Acute Kidney Injury in Critically Ill Children and Subsequent Chronic Kidney Disease

Furosemide stress test to predict acute kidney injury progression in critically ill children

BACKGROUND

Furosemide stress test (FST) is a novel functional biomarker for predicting severe acute kidney injury (AKI); however, pediatric studies are limited.

METHODS

Children 3 months to 18 years of age admitted to the intensive care unit (ICU) of a tertiary care hospital from Nov 2019 to July 2021 were screened and those who developed AKI stage 1 or 2 within 7 days of admission underwent FST (intravenous furosemide 1 mg/kg). Urine output was measured hourly for the next 6 h; a value > 2 ml/kg within the first 2 h was deemed furosemide responsive. Other biomarkers like plasma neutrophil gelatinase-associated lipocalin (NGAL) and proenkephalin (PENK) were also evaluated.

RESULTS

Of the 480 admitted patients, 51 developed AKI stage 1 or 2 within 7 days of admission and underwent FST. Nine of these patients were furosemide non-responsive. Thirteen (25.5%) patients (eight of nine from FST non-responsive group) developed stage 3 AKI within 7 days of FST, nine (17.6%) of whom (seven from non-responsive group) required kidney support therapy (KST). FST emerged as a good biomarker for predicting stage 3 AKI and need for KST with area-under-the-curve (AUC) being 0.93 ± 0.05 (95% CI 0.84-1.0) and 0.96 ± 0.03 (95% CI 0.9-1.0), respectively. FST outperformed NGAL and PENK in predicting AKI stage 3 and KST; however, the combination did not improve the diagnostic accuracy.

CONCLUSIONS

Furosemide stress test is a simple, inexpensive, and robust biomarker for predicting stage 3 AKI and KST need in critically ill children. Further research is required to identify the best FST cut-off in children.

Pediatric acute kidney injury and adverse health outcomes: using a foundational framework to evaluate a causal link

Acute kidney injury (AKI) is a major global health problem, expensive to manage, and its associations with negative pediatric health outcomes have been clearly demonstrated. One of the most fundamental questions to consider as we use previous epidemiological information to advance research and care paradigms is the strength of the causal link between pediatric AKI and health outcomes. In this review, we apply the foundational framework of the Bradford Hill criteria to evaluate the extent to which a causal link exists between AKI and the associated adverse outcomes in children. Available data in children support a causal link between AKI and short-term outcomes including mortality, length of stay, and ventilation time. Clarifying the causal nature of longer term associations requires further high-quality observational studies in children, careful consideration of what defines the most meaningful and measurable longer term outcomes after pediatric AKI, and integration of evolving biological data related to mechanisms of disease. Preventing or mitigating AKI should lead to improved outcomes. Demonstrating such reversibility will solidify confidence in the causal relationship, improve child health, and highlight an aspect which is highly relevant to clinicians, scientists, and policy makers.

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.

Open-label, controlled, phase 2 clinical trial assessing the safety, efficacy, and pharmacokinetics of INM004 in pediatric patients with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome

BACKGROUND

Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is a severe condition mainly affecting children. It is one of the leading causes of acute kidney injury in the pediatric population. There is no established therapy for this disease. INM004 is an anti-Shiga toxin composed of equine polyclonal antibodies. This study is aimed at assessing the safety, pharmacokinetics, and efficacy of INM004 in pediatric patients with STEC-HUS.

METHODS

Phase 2, open-label clinical trial with an historical control arm. Patients in the treatment arm received two doses of INM004. The primary endpoints were the safety profile, pharmacokinetics, and efficacy (dialysis days) of INM004. Secondary endpoints included other kidney and extrarenal outcomes. Propensity score matching was used for efficacy comparisons between arms.

RESULTS

Fifty-seven and 125 patients were enrolled in the treatment and control arm, respectively. After propensity score matching, 52 patients remained in each arm. INM004 was well-tolerated. Eight adverse events were considered possibly related, none of which were serious or severe. In the primary efficacy endpoint, patients of the treatment arm presented a non-statistically significant difference of two dialysis days. On secondary endpoints, non-statistically significant trends toward fewer patients needing dialysis and dialysis for more than 10 days, and shorter time to glomerular filtration rate normalization, were observed favoring the treatment arm.

CONCLUSIONS

INM004 showed an adequate safety profile. Efficacy non-statistically significant trends suggesting a beneficial effect in the amelioration of kidney injury were observed. These results encourage the conduction of a phase 3 study of INM004 in pediatric patients with STEC-HUS.

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.

Systematic Review and Meta-Analysis of the Incidence of Chronic Kidney Disease After Pediatric Critical Illness

OBJECTIVE

Survivors of pediatric critical illnesses are at risk of significant long-term organ sequelae. Chronic kidney disease (CKD) is a complication of critical illness (and ICU interventions) associated with growth impairment, cardiovascular disease, and early death. Our objective was to synthesize the evidence on the incidence of CKD among survivors of pediatric critical illness.

DATA SOURCES

MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Register of Controlled Trials from inception to February 2024.

STUDY SELECTION

Observational studies reporting the incidence of de novo CKD among survivors of pediatric critical illness.

DATA EXTRACTION

Two reviewers independently extracted data on study design, setting, population, demographics, diagnostic criteria, and outcome.

DATA SYNTHESIS

Meta-analysis was used to describe the incidence of CKD among survivors, risk of bias (RoB) assessed using the Joanna Briggs Institute Tool, and strength and reliability of evidence assessed with GRADE (Grading of Recommendations, Assessment, Development, and Evaluations). CKD was quantified as an estimated glomerular filtration rate (eGFR) less than 90 mL/min/1.73 m2 (outcome 1), eGFR less than 60 mL/min/1.73 m2 (outcome 2), and end-stage renal disease (ESRD) as eGFR less than 15 mL/min per 1.73 m2 (outcome 3). Twelve studies (3642 patients) met selection criteria and reported at least one measure of CKD. The median duration of follow-up was 2, 3.6, and 5 years, respectively, for outcomes 1, 2, and 3. For each threshold, the pooled estimate of CKD incidence was 24% (95% CI, 16-32%) for eGFR less than 90, 14% (95% CI, 6-23%) less than 60, and 4% (95% CI, 0-7%) for ESRD. The overall quality assessment indicated a moderate RoB.

CONCLUSIONS

Among a heterogenous population of pediatric critical illness survivors, an important minority of survivors developed CKD or ESRD. This study highlights the importance of diagnostic criteria for reporting, a greater focus on postcritical care surveillance and follow-up to identify those with CKD. Further study would facilitate the delineation of high-risk groups and strategies for improved outcomes.

Patterns of Multiple Organ Dysfunction and Renal Recovery in Critically Ill Children and Young Adults Receiving Continuous Renal Replacement Therapy

OBJECTIVES

Acute kidney injury requiring dialysis (AKI-D) commonly occurs in the setting of multiple organ dysfunction syndrome (MODS). Continuous renal replacement therapy (CRRT) is the modality of choice for AKI-D. Mid-term outcomes of pediatric AKI-D supported with CRRT are unknown. We aimed to describe the pattern and impact of organ dysfunction on renal outcomes in critically ill children and young adults with AKI-D.

DESIGN

Retrospective cohort.

SETTING

Two large quarternary care pediatric hospitals.

PATIENTS

Patients 26 y old or younger who received CRRT from 2014 to 2020, excluding patients with chronic kidney disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Organ dysfunction was assessed using the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) score. MODS was defined as greater than or equal to two organ dysfunctions. The primary outcome was major adverse kidney events at 30 days (MAKE30) (decrease in estimated glomerular filtration rate greater than or equal to 25% from baseline, need for renal replacement therapy, and death). Three hundred seventy-three patients, 50% female, with a median age of 84 mo (interquartile range [IQR] 16-172) were analyzed. PELOD-2 increased from 6 (IQR 3-9) to 9 (IQR 7-12) between ICU admission and CRRT initiation. Ninety-seven percent of patients developed MODS at CRRT start and 266 patients (71%) had MAKE30. Acute kidney injury (adjusted odds ratio [aOR] 3.55 [IQR 2.13-5.90]), neurologic (aOR 2.07 [IQR 1.15-3.74]), hematologic/oncologic dysfunction (aOR 2.27 [IQR 1.32-3.91]) at CRRT start, and progressive MODS (aOR 1.11 [IQR 1.03-1.19]) were independently associated with MAKE30.

CONCLUSIONS

Ninety percent of critically ill children and young adults with AKI-D develop MODS by the start of CRRT. Lack of renal recovery is associated with specific extrarenal organ dysfunction and progressive multiple organ dysfunction. Currently available extrarenal organ support strategies, such as therapeutic plasma exchange lung-protective ventilation, and other modifiable risk factors, should be incorporated into clinical trial design when investigating renal recovery.

Acute kidney injury in hospitalized children with proteinuria: A multicenter retrospective analysis

BACKGROUND AND OBJECTIVE

Acute kidney injury (AKI) is a common complication in hospitalized pediatric patients. Previous studies focused on adults found that proteinuria detected during an admission urinalysis is fit to serve as an indicator for AKI and associated clinical outcomes. The objective of this study is to evaluate if proteinuria on the first day of hospital services in hospitalized children is associated with AKI, need for renal replacement therapy, shock and/or antibiotic use, critical care services, and all-cause mortality at 30 days, hypothesizing that it is associated with these outcomes.

METHODS

This is a retrospective cohort study using TriNetX electronic health record data of patients 2 to 18 years of age who underwent urinalysis laboratory testing on hospital admission, had three subsequent days of hospital or critical care services billing codes and creatinine laboratory values, and no pre-existing renal-related complex chronic condition. This study evaluated for the frequency, odds, and severity of AKI as defined by Kidney Disease: Improving Global Outcomes modified criteria and assessed for associated clinical outcomes.

RESULTS

This study included 971 pediatric subjects [435 (44.7%) with proteinuria]. Proteinuria on the first day of hospital services was associated with an increased odds for higher severity AKI on any day of hospitalization (odds ratio [OR] 2.41, CI 1.8-3.23, p<0.001), need for renal replacement therapy (OR 4.58, CI 1.69-12.4, p = 0.001), shock and/or antibiotic use (OR 1.34, CI 1.03-1.75, p = 0.033), and all-cause mortality at 30 days post-admission (OR 10.0, CI 1.25-80.5, p = 0.013).

CONCLUSION

Children with proteinuria on the first day of hospital care services may have an increased odds of higher severity AKI, need for renal replacement therapy, shock and/or antibiotic use, and all-cause mortality at 30 days post-admission, with no significant association found for critical care services, mechanical intubation, or inotrope or vasopressor use.

Epidemiology of acute kidney injury in children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

The nephrology and critical care communities have seen an increase in studies exploring acute kidney injury (AKI) epidemiology in children. As a result, we now know that AKI is highly prevalent in critically ill neonates, children, and young adults. Furthermore, children who develop AKI experience greater morbidity and higher mortality. Yet knowledge gaps still exist that suggest a more comprehensive understanding of AKI will form the foundation for future efforts designed to improve outcomes. In particular, the areas of community acquired AKI, AKI in non-critically ill children, and cohorts from low-middle income countries have not been well studied. Longer-term functional outcomes and patient-centric metrics including social determinants of health, quality of life, and healthcare utilization should be the foci of the next phase of scholarship. Current definitions identify AKI-based upon evidence of dysfunction which serves as a proxy for injury; biomarkers capable of identifying injury as it occurs are likely to more accurately define populations with AKI. Despite the strength of the association, the causal and mechanistic relationships between AKI and poorer outcomes remain inadequately examined. A more robust understanding of the relationship represents a potential to identify therapeutic targets. Once established, a more comprehensive understanding of AKI epidemiology in children will allow investigation of preventive, therapeutic, and quality improvement interventions more effectively.

Advances in pediatric acute kidney injury pathobiology: a report from the 26th Acute Disease Quality Initiative (ADQI) conference

BACKGROUND

In the past decade, there have been substantial advances in our understanding of the pathobiology of pediatric acute kidney injury (AKI). In particular, animal models and studies focused on the relationship between kidney development, nephron number, and kidney health have identified a number of heterogeneous pathophysiologies underlying AKI. Despite this progress, gaps remain in our understanding of the pathobiology of pediatric AKI.

METHODS

During the 26th Acute Disease Quality Initiative (ADQI) Consensus conference, a multidisciplinary group of experts discussed the evidence and used a modified Delphi process to achieve consensus on recommendations for opportunities to advance translational research in pediatric AKI. The current state of research understanding as well as gaps and opportunities for advancement in research was discussed, and recommendations were summarized.

RESULTS

Consensus was reached that to improve translational pediatric AKI advancements, diverse teams spanning pre-clinical to epidemiological scientists must work in concert together and that results must be shared with the community we serve with patient involvement. Public and private research support and meaningful partnerships with adult research efforts are required. Particular focus is warranted to investigate the pediatric nuances of AKI, including the effect of development as a biological variable on AKI incidence, severity, and outcomes.

CONCLUSIONS

Although AKI is common and associated with significant morbidity, the biologic basis of the disease spectrum throughout varying nephron developmental stages remains poorly understood. An incomplete understanding of factors contributing to kidney health, the diverse pathobiologies underlying AKI in children, and the historically siloed approach to research limit advances in the field. The recommendations outlined herein identify gaps and outline a strategic approach to advance the field of pediatric AKI via multidisciplinary translational research.

Acute and chronic kidney injury during therapy for pediatric acute leukemia: A report from the Leukemia Electronic Abstraction of Records Network (LEARN)

Children with acute leukemia are at increased risk of kidney injury. Using electronic health record data from three centers between 2010 and 2018, this study retrospectively described acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence in children with acute lymphoblastic or myeloid leukemia (ALL, AML) using Common Terminology Criteria for Adverse Events (CTCAE) and Kidney Disease Improving Global Outcomes (KDIGO) definitions. AKI during therapy was 25% (ALL) and 32% (AML) using CTCAE, versus 84% (ALL) and 74% (AML) using KDIGO. CKD prevalence was low and Grade 1/Stage 2. Further investigation is needed to optimally define kidney injury in acute leukemia.

Long-term kidney follow-up after pediatric acute kidney support therapy for children less than 15 kg

BACKGROUND

In small children, acute dialysis (pediatric acute kidney support therapy (paKST)) is increasingly used; however, it is challenging for many reasons. We compared clinical characteristics and predictors of long-term outcomes of patients < 15 kg on peritoneal dialysis (PD), hemodialysis (HD), and continuous kidney replacement therapy (CKRT).

METHODS

Patients with history of paKST (CKRT, HD, PD) weighing < 15 kg and ≥ 6 months of follow-up at Hacettepe University were included. Surviving patients were evaluated at last visit.

RESULTS

109 patients (57 females) were included. Median age at paKST was 10.1 months (IQR: 2-27 months). In total, 43 (39.4%) patients received HD, 37 (34%) PD, and 29 (26.6%) CKRT. 64 (58.7%) patients died a median 3 days (IQR: 2-9.5 days) after paKST. Percentages of patients using vasopressor agents, with sepsis, and undergoing mechanical ventilation were lower in those who survived. After mean follow-up of 2.9 ± 2.1 years, 34 patients were evaluated at mean age 4.7 ± 2.4 years. Median spot urine protein/creatinine was 0.19 (IQR: 0.13-0.37) and 12 patients (35.3%) had non-nephrotic proteinuria. Three patients had estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73m2 and 2 (6%) had hyperfiltration. In total 22 patients (64.7%) had ≥ 1 kidney risk factor (elevated blood pressure/hypertension, hyperfiltration, eGFR < 90 ml/min/1.73m2, and/or proteinuria) at last visit. Among 28 patients on paKST < 32 months, 21 had ≥ 1 risk factor (75%), whereas among 6 patients who had paKST ≥ 32 months, one patient had ≥ 1 risk factor (16.7%), (p = 0.014).

CONCLUSIONS

Patients on paKST who undergo mechanical ventilation and vasopressor treatment should be followed-up more closely. After surviving the acute period, patients on paKST need to be followed-up closely during the chronic stage. A higher resolution version of the Graphical abstract is available as Supplementary information.

Early recognition and prevention of acute kidney injury in hospitalised children

Acute kidney injury is common in hospitalised children and is associated with poor patient outcomes. Once acute kidney injury occurs, effective therapies to improve patient outcomes or kidney recovery are scarce. Early identification of children at risk of acute kidney injury or at an early injury stage is essential to prevent progression and mitigate complications. Paediatric acute kidney injury is under-recognised by clinicians, which is a barrier to optimisation of inpatient care and follow-up. Acute kidney injury definitions rely on functional biomarkers (ie, serum creatinine and urine output) that are inadequate, since they do not account for biological variability, analytical issues, or physiological responses to volume depletion. Improved predictive tools and diagnostic biomarkers of kidney injury are needed for earlier detection. Novel strategies, including biomarker-guided care algorithms, machine-learning methods, and electronic alerts tied to clinical decision support tools, could improve paediatric acute kidney injury care. Clinical prediction models should be studied in different paediatric populations and acute kidney injury phenotypes. Research is needed to develop and test prevention strategies for acute kidney injury in hospitalised children, including care bundles and therapeutics.

Perspectives of Pediatric Nephrologists, Intensivists and Nurses Regarding AKI Management and Expected Outcomes

Background

Acute kidney injury (AKI) in critically ill children is associated with increased risk for short- and long-term adverse outcomes. Currently, there is no systematic follow-up for children who develop AKI in intensive care unit (ICU).

Objective

This study aimed to assess variation regarding management, perceived importance, and follow-up of AKI in the ICU setting within and between healthcare professional (HCP) groups.

Design

Anonymous, cross-sectional, web-based surveys were administered nationally to Canadian pediatric nephrologists, pediatric intensive care unit (PICU) physicians, and PICU nurses, via professional listservs.

Setting

All Canadian pediatric nephrologists, PICU physicians, and nurses treating children in the ICU were eligible for the survey.

Patients

N/A.

Measurements

Surveys included multiple choice and Likert scale questions on current practice related to AKI management and long-term follow-up, including institutional and personal practice approaches, and perceived importance of AKI severity with different outcomes.

Methods

Descriptive statistics were performed. Categorical responses were compared using Chi-square or Fisher's exact tests; Likert scale results were compared using Mann-Whitney and Kruskal-Wallis tests.

Results

Surveys were completed by 34/64 (53%) pediatric nephrologists, 46/113 (41%) PICU physicians, and 82 PICU nurses (response rate unknown). Over 65% of providers reported hemodialysis to be prescribed by nephrology; a mix of nephrology, ICU, or a shared nephrology-ICU model was reported responsible for peritoneal dialysis and continuous renal replacement therapy (CRRT). Severe hyperkalemia was the most important renal replacement therapy (RRT) indication for both nephrologists and PICU physicians (Likert scale from 0 [not important] to 10 [most important]; median = 10, 10, respectively). Nephrologists reported a lower threshold of AKI for increased mortality risk; 38% believed stage 2 AKI was the minimum compared to 17% of PICU physicians and 14% of nurses. Nephrologists were more likely than PICU physicians and nurses to recommend long-term follow-up for patients who develop any AKI during ICU stay (Likert scale from 0 [none] to 10 [all patients]; mean=6.0, 3.8, 3.7, respectively) (P < .05).

Limitations

Responses from all eligible HCPs in the country could not obtained. There may be differences in opinions between HCPs that completed the survey compared to those that did not. Additionally, the cross-sectional design of our study may not adequately reflect changes in guidelines and knowledge since survey completion, although no specific guidelines have been released in Canada since survey dissemination.

Conclusions

Canadian HCP groups have variable perspectives on pediatric AKI management and follow-up. Understanding practice patterns and perspectives will help optimize pediatric AKI follow-up guideline implementation.

Long-term outcomes of acute kidney injury in children

PURPOSE OF REVIEW

Acute kidney injury (AKI) affects up to 35% of all critically ill children and is associated with substantial short-term morbidity and mortality. However, the link between paediatric AKI and long-term adverse outcomes remains incompletely understood. This review highlights the most recent clinical data supporting the role of paediatric AKI as a risk factor for long-term kidney and cardiovascular consequences. In addition, it stresses the need for long-term surveillance of paediatric AKI survivors.

RECENT FINDINGS

Recent large-scale studies have led to an increasing understanding that paediatric AKI is a significant risk factor for adverse outcomes such as hypertension, cardiovascular disease and chronic kidney disease (CKD) over time. These long-term sequelae of paediatric AKI are most often observed in vulnerable populations, such as critically ill children, paediatric cardiac surgery patients, children who suffer from severe infections and paediatric cancer patients.

SUMMARY

A growing body of research has shown that paediatric AKI is associated with long-term adverse outcomes such as CKD, hypertension and cardiovascular disease. Although therapeutic pathways tailored to individual paediatric AKI patients are yet to be validated, we provide a framework to guide monitoring and prevention in children at the highest risk for developing long-term kidney dysfunction.

Risk factors, outcomes, and predictors of resolution of acute kidney injury in children with diabetic ketoacidosis

BACKGROUND

Acute kidney injury (AKI) is a common complication in patients with diabetic ketoacidosis (DKA) (incidence 35-77%). AKI evolution during DKA treatment/recovery is poorly understood. Our aim was to assess children with DKA for prevalence, short-term kidney outcomes, severity, and predictors of AKI development and resolution.

METHODS

This retrospective cohort study included children aged 2-14 years admitted with DKA between January 2016 and May 2020 in a Saudi tertiary care hospital. We defined AKI as an increase in serum creatinine of > 1.5 times baseline or > 3 mg/dL (26 mmol/L) within 48 h.

RESULTS

Of 213 patients admitted with DKA, 172 (80.75%) developed AKI: stage 1 in 83 (38.96%), stage 2 in 86 (40.37%), and stage 3 in 3 (1.4%). No patient required dialysis. Multivariate analysis showed an increased risk of developing AKI with male gender (OR = 2.85) and lower serum bicarbonate (OR = 0.83) when adjusted for initial heart rate, hematocrit, new onset diabetes, and recurrent AKI. The mean time to AKI resolution was 13.21 ± 6.78 h. Factors leading to prolonged recovery from AKI in linear regression analysis were older age (B coefficient = 0.44, p = 0.01), recurrent DKA episodes (B coefficient = 3.70, p value 0.003), increased acidosis severity (B coefficient =  - 0.44, p = 0.04), increased time to anion gap normalization (B coefficient = 0.44, p = 0.019), and increased initial glucose (B coefficient = 0.01, p = 0.011).

CONCLUSION

In our cohort, AKI is a common, but mostly transient complication in children presenting with DKA, and its severity is associated with longer intensive care stays and time for acidosis resolution. AKI was associated with male gender, and lower serum bicarbonate. Proper consideration of such risk factors is needed for AKI assessment and management in future DKA clinical practice guidelines. A higher resolution version of the Graphical abstract is available as Supplementary information.

Renal medicine in the intensive care unit: a narrative review

Kidney disease, both acute and chronic, is commonly encountered on the intensive care unit. Due to the role the kidneys play in whole body homeostasis, it follows that their dysfunction has wide-ranging implications and can affect prescribing and therapeutic management. This narrative review discusses the pathophysiology of acute kidney injury and chronic kidney disease, and how this relates to critically unwell patients. We cover several aspects of the management of renal dysfunction on the critical care unit, exploring some of the recurrent themes within the literature, including type and timing of kidney replacement therapy, management of acute kidney injury, as well as discussing how novel biomarkers for acute kidney injury may help to identify patients suffering from acute kidney injury as well as risk stratifying these patients. We discuss how early involvement of specialist nephrology services can improve outcomes in patients with kidney disease as well as offer valuable diagnostic and specialist management advice, particularly for patients with established end stage kidney disease and patients who are already known to nephrology services. We also explore some of the ongoing research questions that need to be answered within this arena.

Update on Pediatric Acute Kidney Injury

Acute kidney injury (AKI) is common in children and is associated with significant morbidity and mortality. In the last decade our understanding of AKI has improved significantly, and it is now considered a systemic disorder that affects other organs including heart, lung, and brain. In spite of its limitations, serum creatinine remains the mainstay in the diagnosis of AKI. However, newer approaches such as urinary biomarkers, furosemide stress test, and clinical decision support are being increasingly used and have the potential to improve the accuracy and timeliness of AKI diagnosis.

KIdney aNd blooD prESsure ouTcomes in Childhood Cancer Survivors: Description of Clinical Research Protocol of the KINDEST-CCS Study

Background

Approximately 30% of childhood cancer survivors (CCSs) will develop chronic kidney disease (CKD) or hypertension 15 to 20 years after treatment ends. The incidence of CKD and hypertension in the 5-year window after cancer therapy is unknown. Moreover, extent of monitoring of CCS with CKD and associated complications in current practice is underexplored. To inform the development of new and existing care guidelines for CCS, the epidemiology and monitoring of CKD and hypertension in the early period following cancer therapy warrants further investigation.

Objective

To describe the design and methods of the KIdney aNd blooD prESsure ouTcomes in Childhood Cancer Survivors study, which aims to evaluate the burden of late kidney and blood pressure outcomes in the first ~10 years after cancer therapy, the extent of appropriate screening and complications monitoring for CKD and hypertension, and whether patient, disease/treatment, or system factors are associated with these outcomes.

Design

Two distinct, but related studies; a prospective cohort study and a retrospective cohort study.

Setting

Five Ontario pediatric oncology centers.

Patients

The prospective study will involve 500 CCS at high risk for these late effects due to cancer therapy, and the retrospective study involves 5,000 CCS ≤ 18 years old treated for cancer between January 2008 and December 2020.

Measurements

Chronic kidney disease is defined as Estimated glomerular filtration rate <90 mL/min/1.73 m² or albumin-to-creatinine ratio ≥ 3mg/mmol. Hypertension is defined by 2017 American Academy of Pediatrics guidelines.

Methods

Prospective study: we aim to investigate CKD and hypertension prevalence and the extent to which they persist at 3- and 5-year follow-up in CCS after cancer therapy. We will collect detailed biologic and clinical data, calculate CKD and hypertension prevalence, and progression at 3- and 5-years post-therapy. Retrospective study: we aim to investigate CKD and hypertension monitoring using administrative and health record data. We will also investigate the validity of CKD and hypertension administrative definitions in this population and the incidence of CKD and hypertension in the first ~10 years post-cancer therapy. We will investigate whether patient-, disease/treatment-, or system-specific factors modify these associations in both studies.

Limitations

Results from the prospective study may not be generalizable to non-high-risk CCS. The retrospective study is susceptible to surveillance bias.

Conclusions

Our team and knowledge translation plan is engaging patient partners, researchers, knowledge users, and policy group representatives. Our work will address international priorities to improve CCS health, provide the evidence of new disease burden and practice gaps to improve CCS guidelines, implement and test revised guidelines, plan trials to reduce CKD and hypertension, and improve long-term CCS health.

Consensus-Based Recommendations on Priority Activities to Address Acute Kidney Injury in Children: A Modified Delphi Consensus Statement

IMPORTANCE

Increasing evidence indicates that acute kidney injury (AKI) occurs frequently in children and young adults and is associated with poor short-term and long-term outcomes. Guidance is required to focus efforts related to expansion of pediatric AKI knowledge.

OBJECTIVE

To develop expert-driven pediatric specific recommendations on needed AKI research, education, practice, and advocacy.

EVIDENCE REVIEW

At the 26th Acute Disease Quality Initiative meeting conducted in November 2021 by 47 multiprofessional international experts in general pediatrics, nephrology, and critical care, the panel focused on 6 areas: (1) epidemiology; (2) diagnostics; (3) fluid overload; (4) kidney support therapies; (5) biology, pharmacology, and nutrition; and (6) education and advocacy. An objective scientific review and distillation of literature through September 2021 was performed of (1) epidemiology, (2) risk assessment and diagnosis, (3) fluid assessment, (4) kidney support and extracorporeal therapies, (5) pathobiology, nutrition, and pharmacology, and (6) education and advocacy. Using an established modified Delphi process based on existing data, workgroups derived consensus statements with recommendations.

FINDINGS

The meeting developed 12 consensus statements and 29 research recommendations. Principal suggestions were to address gaps of knowledge by including data from varying socioeconomic groups, broadening definition of AKI phenotypes, adjudicating fluid balance by disease severity, integrating biopathology of child growth and development, and partnering with families and communities in AKI advocacy.

CONCLUSIONS AND RELEVANCE

Existing evidence across observational study supports further efforts to increase knowledge related to AKI in childhood. Significant gaps of knowledge may be addressed by focused efforts.

24-Hour ambulatory blood pressure monitoring 7 years after intensive care unit admission

BACKGROUND

Children who develop acute kidney injury (AKI) in the pediatric intensive care unit (PICU) may be at higher risk of long-term chronic kidney disease and hypertension. The objectives of this study were to determine the prevalence of post-discharge hypertension and albuminuria using reference-standard measurements in children admitted to the PICU, and evaluate their association with AKI.

METHODS

Single-center longitudinal cohort study of children admitted to the PICU from 2005 to 2010 with 7-8 years of follow-up (n = 207). Patients were excluded if they had pre-existing chronic kidney disease, were deceased, lived > 3.5-h drive away, were unwilling/unable to provide consent/assent, or had a clotting disorder. AKI was defined by the Kidney Disease: Improving Global Outcomes creatinine definition. Office blood pressure was evaluated using age, sex, and height-based percentiles. Hypertension was defined using 24-h ambulatory blood pressure monitoring (ABPM). Albuminuria was defined as first morning urine albumin:creatinine ratio ≥ 30 mg/g. Prevalence of blood pressure outcomes was calculated. The association between AKI and outcomes was evaluated using multivariable regression.

RESULTS

Sixty of 207 (29%) children developed AKI during PICU admission. Overall, 6% had albuminuria and 21% had elevated office blood pressure or worse. One-hundred-and-seventy-seven (86%) patients had successful ABPM data. Of these, 10 (6%) had white coat, 18 (10%) had masked, and 5 (3%) had ambulatory hypertension. There was no statistically significant difference in outcomes across AKI stages.

CONCLUSIONS

Blood pressure abnormalities are common in children 7 years after PICU admission. Future studies with longer follow-up are needed to further evaluate the association between AKI and hypertension. A higher-resolution version of the graphical abstract is available as Supplementary information.

Assessing nephrology competence in general paediatrics—A survey of general paediatricians, paediatric nephrologists, residents, and program directors

Objective

The objective of this study was to identify nephrology topics of lowest perceived competency and importance for general paediatricians.

Methods

Surveys were distributed to general paediatricians, paediatric residents, paediatric residency program directors, and paediatric nephrologists. Perceived importance and competence were rated on a 5-point Likert scale. Means and 95% confidence intervals were calculated.

Results

Mean perceived competency from general paediatricians across all nephrology domains was 3.0, 95%CI (2.9 to 3.1) and mean importance was 3.2, 95%CI (3.1 to 3.3). Domains scoring below the means for competence and importance, respectively were kidney stones (2.5, 95%CI [2.2 to 2.7]) and 2.6, 95%CI [2.3 to 2.8]), acute kidney injury (2.5, 95%CI [2.2 to 2.8] and 2.4, 95%CI [2.1 to 2.8]), chronic kidney disease (1.9, 95%CI [1.7 to 2.2] and 2.1, 95%CI [1.8 to 2.4]), tubular disorders (1.8, 95%CI [1.6 to 2.0] and 2.0, 95%CI [1.8 to 2.3]), and kidney transplant (1.6, 95%CI [1.4 to 1.8] and 1.7, 95%CI [1.4 to 1.9]). Residents, program directors, and paediatric nephrologists agreed that stones, chronic kidney disease, tubular disorders, and transplant were of lower importance. However, acute kidney injury was the domain with the largest discrepancy in perceived importance between residents (4.4, 95%CI [4.2 to 4.6]), nephrologists (4.2, 95%CI [3.8 to 4.6]), and program directors (4.2, 95%CI [3.7 to 4.7]) compared to general paediatricians ([2.4, 95%CI [2.1 to 2.8]; P&lt;0.05).

Conclusion

Paediatricians did not believe acute kidney injury was important to their practice, despite expert opinion and evidence of long-term consequences. Educational interventions must address deficits in crucial domains of renal health in paediatrics.

Lesión renal aguda en el paciente pediátrico: revisión integrativa

Introducción: La lesión renal aguda se ha convertido en una complicación común en los niños hospitalizados, especialmente cuando están en una situación clínica crítica. Objetivo: Conocer y sintetizar la bibliografía científica más actualizada sobre la lesión renal aguda en la población pediátrica. Metodología: Estudio descriptivo de revisión integrativa. La búsqueda de artículos se ha realizado en las bases de datos Pubmed, Scopus y Google Scholar. La estrategia de búsqueda se estableció con los siguientes términos MeSH: ”acute kidney injury”, “children” y “pediatric”. La calidad metodológica se realizó mediante la escala STROBE. Resultados: Se incluyeron 35 artículos, 19 de diseño observacional retrospectivo, 12 observacionales prospectivos, 3 revisiones bibliográficas y 1 estudio cualitativo. No hay variables sociodemográficas destacables que impliquen mayor probabilidad de presentar lesión renal aguda. Tanto la etiología como los factores de riesgo son muy variables. La lesión renal aguda se asocia a mayor número de complicaciones y estancia hospitalaria. No hay evidencia de cuidados enfermeros en la lesión renal aguda en pacientes pediátricos. Conclusiones: Se observa una falta de homogeneidad en los criterios de definición, incidencia, etiología, factores de riesgo y de tratamiento en los pacientes pediátricos con lesión renal aguda, y escasez de artículos originales de investigación. La lesión renal aguda pediátrica se asocia a mayor mortalidad, morbilidad, mayor estancia hospitalaria y mayor duración de la ventilación mecánica. El papel de enfermería en el manejo del tratamiento conservador y de las terapias de reemplazo renal de este cuadro, es fundamental en la supervivencia de estos pacientes.

Risk Factors and Consequences of Acute Kidney Injury After Noncardiac Surgery in Children

BACKGROUND

Postoperative acute kidney injury (AKI) is a serious complication that is associated with prolonged hospital stay, high risk of short-term postsurgical mortality, need for dialysis, and possible progression to chronic kidney disease. To date, very little data exist on the risk of postoperative AKI among children undergoing noncardiac surgical procedures. We used data from a large multicenter cohort to determine the factors associated with AKI among children who underwent inpatient noncardiac surgical procedures and its impact on the postoperative course.

METHODS

We utilized the National Surgical Quality Improvement Program Pediatric participant user files to identify a cohort of children who underwent inpatient surgery between 2012 and 2018 (n = 257,439). We randomly divided the study population into a derivation cohort of 193,082 (75%) and a validation cohort of 64,357 (25%), and constructed a multivariable logistic regression model to identify independent risk factors for AKI. We defined AKI as the occurrence of either acute renal failure or progressive renal insufficiency within the 30 days after surgery.

RESULTS

The overall rate of postoperative AKI was 0.10% (95% confidence interval [CI], 0.09-0.11). In a multivariable model, operating times longer than 140 minutes, preexisting hematologic disorder, and preoperative sepsis were the strongest independent predictors of AKI. Other independent risk factors for AKI were American Society of Anesthesiologists (ASA) physical status ≥III, preoperative inotropic support, gastrointestinal disease, ventilator dependency, and corticosteroid use. The 30-day mortality rate was 10.1% in children who developed AKI and 0.19% in their counterparts without AKI (P < .001). Children who developed AKI were more likely to require an extended hospital stay (≥75th percentile of the study cohort) relative to their peers without AKI (77.4% vs 21.0%; P < .001).

CONCLUSIONS

Independent preoperative risk factors for AKI in children undergoing inpatient noncardiac surgery were hematologic disorder, preoperative sepsis, ASA physical status ≥III, inotropic support, gastrointestinal disease, ventilator dependency, and steroid use. Children with AKI were 10 times more likely to die and nearly 3 times more likely to require an extended hospital stay, relative to their peers without AKI.

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.

Renal Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Renal dysfunction is associated with poor outcomes in critically ill children.

OBJECTIVE

To evaluate the current evidence for criteria defining renal dysfunction in critically ill children and association with adverse outcomes. To develop contemporary consensus criteria for renal dysfunction in critically ill children.

DATA SOURCES

PubMed and Embase were searched from January 1992 to January 2020.

STUDY SELECTION

Included studies evaluated critically ill children with renal dysfunction, performance characteristics of assessment tools for renal dysfunction, and outcomes related to mortality, functional status, or organ-specific or other patient-centered outcomes. Studies with adults or premature infants (≤36 weeks' gestational age), animal studies, reviews, case series, and studies not published in English with inability to determine eligibility criteria were excluded.

DATA EXTRACTION

Data were extracted from included studies into a standard data extraction form by task force members.

RESULTS

The systematic review supported the following criteria for renal dysfunction: (1) urine output <0.5 mL/kg per hour for ≥6 hours and serum creatinine increase of 1.5 to 1.9 times baseline or ≥0.3 mg/dL, or (2) urine output <0.5 mL/kg per hour for ≥12 hours, or (3) serum creatinine increase ≥2 times baseline, or (4) estimated glomerular filtration rate <35 mL/minute/1.73 m2, or (5) initiation of renal replacement therapy, or (6) fluid overload ≥20%. Data also support criteria for persistent renal dysfunction and for high risk of renal dysfunction.

LIMITATIONS

All included studies were observational and many were retrospective.

CONCLUSIONS

We present consensus criteria for renal dysfunction in critically ill children.

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.

Association of pediatric cardiac surgery-associated acute kidney injury with post-discharge healthcare utilization, mortality and kidney outcomes

BACKGROUND

Acute kidney Injury (AKI) in children undergoing cardiac surgery (CS) is strongly associated with hospital morbidity. Post-discharge CS AKI outcomes are less clear. We evaluated associations between AKI and post-discharge (a) healthcare utilization, (b) chronic kidney disease (CKD) or hypertension and (c) mortality.

METHODS

This is a retrospective two-centre cohort study of children surviving to hospital discharge after CS. Primary exposures were post-operative ≥Stage 1 AKI and ≥Stage 2 AKI defined by Kidney Disease Impoving Global Outcomes. Association of AKI with time to outcomes was determined using multivariable Cox-Proportional Hazards analysis.

RESULTS

Of 350 participants included (age 3.1 (4.5) years), 180 [51.4%] developed AKI and 60 [17.1%] developed ≥Stage 2 AKI. Twenty-eight (9%) participants developed CKD or hypertension (composite outcome), and 17 (5%) died within 5 years of discharge. Post-operative ≥Stage 1 and ≥Stage 2 AKI were not associated with post-discharge hospitalizations, emergency room (ER) visits, physician visits or CKD or hypertension in adjusted analyses. A trend was observed between ≥Stage 2 AKI and mortality but was not statistically significant. In unadjusted stratified analyses, AKI was associated with post-discharge hospitalizations in children with RACHS-1 score ≥3, complex chronic disease classification and children living in urban areas.

CONCLUSIONS

Post-CS AKI is not associated with post-discharge healthcare utilization, death and CKD or hypertension, though it may be associated with healthcare utilization in more complex paediatric CS children. Studies should aim to better understand post-CS healthcare utilization patterns and non-AKI risk factors for CKD, hypertension and mortality, to reduce adverse long-term outcomes after CS.

Long-Term Kidney Outcomes Following Dialysis-Treated Childhood Acute Kidney Injury: A Population-Based Cohort Study

BACKGROUND

AKI is common during pediatric hospitalizations and associated with adverse short-term outcomes. However, long-term outcomes among survivors of pediatric AKI who received dialysis remain uncertain.

METHODS

To determine the long-term risk of kidney failure (defined as receipt of chronic dialysis or kidney transplant) or death over a 22-year period for pediatric survivors of dialysis-treated AKI, we used province-wide health administrative databases to perform a retrospective cohort study of all neonates and children (aged 0-18 years) hospitalized in Ontario, Canada, from April 1, 1996, to March 31, 2017, who survived a dialysis-treated AKI episode. Each AKI survivor was matched to four hospitalized pediatric comparators without dialysis-treated AKI, on the basis of age, sex, and admission year. We reported the incidence of each outcome and performed Cox proportional hazards regression analyses, adjusting for relevant covariates.

RESULTS

We identified 1688 pediatric dialysis-treated AKI survivors (median age 5 years) and 6752 matched comparators. Among AKI survivors, 53.7% underwent mechanical ventilation and 33.6% had cardiac surgery. During a median 9.6-year follow-up, AKI survivors were at significantly increased risk of a composite outcome of kidney failure or death versus comparators. Death occurred in 113 (6.7%) AKI survivors, 44 (2.6%) developed kidney failure, 174 (12.1%) developed hypertension, 213 (13.1%) developed CKD, and 237 (14.0%) had subsequent AKI. AKI survivors had significantly higher risks of developing CKD and hypertension versus comparators. Risks were greatest in the first year after discharge and gradually decreased over time.

CONCLUSIONS

Survivors of pediatric dialysis-treated AKI are at higher long-term risks of kidney failure, death, CKD, and hypertension, compared with a matched hospitalized cohort.

Chronic kidney disease ten years after pediatric allogeneic hematopoietic stem cell transplantation

Chronic kidney disease (CKD) is an important sequela of hematopoietic stem cell transplantation (HSCT), but data regarding CKD after pediatric HSCT are limited. In this single center cohort study, we evaluated the estimated glomerular filtration rate (eGFR) dynamics, proteinuria and hypertension in the first decade after HSCT and assessed risk factors for CKD in 216 pediatric HSCT survivors, transplanted 2002-2012. The eGFR decreased from a median of 148 to 116 ml/min/1.73 m² between pre-HSCT to ten years post-HSCT. CKD (KDIGO stages G2 or A2 or more; eGFR under 90 ml/min/1.73m² and/or albuminuria) occurred in 17% of patients. In multivariate analysis, severe prolonged stage 2 or more acute kidney injury (AKI), with an eGFR under 60ml/min/1.73m² and duration of 28 days or more, was the main risk factor for CKD (hazard ratio 9.5, 95% confidence interval 3.4-27). Stage 2 or more AKI with an eGFR of 60ml/min/1.73m² or more and KDIGO stage 2 or more AKI with eGFR under 60ml/min/1.73m² but recovery within 28 days were not associated with CKD. Furthermore, hematological malignancy as HSCT indication was an independent risk factor for CKD. One third of patients had both CKD criteria, one third had isolated eGFR reduction and one third only had albuminuria. Hypertension occurred in 27% of patients with CKD compared to 4.4% of patients without. Tubular proteinuria was present in 7% of a subgroup of 71 patients with available β2-microglobulinuria. Thus, a significant proportion of pediatric HSCT recipients developed CKD within ten years. Our data stress the importance of structural long-term monitoring of eGFR, urine and blood pressure after HSCT to identify patients with incipient CKD who can benefit from nephroprotective interventions.

Baseline creatinine determination method impacts association between acute kidney injury and clinical outcomes

BACKGROUND

Current consensus definition for acute kidney injury (AKI) does not specify how baseline serum creatinine should be determined. We assessed how baseline determination impacted AKI incidence and association between AKI and clinical outcomes.

METHODS

We retrospectively applied empirical (measured serum creatinine) and imputed (age/height) baseline estimation methods to pediatric patients discharged between 2014 and 2019 from an academic hospital. Using each method, we estimated AKI incidence and assessed area under ROC curve (AUROC) for AKI as a predictor of three clinical outcomes: application of AKI billing code (proxy for more clinically overt disease), inpatient mortality, and post-hospitalization chronic kidney disease.

RESULTS

Incidence was highly variable across baseline methods (12.2-26.7%). Incidence was highest when lowest pre-admission creatinine was used if available and Schwartz bedside equation was used to impute one otherwise. AKI was more predictive of application of an AKI billing code when baseline was imputed universally, regardless of pre-admission values (AUROC 80.7-84.9%) than with any empirical approach (AUROC 64.5-76.6%). AKI was predictive of post-hospitalization CKD when using universal imputation baseline methods (AUROC 67.0-74.6%); AKI was not strongly predictive of post-hospitalization CKD when using empirical baseline methods (AUROC 46.4-58.5%). Baseline determination method did not affect the association between AKI and inpatient mortality.

CONCLUSIONS

Method of baseline determination influences AKI incidence and association between AKI and clinical outcomes, illustrating the need for standard criteria. Imputing baseline for all patients, even when preadmission creatinine is available, may identify a more clinically relevant subset of the disease.

Cumulative Application of Creatinine and Urine Output Staging Optimizes the Kidney Disease: Improving Global Outcomes Definition and Identifies Increased Mortality Risk in Hospitalized Patients With Acute Kidney Injury

OBJECTIVES

Acute kidney injury is diagnosed according to creatinine and urine output criteria. Traditionally, both are applied, and a severity stage (1-3) is conferred based upon the more severe of the two; information from the other criteria is discarded. Physiologically, however, rising creatinine and oliguria represent two distinct types of renal dysfunction. We hypothesized that using the information from both criteria would more accurately characterize acute kidney injury severity and outcomes.

DESIGN

Prospective cohort study.

SETTING

Multicenter, international collaborative of ICUs.

PATIENTS

Three thousand four hundred twenty-nine children and young adults admitted consecutively to ICUs as part of the Assessment of the Worldwide Acute Kidney Injury, Renal Angina and Epidemiology Study.

MEASUREMENTS AND MAIN RESULTS

The Kidney Disease: Improving Global Outcomes creatinine and urine output acute kidney injury criteria were applied sequentially, and the two stages were summed, generating an Acute Kidney Injury (AKI) Score ranging from 1 to 6. The primary outcome was 28-day mortality; secondary outcomes were time until ICU discharge and nonrecovery from acute kidney injury. Models considered associations with AKI Score, assessing the relationship unadjusted and adjusted for covariates. Twenty-eight-day mortality and nonrecovery from acute kidney injury were modeled using logistic regression. For 28-day ICU discharge, competing risks analysis was performed. Although AKI Scores 1-3 had similar mortality to no Acute Kidney Injury, AKI Scores 4-6 were associated with increased mortality. Relative to No Acute Kidney Injury, AKI Scores 1-6 were less likely to be discharged from the ICU within 28 days. Relative to AKI Score 1, AKI Scores 2-6 were associated with higher risk of nonrecovery. Within the traditional Kidney Disease: Improving Global Outcomes Stage 3 acute kidney injury cohort, when compared with AKI Score 3, AKI Scores 4-6 had increased mortality, AKI Scores 5-6 had prolonged time to ICU discharge, and AKI Score 6 experienced higher nonrecovery rates.

CONCLUSIONS

Cumulative application of the creatinine and urine output criteria characterizes renal excretory and fluid homeostatic dysfunction simultaneously. This Acute Kidney Injury score more comprehensively describes the outcome implications of severe acute kidney injury than traditional staging methods.

Impact of integrated clinical decision support systems in the management of pediatric acute kidney injury: a pilot study

BACKGROUND

Acute kidney injury (AKI) is common but not often recognized. Early recognition and management may improve patient outcomes.

METHODS

This is a prospective, nonrandomized study of clinical decision support (CDS) system [combining electronic alert and standardized care pathway (SCP)] to evaluate AKI detection and progression in hospitalized children. The study was done in three phases: pre-, intervention (CDS) and post. During CDS, text-page with AKI stage and link to SCP was sent to patient's contact provider at diagnosis of AKI using creatinine. The SCP provided guidelines on AKI management [AEIOU: Assess cause of AKI, Evaluate drug doses, Intake-Output charting, Optimize volume status, Urine dipstick].

RESULTS

In all, 239 episodes of AKI in 225 patients (97 females, 43.1%) were analyzed. Proportion of patients with decrease in the stage of AKI after onset was 71.4% for CDS vs. 64.4% for pre- and 55% for post-CDS phases (p = 0.3). Documentation of AKI was higher during CDS (74.3% CDS vs. 47.5% pre- and 57.5% post-, p < 0.001). Significantly greater proportion of patients had nephrotoxic medications adjusted, or fluid plan changed during CDS. Patients from CDS phase had higher eGFR at discharge and at follow-up.

CONCLUSIONS

AKI remains under-recognized. CDS (electronic alerts and SCP) improve recognition and allow early intervention. This may improve long-term outcomes, but larger studies are needed.

IMPACT

Acute kidney injury can cause significant morbidity and mortality. It is under-recognized in children. Clinical decision support can be used to leverage existing data in the electronic health record to improve AKI recognition. This study demonstrates the use of a novel, electronic health record-linked, clinical decision support tool to improve the recognition of AKI and guideline-adherent clinical care.

Serum Creatinine Monitoring After Acute Kidney Injury in the PICU

OBJECTIVES

It is unknown whether children with acute kidney injury during PICU admission have kidney function monitored after discharge. Objectives: 1) describe postdischarge serum creatinine monitoring after PICU acute kidney injury and 2) determine factors associated with postdischarge serum creatinine monitoring.

DESIGN

Secondary analysis of longitudinal cohort study data.

SETTING

Two PICUs in Montreal and Edmonton, Canada.

PATIENTS

Children (0-18 yr old) surviving PICU admission greater than or equal to 2 days from 2005 to 2011. Exclusions: postcardiac surgery and prior kidney disease. Exposure: acute kidney injury by Kidney Disease: Improving Global Outcomes serum creatinine definition.

INTERVENTIONS

None.

MEASUREMENTS

Primary outcome: postdischarge serum creatinine measured by 90 days, 1 year, and 5-7 years.

SECONDARY OUTCOMES

Healthcare events and nephrology follow-up.

ANALYSIS

Proportions with outcomes; logistic regression to evaluate factors associated with the primary outcome. Kaplan-Meier analysis of time to serum creatinine measurement and healthcare events.

MAIN RESULTS

Of n = 277, 69 (25%) had acute kidney injury; 29/69 (42%), 34/69 (49%), and 51/69 (74%) had serum creatinine measured by 90 days, 1 year, and 5-7 year postdischarge, respectively. Acute kidney injury survivors were more likely to have serum creatinine measured versus nonacute kidney injury survivors at all time points (p ≤ 0.01). Factors associated with 90-day serum creatinine measurement were inpatient nephrology consultation (unadjusted odds ratio [95% CI], 14.9 [1.7-127.0]), stage 2-3 acute kidney injury (adjusted odds ratio, 3.4 [1.1-10.2]), and oncologic admission diagnosis (adjusted odds ratio, 10.0 [1.1-93.5]). A higher proportion of acute kidney injury versus nonacute kidney injury survivors were readmitted by 90 days (25 [36%] vs 44 [21%]; p = 0.01) and 1 year (33 [38%] vs 70 [34%]; p = 0.04). Of 24 acute kidney injury survivors diagnosed with chronic kidney disease or hypertension at 5-7 year follow-up, 16 (67%) had serum creatinine measurement and three (13%) had nephrology follow-up postdischarge.

CONCLUSIONS

Half of PICU acute kidney injury survivors have serum creatinine measured within 1-year postdischarge and follow-up is suboptimal for children developing long-term kidney sequelae. Knowledge translation strategies should emphasize the importance of serum creatinine monitoring after childhood acute kidney injury.

Analysis of intraoperative modifiable factors to prevent acute kidney injury after elective noncardiac surgery: intraoperative hypotension and crystalloid administration related to acute kidney injury

Background

The optimal intraoperative blood pressure range and crystalloid administration protocol for the prevention of acute kidney injury (AKI) after elective noncardiac surgery remain unknown.

Methods

This single-center retrospective cohort study included 6296 patients aged ≥ 50 years who had undergone elective noncardiac surgery under general anesthesia. We evaluated the relationship between duration of intraoperative hypotension and AKI. To assess whether the effects of crystalloid administration differed according to baseline estimated glomerular filtration rate (eGFR), we examined the interaction between intraoperative crystalloid administration and eGFR. We calculated univariable and multivariable adjusted odds ratios (ORs) and their 95% confidence intervals (95% CIs) for the prevalence of AKI.

Results

AKI occurred in 431 (6.8%) patients and was associated with intraoperative hypotension. Effects of intraoperative crystalloid administration differed significantly according to baseline eGFR. Increased risk of AKI was noted in patients with eGFR ≤45 ml min⁻¹ 1.73m⁻² who were managed with restrictive or liberal crystalloid administration [OR 4.79 (95% CI 3.10 to 7.32) and 6.43 (95% CI 2.23 to 16.03), respectively] as opposed to those with eGFR >45 ml min⁻¹ 1.73m⁻² who were managed with moderately restrictive crystalloid administration.

Conclusions

Our findings suggest that anesthesiologists should avoid intraoperative hypotension as well as either restrictive or liberal (as opposed to moderately restrictive) crystalloid administration in patients with decreased eGFR. Intraoperative blood pressure and crystalloid administration protocol are major modifiable factors that must be optimized to prevent postoperative AKI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40981-021-00429-9.

Acute Kidney Injury in Critically Ill Children Is Not all Acute: Lessons Over the Last 5 Years

Acute kidney injury (AKI) in the pediatric intensive care unit (PICU) is an important risk factor for increased morbidity and mortality during hospitalization. Over the past decade, accumulated data on children and young people indicates that acute episodes of kidney dysfunction can have lasting consequences on multiple organ systems and health outcomes. To date, there are no guidelines for follow-up of surviving children that may be at risk of long-term sequelae following AKI in the PICU. This narrative review aims to describe literature from the last 5 years on the risk of medium and long-term kidney and non-kidney outcomes after AKI in the PICU. More specifically, we will focus on outcomes in children and young people following AKI in the general PICU population and children undergoing cardiac surgery. These outcomes include mortality, hypertension, proteinuria, chronic kidney disease, and healthcare utilization. We also aim to highlight current gaps in knowledge in medium and long-term outcomes in this pediatric population. We suggest a framework for future research to develop evidence-based guidelines for follow-up of children surviving an episode of critical illness and AKI.

A Review on the Application and Limitations of Administrative Health Care Data for the Study of Acute Kidney Injury Epidemiology and Outcomes in Children

Administrative health care databases contain valuable patient information generated by health care encounters. These "big data" repositories have been increasingly used in epidemiological health research internationally in recent years as they are easily accessible and cost-efficient and cover large populations for long periods. Despite these beneficial characteristics, it is also important to consider the limitations that administrative health research presents, such as issues related to data incompleteness and the limited sensitivity of the variables. These barriers potentially lead to unwanted biases and pose threats to the validity of the research being conducted. In this review, we discuss the effectiveness of health administrative data in understanding the epidemiology of and outcomes after acute kidney injury (AKI) among adults and children. In addition, we describe various validation studies of AKI diagnostic or procedural codes among adults and children. These studies reveal challenges of AKI research using administrative data and the lack of this type of research in children and other subpopulations. Additional pediatric-specific validation studies of administrative health data are needed to promote higher volume and increased validity of this type of research in pediatric AKI, to elucidate the large-scale epidemiology and patient and health systems impacts of AKI in children, and to devise and monitor programs to improve clinical outcomes and process of care.

Role of Hemoperfusion With CytoSorb Associated With Continuous Kidney Replacement Therapy on Renal Outcome in Critically III Children With Septic Shock

Introduction: Sepsis-associated acute kidney injury (SA-AKI) represents a relevant cause of mortality and morbidity in critically ill children. Since with the "inflammatory theory" the authors have been witnessed an important role of inflammatory mediators in the pathophysiology and in the prognosis of SA-AKI, making the need of adjunctive therapies in association with kidney replacement therapies mandatory. Hemoperfusion with CytoSorb is a safe and well-tolerated therapy in septic shock: the very high surface area of the absorber means it is able to efficiently remove cytokines and other medium size molecules involved in cytokine storm, thus playing a synergistic effect with Continuous Kidney Replacement Therapy (CKRT). Materials and Methods: We retrospectively analyzed data from a cohort of eight critically ill children treated from January 2018 to March 2020 describing the impact of CKRT plus hemoperfusion with CytoSorb on renal outcome in critically ill children with septic shock. Results: We evidenced a significant reduction in interleukin (IL)-6 an IL-10 after hemoperfusion with CytoSorb in our pediatric population. Furthermore, we were able to show a significant improvement of creatinine and blood urea nitrogen (BUN) after blood purification and at pediatric intensive care units (PICU) discharge. We have observed a median of 2.5 CKRT days after stop of hemoperfusion (Q₁ 0.25; Q₃ 18.75). None of our patients required CKRT 30 days after PICU discharge (PICU-D). None of them developed CKD. Conclusion: Hemoperfusion with CytoSorb is a valuable therapeutic option in combination with CKRT in SA-AKI. More studies are warranted to confirm our results and in particular to define the role of this adjuvant therapy as a preemptive strategy to protect renal function in pediatric septic shock.

Acute kidney injury in children with chronic kidney disease is associated with faster decline in kidney function

BACKGROUND

This study aimed to investigate the association of acute kidney injury (AKI) with change in estimated glomerular filtration rate (eGFR) in children with advanced chronic kidney disease (CKD).

METHODS

Single centre, retrospective longitudinal study including all prevalent children aged 1-18 years with nondialysis CKD stages 3-5. Variables associated with CKD were analysed for their potential effect on annualised eGFR change (ΔGFR/year) following multiple regression analysis. Composite end-point including 25% reduction in eGFR or progression to kidney replacement therapy was evaluated.

RESULTS

Of 147 children, 116 had at least 1-year follow-up in a dedicated CKD clinic with mean age 7.3 ± 4.9 years with 91 (78.4%) and 77 (66.4%) with 2- and 3-year follow-up respectively. Mean eGFR at baseline was 29.8 ± 11.9 ml/min/1.73 m² with 79 (68%) boys and 82 (71%) with congenital abnormalities of kidneys and urinary tract (CAKUT). Thirty-nine (33.6%) had at least one episode of AKI. Mean ΔGFR/year for all patients was - 1.08 ± 5.64 ml/min/1.73 m² but reduced significantly from 2.03 ± 5.82 to - 3.99 ± 5.78 ml/min/1.73 m² from youngest to oldest age tertiles (P < 0.001). There was a significant difference in primary kidney disease (PKD) (77% versus 59%, with CAKUT, P = 0.048) but no difference in AKI incidence (37% versus 31%, P = 0.85) between age tertiles. Multiple regression analysis identified age (β = - 0.53, P < 0.001) and AKI (β = - 3.2, P = 0.001) as independent predictors of ΔGFR/year. 48.7% versus 22.1% with and without AKI reached composite end-point (P = 0.01).

CONCLUSIONS

We report AKI in established CKD as a predictor of accelerated kidney disease progression and highlight this as an additional modifiable risk factor to reduce progression of kidney dysfunction. Graphical abstract.

Clinical phenotypes of acute kidney injury are associated with unique outcomes in critically ill septic children

BACKGROUND

Assessment of acute kidney injury (AKI) in septic patients remains imprecise. In adults, the classification of septic patients by clinical AKI phenotypes (severity and timing) demonstrates unique associations with patient outcome vs. broadly defined AKI.

METHODS

In a multinational prospective observational study, AKI diagnosis in critically ill septic children was stratified by duration (transient vs. persistent) and severity (mild vs. severe by creatinine change and urine output). The outcomes of interest were mortality and intensive care unit resource complexity at 28 days.

RESULTS

Seven hundred and fifty-seven septic children were studied (male 52.7%, age 4.6 years (1.5-11.9)). Mortality (overall 12.1%) was different between severe AKI and mild AKI (18.3 vs. 4.4%, p < 0.001) as well as intensive care unit (ICU) complexity (overall 34.5%, 45 vs. 21.7%, p < 0.001). Patients with Persistent AKI had fewer ICU-free days (17 (7, 21) vs. 24 (17, 26), p < 0.001) and higher ICU complexity (52.8 vs. 22.9%, p = 0.002) than transient AKI, even after exclusion of patients with early mortality. AKI phenotypes incorporating temporal and severity data correlate with unique survival (range 4.4-21.6%) and ICU-free days (range of 15-25 days) CONCLUSIONS: The outcome of septic children with AKI changes by clinical phenotype. Our findings underscore the importance of prognostic enrichment in sepsis and AKI for the purpose of trial design and patient management.

IMPACT

Although AKI occurs commonly in patients with sepsis (S-AKI), outcomes for children with S-AKI varies based on the severity and timing of the AKI. Existing S-AKI pediatric data utilize a broad singular definition of kidney injury. Increasing the precision of AKI classification results in a new understanding of how S-AKI associates with patient outcome. A refined classification of S-AKI identifies subgroups of children, making possible a targeted and a personalized medicine approach to S-AKI study and management.

The association of acute kidney injury with hospital readmission and death after pediatric cardiac surgery

Background

Acute kidney injury (AKI) in children undergoing cardiac surgery (CS) is strongly associated with increased hospital mortality and length of stay. The association of AKI with postdischarge outcomes is unclear. We evaluated the association of AKI with all-cause readmissions and death within 30 days and 1 year of CS discharge.

Methods

This was a prospective, 3-center cohort study of children after CS with cardiopulmonary bypass. The primary exposures were postoperative ≥stage 1 AKI and ≥stage 2 AKI defined by Kidney Disease: Improving Global Outcomes AKI definition. Two separate outcomes were hospital readmission and death within 30 days and 1 year of discharge. Association of AKI with time to outcomes was determined using multivariable Cox-proportional hazards analysis. Age, The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery risk adjustment tool score ≥3, cardiopulmonary bypass >120 minutes, and cyanotic heart disease were evaluated as effect modifiers.

Results

Of 402 participants included (median age 1.8 years [interquartile range 0.4, 5.2]), 32 (8.0%) and 109 (27.1%) were readmitted; 7 (1.7%) and 9 (2.2%) died within 30 days and 1 year of CS, respectively. AKI was not associated with readmission at 30 days or 1 year postdischarge. ≥Stage 2 AKI (adjusted hazard ratio, 11.68 [1.88, 72.61]) was associated with mortality 30 days post-CS.

Conclusions

Postoperative AKI was not associated with readmission at 30 days and 1-year postdischarge. However, more severe AKI (≥stage 2) appears to be associated with increased morality risk at 30 days post-CS.

Long-term complications of acute kidney injury in children

PURPOSE OF REVIEW

The current review will describe the current evidence and mechanisms of acute kidney injury (AKI) as a risk factor for long-term kidney complications, summarize the rationale for AKI follow-up and present an approach to monitoring children with AKI. Despite emerging evidence linking AKI with risk for long-term kidney and cardiovascular outcomes, many children who develop AKI are not followed for kidney disease development after hospital discharge. Better understanding of long-term complications after AKI and practical algorithms for follow-up will hopefully increase the rate and quality of post-AKI monitoring.

RECENT FINDINGS

Recent evidence shows that pediatric AKI is associated with long-term renal outcomes such as chronic kidney disease (CKD) and hypertension, both known to increase cardiovascular risk. The mechanism of AKI progression to CKD involves maladaptive regeneration of tubular epithelial and endothelial cells, inflammation, fibrosis and glomerulosclerosis. Many AKI survivors are not followed, and no guidelines for pediatric AKI follow-up have been published.

SUMMARY

Children who had AKI are at increased risk of long-term renal complications but many of them are not monitored for these complications. Recognizing long-term outcomes post-AKI and integration of follow-up programs may have a long-lasting positive impact on patient health.

Acute kidney injury in critically ill children and 5-year hypertension

BACKGROUND

To develop a pediatric-specific hypertension algorithm using administrative data and use it to evaluate the association between acute kidney injury (AKI) in the intensive care unit (ICU) and hypertension diagnosis 5 years post-discharge.

METHODS

Two-center retrospective cohort study of children (≤ 18 years old) admitted to the pediatric ICU in Montreal, Canada, between 2003 and 2005 and followed until 2010. Patients with a valid healthcare number and without end-stage renal disease were included. Patients who could not be merged with the provincial database, did not survive admission, underwent cardiac surgery, had pre-existing renal disease associated with hypertension or a prior diagnosis of hypertension were excluded. AKI defined using the Kidney Disease: Improving Global Outcomes (KDIGO) definition. Using diagnostic codes and medications from administrative data, novel pediatric-specific hypertension definitions were designed. Both the evaluation of the prevalence of hypertension diagnosis and the association between AKI and hypertension occurred.

RESULTS

Nineteen hundred and seventy eight patients were included (median age at admission [interquartile range] 4.3 years [1.1-11.8], 44% female, 325 (16.4%) developed AKI). Of these patients, 130 (7%) had a hypertension diagnosis 5 years after discharge. Patients with AKI had a higher prevalence of hypertension diagnosis [non-AKI: 84/1653 (5.1%) vs. AKI: 46/325 (14.2%), p < .001]. Children with AKI had a higher adjusted risk of hypertension diagnosis (hazard ratio [95% confidence interval] 2.19 [1.47-3.26]).

CONCLUSIONS

Children admitted to the ICU have a high prevalence of hypertension post-discharge and children with AKI have over two times higher risk of hypertension compared to those with no AKI.