Impact of the Magnitude and Timing of Fluid Overload on Outcomes in Critically Ill Children: A Report From the Multicenter International Assessment of Worldwide Acute Kidney Injury, Renal Angina, and Epidemiology (AWARE) Study.

OBJECTIVES: With the recognition that fluid overload (FO) has a detrimental impact on critically ill children, the critical care nephrology community has focused on identifying clinically meaningful targets for intervention. The current study aims to evaluate the epidemiology and outcomes associated with FO in an international multicenter cohort of critically ill children. The current study also aims to evaluate the association of FO at predetermined clinically relevant thresholds and time points (FO ≥ 5% and FO ≥ 10% at the end of ICU days 1 and 2) with outcomes. DESIGN: Prospective cohort study. SETTING: Multicenter, international collaborative of 32 pediatric ICUs. PATIENTS: A total of 5,079 children and young adults admitted consecutively to pediatric ICUs as part of the Assessment of the Worldwide Acute Kidney Injury, Renal Angina and Epidemiology Study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The FO thresholds at the time points of interest occurred commonly in the cohort (FO ≥ 5%Day1 in 38.1% [ n = 1753], FO ≥ 10%Day1 in 11.7% [ n = 537], FO ≥ 5%Day2 in 53.3% [ n = 1,539], FO ≥ 10%Day2 in 25.1% [ n = 724]). On Day1, multivariable modeling demonstrated that FO ≥ 5% was associated with fewer ICU-free days, and FO ≥ 10% was associated with higher mortality and fewer ICU and ventilator-free days. On multivariable modeling, FO-peak, Day2 FO ≥ 5%, and Day2 FO ≥ 10% were associated with higher mortality and fewer ICU and ventilator-free days. CONCLUSIONS: This study found that mild-to-moderate FO as early as at the end of ICU Day1 is associated with adverse outcomes. The current study fills an important void in the literature by identifying critical combinations of FO timing and quantity associated with adverse outcomes (FO ≥ 5%Day1, FO ≥10%Day1, FO ≥ 5%Day2, and FO ≥ 10%Day2). Those novel findings will help guide the development of interventional strategies and trials targeting the treatment and prevention of clinically relevant FO.

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.

Acute kidney injury during cisplatin therapy and associations with kidney outcomes 2 to 6 months post-cisplatin in children: a multi-centre, prospective observational study.

BACKGROUND: Few studies describe acute kidney injury (AKI) burden during paediatric cisplatin therapy and post-cisplatin kidney outcomes. We determined risk factors for and rate of (1) AKI during cisplatin therapy, (2) chronic kidney disease (CKD) and hypertension 2-6 months post-cisplatin, and (3) whether AKI is associated with 2-6-month outcomes. METHODS: This prospective cohort study enrolled children (aged < 18 years at cancer diagnosis) treated with cisplatin from twelve Canadian hospitals. AKI during cisplatin therapy (primary exposure) was defined based on Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria (≥ stage one). Severe electrolyte abnormalities (secondary exposure) included ≥ grade three hypophosphatemia, hypokalemia, or hypomagnesemia (National Cancer Institute Common Terminology Criteria for Adverse Events v4.0). CKD was albuminuria or decreased kidney function for age (KDIGO guidelines). Hypertension was defined based on the 2017 American Academy of Pediatrics guidelines. RESULTS: Of 159 children (median [interquartile range [IQR]] age: 6 [2-12] years), 73/159 (46%) participants developed AKI and 55/159 (35%) experienced severe electrolyte abnormalities during cisplatin therapy. At median [IQR] 90 [76-110] days post-cisplatin, 53/119 (45%) had CKD and 18/128 (14%) developed hypertension. In multivariable analyses, AKI was not associated with 2-6-month CKD or hypertension. Severe electrolyte abnormalities during cisplatin were associated with having 2-6-month CKD or hypertension (adjusted odds ratio (AdjOR) [95% CI]: 2.65 [1.04-6.74]). Having both AKI and severe electrolyte abnormalities was associated with 2-6-month hypertension (AdjOR [95% CI]: 3.64 [1.05-12.62]). CONCLUSIONS: Severe electrolyte abnormalities were associated with kidney outcomes. Cisplatin dose optimization to reduce toxicity and clear post-cisplatin kidney follow-up guidelines are needed. A higher resolution version of the Graphical abstract is available as Supplementary information.

Albuminuria screening in children with type 1 diabetes prior to and during the COVID-19 pandemic.

BACKGROUND: Albuminuria is an important risk factor for adverse renal and cardiovascular outcomes in type 1 diabetes (T1D). We sought to describe: (1) adherence to albuminuria screening prior to and during the COVID-19 pandemic and (2) occurrence of abnormal urine albumin-creatinine ratio (ACR) tests in children with T1D. METHODS: This cohort study involved children aged 18 years or younger with T1D followed in the diabetes clinic at a pediatric tertiary center. Data was collected from 2016 to 2020. Adherence was defined by Diabetes Canada (DC) Guidelines for T1D in Children and Adolescents (2018). RESULTS: Of the 165 children who met DC criteria for screening; 88 (32%) were male and the median age at diagnosis was 5.8 years. Twenty-eight (17%) children had not completed a single ACR test, and 30 (18%) completed all eligible ACR tests. Test completion decreased from 66% in 2019 to 45% in 2020. Of the 345 ACR tests completed, 40 (11%) were abnormal (>2.5 mg/mmol) and 29 abnormal ACR tests (72%) were not repeated. CONCLUSION: Adherence to albuminuria screening in this pediatric diabetes clinic is suboptimal with deterioration during the COVID-19 pandemic. Patient/physician and program-level strategies to improve adherence will play an important role in quality improvement. IMPACT: Albuminuria screening is an important part of pediatric diabetes care. In our study, pediatric albuminuria screening adherence was suboptimal at 66% in 2019 and deteriorated during the pandemic to 45% in 2020. Program and patient-level adherence to clinical guidelines and barriers to accessing diabetes care during the pandemic merit further study.

Wide variation in glucocorticoid dosing in paediatric ANCA-associated vasculitis with renal disease: a paediatric vasculitis initiative study.

OBJECTIVES: High-dose glucocorticoids for remission-induction of ANCA-associated vasculitis are recommended and commonly used in adults, but recent studies suggest lower glucocorticoid doses can reduce toxicity without reducing efficacy. No paediatric-specific data exists to inform optimal glucocorticoid dosing in paediatric ANCA-associated vasculitis (pAAV). Our objectives were to describe glucocorticoid use in pAAV-related renal disease, and to explore associations between glucocorticoid dose, baseline patient characteristics and 12-month outcomes. METHODS: Youth <18 years with pAAV, biopsy-confirmed pauci-immune glomerulonephritis and 12-month follow-up data were included from an international paediatric vasculitis registry. Presenting features and 12-month outcomes (eGFR, glucocorticoid-related adverse effects), were compared between patients receiving no, low-moderate (≤90mg/kg) and high (>90mg/kg) cumulative intravenous methylprednisolone (IVMP), and low (<0.5mg/kg/day prednisone equivalent), moderate (0.5-1.5mg/kg/day) and high (>1.5mg/kg/day) starting doses of oral glucocorticoids. RESULTS: Among 131 patients (101 granulomatosis with polyangiitis, 30 microscopic polyangiitis), 27 (21%) received no IVMP, 64 (49%) low-moderate and 29 (22%) high-dose IVMP, while 9 (7%) received low, 75 (57%) moderate and 47 (36%) high initial doses of oral glucocorticoids. Renal failure at diagnosis (p=0.022) and plasmapheresis use (p=0.0001) were associated with high-dose IVMP. Rates of glucocorticoid-related adverse effects ranged from 15-31% across dose levels, and glucocorticoid dosing did not associate with 12-month outcomes. CONCLUSIONS: Glucocorticoid dosing for pAAV-related renal disease was highly variable, and rates of adverse effects were high across all dosing groups. A significant proportion of patients received oral glucocorticoid or IVMP doses that were discordant with current adult guidelines. Higher glucocorticoid doses did not associate with improved outcomes.

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.

Germline De Novo Mutations in ATP1A1 Cause Renal Hypomagnesemia, Refractory Seizures, and Intellectual Disability.

Over the last decades, a growing spectrum of monogenic disorders of human magnesium homeostasis has been clinically characterized, and genetic studies in affected individuals have identified important molecular components of cellular and epithelial magnesium transport. Here, we describe three infants who are from non-consanguineous families and who presented with a disease phenotype consisting of generalized seizures in infancy, severe hypomagnesemia, and renal magnesium wasting. Seizures persisted despite magnesium supplementation and were associated with significant intellectual disability. Whole-exome sequencing and conventional Sanger sequencing identified heterozygous de novo mutations in the catalytic Na+, K+-ATPase α1 subunit (ATP1A1). Functional characterization of mutant Na+, K+-ATPase α1 subunits in heterologous expression systems revealed not only a loss of Na+, K+-ATPase function but also abnormal cation permeabilities, which led to membrane depolarization and possibly aggravated the effect of the loss of physiological pump activity. These findings underline the indispensable role of the α1 isoform of the Na+, K+-ATPase for renal-tubular magnesium handling and cellular ion homeostasis, as well as maintenance of physiologic neuronal activity.

Fluid overload and acute kidney injury in children with tumor lysis syndrome.

AIM: Tumor lysis syndrome (TLS) is a common oncologic emergency among patients with pediatric hematologic malignancies. The mainstay of TLS management is aggressive intravenous hydration. However, the epidemiology of fluid overload (FO) and acute kidney injury (AKI) in this population is understudied. In this study, we aimed to describe the incidence, severity, and complications of FO and AKI among pediatric patients with TLS. METHODS: We completed a single-center retrospective cohort study of pediatric patients with a new diagnosis of hematologic malignancy over a 10-year period. Patients with TLS were analyzed in two groups based on the severity of AKI and FO. Charts were reviewed for complications associated with AKI and FO including hypoxemia, mechanical ventilation, hyponatremia, pulmonary edema, pediatric intensive care (PICU) admission, and need for renal replacement therapy (RRT). RESULTS: We analyzed 56 patients with TLS for FO and AKI. We found severe FO (≥10%) occurred in 35.7% (n = 20). PICU admission occurred in 35% of patients with severe FO compared to 8.3% in those with mild/moderate FO <10% (p = .013). Complications of hypoxemia (30% vs. 5.6%, p = .012) and pulmonary edema (25% vs. 2.8%, p = .010) were more common among those with severe FO. AKI occurred in 37.5% (n = 21) patients and resulted in a significant increase in PICU admission and requirement for RRT (p = .001 and <.001, respectively). CONCLUSION: Our results show FO and AKI are common, and often unrecognized complications of TLS associated with increased morbidity. Prospective, multicenter studies are needed to further dissect the burden of FO and AKI within this vulnerable population.

Dietary intakes of children with nephrotic syndrome.

BACKGROUND: Our multidisciplinary clinical pathway for treatment of childhood nephrotic syndrome (NS) was established with the goal of standardizing local clinical practice. This descriptive study aimed to assess nutrient intakes of children with newly diagnosed NS compared with nutrition goals defined by our pathway. METHODS: Our pathway includes evidence-based recommendations that target daily intakes during corticosteroid induction therapy: energy (Estimated Energy Requirements (EER) × Sedentary Physical Activity (PA)), sodium (1 mg/kcal), calcium (Dietary Reference Intake (DRI) + 500 mg elemental calcium), and vitamin D (DRI +800-1000 IU). After dietitian-led education at initial diagnosis, 3-day food records were completed at 4 weeks post-diagnosis. Daily nutrient intakes were compared to pathway targets and DRIs. RESULTS: Thirty-six children (median age 4.8 years, 44% female) with newly diagnosed NS submitted food records. Mean energy and sodium intakes were 103±22% and 99±53% of pathway targets, respectively. Fourteen (39%) children exceeded pathway sodium recommendations, with four (11%) exceeding them by greater than 50%. Seven (19%) children met DRI for calcium, while six (17 %) met pathway targets for calcium. No children met DRI for vitamin D from diet alone; and only one met the target with supplementation. CONCLUSIONS: This is the first study to describe dietary intakes of children with newly diagnosed NS. Our clinical pathway targets for energy and sodium were achievable; however, calcium and vitamin D intakes fell short of pathway guidelines and DRIs. Prescription of supplemental calcium and vitamin D may be needed to achieve target intakes of calcium and vitamin D.

Quantifying Proximal Collecting Tubule Deficiency in Angiotensin-Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker Fetopathy.

INTRODUCTION: Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers (AAs) are used for several indications, with cessation recommended in pregnancy due to toxic effects. AA fetopathy phenotype is similar to renal tubular dysgenesis including reduced proximal convoluted tubules (PCTs). Our study aimed to quantify the reduction of PCTs in fetuses and infants with prenatal exposure to AAs. MATERIALS AND METHODS: We identified 5 fetal AA exposure cases that underwent autopsy at our institution between 2011 and 2018 and compared with 5 gestational age-matched controls. Immunohistochemistry with CD10 and epithelial membrane antigen (EMA) was utilized. RESULTS: CD10 and EMA identified a median PCT density of 19.0% ± 12.3% in AA fetopathy patients, significantly less than controls (52.8% ± 4.4%; p < 0.0001). One case with in utero cessation had a PCT density of 34.2% ± 0.2%. Among other AA fetopathy findings, 1 case demonstrated unilateral renal vein thrombosis and 4 had hypocalvaria. CONCLUSIONS: We have quantified the reduction in AA fetopathy PCT density, and demonstrated in utero cessation may recover PCT differentiation. Future studies may benefit from calculating PCT percentage as a potential biomarker to correlate with post-natal renal function and maternal factors including medication type, dosage, duration, and time from medication cessation.

The impact of fluid balance on outcomes in premature neonates: a report from the AWAKEN study group.

BACKGROUND: We evaluated the epidemiology of fluid balance (FB) over the first postnatal week and its impact on outcomes in a multi-center cohort of premature neonates from the AWAKEN study. METHODS: Retrospective analysis of infants <36 weeks' gestational age from the AWAKEN study (N = 1007). FB was defined by percentage of change from birth weight. OUTCOME: Mechanical ventilation (MV) at postnatal day 7. RESULTS: One hundred and forty-nine (14.8%) were on MV at postnatal day 7. The median peak FB was 0% (IQR: -2.9, 2) and occurred on postnatal day 2 (IQR: 1,5). Multivariable models showed that the peak FB (aOR 1.14, 95% CI 1.10-1.19), lowest FB in first postnatal week (aOR 1.12, 95% CI 1.07-1.16), and FB on postnatal day 7 (aOR 1.10, 95% CI 1.06-1.13) were independently associated with MV on postnatal day 7. In a similar analysis, a negative FB at postnatal day 7 protected against the need for MV at postnatal day 7 (aOR 0.21, 95% CI 0.12-0.35). CONCLUSIONS: Positive peak FB during the first postnatal week and more positive FB on postnatal day 7 were independently associated with MV at postnatal day 7. Those with a negative FB at postnatal day 7 were less likely to require MV.

Stable renal function in children and adolescents with sickle cell disease after nonmyeloablative hematopoietic stem cell transplantation.

BACKGROUND: Sickle cell disease (SCD) is associated with renal complications starting as early as infancy. Allogeneic hematopoietic stem cell transplant (HSCT) treatments using newer nonmyeloablative (NMA) conditioning regimens show promising results in treating SCD in the pediatric population, but renal outcome parameters after transplantation have not been described. AIM: To describe baseline renal parameters as well as short- and long-term renal outcomes in pediatric patients with SCD who underwent NMA-HSCT. METHODS: A retrospective chart review of pediatric patients who received NMA-HSCT in Alberta, Canada. Short-term renal outcomes evaluated were: (1) acute kidney injury (AKI), (2) fluid overload (FO), and (3) hypertension. Long-term outcomes evaluated were: (1) estimated glomerular filtration rate (eGFR) development and at last follow-up with hyperfiltration defined as eGFR ≥ 150 mL/min/1.73 m2 , (2) proteinuria, and (3) hypertension. RESULTS: The mean follow-up time was 128.6 weeks (standard deviations, 69.3). No posttransplant AKI events or FO were observed. eGFR remained > 90 mL/min/1.73 m2 at last follow-up in all patients, whereas hyperfiltration was present in eight (44.4%) and four (22.2%) patients pre- and post-HSCT, respectively, which are significantly different (P < 0.0001). Consequently, median GFR was significantly higher pre-HSCT compared with 24 months HSCT (P < 0.009). Long-term hypertension post-HSCT was present in six patients (33.3%). CONCLUSION: This study describes stable kidney function in children with SCD after NMA-HSCT without evidence of AKI or FO episodes. Rates of hyperfiltration decreased post-HSCT, which signifies that NMA-HSCT could potentially preserve long-term renal function in this population at risk of progressive chronic kidney disease. Further prospective studies are needed to confirm these novel findings.

Henoch-Schönlein purpura in children: Use of corticosteroids for prevention and treatment of renal disease.

QUESTION: A few patients have previously presented to my clinic with palpable purpura, joint inflammation, and severe abdominal pain characteristic of Henoch-Schönlein purpura (HSP). Considering that renal injury is the primary long-term complication of HSP, are corticosteroids effective in preventing or treating renal disease in children with HSP? ANSWER: Henoch-Schönlein purpura is self-limiting in 94% of children, but permanent renal injury is reported in one-fifth of children with nephritic or nephrotic features. Corticosteroids have been considered as candidates for preventing and treating renal involvement in HSP. There is a moderate level of evidence to suggest corticosteroids are not effective in preventing renal involvement in HSP. However, based on low-level evidence and similarities with primary immunoglobulin A nephropathy, experts recommend corticosteroids in treating renal involvement in HSP to prevent long-term kidney injury. Dose and duration of therapy should be carefully considered in consultation with a pediatric nephrologist.

The Canadian childhood nephrotic syndrome (CHILDNEPH) study: report on mid-study feasibility, recruitment and main measures.

BACKGROUND: To assess reasons for continuing practice variation in the management of childhood nephrotic syndrome despite expert reviews and guidelines, we are conducting a longitudinal cohort study in children with glucocorticoid sensitive nephrotic syndrome. Objectives of this mid-study report are to describe patient and physician recruitment characteristics, glucocorticoid prescriptions, use of second line agents, biopsy practices, and adherence to study protocol. METHODS: Children with new onset nephrotic syndrome and providers are being recruited from all 12 pediatric nephrology centres across Canada with > 2½ years follow-up. Data collection points of observation are over a minimum 36 months. Details of prescribed glucocorticoids and of all second line agents used during treatment are being collected. All relapses are being recorded with time to urinary remission of proteinuria. RESULTS: To date, 243 patients (57.1% male) from 12 centres were included. Median number of patients per centre was 29 (range 2-45), and median age of cohort was 7.3 (IQR 4.2) at enrollment. Forty-eight physicians were recruited, median 5 (range 2-8) per site. Median number of relapses per patient year of follow-up was 2.1 (IQR 4). Cumulative dose variability of glucocorticoids prescribed per episode of proteinuria and length of treatment was observed between participating centres. CONCLUSION: The Canadian pediatric nephrology community established a longitudinal childhood nephrotic syndrome cohort study that confirms ongoing practice variability. The study will help to evaluate its impact on patient outcomes, and facilitate clinical trial implementation in nephrotic syndrome.

Delays in diagnosis of nephrotic syndrome in children: A survey study.

BACKGROUND: Clinical experience suggests that childhood nephrotic syndrome is frequently diagnosed incorrectly, leading to delays in providing effective treatment. We hypothesized that the health care setting is an important determinant of diagnostic success, with implications for the patient and family health care experience. Our objectives were: (1) to characterize the relationship between diagnostic success and health care setting for the diagnosis of nephrotic syndrome, (2) to determine types and frequencies of incorrect diagnoses, and (3) to understand the burden placed on patients and families as a result of incorrect and incomplete diagnoses. METHODS: A survey was conducted by phone or in-person with legal guardians of children 1 to 18 years diagnosed with nephrotic syndrome within 24 months before the study. The survey elicited information on type of health care setting utilized (e.g., family practice, emergency room) and on diagnoses and treatments. RESULTS: Seventy-four patients with varying ethnicities and socioeconomic profiles (37 male, 37 female, median age 4.8 years, range: 1.2 to 14.8) were included from four Canadian paediatric nephrology centres. Proportions of diagnostic success were high in emergency and paediatric care settings (66% and 64% correct, respectively), but low in primary care settings (17% family practice and 17% walk-in clinic, respectively). Diagnostic delays ranged from 0 to 428 days (median 9.5, interquartile range [IQR] = 20.5). "Allergies" was the most common incorrect diagnosis (47%). Parents and legal guardians reported missed work (55%) and added expenses (50%) prior to obtaining a correct diagnosis. CONCLUSIONS: Childhood nephrotic syndrome is often incorrectly diagnosed, especially in primary care settings.

High incidence of acute kidney injury during chemotherapy for childhood acute myeloid leukemia.

BACKGROUND/OBJECTIVES: Childhood acute myeloid leukemia (AML) is a rare and heterogeneous disease. Pediatric data on the epidemiology of acute kidney injury (AKI) in AML are limited. We report on the incidence of AKI in childhood AML and the risk factors associated with AKI episodes. METHODS: A retrospective cohort of 53 patients (≤18 years), with de novo AML, receiving chemotherapy over a 10-year period. All serum creatinine (SCr) levels during therapy-related hospitalizations were assessed to stage AKI episodes as per Kidney Disease: Improving Global Outcomes criteria. Severe AKI was defined as AKI stages 2 or 3 and urine output criteria were not used. AKI risk factors were assessed independently in both cycle 1 alone and combining all chemotherapy cycles. RESULTS: AKI developed in 34 patients (64%) with multiple AKI episodes in 10 patients (46 total episodes). Twenty-four severe AKI episodes occurred in 23 patients (43.4%) with a mean duration of 26.1 days (SD 7.3). In cycle 1, hyperleukocytosis was not predictive of AKI, but severe sepsis was an independent risk factor of severe AKI (odds ratio [OR]: 13.4; 95% CI 1.9-94.9). With cycles combined, all subjects with AKI had severe sepsis and older age (≥10 years) was associated with severe AKI (OR: 20.8; 95% CI 3.8-112.2). CONCLUSION: There was a high incidence of AKI in our AML cohort with a strong association with older age (≥10 years) and severe sepsis. Larger prospective studies are needed to confirm the high burden of AKI and risk factors in this susceptible population.

Pediatric acute kidney injury and the subsequent risk for chronic kidney disease: is there cause for alarm?

Acute kidney injury (AKI) is characterized clinically as an abrupt decline in renal function marked by reduced excretion of waste products, disordered electrolytes, and disrupted fluid homeostasis. The recent development of a standardized AKI definition has transformed our understanding of AKI epidemiology and outcomes. We now know that in the short term, children with AKI experience greater morbidity and mortality; additionally, observational studies have established that chronic renal sequelae are far more common after AKI events than previously realized. Many of these studies suggest that patients who develop AKI are at greater risk for the subsequent development of chronic kidney disease (CKD). The goal of this review is to critically evaluate the data regarding the association between AKI and CKD in children. Additionally, we describe best practice approaches for future studies, including the use of consensus AKI criteria, the application of rigorous definitions for CKD and renal sequelae, and the inclusion of non-AKI comparator groups. Finally, based upon existing data, we suggest an archetypal approach to follow-up care for the AKI survivors who may be at greater CKD risk, including children with more severe AKI, those who endure repeated AKI episodes, patients who do not experience full recovery, and those with pre-existing CKD.

Induction prednisone dosing for childhood nephrotic syndrome: how low should we go?

BACKGROUND: Historically, children with nephrotic syndrome (NS) across British Columbia (BC), Canada have been cared for without formal standardization of induction prednisone dosing. We hypothesized that local historical practice variation in induction dosing was wide and that children treated with lower doses had worse relapsing outcomes. METHODS: This retrospective cohort study included 92 NS patients from BC Children's Hospital (1990-2010). We excluded secondary causes of NS, age < 1 year at diagnosis, steroid resistance, and incomplete induction due to early relapse. We explored cumulative induction dose and defined dosing quartiles. Relapsing outcomes above and below each quartile threshold were compared including total relapses in 2 years, time to first relapse, and proportions developing frequently relapsing NS (FRNS) or starting a steroid-sparing agent (SSA). RESULTS: Cumulative prednisone was widely distributed with approximated median, 1st, and 3rd quartile doses of 2500, 2000, and 3000 mg/m2 respectively. Doses ≤ 2000 mg/m2 showed significantly higher relapses (4.2 vs 2.7), shorter time to first relapse (61 vs 175 days), and higher SSA use (36 vs 14%) compared to higher doses. Doses ≤ 2500 mg/m2 also showed significantly more relapses (3.9 vs 2.2), quicker first relapse (79 vs 208 days), and higher FRNS (37 vs 17%) and SSA use (28 vs 11%). Relapsing outcomes lacked statistical difference in ≤ 3000 vs > 3000 mg/m2 doses. CONCLUSIONS: Results strongly justify our development of a standardized, province-wide NS clinical pathway to reduce practice variation and minimize under-treatment. The lowest induction prednisone dosing threshold to minimize future relapsing risks is likely between 2000 and 2500 mg/m2. Further prospective studies are warranted.

The path to chronic kidney disease following acute kidney injury: a neonatal perspective.

The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms. Other factors, including prematurity and low birth weight, have an independent relationship with the development of CKD, but they may also be positive effect modifiers in the relationship of AKI and CKD. The large degree of heterogeneity in the literature on AKI in the neonatal population, including the use of various AKI definitions and CKD outcomes, has hampered the medical community's ability to properly assess the relationship of AKI and CKD in this vulnerable population. Larger prospective cohort studies with control groups which utilize recently proposed neonatal AKI definitions and standardized CKD definitions are much needed to properly quantify the risk of CKD following an episode of AKI. Until there is further evidence to guide us, we recommend that all neonates with an identified episode of AKI should have an appropriate longitudinal follow-up in order to identify CKD at its earliest stages.