [IQR], 102 [84-124] days vs 90 [71-110] days). In multivariable analysis, a diagnosis of fluid-corrected AKI was associated with increased odds of adverse clinical outcomes, including ventilation (adjusted OR, 2.23; 95% CI, 1.56-3.18) and severe BPD (adjusted OR, 2.05; 95% CI, 1.15-3.64).

Conclusions and Relevance

In this post hoc cohort study of premature neonates, fluid correction increased the number of premature neonates with a diagnosis of AKI and was associated with increased odds of adverse clinical outcomes, including ventilation and BPD. Failing to correct serum creatinine for fluid balance underestimates the prevalence and impact of AKI in premature neonates. Future studies should consider correcting AKI for fluid balance.

Trial Registration

ClinicalTrials.gov Identifier: NCT01378273.

Acute Kidney Injury: Gaps and Opportunities for Knowledge and Growth

Acute kidney injury (AKI) occurs frequently in hospitalized patients, regardless of age or prior medical history. Increasing awareness of the epidemiologic problem of AKI has directly led to increased study of global recognition, diagnostic tools, both reactive and proactive management, and analysis of long-term sequelae. Many gaps remain, however, and in this article we highlight opportunities to add significantly to the increasing bodies of evidence surrounding AKI. Practical considerations related to initiation, prescription, anticoagulation, and monitoring are discussed. In addition, the importance of AKI follow-up evaluation, particularly for those surviving the receipt of renal replacement therapy, is highlighted as a push for global equity in the realm of critical care nephrology is broached. Addressing these gaps presents an opportunity to impact patient care directly and improve patient outcomes.

Risk factors for severe acute kidney injury after pediatric hematopoietic cell transplantation

BACKGROUND

Acute kidney injury (AKI) is common after hematopoietic cell transplantation (HCT) and is associated with poorer outcomes. Risk factors for AKI after pediatric HCT are not fully understood. The study objective was to assess unique risk factors for AKI in the HCT population and evaluate post-HCT AKI patterns.

METHODS

We conducted a retrospective cohort study of patients < 21 years of age who underwent HCT at Seattle Children's Hospital/Fred Hutchinson Cancer Center from September 2008 to July 2017 (n = 484). We defined AKI using KDIGO criteria. We collected demographics, baseline HCT characteristics, post-HCT complications, and mortality. Multinomial logistic regression was used to estimate association between AKI and potential risk factors. We used adjusted Cox proportional hazard ratios to evaluate differences in mortality.

RESULTS

One hundred and eighty-six patients (38%) developed AKI. Seventy-nine (42%) had severe AKI and 27 (15%) required kidney replacement therapy. Fluid overload was common in all groups and 67% of those with severe AKI had > 10% fluid overload. Nephrology was consulted in less than 50% of those with severe AKI. In multivariable analysis, risk of severe AKI was lower in those taking a calcineurin inhibitor (CNI). Risk of death was higher in severe AKI compared to no AKI (RR 4.6, 95% CI 2.6-8.1).

CONCLUSIONS

AKI and fluid overload are common in pediatric patients after HCT. Severe AKI occurred less often with CNI use and was associated with higher mortality. Future interventions to reduce AKI and its associated complications such as fluid overload are approaches to reducing morbidity and mortality after HCT. A higher resolution version of the Graphical abstract is available as Supplementary information.

Etiology and outcomes of acute kidney disease in children: a cohort study

BACKGROUND

There is paucity of information regarding the etiology and outcomes of Acute Kidney Disease (AKD) in children.

METHODS

The objectives of this cohort study were to evaluate the etiology and outcomes of AKD; and analyze predictors of kidney survival (defined as free of CKD 2, 3a, 3b, 4 or 5). Patients aged 1 month to 18 years who developed AKD over a 4-year-period (January 2018-December 2021) were enrolled. Survivors were followed-up at the pediatric nephrology clinic, and screened for residual kidney injury.

RESULTS

Among 5710 children who developed AKI, 200 who developed AKD were enrolled. The median (IQR) eGFR was 17.03 (10.98, 28) mL/min/1.73 m². Acute glomerulonephritis, acute tubular necrosis (ATN), hemolytic uremic syndrome (HUS), sepsis-associated AKD, and snake envenomation comprised of 69 (34.5%), 39 (19.5%), 24 (12%), 23 (11.5%) and 15 (7.5%) of the patients respectively. Overall, 88 (44%) children required kidney replacement therapy (KRT). There were 37 (18.5%) deaths within the AKD period. At a follow-up of 90 days, 32 (16%) progressed to chronic kidney disease stage-G2 or greater. At a median (IQR) follow-up of 24 (6, 36.5) months (n = 154), 27 (17.5%) had subnormal eGFR, and 20 (12.9%) had persistent proteinuria and/or hypertension. Requirement of KRT predicted kidney survival (free of CKD 2, 3a, 3b, 4 or 5) in AKD (HR 6.7, 95% CI 1.2, 46.4) (p 0.04).

CONCLUSIONS

Acute glomerulonephritis, ATN, HUS, sepsis-associated AKD and snake envenomation were common causes of AKD. Mortality in AKD was 18.5%, and 16% progressed to CKD-G2 or greater at 90-day follow-up.

Harm! foul! How acute kidney injury SHReDDs patient futures

PURPOSE OF REVIEW

Transition from acute kidney injury (AKI) to chronic kidney disease (CKD) is increasingly accepted. Less well recognized, but supported by very similar data, is development of disease of other organ systems after AKI. Awareness of other-organ sequelae of AKI may inform efforts to improve the care of patients after AKI.

RECENT FINDINGS

Stroke, hypertension, reproductive risk, dementia, and death (SHReDD) are sequelae, which occur with increased risk relative to that of non-AKI within 6 months-3 years after AKI diagnosis, and which are supported by preclinical/mechanistic study. Adjusted hazard ratios for these sequelae are strikingly similar to that of AKI-CKD, ranging from 1.2 to 3.0. Mechanistic studies suggest kidney-centric mechanisms including sodium regulation, volume status regulation, and the renin-angiotensin system are drivers of long-term, extra-renal, change.

SUMMARY

Further clinical characterization and mechanistic insight is necessary, and may have considerable translational impact. Programs which screen or follow post-AKI patients may increase clinical utility if focus is expanded to include the SHReDD complications.

Long-term kidney outcomes in children following continuous kidney replacement therapy

BACKGROUND

Continuous kidney replacement therapy (CKRT) is a mainstay of therapy for management of severe acute kidney injury (AKI) in critically ill pediatric patients. There is limited data on the risk of chronic kidney disease (CKD) after discharge in this population.

METHODS

This is a single-center, retrospective cohort study of all pediatric patients ages 0-17 years who received CKRT from 2013 to 2017. The study excluded patients with pre-existing CKD, those who died prior to discharge, and those who had insufficient follow-up data. Patients were followed after hospital discharge and electronic health record data was collected and analyzed to assess for incidence of and risk factors for kidney sequelae.

RESULTS

A total of 42 patients were followed at a median time of 27 months (IQR 17.2, 39.8). Of these, 26.2% had evidence of CKD and 19% were at risk for CKD. Lower eGFR at hospital discharge was associated with increased odds of kidney sequelae (aOR 0.985; 95% CI 0.972, 0.996). Ages 0- < 1 and 12-17 were not significantly different (aOR 0.235, 95% CI 0.024, 1.718) and had the highest incidence of kidney sequelae (50% and 77%, respectively). Ages 1-5 and 6-11 had a decreased odds of kidney sequelae compared to the 12-17 year age group (aOR 0.098; 95% CI 0.009, 0.703 and aOR 0.035; 95% CI 0.001, 0.39, respectively). Only 54.8% of patients (n = 23) were seen in the nephrology clinic after discharge.

CONCLUSIONS

Patients who receive CKRT for AKI have a significant risk of CKD, while follow-up with a pediatric nephrologist in these high-risk patients is sub-optimal. A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-term Health Care Utilization and Associated Costs After Dialysis-Treated Acute Kidney Injury in Children

RATIONALE & OBJECTIVE

Acute kidney injury (AKI) is common among hospitalized children and is associated with increased hospital length of stay and costs. However, there are limited data on postdischarge health care utilization after AKI hospitalization. Our objectives were to evaluate health care utilization and physician follow-up patterns after dialysis-treated AKI in a pediatric population.

STUDY DESIGN

Retrospective cohort study, using provincial health administrative databases.

SETTING & PARTICIPANTS

All children (0-18 years) hospitalized between 1996 and 2017 in Ontario, Canada. Excluded individuals comprised non-Ontario residents; those with metabolic disorders or poisoning; and those who received dialysis or kidney transplant before admission, a kidney transplant by 104 days after discharge, or were receiving dialysis 76-104 days from dialysis start date.

EXPOSURE

Episodes of dialysis-treated AKI, identified using validated health administrative codes. AKI survivors were matched to 4 hospitalized controls without dialysis-treated AKI by age, sex, and admission year.

OUTCOME

Our primary outcome was postdischarge hospitalizations, emergency department visits, and outpatient physician visits. Secondary outcomes included outpatient visits by physician type and composite health care costs.

ANALYTICAL APPROACH

Proportions with≥1 event and rates (per 1,000 person-years). Total and median composite health care costs. Adjusted rate ratios using negative binomial regression models.

RESULTS

We included 1,688 pediatric dialysis-treated AKI survivors and 6,752 matched controls. Dialysis-treated AKI survivors had higher rehospitalization and emergency department visit rates during the analyzed follow-up periods (0-1, 0-5, and 0-10 years postdischarge, and throughout follow-up), and higher outpatient visit rates in the 0-1-year follow-up period. The overall adjusted rate ratio for rehospitalization was 1.46 (95% CI, 1.25-1.69; P<0.0001) and for outpatient visits was 1.16 (95% CI, 1.09-1.23; P=0.01). Dialysis-treated AKI survivors also had higher health care costs. Nephrologist follow-up was infrequent among dialysis-treated AKI survivors (18.6% by 1 year postdischarge).

LIMITATIONS

Potential miscoding of study exposures or outcomes. Residual uncontrolled confounding. Data for health care costs and emergency department visits was unavailable before 2006 and 2001, respectively.

CONCLUSIONS

Dialysis-treated AKI survivors had greater postdischarge health care utilization and costs versus hospitalized controls. Strategies are needed to improve follow-up care for children after dialysis-treated AKI to prevent long-term complications.

Mild acute kidney injury after pediatric surgery is not-associated with long-term renal dysfunction: A retrospective cohort study

BACKGROUND AND STUDY OBJECTIVE

Acute kidney injury (AKI) is a sudden deterioration in renal function and is common in pediatric patients undergoing cardiac and non-cardiac surgery. Few studies have investigated the association of postoperative AKI with kidney dysfunction seen long-term and other adverse outcomes in pediatric patients. The study aimed to determine the association between postoperative AKI (mild AKI vs. no AKI and mild AKI vs. moderate-severe AKI) and chronic kidney dysfunction (CKD) seen long-term in pediatric patients undergoing cardiac and non-cardiac major surgery.

DESIGN

Restrospective, cohort study.

SETTING

Tertiary care hospital.

PATIENTS

This retrospective cohort study included patients aged 2-18 years who underwent cardiac and non-cardiac major surgery lasting >2 h at the Cleveland Clinic Main Campus between June 2005 and December 2020.

MEASUREMENTS

Postoperative AKI and CKD seen in long-term were defined and staged according to the Kidney Disease: Improving Global Outcomes criteria.

MAIN RESULTS

Among 10,597 children who had cardiac and non-cardiac major surgery, 1,302 were eligible. A total of 682 patients were excluded for missing variables and baseline kidney dysfunction and 620 patients were included. The mean age was 11 years, and 307 (49.5%) were female. Postoperative mild AKI was detected in 5.8% of the patients, while moderate-severe AKI was detected in 2.4%. There was no significant difference in CKD seen in long-term between patients with and without postoperative AKI, p = 0.83. The CKD seen in long-term developed in 27.7% of patients with postoperative mild AKI and 33.3% of patients with postoperative moderate and severe AKI. Patients without postoperative AKI had an estimated 1.09 times higher odds of having CKD seen in long-term compared with patients who have postoperative mild AKI (odds ratio [95% CI] 1.09 [0.48,2.52]).

CONCLUSION

In contrast to adult patients, the authors did not find any association between postoperative AKI and CKD seen in long-term in pediatric patients.

Decreases in Nephrotoxic Pain Medications Are Not Associated With Increased Opioid Utilization in Critically Ill Children

OBJECTIVES

Quality improvement initiatives to decrease rates of nephrotoxic medication exposure have reduced rates of acute kidney injury (AKI) in noncritically ill children. The objective of our study was to analyze the implementation of a similar program in critically ill children and to measure important balancing measures including opioid and benzodiazepine exposure.

DESIGN

Prospective quality improvement study.

SETTING

PICU at Children's Hospital Colorado between 2018 and 2020.

PATIENTS

All children admitted to PICU.

INTERVENTIONS

Quality improvement initiative called Nephrotoxic Injury Negated by Just-In-Time Action (NINJA).

MEASUREMENT AND MAIN RESULTS

Eight thousand eight hundred thirty-three PICU patient admissions were included. Mean rates of nephrotoxic medication exposure/1,000 PICU patient days decreased from 46 to 26, whereas rates of nephrotoxic AKI/1,000 PICU patient days did not change. Nonsteroidal anti-inflammatory drug dispenses per 1,000 patient days were reduced from 521 to 456. Similarly, opioid and benzodiazepine exposures per 1,000 patient days were reduced from 812 to 524 and 441 to 227, respectively, during the study observation period.

CONCLUSIONS

The NINJA intervention was efficaciously implemented in our single-center PICU. Nephrotoxic exposure is a modifiable factor that did not inadvertently increase exposure to opioids and benzodiazepines.

Feasibility of contrast-enhanced ultrasonography (CEUS) in evaluating renal microvascular perfusion in pediatric patients

Background

Changes in renal microvascular perfusion are involved in several kidney diseases. Contrast-enhanced ultrasonography (CEUS) quantitative analysis can enable the estimation of renal microvascular perfusion non-invasively. However, to date, few pediatric patients with renal disease have been subjected to CEUS quantitative analysis. This study aimed to explore the feasibility of CEUS in evaluating renal microvascular perfusion in pediatric patients and paving its way to clinical practice.

Methods

Seventeen pediatric patients with chronic kidney disease (CKD) and five children without kidney disease were consecutively examined using CEUS. Quantitative analysis of CEUS images based on time-intensity curve (TIC) fittings was performed using specialized software. Quantitative parameters of wash-in microvascular blood flow, including A, k, B, and TtoPk, were generated from three regions of interest (ROIs) each in the cortex and medulla of each kidney.

Results

CEUS was performed in all children successfully and safely without the use of sedatives. All parameters (A, B, k, and TtoPk) demonstrated no statistical differences among the three sampling ROIs in the renal cortex and medulla. All parameters (A, B, k, and TtoPk) showed no statistical differences between the left and right sides of kidneys both in cortices and medullas. Comparing with patients with CKD stage 3–5, both control group and patients with CKD stage 1–2 had significantly higher values of parameter A in the renal cortex (p = 0.025 and p = 0.031, respectively). In control group and patients stage 1–2, the values of parameters k in the renal cortices were significantly higher than that in the renal medullas, while in patients with CKD stage 3–5, parameter k showed no statistically significant differences between the renal cortex and medulla (p = 0.173).

Conclusion

CEUS is safe and practicable in pediatric patients with chronic kidney disease. Renal microvascular perfusion estimated by CEUS could be a robust approach in the evaluation of pediatric renal diseases. Parameters A and k derived from CEUS quantitative analysis can provide great potential in non-invasive assessment of renal microvascular perfusion impairment in pediatric CKD.

Serum and urinary biomarkers to predict acute kidney injury in premature infants: a systematic review and meta-analysis of diagnostic accuracy

BACKGROUND

Premature infants are at high risk for acute kidney injury (AKI) and current diagnostic criteria are flawed. The objective of this study was to determine the diagnostic accuracy of urine and serum biomarkers not currently used in routine clinical practice to predict AKI in premature infants.

METHOD

A systematic review was performed that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA). Data were extracted on the diagnostic accuracy of AKI biomarkers using serum creatinine or urine output as the reference standard. Quality and validity were assessed using modified Standards for Reporting Diagnostic Accuracy (STARD) criteria.

RESULTS

We identified 1024 articles, with 15 studies (791 infants) eligible for inclusion. Twenty-seven biomarkers were identified including serum cystatin C and urinary neutrophil gelatinase-associated lipocalin (uNGAL), osteopontin, kidney injury molecule-1, epidermal growth factor, and protein S100-P. However, many were only reported by one study each. A meta-analysis could only be conducted on uNGAL (288 infants from 6 studies) using a hierarchical, random-effects logistic-regression model. uNGAL had a summary sensitivity of 77% (95% CI 58-89%), specificity of 76% (95% CI 57-88%) and AUC-SROC of 0.83 (95% CI 0.80-0.86) for the diagnosis of AKI. By utilising uNGAL, the post-test probability of AKI increased to 52% (95% CI 37-66%) with a positive test and decreased to 9% (95% CI 5-16%) with a negative test if the pre-test probability was 25%.

CONCLUSION

uNGAL shows promise as a diagnostically accurate biomarker for AKI in premature infants.

Acute kidney injury and diabetic kidney disease in children with acute complications of diabetes

BACKGROUND

Diabetic ketoacidosis (DKA) and hyperglycaemia without ketoacidosis are common acute complications of diabetes. Their association with acute kidney injury (AKI) and diabetic kidney disease (DKD) was studied.

METHODS

The study group consisted of 197 children with type 1 diabetes with average diabetes duration of 8.08 ± 2.32 years. The medical history of the patients was retrospectively reviewed. The number of children with severe hyperglycaemia, DKA and AKI was assessed. The association with the risk of chronic kidney disease (CKD) was analysed.

RESULTS

AKI was found in 14% of cases hospitalised for DKA and 8% of cases hospitalised for hyperglycaemia. Patients with AKI showed a significantly increased corrected sodium (141.23 ± 5.09 mmol/L, p = 0.035). Patients with AKI in DKA showed a significant increase in WBC (20.73 ± 8.71 × 10³/µL, p = 0.0009). Follow-up analysis after a minimum of 5 years of diabetes revealed that a single episode of DKA was found in 63 patients and a single episode of AKI in 18 patients. Two or more episodes of DKA were found in 18 patients, and nine cases were complicated by AKI. These patients showed a significant increase in urinary albumin excretion (44.20 ± 64.21 mg/24 h), the highest values of eGFR and the worst glycaemic control.

CONCLUSIONS

Diabetic children can develop AKI in the course of DKA and hyperglycaemia without ketoacidosis, which is associated with volume depletion and reflected by corrected sodium concentration. AKI in DKA seems to be complicated by stress and inflammation activation. AKI and poor glycaemic control with repeated DKA episodes can magnify the risk of progression to DKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Upregulation of Mineralocorticoid Receptor Contributes to Development of Salt-Sensitive Hypertension after Ischemia-Reperfusion Injury in Rats

The ischemia-reperfusion injury (IRI) of rat kidneys is used as a model of acute kidney injury. Salt-sensitive hypertension occurs in rats after IRI, and the distal nephrons play important roles in the development of this condition. We investigated the role of the mineralocorticoid receptor (MR) in the progression of IRI-induced salt-sensitive hypertension in rats. Fourteen days after right-side nephrectomy, IRI was induced by clamping the left renal artery, with sham surgery performed as a control. IRI rats were provided with normal water or water with 1.0% NaCl (IRI/NaCl), or they were implanted with an osmotic mini-pump to infuse vehicle or aldosterone (IRI/Aldo). Esaxerenone, a non-steroidal MR blocker (MRB), was administered to IRI/NaCl and IRI/Aldo rats for 6 weeks. MR expression increased by day 7 post-IRI. Blood pressure and urinary protein excretion increased in IRI/NaCl and IRI/Aldo rats over the 6-week period, but these effects were negated by MRB administration. The MRB attenuated the expression of the gamma-epithelial sodium channel (ENaC) and renal damage. The ENaC inhibitor, amiloride, ameliorated hypertension and renal damage in IRI/NaCl and IRI/Aldo rats. Our findings thus showed that MR upregulation may play a pivotal role in ENaC-mediated sodium uptake in rats after IRI, resulting in the development of salt-sensitive hypertension in response to salt overload or the activation of the renin-angiotensin-aldosterone system.

A Process for the Design and Development of Novel Bone Morphogenetic Protein-7 (BMP-7) Mimetics With an Example: THR-184

Growth Factors have been evaluated as therapeutic targets for the treatment of a broad spectrum of diseases. Because they are proteins with pleiotropic effects, the quest to harness their beneficial effects has presented challenges. Most Growth Factors operate at the extracellular-receptor level and have natural feedback mechanisms that modulate their effects. As proteins, they are difficult and expensive to manufacture. Frequently proteins must be administered parenterally, may invoke an immune response, and may be neutralized by naturally occurring inhibitors. To circumvent these limitations, we have undertaken an effort to develop mimetics for the Bone Morphogenetic Protein (BMP) signaling pathway effects that incorporate the beneficial effects, eliminate the deleterious effects, and thereby create effective drug-like compounds.To this end, we have designed and tested a family of small peptide BMP mimetics. The design used the three-dimensional structure of BMP-7 to identify likely active surface regions. Lead sequences were then optimized based on in vitro assays that examine the selective binding to BMP receptors, demonstrate the phosphorylation of Smad-1,5,8, detect anti-apoptosis and anti-inflammation, and block the epithelial to mesenchymal transition (EMT) in renal tubular epithelial cells. These sequences were further optimized using in vivo assays of the attenuation of acute kidney injury in a rat-model of unilateral clamp ischemic reperfusion. This process uses a Structure Variance Analysis algorithm (SVA) to identify structure/activity relationships. One member of this family, THR-184, is an agonist of BMP signaling and a potent antagonist of TGFβ signaling. This small peptide mimetic inhibits inflammation, apoptosis, fibrosis and reverses epithelial to mesenchymal transition (EMT) by regulating multiple signaling pathways involved in the cellular injury of multiple organs. Its effects have been shown to control Acute Kidney Injury (AKI). THR-184 has progressed through phase I and II clinical trials for the prevention of Cardio-Vascular Surgery (CVS) associated AKI. This work provides a roadmap for the development of other growth factor mimetics and demonstrates how we might harness their therapeutic potential.

Recurrent acute kidney injury in preterm neonates is common and associated with worse outcomes and higher mortality

BACKGROUND

Acute kidney injury (AKI) in preterm neonates is associated with poor outcomes that may worsen in the setting of recurrent episodes of AKI. This study defines and studies the incidence, risk factors, and outcomes of recurrent AKI (rAKI).

METHODS

Retrospective chart review of the neonates born at a gestational age of ≤28 weeks admitted to the neonatal intensive care unit (NICU) between January 2014 and December 2018. We identified AKI based on the serum creatinine (Scr) concentrations using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. rAKI was defined as the occurrence of AKI after Scr from the prior AKI had returned to baseline.

RESULTS

Forty-nine of the 205 (24%) preterm neonates developed rAKI. An earlier diagnosis (<7 days old) and a higher KDIGO stage (stage 3) at the initial episode of AKI was associated with rAKI (p = 0.03). Preterm neonates with rAKI had higher mortality as compared to those with a single episode of AKI (sAKI) (adjusted odds ratio (aOR) 4.55, 95% confidence interval (CI), 1.12-18.51). Length of stay (LOS) was longer among neonates with rAKI as compared to those with sAKI by 36 days (95% CI 24.9-47.1).

CONCLUSIONS

Recurrent AKI in preterm neonates was associated with earlier episodes and higher KDIGO stage of the initial AKI episode. Neonates with rAKI had higher mortality and longer LOS compared to those with sAKI.

IMPACT

Definition and study of the incidence of rAKI and its associated outcomes among preterm neonates. Recurrent AKI is common among preterm neonates and may contribute to worse outcomes for premature neonates in the NICU. Early recognition of the risk factors for AKI, and effective management of initial AKI and early phase of recurrent AKI may improve outcomes of these preterm neonates.

Acute kidney injury after the arterial switch operation: incidence, risk factors, and outcomes

BACKGROUND

The aim of this retrospective cohort study was to determine the incidence, potential risk factors, characteristics, and outcomes of acute kidney injury in children following the arterial switch operation for transposition of the great arteries.

METHODS

Retrospective review of children who underwent ASO between 2000 and 2020 in our tertiary children's hospital in the Netherlands. Pre-and post-ASO serum creatinine levels were collected. Severe AKI was defined as 100% serum creatinine rise or estimated creatinine clearance <35 ml/min/1.73 m2 according to pRIFLE criteria. Logistic regression was used to adjust for confounders.

RESULTS

A total of 242 children were included. Fifty-seven (24%) children developed severe AKI after ASO. Four patients with severe AKI were treated with renal replacement therapy. Children with severe AKI had a longer duration of mechanical ventilation 4.5 (1.0-29) versus 3 (1.0-12) days (p = 0.001), longer PICU stay 7 (2-76) versus 5 (1-70) days, (p = 0.001), higher rate of myocardial infarction 5% versus 0.5% (p = 0.001), sepsis 24% versus 9% (p = 0.002), post-operative pulmonary hypertension 19% versus 6% (p = 0.002), post-operative bleeding 9% versus 3% (p = 0.044), longer time to sternal closure 3 (1-19) versus 2 (1-6) days, (p = 0.009), and a higher mortality rate 9.0% versus 0.5% (p = 0.001) compared to children without severe AKI. Sepsis was a risk factor for developing severe AKI.

CONCLUSIONS

In this single-centre cohort, 24% of our patients developed severe AKI after ASO, which is associated with increased morbidity, longer PICU stay, and higher mortality.

Long-Term Healthcare Cost Savings of a Pediatric Nephrotoxic Medication-Associated Acute Kidney Injury Reduction Program in a Simulated Sample

BACKGROUND

Nephrotoxic medication exposure is a common cause of acute kidney injury (AKI) in hospitalized children and is associated with chronic kidney disease (CKD). The pharmacist-reliant NINJA program reduced nephrotoxic medication exposure and associated AKI.

OBJECTIVES

We assess potential healthcare cost savings from reduced CKD by preventing AKI with the NINJA program for a pediatric population through age 21.

METHODS

We simulated a cohort of 1000 hospitalized non-critically ill children. From the published literature, 310 develop AKI, 267 survive to 6 months, and 10-70% develop CKD, and NINJA implementation reduced AKI by 23.8%. Allowing for varying CKD rates, we estimated a range of NINJA's savings. We assumed an annual GFR decline of 1.2 (noHTN) ml/min/1.73 m² for half the sample and 1.7 (HTN) ml/min/1.73 m² for the other half to account for CKD progression without and with hypertension (HTN). We model attributable costs including CKD stage-related medications and outpatient visits/tests in 2018 dollars discounted at 3%. We subtract the cost of NINJA screening (daily serum creatinine and pharmacist time) from net savings. We exclude end-stage renal disease (ESRD) and hospitalization costs.

RESULTS

No intervention estimated CKD related costs are $761,852 to $5,735,027. Post-NINJA cost decreases to $616,086 to $4,312,183 (net savings: $145,766 to $1,422 183). Total savings, accounting for NINJA screening ($256,680) are -$110,914 to $1,1 165 503. The breakeven AKI to CKD conversion rate is 13-14% with growth hormone cost included, and 64-65% without.

CONCLUSION

The NINJA program is likely cost beneficial, with greater savings into adulthood by avoiding/delaying ESRD and its costs.

Long-term follow-up of patients after acute kidney injury in the neonatal period: abnormal ambulatory blood pressure findings

Background

Data on the long-term effects of neonatal acute kidney injury (AKI) are limited.

Methods

We invited 302 children who had neonatal AKI and survived to hospital discharge; out of 95 patients who agreed to participate in the study, 23 cases were excluded due to primary kidney, cardiac, or metabolic diseases. KDIGO definition was used to define AKI. When a newborn had no previous serum creatinine, AKI was defined as serum creatinine above the mean plus two standard deviations (SD) (or above 97.5^th percentile) according to gestational age, weight, and postnatal age. Clinical and laboratory features in the neonatal AKI period were recorded for 72 cases; at long-term evaluation (2–12 years), kidney function tests with glomerular filtration rate (eGFR) by the Schwartz formula, microalbuminuria, office and 24-h ambulatory blood pressure monitoring (ABPM), and kidney ultrasonography were performed.

Results

Forty-two patients (58%) had stage I AKI during the neonatal period. Mean age at long-term evaluation was 6.8 ± 2.9 years (range: 2.3–12.0); mean eGFR was 152.3 ± 26.5 ml/min/1.73 m². Office hypertension (systolic and/or diastolic BP ≥ 95^th percentile), microalbuminuria (> 30 mg/g creatinine), and hyperfiltration (> 187 ml/min/1.73 m²) were present in 13.0%, 12.7%, and 9.7% of patients, respectively. ABPM was performed on 27 patients, 18.5% had hypertension, and 40.7% were non-dippers; 48.1% had abnormal findings. Female sex was associated with microalbuminuria; low birth weight (< 1,500 g) and low gestational age (< 32 weeks) were associated with hypertension by ABPM. Twenty-three patients (33.8%) had at least one sign of microalbuminuria, office hypertension, or hyperfiltration. Among 27 patients who had ABPM, 16 (59.3%) had at least one sign of microalbuminuria, abnormal ABPM (hypertension and/or non-dipping), or hyperfiltration.

Conclusion

Even children who experienced stage 1 and 2 neonatal AKI are at risk for subclinical kidney dysfunction. Non-dipping is seen in four out of 10 children. Long-term follow-up of these patients is necessary.

The molecular chaperone GRP170 protects against ER stress and acute kidney injury in mice

Molecular chaperones are responsible for maintaining cellular homeostasis, and one such chaperone, GRP170, is an endoplasmic reticulum (ER) resident that oversees both protein biogenesis and quality control. We previously discovered that GRP170 regulates the degradation and assembly of the epithelial sodium channel (ENaC), which reabsorbs sodium in the distal nephron and thereby regulates salt-water homeostasis and blood pressure. To define the role of GRP170 - and, more generally, molecular chaperones in kidney physiology - we developed an inducible, nephron-specific GRP170-KO mouse. Here, we show that GRP170 deficiency causes a dramatic phenotype: profound hypovolemia, hyperaldosteronemia, and dysregulation of ion homeostasis, all of which are associated with the loss of ENaC. Additionally, the GRP170-KO mouse exhibits hallmarks of acute kidney injury (AKI). We further demonstrate that the unfolded protein response (UPR) is activated in the GRP170-deficient mouse. Notably, the UPR is also activated in AKI when originating from various other etiologies, including ischemia, sepsis, glomerulonephritis, nephrotic syndrome, and transplant rejection. Our work establishes the central role of GRP170 in kidney homeostasis and directly links molecular chaperone function to kidney injury.

Pathophysiology of Perinatal Asphyxia in Humans and Animal Models

Perinatal asphyxia is caused by lack of oxygen delivery (hypoxia) to end organs due to an hypoxemic or ischemic insult occurring in temporal proximity to labor (peripartum) or delivery (intrapartum). Hypoxic-ischemic encephalopathy is the clinical manifestation of hypoxic injury to the brain and is usually graded as mild, moderate, or severe. The search for useful biomarkers to precisely predict the severity of lesions in perinatal asphyxia and hypoxic-ischemic encephalopathy (HIE) is a field of increasing interest. As pathophysiology is not fully comprehended, the gold standard for treatment remains an active area of research. Hypothermia has proven to be an effective neuroprotective strategy and has been implemented in clinical routine. Current studies are exploring various add-on therapies, including erythropoietin, xenon, topiramate, melatonin, and stem cells. This review aims to perform an updated integration of the pathophysiological processes after perinatal asphyxia in humans and animal models to allow us to answer some questions and provide an interim update on progress in this field.

Fasting Intervention for Children With Unilateral Renal Tumors to Reduce Toxicity

Childhood renal tumors account for around 6% of all childhood cancers and 90% of these cases are Wilms tumor. In Europe, the SIOP-RTSG approach is considered standard of care and has resulted in five-year survival rates of over 90%. Efforts to decrease toxicity are now being pursued. Short-term fasting (STF), a short but strong reduction in calorie-intake, is associated with improved fitness, enhanced coping with acute physical stress and a lower risk of age-associated diseases. STF temporarily reduces growth to boost resilience, maintenance, and defense-mechanisms, by which toxic side-effects of (oxidative) damage and inflammation are largely prevented. Renal surgery for Wilms tumor carries a risk of acute kidney injury (AKI) and pediatric patients that had an episode of AKI are at increased risk for developing chronic renal disease. STF could mitigate surgery-induced stress and could further improve outcomes. We aim to investigate the effect of STF on renal function recovery after renal tumor surgery by conducting a single-center, prospective, randomized, non-blinded, intervention study. Children diagnosed with a unilateral renal tumor and opting for curative treatment are eligible for inclusion. The main study objective is to investigate the potential decrease in occurrence of AKI due to STF. Secondary objectives include renal function recovery, child's wellbeing, physical functioning, and feasibility of and adherence to STF in children with cancer.

Extended Interval Aminoglycoside Treatment for Klebsiella Pneumoniae Endocarditis in an Extremely Low Birth Weight Neonate

Infective endocarditis (IE) in neonates is associated with high mortality and incidence has been increasing over the past two decades. The majority of very low birth weight infants will be treated with at least one nephrotoxic medication during their hospital course. Over one-quarter of very low birth weight neonates exposed to gentamicin may develop acute kidney injury (AKI); this is particularly worrisome as AKI is an independent factor associated with increased neonatal mortality and increased length of stay. AKI during periods of neonatal nephrogenesis, which continues until 34-36 weeks postmenstrual age, may also have serious effects on the long-term nephron development which subsequently puts infants at risk of chronic kidney disease. Extended interval (EI) aminoglycoside (AMG) dosing has been used for decades in adult populations and has proven to reduce AKI while being at least as effective as traditional dosing, although there is limited published research for using an EI AMG in endocarditis in adults or pediatric patients. We describe an extremely low birth weight neonate, born preterm at 24 weeks gestation treated for Klebsiella pneumoniae IE that required AMG therapy who also had concurrent AKI. We utilized EI AMG combination therapy for treatment of Klebsiella pneumoniae endocarditis with good outcome and encourage others to report their experiences to improve our knowledge of EI AMG in this population.

Acute kidney injury in the pediatric intensive care unit: outpatient follow-up

BACKGROUND

Few studies have characterized follow-up after pediatric acute kidney injury (AKI). Our aim was to describe outpatient AKI follow-up after pediatric intensive care unit (PICU) admission.

METHODS

Two-center retrospective cohort study (0-18 years; PICU survivors (2003-2005); noncardiac surgery; and no baseline kidney disease). Provincial administrative databases were used to determine outcomes.

EXPOSURE

AKI (KDIGO (Kidney Disease: Improving Global Outcomes) definitions).

OUTCOMES

post-discharge nephrology, family physician, pediatrician, and non-nephrology specialist visits. Regression was used to evaluate factors associated with the presence of nephrology follow-up (Cox) and the number of nephrology and family physician or pediatrician visits (Poisson), among AKI survivors.

RESULTS

Of n = 2041, 355 (17%) had any AKI; 64/355 (18%) had nephrology; 198 (56%) had family physician or pediatrician; and 338 (95%) had family physician, pediatrician, or non-nephrology specialist follow-up by 1 year post discharge. Only 44/142 (31%) stage 2-3 AKI patients had nephrology follow-up by 1 year. Inpatient nephrology consult (adjusted hazard ratio (aHR) 7.76 [95% confidence interval (CI) 4.89-12.30]), kidney admission diagnosis (aHR 4.26 [2.21-8.18]), and AKI non-recovery by discharge (aHR 2.65 [1.55-4.55]) were associated with 1-year nephrology follow-up among any AKI survivors.

CONCLUSIONS

Nephrology follow-up after AKI was uncommon, but nearly all AKI survivors had follow-up with non-nephrologist physicians. This suggests that AKI follow-up knowledge translation strategies for non-nephrology providers should be a priority.

IMPACT

Pediatric AKI survivors have high long-term rates of chronic kidney disease (CKD) and hypertension, justifying regular kidney health surveillance after AKI. However, there is limited pediatric data on follow-up after AKI, including the factors associated with nephrology referral and extent of non-nephrology follow-up. We found that only one-fifth of all AKI survivors and one-third of severe AKI (stage 2-3) survivors have nephrology follow-up within 1 year post discharge. However, 95% are seen by a family physician, pediatrician, or non-nephrology specialist within 1 year post discharge. This suggests that knowledge translation strategies for AKI follow-up should be targeted at non-nephrology healthcare providers.

Outpatient Nephrotoxic Medication Prescription after Pediatric Intensive Care Acute Kidney Injury

BACKGROUND

Nephrotoxic medication (NTM) avoidance may prevent further kidney damage in children with acute kidney injury (AKI). We compared outpatient NTM prescriptions in children with or without AKI during pediatric intensive care (PICU) hospitalization. We hypothesize that children with AKI are prescribed NTMs at the same rate as those without it.

METHODS

This was a retrospective administrative data study of children <18 years, admitted to two PICUs in Montreal, Canada, from 2003 to 2005, with ≥30 days of provincial drug coverage. We evaluated the presence of ≥3 outpatient NTM prescriptions during the first year and 5 years after PICU discharge.

RESULTS

Of 970 children, 23% had PICU AKI. In the 1st-5th years after discharge, 18% AKI vs. 10% non-AKI and 13% AKI vs. 4% non-AKI patients received ≥3 NTM prescriptions, respectively. There was no association between PICU AKI and prescription of ≥3 NTMs during the first year (adjusted RR 1.02 [95% CI 0.95-1.10]) nor in the first 5 years post-discharge (adjusted RR 1.04 [95%CI 0.96-1.12]).

CONCLUSIONS

By offering a better understanding of the current state of outpatient NTM prescription to children with AKI, our study is a step toward considering strategies such as knowledge translation interventions for decreasing NTM exposure and improving outcomes in children with AKI.